U.S. patent application number 17/359730 was filed with the patent office on 2021-10-28 for substrate processing method and substrate processing apparatus.
This patent application is currently assigned to SCREEN Holdings Co., Ltd.. The applicant listed for this patent is SCREEN Holdings Co., Ltd.. Invention is credited to Hiroshi ABE, Yasunori KANEMATSU, Chikara MAEDA, Manabu OKUTANI, Masayuki OTSUJI, Hiroaki TAKAHASHI, Shuichi YASUDA, Yukifumi YOSHIDA.
Application Number | 20210331192 17/359730 |
Document ID | / |
Family ID | 1000005706100 |
Filed Date | 2021-10-28 |
United States Patent
Application |
20210331192 |
Kind Code |
A1 |
YOSHIDA; Yukifumi ; et
al. |
October 28, 2021 |
SUBSTRATE PROCESSING METHOD AND SUBSTRATE PROCESSING APPARATUS
Abstract
A substrate processing method includes a first processing liquid
supplying step of supplying a first processing liquid to an upper
surface of the substrate, a holding layer forming step of
solidifying or curing the first processing liquid to form a
particle holding layer on the upper surface of the substrate, a
holding layer removing step of peeling and removing the particle
holding layer from the upper surface of the substrate, a liquid
film forming step of forming, after removing the particle holding
layer from the substrate, a liquid film of the second processing
liquid, a solidifying step of cooling the liquid film to a
temperature not more than a melting point of the sublimable
substance to make the liquid film solidify on the substrate and
form a solid film, and a sublimating step of sublimating and
thereby removing the solid film from the substrate.
Inventors: |
YOSHIDA; Yukifumi; (Kyoto,
JP) ; TAKAHASHI; Hiroaki; (Kyoto, JP) ;
OTSUJI; Masayuki; (Kyoto, JP) ; OKUTANI; Manabu;
(Kyoto, JP) ; MAEDA; Chikara; (Kyoto, JP) ;
ABE; Hiroshi; (Kyoto, JP) ; YASUDA; Shuichi;
(Kyoto, JP) ; KANEMATSU; Yasunori; (Kyoto,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCREEN Holdings Co., Ltd. |
Kyoto |
|
JP |
|
|
Assignee: |
SCREEN Holdings Co., Ltd.
|
Family ID: |
1000005706100 |
Appl. No.: |
17/359730 |
Filed: |
June 28, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
16203719 |
Nov 29, 2018 |
11101147 |
|
|
17359730 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 21/02057 20130101;
H01L 21/6704 20130101; B08B 7/0014 20130101; B05B 12/10 20130101;
B08B 3/10 20130101 |
International
Class: |
B05B 12/10 20060101
B05B012/10; B08B 3/10 20060101 B08B003/10; B08B 7/00 20060101
B08B007/00; H01L 21/02 20060101 H01L021/02; H01L 21/67 20060101
H01L021/67 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 11, 2017 |
JP |
2017-237068 |
Claims
1. A substrate processing apparatus comprising: a substrate holding
unit which holds a substrate horizontally; a first processing
liquid supplying unit which supplies, to an upper surface of the
substrate, a first processing liquid which contains a solute and a
solvent having volatility and has a property of being solidified or
cured by volatilization of at least a portion of the solvent to
forma particle holding layer on the upper surface of the substrate;
a first heat medium supplying unit which supplies a first heat
medium, which heats the substrate, to a lower surface of the
substrate; a peeling liquid supplying unit which supplies a peeling
liquid, which peels the particle holding layer from the upper
surface of the substrate, to the upper surface of the substrate; a
second processing liquid supplying unit which supplies a second
processing liquid, containing a sublimable substance, to the upper
surface of the substrate; a second heat medium supplying unit which
supplies a second heat medium, which cools the substrate, to the
lower surface of the substrate; a sublimating unit which sublimates
a solid film formed from the second processing liquid; a first heat
medium feeding piping which feeds the first heat medium to the
first heat medium supplying unit from a first heat medium supply
source; a second heat medium feeding piping which feeds the second
heat medium to the second heat medium supplying unit from a second
heat medium supply source; a first heat medium valve which is
interposed in the first heat medium feeding piping; and a second
heat medium valve which is interposed in the second heat medium
feeding piping, wherein the first heat medium supplying unit and
the second heat medium supplying unit are configured to switch a
heat medium supplied to the lower surface of the substrate between
the first heat medium and the second heat medium when the first
heat medium valve and the second heat medium valve are
operated.
2. The substrate processing apparatus according to claim 1, further
comprising: a third heat medium supplying unit which supplies a
third heat medium, which heats the substrate, to the lower surface
of the substrate; a third heat medium feeding piping which feeds
the third heat medium to the third heat medium supplying unit from
a third heat medium supply source: a third heat medium valve which
is interposed in the third heat medium feeding piping; a removing
unit which removes the second processing liquid from the upper
surface of the substrate; and a controller which controls the
second processing liquid supplying unit, the third heat medium
supplying unit and the removing unit, wherein the third heat medium
supplying unit is configured to switch, together with the first
heat medium supplying unit and the second heat medium supplying
unit, the heat medium supplied to the lower surface of the
substrate among the first heat medium, the second heat medium and
the third heat medium when two valves of the first heat medium
valve, the second heat medium valve and the third heat medium valve
are operated, and the controller is programed to execute a liquid
film forming step of supplying the second processing liquid to the
upper surface of the substrate from the second processing liquid
supplying unit to form a liquid film of the second processing
liquid which covers the upper surface of the substrate, a
temperature holding step of supplying the third heat medium to the
lower surface of the substrate from the third heat medium supplying
unit in parallel with the liquid film forming step to hold a
temperature of the liquid film within a temperature range of not
less than a melting point of the sublimable substance and less than
a boiling point of the sublimable substance, and a film thinning
step of removing a portion of the second processing liquid,
constituting the liquid film, from the upper surface of the
substrate to thin the liquid film by the removing unit while the
temperature of the liquid film is within the temperature range.
3. The substrate processing apparatus according to claim 2, wherein
the controller is programmed to close the third heat medium valve
and open the second heat medium valve in the film thinning step to
adjust a timing for switching the heat medium supplied to the lower
surface of the substrate from the third heat medium to the second
heat medium, thereby adjusting a length of a period of the film
thinning step.
4. The substrate processing apparatus according to claim 2, further
comprising: a heat medium supplying piping which supplies the first
heat medium to the first heat medium supplying unit and the second
heat medium to the second heat medium supplying unit; and a lower
surface nozzle which functions as the first heat medium supplying
unit and the second heat medium supplying unit, and discharges the
heat medium in the heat medium supplying piping toward the lower
surface of the substrate, wherein the controller is programed to
execute a solidifying step of discharging the second heat medium in
the heat medium supplying piping from the lower surface nozzle
toward the lower surface of the substrate to cool the liquid film
via the substrate to a temperature not more than the melting point
of the sublimable substance to make the liquid film solidify to
form the solid film, and a heat medium supplying piping heat step
of, after the solidifying step, supplying the first heat medium to
the lower surface nozzle through the heat medium supplying piping
from the first heat medium supply source to discharge the first
heat medium from the lower surface nozzle until the substrate is
carried out and a next substrate is carried in.
5. The substrate processing apparatus according to claim 1, wherein
the first heat medium supplying unit is configured to supply the
first heat medium having a first temperature lower than an
alteration temperature of the solute contained in the first
processing liquid, and The second heat medium supplying unit is
configured to supply the second heat medium having a second
temperature lower than a melting point of the sublimable substance
contained in the second processing liquid.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent
application Ser. No. 16/203,719, filed Nov. 29, 2018, which claims
priority to Japanese Patent Application No. 2017-237068, filed Dec.
11, 2017, the contents of both of which are incorporated herein by
reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present invention relates to a substrate processing
method and a substrate processing apparatus for processing
substrates. Examples of substrates to be processed include
substrates, such as semiconductor wafers, substrates for liquid
crystal display devices, substrates for FPDs (flat panel displays),
such as organic EL (electroluminescence) display devices, etc.,
substrates for optical disks, substrates for magnetic disks,
substrates for magneto-optical disks, substrates for photomasks,
ceramic substrates, substrates for solar cells, etc.
2. Description of the Related Art
[0003] In substrate processing by a single substrate processing
type substrate processing apparatus, substrates are processed one
by one. In detail, a substrate is held substantially horizontally
by a spin chuck. Then, after a cleaning step of cleaning an upper
surface of the substrate is executed, a spin drying step of
rotating the substrate at high speed to dry the upper surface of
the substrate is performed.
[0004] In the cleaning step, various contaminants, a residue of a
processing liquid or a resist, etc., used in a prior step, or
various particles, etc., (may be referred to collectively
hereinafter as "particles") that are attached to the substrate are
removed. Specifically, in the cleaning step, the particles are
removed physically by supplying a cleaning liquid, such as
deionized water (DIW), to the substrate or the particles are
removed chemically by supplying a chemical liquid that reacts
chemically with the particles to the substrate.
[0005] However, with progresses being made in making a pattern
formed on a substrate finer and more complex, it is becoming less
easy to physically or chemically remove particles.
[0006] A method has thus been proposed where a processing liquid,
containing a solute and a solvent having volatility, is supplied to
the upper surface of a substrate, a film (hereinafter referred to
as "particle holding layer") is formed by solidifying or curing the
processing liquid, and the particle holding layer is thereafter
removed (Japanese Patent Application Publication No.
2014-197717).
SUMMARY OF THE INVENTION
[0007] However, with the method described in Japanese Patent
Application Publication No. 2014-197717, the particle holding layer
is dissolved on the substrate by supplying a dissolving processing
liquid to the upper surface of the substrate and therefore
particles may fall off from the particle holding layer that is in
the process of dissolving and become reattached to the substrate. A
particle removal rate thus does not become as high as
anticipated.
[0008] Moreover, the dissolving processing liquid, used to remove
the particles, and a rinse liquid, arranged to wash away the
dissolving processing liquid, enter into an interior of a pattern.
Surface tension of the liquid that entered into the pattern
interior acts on the pattern. The pattern may collapse due to this
surface tension.
[0009] In detail, as shown in FIG. 11, when drying a front surface
of the substrate, a liquid surface (interface between air and
liquid) of the rinse liquid that entered into the pattern interior
is formed inside the pattern. Surface tension of the liquid thus
acts at a position of contact of the liquid surface and the
pattern. Pattern collapse tends to occur when the surface tension
is high. Water, which is a typical rinse liquid, is high in surface
tension and pattern collapse in the spin drying step thus cannot be
ignored.
[0010] Thus, an object of the present invention is to provide a
substrate processing method and a substrate processing apparatus by
which particles can be removed satisfactorily from an upper surface
of a substrate and the upper surface of the substrate can be dried
satisfactorily.
[0011] A preferred embodiment of the present invention provides a
substrate processing method including a substrate holding step of
horizontally holding a substrate, a first processing liquid
supplying step of supplying a first processing liquid, containing a
solute and a solvent having volatility, to an upper surface of the
substrate, a holding layer forming step of supplying a first heat
medium to a lower surface of the substrate to heat the first
processing liquid on the substrate via the substrate and volatilize
at least a portion of the solvent to solidify or cure the first
processing liquid to form a particle holding layer on the upper
surface of the substrate, a holding layer removing step of
supplying a peeling liquid, which peels the particle holding layer,
to the upper surface of the substrate to peel and remove the
particle holding layer from the upper surface of the substrate, a
liquid film forming step of supplying, after removing the particle
holding layer from the substrate, a second processing liquid,
containing a sublimable substance, to the upper surface of the
substrate to form a liquid film of the second processing liquid
which covers the upper surface of the substrate, a solidifying step
of supplying a second heat medium to the lower surface of the
substrate to cool the liquid film via the substrate to a
temperature not more than a melting point of the sublimable
substance to make the liquid film solidify on the substrate to form
a solid film, and a sublimating step of sublimating and thereby
removing the solid film from the substrate.
[0012] With the present method, the first processing liquid on the
substrate is heated by the first heat medium via the substrate in
the holding layer forming step. By the first processing liquid
thereby being solidified or cured, the particle holding layer is
formed on the upper surface of the substrate. When the first
processing liquid is being solidified or cured, particles are
pulled away from the substrate. The particles that are pulled away
become held inside the particle holding layer. Therefore, by
supplying the peeling liquid to the upper surface of the substrate
in the holding layer removing step, the particle holding layer can
be peeled and removed, in a state of holding the particles, from
the upper surface of the substrate.
[0013] Also, with the present method, the liquid film of the second
processing liquid that covers an entirety of the upper surface of
the substrate is formed in the liquid film forming step. Then, in
the solidifying step, the liquid film is cooled to the temperature
not more than the melting point of the sublimable substance by
supplying the second heat medium and the solid film is formed. The
solid film is removed by sublimation. Therefore, the second
processing liquid can be removed from the substrate and the upper
surface of the substrate can be dried without letting surface
tension of the second processing liquid act on the upper surface of
the substrate. Collapse of a pattern formed on the upper surface of
the substrate can thus be suppressed or prevented.
[0014] By the above, the particles can be removed satisfactorily
from the upper surface of the substrate and the upper surface of
the substrate can be dried satisfactorily.
[0015] In the preferred embodiment of the present invention, a
solute component that is the solute contained in the first
processing liquid has properties of being insoluble in the peeling
liquid before being heated to not less than an alteration
temperature and being altered and becoming soluble in the peeling
liquid by being heated to not less than the alteration temperature.
In the holding layer forming step, the substrate is heated such
that a temperature of the first processing liquid, supplied to the
upper surface of the substrate, becomes a temperature less than the
alteration temperature.
[0016] With the present method, in the holding layer forming step,
the substrate is heated such that the temperature of the first
processing liquid becomes the temperature less than the alteration
temperature and the particle holding layer is formed. Although the
particle holding layer is thus poorly soluble or insoluble in the
peeling liquid, it can be peeled by the peeling liquid. Therefore,
in the holding layer removing step, the particle holding layer
formed on the upper surface of the substrate can be peeled and
removed, without dissolving it and with it being in the state of
holding the particles, from the upper surface of the substrate.
[0017] Consequently, by peeling the particle holding layer, in the
state of holding the particles, from the upper surface of the
substrate, the particles can be removed at a high removal rate.
Further, a residue, resulting from dissolution of the particle
holding layer in the peeling liquid, can be suppressed from
remaining on or reattaching to the upper surface of the
substrate.
[0018] In the preferred embodiment of the present invention, in the
holding layer forming step, the substrate is heated such that the
temperature of the first processing liquid supplied to the upper
surface of the substrate becomes less than a boiling point of the
solvent.
[0019] With the present method, the solvent can be made to remain
in the particle holding layer after the heating in the holding
layer forming step. The particle holding layer can thus be made
easily peelable from the upper surface of the substrate in the
subsequent holding layer removing step by interaction of the
solvent remaining in the particle holding layer and the peeling
liquid that is supplied. That is, by making the peeling liquid
permeate into the particle holding layer and making the peeling
liquid reach an interface between the particle holding layer and
the substrate, the particle holding layer can be lifted and peeled
from the upper surface of the substrate.
[0020] In the preferred embodiment of the present invention, the
peeling liquid has compatibility with the solvent. When the solvent
is made to remain appropriately in the particle holding layer in
the holding layer forming step, the peeling liquid that is
compatible with the solvent can permeate into the particle holding
layer and reach the interface between the particle holding layer
and the substrate. The particle holding layer can thereby be lifted
and peeled from the upper surface of the substrate.
[0021] In the preferred embodiment of the present invention, the
substrate processing method further includes a residue removing
step of supplying, after the holding layer removing step and before
the liquid film forming step, a residue removing liquid, having a
dissolving ability with respect to the solute component that is the
solute contained in the first processing liquid, to the upper
surface of the substrate to remove a residue remaining on the upper
surface of the substrate after the particle holding layer is
removed.
[0022] With the present method, the residue removing liquid has a
property of dissolving the solute component that forms the particle
holding layer. The residue of the particle holding layer (the
particle holding layer that the peeling liquid could not peel) can
thus be dissolved in the residue removing liquid to remove the
residue from the upper surface of the substrate before supplying
the second processing liquid to the upper surface of the substrate.
The upper surface of the substrate can thereby be dried in a state
where an amount of particles on the upper surface of the substrate
is reduced further.
[0023] In the preferred embodiment of the present invention, the
holding layer forming step includes a rotation elimination step of
rotating the substrate around a rotational axis oriented along a
vertical direction to eliminate a portion of the first processing
liquid from the substrate and a substrate heating step of supplying
the first heat medium to the lower surface of the substrate to heat
the first processing liquid on the substrate via the substrate
after the portion of the first processing liquid is eliminated from
the substrate by rotation of the substrate.
[0024] When volatilizing the solvent of the first processing liquid
in the holding layer forming step, particles, resulting from the
solvent, may become attached to a member positioned in a vicinity
of the substrate. As an amount of the solvent increases, an amount
of the particles attaching to the member positioned in the vicinity
of the substrate increases. After the holding layer removing step,
the particles attached to the member positioned in the vicinity of
the substrate may drift in an atmosphere and become reattached to
the substrate. Thus, by supplying the first heat medium to the
lower surface of the substrate to heat the first processing liquid
on the substrate after the first processing liquid is eliminated
appropriately from the substrate by the rotation of the substrate,
an amount of the solvent that volatilizes can be reduced and an
amount of the solvent attaching to the member positioned in the
vicinity of the substrate can thus be reduced. Reattachment of
particles to the substrate after the holding layer removing step
can thus be suppressed.
[0025] In the preferred embodiment of the present invention, the
substrate processing method further includes a detecting step of
detecting interference fringes of the first processing liquid on
the substrate. The holding layer forming step includes a first
heating starting step of starting the heating of the substrate at a
timing at which the interference fringes are no longer
detected.
[0026] The present inventors found that by heating the substrate to
volatilize the solvent of the first processing liquid in a state
where an amount of the first processing liquid on the substrate is
made an amount such that interference fringes are not formed, the
amount of the particles attached onto the substrate after the
forming of holding layer can be reduced sufficiently.
[0027] Thus, by starting the heating of the substrate at the timing
at which the interference fringes are no longer detected, an amount
of the solvent of the first processing liquid that is to be
volatilized can be reduced appropriately. Reattachment of the
particles to the substrate after the holding layer removing step
can thereby be suppressed reliably.
[0028] In the preferred embodiment of the present invention, the
holding layer forming step includes a supply stopping step of
stopping the supply of the first processing liquid to the upper
surface of the substrate and a second heating starting step of
starting the heating of the substrate after elapse of a
predetermined time from the stopping of the supply of the first
processing liquid.
[0029] The present inventors found that a time required for the
interference fringes to disappear (disappearance requirement time)
can be predicted based on a rotational speed of the substrate. The
amount of the solvent of the first processing liquid that is to be
volatilized can thus be reduced appropriately by starting the
heating of the substrate after elapse of the disappearance
requirement time from the stopping of the supply of the first
processing liquid. Reattachment of the particles to the substrate
after the holding layer removing step can thereby be suppressed
reliably.
[0030] In the preferred embodiment of the present invention, the
substrate processing method further includes a temperature holding
step of supplying a third heat medium to the lower surface of the
substrate to hold a temperature of the liquid film, after the
supply of the second processing liquid is stopped, within a
temperature range of not less than the melting point of the
sublimable substance and less than a boiling point of the
sublimable substance and a film thinning step of removing a portion
of the second processing liquid, constituting the liquid film, from
the upper surface of the substrate while the temperature of the
liquid film is within the temperature range to thin the liquid
film.
[0031] With the present method, by holding the temperature of the
liquid film of the second processing liquid within the above-stated
temperature range in the temperature holding step, solidification
of the liquid film can be suppressed and the second processing
liquid on the substrate can be maintained in a liquid phase before
the solidifying step. For example, even if the liquid film of the
second processing liquid undergoes partial solidification in the
liquid film forming step, it can be remelted and put in liquid form
in the temperature holding step.
[0032] In the film thinning step, by removing excess second
processing liquid while the temperature of the liquid film of the
second processing liquid is within the above-stated temperature
range and solidification of the liquid film of the second
processing liquid does not occur, a film thickness of the solid
film formed in the solidifying step can be reduced appropriately.
By reducing the film thickness of the solid film, an internal
stress that remains in the solid film can be reduced. A force that
acts on the upper surface of the substrate due to the internal
stress can thus be reduced and pattern collapse can thus be
suppressed further. Therefore, by sublimating and removing the
solid film in the subsequent sublimating step, the upper surface of
the substrate can be dried while further suppressing pattern
collapse.
[0033] In the preferred embodiment of the present invention, the
substrate processing method further includes a guard disposing step
of disposing a guard at a side of the substrate in the first
processing liquid supplying step and a proximity disposing step of
disposing a facing member, having a facing surface facing the upper
surface of the substrate, at a proximity position in proximity to
the upper surface of the substrate in the holding layer forming
step.
[0034] The first heat medium supplied to the lower surface of the
substrate in the holding layer forming step splashes outside the
substrate. The first heat medium that splashed outside the
substrate is received by the guard disposed at the side of the
substrate. A portion of the first heat medium received by the guard
splashes back from the guard. Thus, by putting the facing member in
proximity to the upper surface of the substrate in the holding
layer forming step, attachment of the first heat medium to a front
surface of the particle holding layer can be suppressed. Particles
resulting from the splashing back of the first heat medium from the
guard can thus be suppressed.
[0035] In the preferred embodiment of the present invention, the
liquid film forming step includes a liquid feeding step of feeding
the second processing liquid toward a discharge port, provided at
the facing surface of the facing member, via a second processing
liquid piping, a discharging step of discharging the second
processing liquid toward the upper surface of the substrate from
the discharge port, and a suctioning step of suctioning the second
processing liquid inside the second processing liquid piping after
end of the discharging step.
[0036] After the end of the discharging step, the second processing
liquid remains inside the second processing liquid piping and at
the discharge port. Thus, by suctioning the second processing
liquid inside the second processing liquid piping after the end of
the discharging step, the second processing liquid can be removed
from the second processing liquid piping and the discharge port
before the second processing liquid solidifies. Solidification due
to heat of vaporization of the second processing liquid remaining
inside the second processing liquid piping and at the discharge
port can thus be suppressed. Clogging of the second processing
liquid piping can thus be suppressed or prevented.
[0037] In the preferred embodiment of the present invention, the
substrate processing method further includes a processing liquid
piping temperature holding step of holding a temperature of the
second processing liquid piping within a control temperature range
of not less than the melting point of the sublimable substance and
less than the boiling point of the sublimable substance. The second
processing liquid remaining inside the second processing liquid
piping can thus be heated and therefore the solidification of the
second processing liquid remaining inside the second processing
liquid piping and at the discharge port can be suppressed or
prevented.
[0038] In the preferred embodiment of the present invention, the
substrate holding step includes a step of making a state, in which
the substrate is held by a substrate holding unit, provided inside
a chamber, continue until the sublimating step ends.
[0039] With the present method, the first processing liquid
supplying step, the holding layer forming step, the holding layer
removing step, the liquid film forming step, the solidifying step,
and the sublimating step can be executed inside a single chamber
without having to transfer the substrate to another chamber in the
middle of the substrate processing. Time necessary for processing a
single substrate (throughput) can thus be reduced.
[0040] In the preferred embodiment of the present invention, the
substrate holding step includes a first substrate gripping step of
gripping the substrate by both a plurality of first gripping pins
and a plurality of second gripping pins provided in the substrate
holding unit, a first separating step of gripping the substrate by
the plurality of second gripping pins and separating the plurality
of first gripping pins from the substrate, a second separating step
of gripping the substrate by the plurality of first gripping pins
and separating the plurality of second gripping pins from the
substrate, and a second substrate gripping step of gripping the
substrate by both the plurality of first gripping pins and the
plurality of second gripping pins after the first separating step
and the second separating step. Also, the first separating step,
the second separating step, and the second substrate gripping step
are executed while the peeling liquid is being supplied onto the
substrate in the holding layer removing step.
[0041] The peeling liquid does not readily reach portions of the
substrate that are in contact with the first gripping pins or the
second gripping pins. Thus, by passing through a state where the
plurality of first gripping pins are separated from the substrate
and a state where the plurality of second gripping pins are
separated from the substrate while the peeling liquid is being
supplied onto the substrate in the holding layer removing step, the
peeling liquid can be supplied sufficiently to the portions of the
substrate that are in contact with the first gripping pins or the
second gripping pins. The particle holding layer can thus be
removed sufficiently from the upper surface of the substrate in the
holding layer removing step.
[0042] In the preferred embodiment of the present invention, the
holding layer forming step includes a step of heating the first
processing liquid on the substrate via the substrate by discharging
the first heat medium from a lower surface nozzle facing the lower
surface of the substrate. Also, the solidifying step includes a
step of cooling the liquid film via the substrate by discharging
the second heat medium from the lower surface nozzle. Also, the
substrate processing method further includes a heat medium supply
piping heating step of heating a heat medium supply piping which
supplies the first heat medium and the second heat medium toward
the lower surface nozzle, by supplying the first heat medium to the
heat medium supply piping after the solidifying step.
[0043] When the second heat medium is discharged from the lower
surface nozzle, the heat medium supply piping which supplies the
second heat medium to the lower surface nozzle, is cooled.
Therefore, when after ending the substrate processing of one
substrate, the substrate processing of the next substrate is
started, the first heat medium may be discharged from the lower
surface nozzle through the cooled heat medium supply piping in the
holding layer forming step. Thus, by supplying the first heat
medium to heat the heat medium supply piping in advance after the
solidifying step, it is made possible, in the holding layer forming
step of the substrate processing of the next substrate, to heat the
first processing liquid on the substrate to the desired
temperature.
[0044] A preferred embodiment of the present invention provides a
substrate processing apparatus including a substrate holding unit
which holds a substrate horizontally, a first processing liquid
supplying unit which supplies, to an upper surface of the
substrate, a first processing liquid, which contains a solute and a
solvent having volatility and is the first processing liquid that
is solidified or cured by at least a portion of the solvent
volatilizing to form a particle holding layer on the upper surface
of the substrate, a first heat medium supplying unit which supplies
a first heat medium, which heats the substrate, to a lower surface
of the substrate, a peeling liquid supplying unit which supplies a
peeling liquid, which peels the particle holding layer, to the
upper surface of the substrate, a second processing liquid
supplying unit which supplies a second processing liquid,
containing a sublimable substance, to the upper surface of the
substrate, a second heat medium supplying unit which supplies a
second heat medium, which cools the substrate, to the lower surface
of the substrate, a sublimating unit which sublimates a solid film
formed from the second processing liquid, and a controller which
controls the substrate holding unit, the first processing liquid
supplying unit, the first heat medium supplying unit, the peeling
liquid supplying unit, the second processing liquid supplying unit,
the second heat medium supplying unit, and the sublimating
unit.
[0045] The controller is programmed to execute a substrate holding
step of horizontally holding the substrate by the substrate holding
unit, a first processing liquid supplying step of supplying the
first processing liquid from the first processing liquid supplying
unit to the upper surface of the substrate, a holding layer forming
step of supplying the first heat medium from the first heat medium
supplying unit to heat the first processing liquid on the substrate
via the substrate to solidify or cure the first processing liquid
to form the particle holding layer on the upper surface of the
substrate, a holding layer removing step of supplying the peeling
liquid from the peeling liquid supplying unit to the upper surface
of the substrate to peel and remove the particle holding layer from
the upper surface of the substrate, a liquid film forming step of
supplying the second processing liquid from the second processing
liquid supplying unit to the upper surface of the substrate to
forma liquid film of the second processing liquid which covers the
upper surface of the substrate, a solidifying step of supplying the
second heat medium from the second heat medium supplying unit to
the lower surface of the substrate to cool the liquid film via the
substrate to a temperature not more than a melting point of the
sublimable substance to make the liquid film solidify to form a
solid film, and a sublimating step of sublimating the solid film by
the sublimating unit to remove the solid film from the
substrate.
[0046] With the present configuration, the first processing liquid
on the substrate is heated by the first heat medium via the
substrate in the holding layer forming step. By the first
processing liquid thereby being solidified or cured, the particle
holding layer is formed on the upper surface of the substrate. When
the first processing liquid is being solidified or cured, particles
are pulled away from the substrate. The particles that are pulled
away become held inside the particle holding layer. Therefore, in
the holding layer removing step, the particle holding layer in a
state of holding the particles can be peeled and removed from the
upper surface of the substrate by supplying the peeling liquid to
the upper surface of the substrate.
[0047] Also, with the present configuration, the liquid film of the
second processing liquid that covers an entirety of the upper
surface of the substrate is formed in the liquid film forming step.
Then, in the solidifying step, the liquid film is cooled to the
temperature not more than the melting point of the sublimable
substance by supplying the second heat medium and the solid film is
formed. The solid film is removed by sublimation. Therefore, the
second processing liquid can be removed from the substrate and the
upper surface of the substrate can be dried without letting surface
tension of the second processing liquid act on the upper surface of
the substrate. Collapse of a pattern formed on the upper surface of
the substrate can thus be suppressed or prevented.
[0048] By the above, the particles can be removed satisfactorily
from the upper surface of the substrate and the upper surface of
the substrate can be dried satisfactorily.
[0049] In the preferred embodiment of the present invention, a
solute component that is the solute contained in the first
processing liquid has properties of being insoluble in the peeling
liquid before being heated to not less than an alteration
temperature and being altered and becoming soluble in the peeling
liquid by being heated to not less than the alteration temperature.
Also, the controller is programmed to supply the first heat medium
from the first heat medium supplying unit in the holding layer
forming step such as to heat the substrate such that a temperature
of the first processing liquid, supplied to the upper surface of
the substrate, becomes a temperature less than the alteration
temperature.
[0050] With the present configuration, in the holding layer forming
step, the substrate is heated such that the temperature of the
first processing liquid becomes the temperature less than the
alteration temperature and the particle holding layer is formed.
Although the particle holding layer is thus poorly soluble or
insoluble in the peeling liquid, it can be peeled by the peeling
liquid. Therefore, in the holding layer removing step, the particle
holding layer formed on the upper surface of the substrate can be
peeled and removed, without dissolving the particle holding layer
and with the particle holding layer being in the state of holding
the particles, from the upper surface of the substrate.
[0051] Consequently, by peeling the particle holding layer, in the
state of holding the particles, from the upper surface of the
substrate, the particles can be removed at a high removal rate.
Further, a residue, resulting from dissolution of the particle
holding layer in the peeling liquid, can be suppressed from
remaining on or reattaching to the upper surface of the
substrate.
[0052] In the preferred embodiment of the present invention, the
controller is programmed to supply the first heat medium from the
first heat medium supplying unit in the holding layer forming step
so as to heat the substrate such that the temperature of the first
processing liquid supplied to the upper surface of the substrate
becomes less than a boiling point of the solvent.
[0053] With the present configuration, the solvent can be made to
remain in the particle holding layer after the heating in the
holding layer forming step. The particle holding layer can thus be
made easily peelable from the upper surface of the substrate in the
subsequent holding layer removing step by interaction of the
solvent remaining in the particle holding layer and the peeling
liquid that is supplied. That is, by making the peeling liquid
permeate into the particle holding layer and making the peeling
liquid reach an interface between the particle holding layer and
the substrate, the particle holding layer can be lifted and peeled
from the upper surface of the substrate.
[0054] In the preferred embodiment of the present invention, the
peeling liquid has compatibility with the solvent. When the solvent
is made to remain appropriately in the particle holding layer in
the holding layer forming step, the peeling liquid that is
compatible with the solvent can permeate into the particle holding
layer and reach the interface between the particle holding layer
and the substrate. The particle holding layer can thereby be lifted
and peeled from the upper surface of the substrate.
[0055] In the preferred embodiment of the present invention, the
substrate processing apparatus further includes a residue removing
liquid supplying unit which supplies a residue removing liquid,
having a dissolving ability with respect to the solute component
that is the solute contained in the first processing liquid, to the
upper surface of the substrate. Also, the controller is programmed
to execute, after the holding layer removing step and before the
liquid film forming step, a residue removing step of supplying the
residue removing liquid from the residue removing liquid supplying
unit to the upper surface of the substrate to remove a residue
remaining on the upper surface of the substrate after the particle
holding layer is removed.
[0056] With the present configuration, the residue removing liquid
has a property of dissolving the solute component that forms the
particle holding layer. The residue of the particle holding layer
(the particle holding layer that could not be peeled by the peeling
liquid) can thus be dissolved in the residue removing liquid to
remove the residue from the upper surface of the substrate before
supplying the second processing liquid to the upper surface of the
substrate. The upper surface of the substrate can thereby be dried
in a state where an amount of particles on the upper surface of the
substrate is reduced further.
[0057] In the preferred embodiment of the present invention, the
substrate processing apparatus further includes a substrate
rotating unit which rotates the substrate around a rotational axis
oriented along a vertical direction.
[0058] The controller is programmed to execute, in the holding
layer forming step, a rotation elimination step of making the
substrate rotating unit rotate the substrate to remove the first
processing liquid from the substrate and is programmed to execute,
in the holding layer forming step, a substrate heating step of
supplying the first heat medium from the first heat medium
supplying unit to the lower surface of the substrate to heat the
first processing liquid on the substrate via the substrate after a
portion of the first processing liquid is eliminated from the
substrate by rotation of the substrate.
[0059] When volatilizing the solvent of the first processing liquid
in the holding layer forming step, particles, resulting from the
solvent, may become attached to a member positioned in a vicinity
of the substrate. An amount of the particles attaching to the
member positioned in the vicinity of the substrate increases as an
amount of the solvent increases. After the holding layer removing
step, the particles attached to the member positioned in the
vicinity of the substrate may drift in an atmosphere and become
reattached to the substrate. Thus, by supplying the first heat
medium to the lower surface of the substrate to heat the first
processing liquid on the substrate after the first processing
liquid is eliminated appropriately from the substrate by the
rotation of the substrate, an amount of the solvent that
volatilizes can be reduced and an amount of the solvent attaching
to the member positioned in the vicinity of the substrate can thus
be reduced. Reattachment of particles to the substrate after the
holding layer removing step can thus be suppressed.
[0060] In the preferred embodiment of the present invention, the
substrate processing apparatus further includes a detecting unit
that detects interference fringes of the first processing liquid on
the substrate. Also, the controller is programmed to execute a
detecting step of detecting the interference fringes by the
detecting unit and a first heating starting step of starting, in
the holding layer forming step, the heating of the substrate at a
timing at which the interference fringes are no longer detected by
the detecting unit.
[0061] The present inventors found that by heating the substrate to
volatilize the solvent of the first processing liquid in a state
where a thickness of the first processing liquid on the substrate
is made a thickness such that interference fringes are not formed,
the amount of the particles attached onto the substrate after the
forming of holding layer can be reduced sufficiently.
[0062] Thus, by starting the heating of the substrate at the timing
at which the interference fringes are no longer detected, an amount
of the solvent of the first processing liquid that is to be
volatilized can be reduced appropriately. Reattachment of the
particles to the substrate after the holding layer removing step
can thereby be suppressed reliably.
[0063] In the preferred embodiment of the present invention, the
controller is programmed to execute, in the holding layer forming
step, a supply stopping step of stopping the supply of the first
processing liquid to the upper surface of the substrate and is
programmed to execute, in the holding layer forming step, a second
heating starting step of starting the heating of the substrate
after elapse of a predetermined time from the stopping of the
supply of the first processing liquid.
[0064] The present inventors found that a time required for the
interference fringes to disappear (disappearance requirement time)
can be predicted based on a rotational speed of the substrate. The
amount of the solvent of the first processing liquid that is to be
volatilized can thus be reduced appropriately by starting the
heating of the substrate after elapse of the disappearance
requirement time from the stopping of the supply of the first
processing liquid. Reattachment of the particles to the substrate
after the holding layer removing step can thereby be suppressed
reliably.
[0065] In the preferred embodiment of the present invention, the
substrate processing apparatus further includes a third heat medium
supplying unit which supplies a third heat medium to the lower
surface of the substrate, and a removing unit which removes the
second processing liquid from the substrate.
[0066] Also, the controller is programmed to execute a temperature
holding step of supplying the third heat medium from the third heat
medium supplying unit to the lower surface of the substrate to hold
a temperature of the liquid film, after the supply of the second
processing liquid is stopped, within a temperature range of not
less than the melting point of the sublimable substance and less
than a boiling point of the sublimable substance and a film
thinning step, where the removing unit removes a portion of the
second processing liquid, constituting the liquid film, from the
upper surface of the substrate while the temperature of the liquid
film is within the temperature range to thin the liquid film.
[0067] With the present configuration, by holding the temperature
of the liquid film of the second processing liquid within the
above-stated temperature range in the temperature holding step,
solidification of the liquid film can be suppressed and the second
processing liquid on the substrate can be maintained in a liquid
phase before the solidifying step. For example, even if the liquid
film of the second processing liquid undergoes partial
solidification in the liquid film forming step, it can be remelted
and put in liquid form in the temperature holding step.
[0068] In the film thinning step, by removing excess second
processing liquid while the temperature of the liquid film of the
second processing liquid is within the above-stated temperature
range and solidification of the liquid film of the second
processing liquid does not occur, a film thickness of the solid
film formed in the solidifying step can be reduced appropriately.
An internal stress that remains in the solid film can thereby be
reduced. A force that acts on the upper surface of the substrate
due to the internal stress can thus be reduced and pattern collapse
can thus be suppressed further. Therefore, by sublimating and
removing the solid film in the subsequent sublimating step, the
upper surface of the substrate can be dried while further
suppressing pattern collapse.
[0069] In the preferred embodiment of the present invention, the
substrate processing apparatus further includes a guard, disposed
at a side of the substrate, and a facing member which has a facing
surface facing the upper surface of the substrate and is elevated
and lowered with respect to the substrate. Also, the controller is
programmed to execute, in the holding layer forming step, a
proximity disposing step of disposing the facing member at a
proximity position in proximity to the upper surface of the
substrate.
[0070] The first heat medium supplied to the lower surface of the
substrate in the holding layer forming step splashes outside the
substrate. The first heat medium that splashed outside the
substrate is received by the guard disposed at the side of the
substrate. A portion of the first heat medium received by the guard
splashes back from the guard. Thus, by putting the facing member in
proximity to the upper surface of the substrate in the holding
layer forming step, attachment of the first heat medium to a front
surface of the particle holding layer can be suppressed. Particles
resulting from the splashing back of the first heat medium from the
guard can thus be suppressed.
[0071] In the preferred embodiment of the present invention, the
second processing liquid supplying unit includes a discharge port,
provided at the facing surface of the facing member, and a second
processing liquid piping which supplies the second processing
liquid to the discharge port. Also, the substrate processing
apparatus further includes a suction unit that suctions the second
processing liquid piping.
[0072] After discharge of the second processing liquid from the
discharge port ends, the second processing liquid remains inside
the second processing liquid piping and at the discharge port.
Thus, by suctioning the second processing liquid inside the second
processing liquid piping after the end of the discharge of the
second processing liquid, the second processing liquid can be
removed from the second processing liquid piping and the discharge
port before the second processing liquid solidifies. Solidification
due to heat of vaporization of the second processing liquid
remaining inside the second processing liquid piping and at the
discharge port can thus be suppressed. Clogging of the second
processing liquid piping can thus be suppressed or prevented.
[0073] In the preferred embodiment of the present invention, the
substrate processing apparatus further includes a second processing
liquid piping temperature holding unit that holds a temperature of
the second processing liquid piping within a control temperature
range of not less than the melting point of the sublimable
substance and less than the boiling point of the sublimable
substance. The second processing liquid remaining inside the second
processing liquid piping and at the discharge port can thus be
heated and therefore the solidification of the second processing
liquid remaining inside the second processing liquid piping and at
the discharge port can be suppressed or prevented.
[0074] In the preferred embodiment of the present invention, the
substrate processing apparatus further includes a chamber, housing
the substrate holding unit. Also, the controller is programmed to
continue the substrate holding step until the sublimating step
ends.
[0075] With the present configuration, the first processing liquid
supplying step, the holding layer forming step, the holding layer
removing step, the liquid film forming step, the solidifying step,
and the sublimating step can be executed inside a single chamber
without having to transfer the substrate to another chamber in the
middle of the substrate processing. Throughput can thus be
reduced.
[0076] In the preferred embodiment of the present invention, the
substrate holding unit includes a plurality of first gripping pins
and a plurality of second gripping pins that hold the
substrate.
[0077] Also, the controller is programmed to execute, in the
substrate holding step, a first substrate gripping step of gripping
the substrate by both the plurality of first gripping pins and the
plurality of second gripping pins, a first separating step, where
the substrate is gripped by the plurality of second gripping pins
and the plurality of first gripping pins are separated from the
substrate, a second separating step, where the substrate is gripped
by the plurality of first gripping pins and the plurality of second
gripping pins are separated from the substrate, and a second
substrate gripping step of gripping the substrate by both the
plurality of first gripping pins and the plurality of second
gripping pins after the first separating step and the second
separating step. Also, the first separating step, the second
separating step, and the second substrate gripping step are
executed while the peeling liquid is being supplied onto the
substrate in the holding layer removing step.
[0078] The peeling liquid does not readily reach portions of the
substrate that are in contact with the first gripping pins or the
second gripping pins. Thus, by passing through a state where the
plurality of first gripping pins are separated from the substrate
and a state where the plurality of second gripping pins are
separated from the substrate while the peeling liquid is being
supplied onto the substrate in the holding layer removing step, the
peeling liquid can be supplied sufficiently to the portions of the
substrate that are in contact with the first gripping pins or the
second gripping pins. The particle holding layer can thus be
removed sufficiently from the upper surface of the substrate in the
holding layer removing step.
[0079] In the preferred embodiment of the present invention, the
substrate processing apparatus further includes a lower surface
nozzle which discharges the first heat medium and the second heat
medium toward the lower surface of the substrate, and a heat medium
supply piping which is connected to the lower surface nozzle. Also,
the controller is programmed to execute a heat medium supply piping
heating step of heating the heat medium supply piping by supplying
the first heat medium to the heat medium supply piping after the
solidifying step.
[0080] When the second heat medium is discharged from the lower
surface nozzle, the heat medium supply piping, which supplies the
second heat medium to the lower surface nozzle, is cooled.
Therefore, when after ending the substrate processing of one
substrate, the substrate processing of the next substrate is
started, the first heat medium may be discharged from the lower
surface nozzle through the cooled heat medium supply piping in the
holding layer forming step. Thus, by supplying the first heat
medium to heat the heat medium supply piping in advance after the
solidifying step, it is made possible, in the holding layer forming
step of the substrate processing of the next substrate, to heat the
first processing liquid on the substrate to the desired
temperature.
[0081] The above and other elements, features, steps,
characteristics and advantages of the present invention will become
more apparent from the following detailed description of the
preferred embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0082] FIG. 1 is a schematic plan view for describing a layout of
an interior of a substrate processing apparatus according to a
preferred embodiment of the present invention.
[0083] FIG. 2 is a schematic view of a processing unit included in
the substrate processing apparatus.
[0084] FIG. 3A is a plan view of a spin base and a chuck unit
included in the processing unit and is a diagram for describing a
closed state of the chuck unit.
[0085] FIG. 3B is a plan view of the spin base and the chuck unit
and is a diagram for describing a first separated state of the
chuck unit.
[0086] FIG. 3C is a plan view of the spin base and the chuck unit
and is a diagram for describing a second separated state of the
chuck unit.
[0087] FIG. 4 is a schematic view of a heat medium supply piping
included in the substrate processing apparatus.
[0088] FIG. 5 is a block diagram for describing the electrical
configuration of a main portion of the substrate processing
apparatus.
[0089] FIG. 6 is a flowchart for describing an example of substrate
processing by the substrate processing apparatus.
[0090] FIG. 7A to FIG. 7L are illustrative sectional views for
describing the substrate processing.
[0091] FIG. 8A and FIG. 8B are illustrative sectional views for
describing conditions of a particle holding layer in the substrate
processing.
[0092] FIG. 9A and FIG. 9B are schematic views for describing a
timing for starting heating of the substrate in a holding layer
forming step (S3 of FIG. 6) of the substrate processing.
[0093] FIG. 10A is a graph showing disappearance requirement times
at respective rotational speeds in cases, in each of which a
substrate is rotated at a fixed rotational speed in a rotation
elimination step in the holding layer forming step.
[0094] FIG. 10B is a graph showing integrated numbers of rotations
at respective rotational speeds in cases, in each of which the
substrate is rotated at a fixed rotational speed in the rotation
elimination step.
[0095] FIG. 11 is an illustrative sectional view for describing
principles of pattern collapse due to surface tension.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0096] FIG. 1 is a schematic plan view for describing a layout of
an interior of a substrate processing apparatus 1 according to a
preferred embodiment of the present invention. The substrate
processing apparatus 1 is a single substrate processing type
apparatus that processes substrates W, such as silicon wafers,
etc., one at a time. Referring to FIG. 1, the substrate processing
apparatus 1 includes a plurality of processing units 2 that process
the substrates W with processing fluids, load ports LP, in which
are placed carriers C that house the plurality of substrates W to
be processed by the processing units 2, transfer robots IR and CR,
transferring the substrates W between the load ports LP and the
processing units 2, and a controller 3 controlling the substrate
processing apparatus 1.
[0097] The transfer robot IR transfers the substrates W between the
carriers C and the transfer robot CR. The transfer robot CR
transfers the substrates W between the transfer robot IR and the
processing units 2. The plurality of processing units 2 have, for
example, the same configuration. The processing fluids include
liquids, such as a first processing liquid, a second processing
liquid, a rinse liquid, peeling liquids, a residue removing liquid,
heat medium, etc., and a gas, such as an inert gas, etc., to be
described later.
[0098] FIG. 2 is a schematic view for describing an configuration
example of a processing unit 2. The processing unit 2 includes a
chamber 4, having an internal space, and a spin chuck 5, rotating a
substrate W around a vertical rotational axis A1 passing through
its central portion while holding the substrate W horizontally
inside the chamber 4, a facing member 6, facing an upper surface of
the substrate W held by the spin chuck 5, a cylindrical processing
cup 7, receiving liquid splashing outward from the substrate W, an
exhaust unit 8, exhausting an atmosphere inside the chamber 4, and
an imaging unit 9, taking an image of a condition of the upper
surface of the substrate W.
[0099] The chamber 4 includes a box-shaped partition wall 24,
provided with a carry-in/carry-out port 24a, through which the
substrate W passes, a shutter 25, opening and closing the
carry-in/carry-out port 24a, and an FFU (fan filter unit) 29 as a
blower unit feeding clean air from an upper portion of the
partition wall 24 into an interior of the partition wall 24
(corresponding to an interior of the chamber 4). The clean air,
which is air filtered by the FFU 29, is constantly supplied from
the upper portion of the partition wall 24 into the interior of the
chamber 4.
[0100] The spin chuck 5 is an example of a substrate holding unit
that holds the substrate W horizontally. The substrate holding unit
is also referred to as a substrate holder. The spin chuck 5
includes a chuck unit 20, a spin base 21, a rotating shaft 22, and
an electric motor 23.
[0101] FIG. 3A to FIG. 3C are plan views of the spin base 21 and
the chuck unit 20. Referring to FIG. 3A, the spin base 21 has a
disk shape oriented along a horizontal direction. The chuck unit 20
includes a plurality (for example, three) of first gripping pins
20A and a plurality (for example, three) of second gripping pins
20B disposed on an upper surface of the spin base 21. The first
gripping pins 20A and the second gripping pins 20B are disposed
alternately along a peripheral direction.
[0102] The chuck unit 20 is capable of changing among a closed
state, an opened state, a first separated state, and a second
separated state by the first gripping pins 20A and the second
gripping pins 20B moving with respect to the substrate W.
[0103] The closed state is a state in which a peripheral edge of
the substrate W is gripped by both the plurality of first gripping
pins 20A and the plurality of second gripping pins 20B as shown in
FIG. 3A. The first separated state is a state in which the
peripheral edge of the substrate W is gripped by the plurality of
second gripping pins 20B and the plurality of first gripping pins
20A are separated from the peripheral edge of the substrate W as
shown in FIG. 3B. The second separated state is a state in which
the peripheral edge of the substrate W is gripped by the plurality
of first gripping pins 20A and the plurality of second gripping
pins 20B are separated from the peripheral edge of the substrate W
as shown in FIG. 3C.
[0104] Although not illustrated, a state in which the peripheral
edge of the substrate W is not gripped by either of the first
gripping pins 20A and the second gripping pins 20B is referred to
as the opened state. When the state of each chuck unit 20 is the
opened state, the transfer robot CR (see FIG. 1) can receive the
substrates W from the plurality of chuck units 20.
[0105] Referring again to FIG. 2, each processing unit 2 further
includes a pin driving unit 30 that drives the plurality of first
gripping pins 20A and the plurality of second gripping pins 20B to
open and close. The pin driving unit 30 includes, for example, a
link mechanism 31, incorporated in the spin base 21, and a driving
source 32, disposed outside the spin base 21. The driving source 32
includes, for example, a ball-screw mechanism and an electric motor
applying a driving force thereto. The pin driving units 30 can
change the states of plurality of chuck units 20 to any of the
closed state, the opened state, the first separated state, and the
second separated state by driving the plurality of first gripping
pins 20A and the plurality of second gripping pins 20B.
[0106] Each rotating shaft 22 extends in a vertical direction along
the rotational axis A1. An upper end portion of the rotating shaft
22 is coupled to a lower surface center of the spin base 21. A
penetrating hole 21a, penetrating through the spin base 21
vertically, is formed in a central region of the spin base 21 in
plan view. The penetrating hole 21a is in communication with an
internal space 22a of the rotating shaft 22.
[0107] The electric motor 23 applies a rotating force to the
rotating shaft 22. The spin base 21 is rotated by the rotating
shaft 22 being rotated by the electric motor 23. The substrate W is
thereby rotated around the rotational axis A1. In the following
description, an inner side in a radial direction centered at the
rotational axis A1 shall be referred to simply as the "radially
inner side" and an outer side in the radial direction centered at
the rotational axis A1 shall be referred to simply as the "radially
outer side." The electric motor 23 is included in a substrate
rotating unit that rotates the substrate W around the rotational
axis A1.
[0108] The processing cup 7 includes a plurality of guards 71,
receiving liquid splashing outward from the substrate W held by the
spin chuck 5, a plurality of cups 72, receiving the liquid guided
downward by the plurality of guards 71, and an outer wall member 73
of circular cylindrical shape that surrounds the plurality of
guards 71 and the plurality of cups 72. With the present preferred
embodiment, an example where two guards 71 (a first guard 71A and a
second guard 71B) and two cups 72 (a first cup 72A and a second cup
72B) are provided is illustrated.
[0109] Each of the first cup 72A and the second cup 72B has an
upwardly-open, groove-shaped form. The first guard 71A surrounds
the spin base 21. The second guard 71B surrounds the spin base 21
at a further radially outer side than the first guard 71A. The
first cup 72A receives the liquid guided downward by the first
guard 71A. The second cup 72B is formed integral to the first guard
71A and receives the liquid guided downward by the second guard
71B.
[0110] The processing unit 2 includes a guard elevating/lowering
unit 74 that elevates and lowers each of the first guard 71A and
the second guard 71B separately. The guard elevating/lowering unit
74 elevates and lowers the first guard 71A between a lower position
and an upper position. The guard elevating/lowering unit 74
elevates and lowers the second guard 71B between a lower position
and an upper position. The first guard 71A is positioned laterally
to the substrate W in an entirety of a movable range between the
upper position and the lower position. The second guard 71B is
positioned laterally to the substrate Win an entirety of a movable
range between the upper position and the lower position. The upper
position and the lower position are included in each movable
range.
[0111] The guard elevating/lowering unit 74 includes, for example,
a first ball-screw mechanism (not shown), mounted to the first
guard 71A, a first motor (not shown), applying a driving force to
the first ball screw, a second ball-screw mechanism (not shown),
mounted to the second guard 71B, and a second motor (not shown),
applying a driving force to the second ball screw. The guard
elevating/lowering unit 74 is also referred to as a guard
lifter.
[0112] The exhaust unit 8 includes an exhaust duct 26, connected to
a bottom portion of the outer wall member 73 of the processing cup
7, and an exhaust valve 27, opening and closing the exhaust duct
26. A flow rate (exhaust flow rate) of a gas flowing through the
exhaust duct 26 can be adjusted by adjusting an opening degree of
the exhaust valve 27. The exhaust duct 26 is connected, for
example, to an exhaust apparatus 28 that suctions the interior of
the chamber 4. The exhaust apparatus 28 may be a portion of the
substrate processing apparatus 1 or may be provided separately from
the substrate processing apparatus 1. In a case where the exhaust
apparatus 28 is a portion of the substrate processing apparatus 1,
the exhaust apparatus 28 is, for example, a vacuum pump, etc. A gas
inside the chamber 4 is emitted from the chamber 4 through the
exhaust duct 26. A downflow of clean air is thereby formed
constantly in the interior of the chamber 4.
[0113] The facing member 6 faces the substrate W, held by the spin
chuck 5, from above. The facing member 6 is formed to a disk shape
having substantially same diameter as or a diameter not less than
that of the substrate Wand is disposed substantially horizontally
above the spin chuck 5. The facing member 6 has a facing surface 6a
facing the upper surface of the substrate W.
[0114] A hollow shaft 60 is fixed to a surface of the facing member
6 at an opposite side to the facing surface 6a. A communicating
hole, penetrating vertically through the facing member 6 and being
in communication with an internal space of the hollow shaft 60, is
formed in a portion of the facing member 6 including a position
overlapping with the rotational axis A1 in plan view.
[0115] The facing member 6 blocks an atmosphere, inside a space
between the facing surface 6a of the facing member 6 and the upper
surface of the substrate W, from an atmosphere at an exterior of
the space. The facing member 6 is thus also called a blocking
plate.
[0116] The processing unit 2 further includes a facing member
elevating/lowering unit 61 that drives elevation and lowering of
the facing member 6. The facing member elevating/lowering unit 61
is capable of positioning the facing member 6 at any position
(height) from a lower position to an upper position. The lower
position is a position within the movable range of the facing
member 6 at which the facing surface 6a of the facing member 6 is
positioned most proximate to the substrate W. The upper position is
a position within the movable range of the facing member 6 at which
the facing surface 6a of the facing member 6 is separated furthest
from the substrate W.
[0117] The facing member elevating/lowering unit 61 includes, for
example, a ball-screw mechanism (not shown), mounted to a
supporting member (not shown) supporting the hollow shaft 60, and
an electric motor (not shown), applying a driving force thereto.
The facing member elevating/lowering unit 61 is also referred to as
a facing member lifter (a shielding plate lifter).
[0118] The imaging unit 9 is, for example, a CCD (charge coupled
device) camera or CMOS (complementary metal oxide semiconductor)
camera and is configured to be adjustable in exposure time and
number of frames as parameters for imaging. The imaging unit 9 is
mounted to the partition wall 24 of the chamber 4. The imaging unit
9 takes an image of the upper surface of the substrate W from an
obliquely upward position.
[0119] The processing unit 2 includes a first moving nozzle 10,
movable at least in a horizontal direction, a second moving nozzle
11, movable at least in a horizontal direction, a central nozzle
12, inserted through the hollow shaft 60 and facing a central
region of the upper surface of the substrate W, a lower surface
nozzle 13, inserted through the rotating shaft 22 and facing a
central region of a lower surface of the substrate W, and a side
nozzle 14, disposed at a side of the spin base 21.
[0120] The first moving nozzle 10 is an example of a processing
liquid supplying unit that supplies (discharges) the first
processing liquid toward the upper surface of the substrate W. The
first processing liquid discharged from the first moving nozzle 10
contains a solute and a solvent having volatility. The first
processing liquid solidifies or cures upon volatilization of at
least a portion of the solvent to form a particle holding layer
that pulls away particles, attached to the upper surface of the
substrate W, from the substrate W and holds the particles.
[0121] Here, "solidification of the first processing liquid"
refers, for example, to hardening of the solute due to forces
acting between molecules or between atoms, etc., in accompaniment
with the volatilization of the solvent. "Curing of the first
processing liquid" refers, for example, to hardening of the solute
due to a chemical change, such as polymerization, crosslinking,
etc. "Solidifying or curing of the first processing liquid" thus
expresses the "hardening" of the solute of the first processing
liquid due to various causes.
[0122] A resin used as the solute of the first processing liquid
is, for example, a resin (may hereinafter be referred to at times
as the "thermosensitive water-soluble resin"), having properties of
being poorly soluble or insoluble in water before being heated to
not less than a predetermined alteration temperature and altering
and becoming water soluble by being heated to not less than the
alteration temperature.
[0123] The thermosensitive water-soluble resin expresses water
solubility, for example, by decomposing and exposing a functional
group with polarity upon being heated to the predetermined
alteration temperature (for example, not less than 200.degree.
C.)
[0124] As the solvent of the first processing liquid, a solvent,
having a dissolving ability with respect to the thermosensitive
water-soluble resin before alteration and having volatility, may be
used. Here, "having volatility" means being high in volatility in
comparison to water. As the solvent of the first processing liquid,
for example, PGEE (propylene glycol monoethyl ether) is used.
[0125] The first moving nozzle 10 is connected to a first
processing liquid piping 40, in which a first processing liquid
valve 50 is interposed. When the first processing liquid valve 50,
interposed in the first processing liquid piping 40, is opened, the
first processing liquid is discharged continuously downward from a
discharge port 10a of the first moving nozzle 10.
[0126] The first moving nozzle 10 is moved in the horizontal
direction and the vertical direction by a first nozzle moving unit
33. The first moving nozzle 10 is capable of moving between a
central position and a home position (retracted position). When
positioned at the central position, the first moving nozzle 10
faces a rotation center of the upper surface of the substrate W.
The rotation center of the upper surface of the substrate W is a
position of intersection of the rotational axis A1 in the upper
surface of the substrate W. When positioned at the home position,
the first moving nozzle 10 does not face the upper surface of the
substrate W and is positioned outside the processing cup 7 in plan
view.
[0127] When the facing member 6 is positioned at the upper
position, the first moving nozzle 10 can enter between the facing
surface 6a of the facing member 6 and the upper surface of the
substrate W. By moving in the vertical direction, the first moving
nozzle 10 can approach the upper surface of the substrate W or
retract upward from the upper surface of the substrate W.
[0128] The first nozzle moving unit 33 includes, for example, a
pivoting shaft (not shown), oriented along the vertical direction,
an arm (not shown), coupled to the pivoting shaft and extending
horizontally, and a pivoting shaft driving unit (not shown) that
elevates, lowers, and pivots the pivoting shaft. The pivoting shaft
driving unit pivots the pivoting shaft around a vertical pivoting
axis to swing the arm. Further, the pivoting shaft driving unit
elevates and lowers the pivoting shaft along the vertical direction
to move the arm vertically. The first moving nozzle 10 is fixed to
the arm. The first moving nozzle 10 moves in the horizontal
direction and the vertical direction in accordance with the
swinging and elevating/lowering of the arm.
[0129] The processing unit 2 includes a cleaning unit 80 arranged
to clean the discharge port 10a of the first moving nozzle 10. The
cleaning unit 80 includes a cleaning pot 81, storing a cleaning
liquid, a cleaning liquid supply pipe 83, supplying the cleaning
liquid to the cleaning pot 81, and a cleaning liquid drain pipe 84,
draining the cleaning liquid from the cleaning pot 81. The cleaning
liquid is, for example, IPA. By opening a cleaning liquid valve 86,
interposed in the cleaning liquid supply pipe 83, the cleaning
liquid is supplied to the cleaning pot 81. By opening a waste
liquid valve 87, interposed in the cleaning liquid drain pipe 84,
the cleaning liquid is drained from the cleaning pot 81.
[0130] The cleaning pot 81 is disposed below the first moving
nozzle 10 positioned at the retracted position. The discharge port
10a of the first moving nozzle 10 is cleaned by downwardly moving
the first moving nozzle 10, positioned at the retracted position,
such that the discharge port 10a of the first moving nozzle 10 is
positioned lower than a liquid surface of the cleaning liquid
stored inside the cleaning pot 81 (for example, at a position shown
in FIG. 2).
[0131] By opening the cleaning liquid valve 86 and the waste liquid
valve 87 during the cleaning or after the cleaning of the discharge
port 10a of the first moving nozzle 10, decrease of purity of the
cleaning liquid inside the cleaning pot 81 can be suppressed or
prevented. Attachment of particles to the first moving nozzle 10
from the cleaning liquid inside the cleaning pot 81 can thereby be
suppressed or prevented.
[0132] The second moving nozzle 11 is an example of a peeling
liquid supplying unit that supplies (discharges) the peeling
liquids toward the upper surface of the substrate W. Each peeling
liquid is a liquid for peeling the particle holding layer, formed
by the first processing liquid, from the upper surface of the
substrate W. A liquid having compatibility with the solvent
contained in the first processing liquid is preferably used as the
peeling liquid.
[0133] As the peeling liquid, for example, a water-based peeing
liquid is used. As the water-based peeling liquid, the peeling
liquid is not restricted to DIW, and carbonated water, electrolyzed
ion water, hydrogen water, ozone water, as well as aqueous
hydrochloric acid solution and aqueous alkaline solution of dilute
concentrations (for example, approximately 10 ppm to 100 ppm),
etc., can be cited. As the aqueous alkaline solution, SC1 solution
(ammonia-hydrogen peroxide mixture), aqueous ammonia solution,
aqueous solution of a quaternary ammonium hydroxide, such as
tetramethylammonium hydroxide, etc., aqueous choline solution,
etc., can be cited.
[0134] In the present preferred embodiment, the second moving
nozzle 11 is connected to a common piping 41 with a common valve 51
interposed therein. A first SC1 liquid piping 42, with a first SC1
liquid valve 52 interposed therein, and a first DIW liquid piping
43, with a first DIW liquid valve 53 interposed therein, are
connected to a portion of the common piping 41 at a further
upstream side than the common valve 51. When the common valve 51
and the first SC1 liquid valve 52 are opened, the SC1 liquid is
discharged continuously downward as the peeling liquid from a
discharge port of the second moving nozzle 11. When the common
valve 51 and the first DIW liquid valve 53 are opened, DIW is
discharged continuously downward as the peeling liquid from the
discharge port of the second moving nozzle 11.
[0135] DIW also functions as the rinse liquid that washes away a
chemical liquid, such as the peeling liquid, etc., on the substrate
W. The rinse liquid is, for example, DIW. Besides DIW, carbonated
water, electrolyzed ion water, hydrogen water, ozone water, ammonia
water, and aqueous hydrochloric acid solution of dilute
concentration (for example, approximately 10 ppm to 100 ppm) can be
cited as the rinse liquid. The second moving nozzle 11 can thus
also function as a rinse liquid supplying unit that supplies the
rinse liquid to the upper surface of the substrate W.
[0136] The second moving nozzle 11 is moved in the horizontal
direction and the vertical direction by a second nozzle moving unit
34. The second moving nozzle 11 is capable of moving between a
central position and a home position (retracted position). When
positioned at the central position, the second moving nozzle 11
faces the rotation center of the upper surface of the substrate W.
When positioned at the home position, the second moving nozzle 11
does not face the upper surface of the substrate W and is
positioned outside the processing cup 7 in plan view.
[0137] When the facing member 6 is positioned at the upper
position, the second moving nozzle 11 can enter between the facing
surface 6a of the facing member 6 and the upper surface of the
substrate W. By moving in the vertical direction, the second moving
nozzle 11 can approach the upper surface of the substrate W or
retract upward from the upper surface of the substrate W.
[0138] The second nozzle moving unit 34 has the same configuration
as the first nozzle moving unit 33. That is, the second nozzle
moving unit 34 includes, for example, a pivoting shaft (not shown),
oriented along the vertical direction, an arm (not shown), coupled
to the pivoting shaft and the second moving nozzle 11 and extending
horizontally, and a pivoting shaft driving unit (not shown) that
elevates, lowers, and pivots the pivoting shaft.
[0139] The central nozzle 12 includes a plurality of inner tubes (a
first tube 91, a second tube 92, a third tube 93, and a fourth tube
94) that discharge processing liquids downward and a cylindrical
casing 90, surrounding the plurality of inner tubes. The first tube
91, the second tube 92, the third tube 93, the fourth tube 94, and
the casing 90 extend in an up/down direction along the rotational
axis A1. An inner peripheral surface of the facing member 6 and an
inner peripheral surface of the hollow shaft 60 surround an outer
peripheral surface of the casing 90 across an interval in a
rotational radius direction. A discharge port 12a of the central
nozzle 12 is provided at the facing surface 6a of the facing member
6. The discharge port 12a of the central nozzle 12 is also a
discharge port of the first tube 91, the second tube 92, the third
tube 93, and the fourth tube 94.
[0140] The first tube 91 discharges the second processing liquid
toward the upper surface of the substrate W. A second processing
liquid supply piping 44, with a second processing liquid valve 54
interposed therein, is connected to the first tube 91. When the
second processing liquid valve 54 is opened, the second processing
liquid is supplied from the second processing liquid supply piping
44 to the first tube 91 and is discharged continuously downward
from the discharge port of the first tube 91 (the discharge port
12a of the central nozzle 12). The central nozzle 12 is an example
of a second processing liquid supplying unit that supplies the
second processing liquid to the upper surface of the substrate
W.
[0141] The second processing liquid is a liquid that contains a
sublimable substance. As the liquid containing the sublimable
substance, for example, that containing the sublimable substance in
a molten state, such as a melt of the sublimable substance, etc.,
or a solution, in which the sublimable substance is dissolved as a
solute in a solvent, etc., may be used. Here, "molten state" refers
to a state where the sublimable substance has fluidity due to being
molten completely or partially and assumes a liquid state. As the
sublimable substance, any of various substances that is high in
vapor pressure at an ordinary temperature (5.degree. C. to
35.degree. C.) and changes from a solid phase to a gas phase
without passing through a liquid phase is used.
[0142] With the present preferred embodiment, an example where
1,1,2,2,3,3,4-heptafluorocyclopentane is used as the sublimable
substance shall be described. This compound has a vapor pressure at
20.degree. C. of approximately 8266 Pa, a melting point (freezing
point) of 20.5.degree. C., and a boiling point of 82.5.degree.
C.
[0143] As the solvent in a case where the sublimable substance in
the molten state is to be mixed, a solvent that exhibits
compatibility with the sublimable substance in the molten state is
preferable. Also, if the sublimable substance is to be dissolved as
a solute, a solvent exhibiting a dissolving ability with respect to
the sublimable substance is preferable.
[0144] As the solvent used in the second processing liquid, for
example, at least one type of solvent selected from the group
consisting of DIW, pure water, aliphatic hydrocarbons, aromatic
hydrocarbons, esters, alcohols, ethers, etc., can be cited.
[0145] Specifically, for example, at least one type of solvent
selected from the group consisting of DIW, pure water, methanol,
ethanol, IPA, butanol, ethylene glycol, propylene glycol, NMP
(N-methyl-2-pyrrolidone), DMF (N,N-dimethylformamide), DMA
(dimethylacetamide), DMSO (dimethylsulfoxide), hexane, toluene,
PGMEA (propylene glycol monomethyl ether acetate), PGME (propylene
glycol monomethyl ether), PGPE (propylene glycol monopropyl ether),
PGEE (propylene glycol monoethyl ether), GBL
(.gamma.-butyrolactone), acetylacetone, 3-pentanone, 2-heptanone,
ethyl lactate, cyclohexanone, dibutyl ether, HFE
(hydrofluoroether), ethyl nonafluoroisobutyl ether, ethyl
nonafluorobutyl ether, and m-xylene hexafluoride, can be cited.
[0146] A suction piping 96 is branchingly connected to the second
processing liquid piping 44 at a position further to the downstream
side (first tube 91 side) than the second processing liquid valve
54. A suction valve 97, opening and closing a flow passage inside
the suction piping 96, is interposed in the suction piping 96. A
suction unit 98, arranged to suction the second processing liquid
inside the first tube 91 and the second processing liquid piping 44
is connected to the suction piping 96. The suction unit 98 is, for
example, a vacuum pump. Although in FIG. 2, the suction unit 98 is
disposed in the chamber 4, it may be disposed outside the chamber 4
instead.
[0147] The processing unit 2 includes a heater 99 that heats the
second processing liquid inside the first tube 91 and the second
processing liquid piping 44 to keep a temperature of the second
processing liquid inside the first tube 91 and the second
processing liquid piping 44 at not less than the melting point of
the sublimable substance. The heater 99 is, for example,
incorporated in the hollow shaft 60.
[0148] The second tube 92 discharges DIW toward the upper surface
of the substrate W. A second DIW piping 45, with a second DIW valve
55 interposed therein, is connected to the second tube 92. When the
second DIW valve 55 is opened, DIW is supplied from the second DIW
piping 45 to the second tube 92 and is discharged continuously
downward from the discharge port of the second tube 92 (the
discharge port 12a of the central nozzle 12). The central nozzle 12
is an example of the rinse liquid supplying unit that supplies the
rinse liquid to the upper surface of the substrate W. As mentioned
above, DIW also functions as the peeling liquid and therefore the
central nozzle 12 is also capable of functioning as the peeling
liquid supplying unit that supplies (discharges) the peeling liquid
toward the upper surface of the substrate W.
[0149] The third tube 93 discharges IPA toward the upper surface of
the substrate W. An IPA piping 46, with an IPA valve 56 interposed
therein, is connected to the third tube 93. When the IPA valve 56
is opened, IPA is supplied from the IPA piping 46 to the third tube
93 and is discharged continuously downward from the discharge port
of the third tube 93 (the discharge port 12a of the central nozzle
12).
[0150] IPA is an example of the residue removing liquid having a
dissolving ability with respect to the solute of the first
processing liquid. The central nozzle 12 is thus an example of a
residue removing liquid supplying unit that supplies the residue
removing liquid to the upper surface of the substrate W.
[0151] When a thermosensitive water-soluble resin is used as the
solute of the first processing liquid, a liquid having a dissolving
ability with respect to the thermosensitive water-soluble resin
before alteration may be used as the residue removing liquid. An
example of the liquid used as the residue removing liquid when a
thermosensitive water-soluble resin is used as the solute of the
first processing liquid is IPA. The residue removing liquid is
preferably a liquid having compatibility with the water-based
peeling liquid.
[0152] The fourth tube 94 discharges the gas, such as nitrogen gas,
etc., toward the upper surface of the substrate W. A first gas
piping 47, with a first gas valve 57 interposed therein, is
connected to the fourth tube 94. When the first gas valve 57 is
opened, the gas is supplied from the first gas piping 47 to the
fourth tube 94 and is discharged continuously downward from the
discharge port of the fourth tube 94 (the discharge port 12a of the
central nozzle 12). The central nozzle 12 is an example of a gas
supplying unit that supplies the gas to the upper surface of the
substrate W.
[0153] The gas discharged from the fourth tube 94 is preferably an
inert gas. The inert gas refers to a gas that is inert with respect
to the upper surface and a pattern of the substrate W and may, for
example, be a noble gas, such as argon, etc. The gas discharged
from the fourth tube 94 may be air.
[0154] A fifth tube 95 is disposed between the casing 90 of the
central nozzle 12 and the inner peripheral surface of the facing
member 6 and between the casing 90 and an inner peripheral surface
of the hollow shaft 60. The fifth tube 95 discharges a gas, such as
nitrogen gas, etc., downward. A second gas piping 78, with a second
gas valve 77 interposed therein, is connected to the fifth tube 95.
When the second gas valve 77 is opened, the gas is supplied from
the second gas piping 78 to the fifth tube 95 and is discharged
continuously downward from a discharge port of the fifth tube 95.
The fifth tube 95 is an example of an atmosphere replacing unit
that supplies the gas to the space between the upper surface of the
substrate W and the facing surface 6a of the facing member 6 to
replace the atmosphere between the upper surface of the substrate W
and the facing surface 6a of the facing member 6.
[0155] The gas discharged from the fifth tube 95 is preferably an
inert gas. The inert gas refers to a gas that is inert with respect
to the upper surface and the pattern of the substrate W and may,
for example, be a noble gas, such as argon, etc. The gas discharged
from the fifth tube 95 may be air.
[0156] The side nozzle 14 is fixed to the first guard 71A. The side
nozzle 14 is connected to a second SC1 liquid piping 48 with a
second SC1 liquid valve 58 interposed therein. When the second SC1
liquid valve 58 is opened, the SC1 liquid is continuously
discharged laterally from a discharge port of the side nozzle 14.
When the first guard 71A is positioned at a predetermined cleaning
position, the side nozzle 14 faces the chuck unit 20 laterally. The
first gripping pins 20A and the second gripping pins 20B are
cleaned by the SC1 liquid being discharged from the discharge port
of the side nozzle 14 in a state where the first guard 71A is
positioned at the predetermined cleaning position and the spin base
21 is rotating.
[0157] The lower surface nozzle 13 is inserted in the penetrating
hole 21a opening at a central portion of the upper surface of the
spin base 21. A discharge port 13a of the lower surface nozzle 13
is exposed from the upper surface of the spin base 21. The
discharge port 13a of the lower surface nozzle 13 faces a central
portion of the lower surface of the substrate W from below.
[0158] The processing unit 2 includes a processing fluid supply
piping 49 supplying a plurality of types of processing fluids to
the lower surface nozzle 13. FIG. 4 is a schematic view of the
processing fluid supply piping 49.
[0159] The processing fluids discharged from the discharge port 13a
of the lower surface nozzle 13 are, for example, a peeling liquid
and the heat medium. Each heat medium is a fluid for transmitting
heat to the substrate W. DIW can be cited as an example of the heat
medium. The heat medium is not restricted to a liquid and may be a
gas. The processing fluid supply piping 49 is capable of supplying
the heat medium to the lower surface 13 and is therefore also
called a heat medium supply piping.
[0160] The processing fluid supply piping 49 includes a processing
fluid feeding piping 100, a processing fluid common piping 101, a
high temperature DIW feeding piping 102, a low temperature DIW
feeding piping 103, a medium temperature DIW feeding piping 104, an
H.sub.2O.sub.2 feeding piping 105, and an ammonia water feeding
piping 106.
[0161] The processing fluid feeding piping 100 feeds the processing
fluid from the processing fluid common piping 101 to the discharge
port 13a of the lower surface nozzle 13. The high temperature DIW
feeding piping 102 feeds high temperature DIW from a high
temperature DIW supply source 112 to the processing fluid common
piping 101. The low temperature DIW feeding piping 103 feeds low
temperature DIW from a low temperature DIW supply source 113 to the
processing fluid common piping 101. The medium temperature DIW
feeding piping 104 feeds medium temperature DIW from a medium
temperature DIW supply source 114 to the processing fluid common
piping 101. The H.sub.2O.sub.2 feeding piping 105 feeds hydrogen
peroxide solution (H.sub.2O.sub.2) from an H.sub.2O.sub.2 supply
source 115 to the processing fluid common piping 101. The ammonia
water feeding piping 106 feeds ammonia water from an ammonia water
supply source 116 to the processing fluid common piping 101.
[0162] By two or more types of processing fluids being fed to the
processing fluid common piping 101 at the same time, the processing
fluids are mixed with each other. By hydrogen peroxide solution,
ammonia water, and DIW being fed to the processing fluid common
piping 101, the SC1 liquid is prepared.
[0163] A liquid draw-off piping 107, draining the processing fluid
inside the processing fluid common piping 101, is connected to the
processing fluid common piping 101.
[0164] A processing fluid valve 59, opening and closing a flow
passage inside the processing fluid feeding piping 100, is
interposed in the processing fluid feeding piping 100. A high
temperature DIW valve 122, opening and closing a flow passage
inside the high temperature DIW feeding piping 102, is interposed
in the high temperature DIW feeding piping 102. A low temperature
DIW valve 123, opening and closing a flow passage inside the low
temperature DIW feeding piping 103, is interposed in the low
temperature DIW feeding piping 103. A medium temperature DIW valve
124, opening and closing a flow passage inside the medium
temperature DIW feeding piping 104, is interposed in the medium
temperature DIW feeding piping 104. An H.sub.2O.sub.2 valve 125,
opening and closing a flow passage inside the H.sub.2O.sub.2
feeding piping 105, is interposed in the H.sub.2O.sub.2 feeding
piping 105. An ammonia water valve 126, opening and closing a flow
passage inside the ammonia water feeding piping 106, is interposed
in the ammonia water feeding piping 106. A liquid draw-off valve
127, opening and closing a flow passage inside the liquid draw-off
piping 107, is interposed in the liquid draw-off piping 107.
[0165] A temperature of the DIW (high temperature DIW) supplied
from the high temperature DIW supply source 112 is, for example,
60.degree. C. to 80.degree. C. The high temperature DIW functions
as a first heat medium that heats the substrate W. A temperature of
the DIW (low temperature DIW) supplied from the low temperature DIW
supply source 113 is, for example, 4.degree. C. to 19.degree. C.
The low temperature DIW functions as a second heat medium that
cools the substrate W. A temperature of the DIW (medium temperature
DIW) supplied from the medium temperature DIW supply source 114 is,
for example, 25.degree. C. The medium temperature DIW functions as
a third heat medium for holding the temperature within a
temperature range of not less than the melting point (20.5.degree.
C.) of the sublimable substance and less than the boiling point
(82.5.degree. C.) of the sublimable substance.
[0166] When the high temperature DIW valve 122 and the processing
fluid valve 59 are opened, the high temperature DIW (first heat
medium) is discharged from the lower surface nozzle 13 toward the
lower surface of the substrate W via the high temperature DIW
feeding piping 102, the processing fluid common piping 101, and the
processing fluid feeding piping 100. The lower surface nozzle 13
functions as a first heat medium supplying unit that supplies the
first heat medium to the lower surface of the substrate W.
[0167] When the low temperature DIW valve 123 and the processing
fluid valve 59 are opened, the low temperature DIW (second heat
medium) is discharged from the lower surface nozzle 13 toward the
lower surface of the substrate W via the low temperature DIW
feeding piping 103, the processing fluid common piping 101, and the
processing fluid feeding piping 100. The lower surface nozzle 13
thus also functions as a second heat medium supplying unit.
[0168] When the medium temperature DIW valve 124 and the processing
fluid valve 59 are opened, the medium temperature DIW (third heat
medium) is discharged from the lower surface nozzle 13 toward the
lower surface of the substrate W via the medium temperature DIW
feeding piping 104, the processing fluid common piping 101, and the
processing fluid feeding piping 100. The lower surface nozzle 13
thus also functions as a third heat medium supplying unit.
[0169] FIG. 5 is a block diagram for describing the electrical
configuration of a main portion of the substrate processing
apparatus 1. The controller 3 includes a microcomputer and controls
control objects included in the substrate processing apparatus 1 in
accordance with a predetermined program. More specifically, the
controller 3 includes a processor (CPU) 3A and a memory 3B, storing
the program, and is arranged such that various controls for
substrate processing are executed by the processor 3A executing the
program.
[0170] In particular, the controller 3 controls operations of the
transfer robot IR, the transfer robot CR, the FFU 29, the electric
motor 23, the first nozzle moving unit 33, the second nozzle moving
unit 34, the facing member elevating/lowering unit 61, the guard
elevating/lowering unit 74, the heater 99, the imaging unit 9, the
pin driving unit 30, the exhaust apparatus 28, the suction unit 98,
and the exhaust valve 27, the first processing liquid valve 50, the
common valve 51, the first SC1 liquid valve 52, the first DIW valve
53, the second processing liquid valve 54, the second DIW valve 55,
the IPA valve 56, the first gas valve 57, the second SC2 liquid
valve 58, the processing fluid valve 59, the second gas valve 77,
the cleaning liquid valve 86, the waste liquid valve 87, the
suction valve 97, the high temperature DIW valve 122, the low
temperature DIW valve 123, the medium temperature DIW valve 124,
the H.sub.2O.sub.2 valve 125, the ammonia water valve 126, and the
liquid draw-off valve 127. By controlling the exhaust valve 27, the
first processing liquid valve 50, the common valve 51, the first
SC1 liquid valve 52, the first DIW valve 53, the second processing
liquid valve 54, the second DIW valve 55, the IPA valve 56, the
first gas valve 57, the second SC2 liquid valve 58, the processing
fluid valve 59, the second gas valve 77, the cleaning liquid valve
86, the waste liquid valve 87, the suction valve 97, the high
temperature DIW valve 122, the low temperature DIW valve 123, the
medium temperature DIW valve 124, the H.sub.2O.sub.2 valve 125, the
ammonia water valve 126, and the liquid draw-off valve 127, control
of whether or not fluids are discharged from the corresponding
nozzles and tubes, etc., is performed.
[0171] FIG. 6 is a flowchart for describing an example of substrate
processing by the substrate processing apparatus 1 and mainly shows
processing realized by the controller 3 executing the program. FIG.
7A to FIG. 7L are illustrative sectional views for describing the
substrate processing.
[0172] In the substrate processing by the substrate processing
apparatus 1, for example, substrate carry-in (S1), a first
processing liquid supplying step (S2), a holding layer forming step
(S3), a holding layer removing step (S4), a rinsing step (S5), a
residue removing step (S6), a liquid film forming step (S7), a film
thinning step (S8), a solidifying step (S9), a sublimating step
(S10), a drying step (S11), and substrate carry-out (S12) are
executed in that order as shown in FIG. 6.
[0173] First, an unprocessed substrate W is carried from a carrier
C into a processing unit 2 by the transfer robot IR and the
transfer robot CR (see FIG. 1) and transferred to the spin chuck 5
(S1). The chuck unit 20 is then put in the closed state. The
substrate W is thereby held horizontally by the spin chuck 5
(substrate holding step). The holding of the substrate W by the
spin chuck 5 is continued until the drying step (S11) ends. At this
point, the substrate W is gripped by both the plurality of first
gripping pins 20A and the plurality of second gripping pins 20B
(first substrate gripping step). Also, the facing member
elevating/lowering unit 61 disposes the facing member 6 at the
upper position.
[0174] Next, referring to FIG. 7A, the first processing liquid
supplying step of supplying the first processing liquid to the
upper surface of the substrate W is executed (S2). The first
processing liquid supplying step is executed in a period, for
example, of 2.4 seconds. In the first processing liquid supplying
step, first, the electric motor 23 (see FIG. 2) rotates the spin
base 21. The substrate W is thereby rotated (substrate rotating
step). In the first processing liquid supplying step, the spin base
21 is rotated at a predetermined first processing liquid supplying
speed. The first processing liquid supplying speed is, for example,
10 rpm. The guard elevating/lowering unit 74 disposes both the
first guard 71A and the second guard 71B at the upper position
(guard disposing step).
[0175] The first nozzle moving unit 33 then disposes the first
moving nozzle 10 at the central position. The first processing
liquid valve 50 is then opened. The first processing liquid is
thereby supplied from the first moving nozzle 10 toward the upper
surface of the substrate W in the rotating state. The first
processing liquid supplied to the upper surface of the substrate W
spreads across the entire upper surface of the substrate W due to a
centrifugal force. Excess first processing liquid is eliminated
radially outward from the substrate W due to the centrifugal force.
The first processing liquid eliminated from the substrate W is
received by the first guard 71A.
[0176] Referring to FIG. 7B and FIG. 7C, after the first processing
liquid is supplied to the substrate W for a fixed time, the holding
layer forming step of solidifying or curing the first processing
liquid to form a particle holding layer 150 (see FIG. 7C) on the
upper surface of the substrate W is executed (S3).
[0177] As shown in FIG. 7B, first, in the holding layer forming
step, the first processing liquid valve 50 is closed to make an
amount of the first processing liquid on the substrate W an
appropriate amount. The discharge (supply) of the first processing
liquid from the discharge port 10a of the first moving nozzle 10 to
the upper surface of the substrate W is thereby stopped (supply
stopping step). The first moving nozzle 10 is then moved to the
retracted position by the first nozzle moving unit 33. A rotation
elimination step of eliminating a portion of the first processing
liquid from the upper surface of the substrate W by a centrifugal
force is then executed.
[0178] In the rotation elimination step, the electric motor 23
changes a rotational speed of the spin base 21 to a predetermined
rotation elimination speed. The rotation elimination speed is, for
example, 300 rpm to 1500 rpm. The rotational speed of the spin base
21 may be kept fixed within a range of 300 rpm to 1500 rpm or may
be changed as appropriate within the range of 300 rpm to 1500 rpm
in the middle of the rotation elimination step. The rotation
elimination step is executed in a period, for example, of 30
seconds.
[0179] Then, referring to FIG. 7C, in the holding layer forming
step, after the rotation elimination step, a substrate heating step
of heating the substrate W to volatilize a portion of the solvent
of the first processing liquid on the substrate W is executed. In
the substrate heating step, the processing fluid valve 59 and the
high temperature DIW valve 122 (see FIG. 4) are opened. The high
temperature DIW (first heat medium) is thereby supplied from the
lower surface nozzle 13 to the central region of the lower surface
of the substrate Wand the first processing liquid on the substrate
W is heated via the substrate W. The substrate heating step is
executed in a period, for example, of 60 seconds. In the substrate
heating step, the electric motor 23 changes the rotational speed of
the spin base 21 to a predetermined substrate heating speed. The
substrate heating speed is, for example, 1000 rpm.
[0180] In the substrate heating step, the substrate W is preferably
heated such that a temperature of the first processing liquid on
the substrate W becomes less than a boiling point of the solvent.
As described above, the solvent can be made to remain in the
particle holding layer 150 by heating the first processing liquid
to a temperature less than the boiling point of the solvent. The
particle holding layer 150 can then be made easily peelable from
the upper surface of the substrate W by interaction of the solvent
remaining in the particle holding layer 150 and the peeling
liquid.
[0181] In the substrate heating step, the substrate W is preferably
heated such that the temperature of the first processing liquid on
the substrate W becomes less than the alteration temperature of the
thermosensitive water-soluble resin in addition to the temperature
of the first processing liquid on the substrate W becoming less
than the boiling point of the solvent. By heating the first
processing liquid to a temperature less than the alteration
temperature, the particle holding layer 150 that is poorly soluble
or insoluble in the water-based peeling liquid can be formed on the
upper surface of the substrate W without altering the
thermosensitive water-soluble resin to be water-soluble.
[0182] By execution of the substrate heating step, the first
processing liquid is solidified or cured and the particle holding
layer 150 is formed on the substrate W. As shown in FIG. 8A, when
the particle holding layer 150 is formed, particles 151 attached to
the upper surface of the substrate W are pulled away from the
substrate W and become held inside the particle holding layer
150.
[0183] The first processing liquid may be solidified or cured to a
degree such as to be capable of holding the particles 151. It is
not necessary for the solvent of the first processing liquid to be
volatilized completely. Also, a "solute component" forming the
particle holding layer 150 may be the solute, contained in the
first processing liquid, itself or may be a component that is
derived from the solute, for example, a component that is obtained
as a result of a chemical change.
[0184] In the substrate heating step, the facing member
elevating/lowering unit 61 disposes the facing member 6 at a first
proximity position (proximity position) (proximity disposing step).
When the facing member 6 is positioned at the first proximity
position, the facing member 6 is positioned just a predetermined
distance (for example, 1 mm) above the upper surface of the
substrate W. The second gas valve 77 is then opened. The gas, such
as nitrogen gas, etc., is thereby supplied from the fifth tube 95
to the space between the upper surface of the substrate Wand the
facing surface 6a. The gas supplied to the space between the facing
surface 6a of the facing member 6 and the upper surface of the
substrate W forms a gas stream moving from the central region of
the upper surface of the substrate W toward a peripheral edge of
the upper surface of the substrate W. The second gas valve 77 may
be maintained open as it is until the drying step (S11) ends.
[0185] After spreading across substantially the entire lower
surface of the substrate W, the high temperature DIW supplied to
the lower surface of the substrate W splashes outside the substrate
W due to the centrifugal force. The high temperature DIW that
splashed outside the substrate W is received by the first guard
71A. A portion of the high temperature DIW received by the first
guard 71A splashes back from the first guard 71A.
[0186] Thus, in the present preferred embodiment, the substrate
heating step is executed in a state where the facing member 6 is
disposed at the first proximity position. The facing member 6
protects the upper surface of the substrate W from the DIW (first
heat medium) splashed back from the first guard 71A. Attachment of
DIW to a front surface of the particle holding layer 150 can thus
be suppressed and particles resulting from the splashing back of
DIW from the first guard 71A can thus be suppressed.
[0187] Further, by forming the gas stream moving from the central
region of the upper surface of the substrate W to the peripheral
edge of the upper surface of the substrate W as in the present
preferred embodiment, the high temperature DIW splashed back from
the first guard 71A can be pushed back toward the first guard 71A.
The attachment of high temperature DIW to the front surface of the
particle holding layer 150 can thus be suppressed further.
[0188] As shown in FIG. 7D and FIG. 7E, after the holding layer
forming step, the holding layer removing step of supplying the
peeling liquids to the upper surface of the substrate W to peel and
remove the particle holding layer 150 from the upper surface of the
substrate W is executed (S4). In the holding layer removing step, a
first peeling liquid supplying step, in which DIW is supplied as a
first peeling liquid to the upper surface of the substrate W, and a
second peeling liquid supplying step, in which the SC1 liquid is
supplied as a second peeling liquid, are executed. Each of the
first peeling liquid supplying step and the second peeling liquid
supplying step is continued, for example, for 60 seconds.
[0189] Referring to FIG. 7D, in the first peeling liquid supplying
step, the facing member elevating/lowering unit 61 disposes the
facing member 6 at the upper position. The electric motor 23 then
changes the rotational speed of the spin base 21 to a predetermined
first peeling liquid speed. The first peeling liquid speed is, for
example, 800 rpm. The high temperature DIW valve 122 is then closed
and the medium temperature DIW valve 124 is opened (see also FIG.
4). The medium temperature DIW is thereby supplied to the lower
surface of the substrate Win place of the high temperature DIW
(first heat medium). The temperature of the substrate W is thereby
made to approach the temperature of the medium temperature DIW (for
example, 25.degree. C.)
[0190] The second nozzle moving unit 34 then disposes the second
moving nozzle 11 at the central position. The common valve 51 and
the first DIW valve 53 are then opened. DIW is thereby supplied
from the second moving nozzle 11 toward the upper surface of the
substrate W (front surface of the particle holding layer 150) in
the rotating state. The DIW supplied to the upper surface of the
substrate W spreads across the entire upper surface of the
substrate W due to the centrifugal force and replaces the first
processing liquid.
[0191] The DIWs supplied to the upper surface and the lower surface
of the substrate W are eliminated radially outward from the
substrate W due to the centrifugal force. The DIWs and the first
processing liquid eliminated from the substrate W are received by
the first guard 71A.
[0192] Referring to FIG. 7E, in the second peeling liquid supplying
step, the electric motor 23 changes the rotational speed of the
spin base 21 to a predetermined second peeling liquid speed. The
second peeling liquid speed is, for example, 800 rpm. In this case,
a rotational speed of the substrate W in the first peeling liquid
supplying step is maintained in the second peeling liquid supplying
step. The first DIW valve 53 is then closed and, on the other hand,
the first SC1 liquid valve 52 is opened. The SC1 liquid is thereby
supplied from the second moving nozzle 11 toward the upper surface
of the substrate W in the rotating state. Then, while maintaining
the state in which the medium temperature DIW valve 124 (see FIG.
4) is opened, the H.sub.2O.sub.2 valve 125 (see FIG. 4) and the
ammonia water valve 126 (see FIG. 4) are opened. The SC1 liquid is
thereby supplied from the lower surface nozzle 13 toward the lower
surface of the substrate W in the rotating state.
[0193] The SC1 liquid supplied to the upper surface of the
substrate W spreads across the entire upper surface of the
substrate W due to the centrifugal force and replaces the DIW on
the substrate W. The SC1 liquids supplied to the upper surface and
the lower surface of the substrate Ware eliminated radially outward
from the substrate W due to the centrifugal force. The DIW and the
SC1 liquids eliminated from the substrate W are received by the
first guard 71A.
[0194] DIW and the SC1 liquid both have compatibility with PGEE,
which is the solvent. Moreover, the particle holding layer 150,
formed by heating the thermosensitive water-soluble resin to less
than its alteration temperature, is, as mentioned above, poorly
soluble or insoluble in DIW and the SC1 liquid, which are
water-based peeling liquids. Thus, due to interactions with the
PGEE remaining inside the particle holding layer 150, these peeling
liquids permeate into the particle holding layer 150 without
dissolving the solute component forming the particle holding layer
150. The peeling liquids then reach an interface with the substrate
W. The particle holding layer 150 is thereby lifted and peeled,
while still holding the particles 151, from the upper surface of
the substrate W as shown in FIG. 8B.
[0195] The particle holding layer 150 peeled from the upper surface
of the substrate W is expelled, together with the peeling liquids,
from the peripheral edge of the upper surface of the substrate W by
an action of the centrifugal force due to the rotation of the
substrate W. That is, the peeled particle holding layer 150 is
removed from the upper surface of the substrate W.
[0196] DIW is lower in effect as a peeling liquid than the SC1
liquid. However, DIW is supplied before the SC1 liquid and
permeates into the particle holding layer 150 to replace at least a
portion of the PGEE remaining inside the particle holding layer
150. The DIW then acts to aid the permeation of the SC1 liquid,
supplied in the second peeling liquid supplying step, into the
particle holding layer 150.
[0197] Although, as the peeling liquid, it is thus preferable to
supply DIW before supplying the SC1 liquid, the supply of DIW
(first peeling liquid supplying step) may be omitted. That is, just
the SC1 liquid may be used as the peeling liquid.
[0198] Referring to FIG. 7F, after the holding layer removing step,
the rinsing step of replacing the peeling liquids on the substrate
W with the rinse liquid is executed (S5). The rinsing step is
executed in a period, for example, of 35 seconds.
[0199] In the rinsing step, the facing member elevating/lowering
unit 61 disposes the facing member 6 at a first processing
position. When the facing member 6 is positioned at the first
processing position, the facing surface 6a of the facing member 6
is separated from the upper surface of the substrate W by just a
predetermined distance (for example, 30 mm).
[0200] The electric motor 23 then changes the rotational speed of
the spin base 21 to a predetermined rinsing speed. The rinsing
speed is, for example, 800 rpm. In this case, the rotational speed
of the substrate Win the second peeling liquid supplying step is
maintained in the rinsing step. The second DIW valve 55 is then
opened. DIW is thereby supplied from the central nozzle 12 toward
the upper surface of the substrate W in the rotating state. Then,
while maintaining the state where the medium temperature DIW valve
124 (see FIG. 4) is opened, the H.sub.2O.sub.2 valve 125 (see FIG.
4) and the ammonia water valve 126 (see FIG. 4) are closed. The
medium temperature DIW is thereby supplied from the lower surface
nozzle 13 toward the lower surface of the substrate W in the
rotating state.
[0201] The DIWs supplied to the upper surface and the lower surface
of the substrate W spread across the entire upper surface of the
substrate W due to the centrifugal force and replace the SC1
liquid. The DIWs supplied to the upper surface and the lower
surface of the substrate W are eliminated radially outward from the
substrate W due to the centrifugal force. The DIWs and the SC1
liquid eliminated from the substrate W are received by the first
guard 71A.
[0202] A peeling liquid does not readily reach portions of the
substrate W that are in contact with the first gripping pins 20A or
the second gripping pins 20B. Thus, during execution of the second
peeling liquid supplying step, a first separating step, in which
the chuck unit 20 that is in the closed state is put in the first
separated state, a second separating step, in which the chuck unit
20 is put in the second separated state, and a second substrate
gripping step, in which the chuck unit 20 is put in the closed
state again, are executed in that order. The peeling liquid can
thereby be supplied sufficiently to the portions of the substrate W
that are in contact with the first gripping pins 20A or the second
gripping pins 20B. The particle holding layer 150 can thus be
removed sufficiently from the upper surface of the substrate W in
the holding layer removing step. The particle holding layer 150
attached to portions of the peripheral edge of the substrate W that
are gripped by the first gripping pins 20A or the second gripping
pins 20B is thereby peeled by the SC1 liquid.
[0203] Referring to FIG. 7G, the residue removing step of supplying
IPA as the residue removing liquid onto the substrate W after the
rinsing step to remove a residue remaining on the upper surface of
the substrate W after the particle holding layer 150 (see FIG. 7E)
is removed is executed (S6). The residue removing step is executed
in a period, for example, of 30 seconds.
[0204] In the residue removing step, the guard elevating/lowering
unit 74 disposes the first guard 71A at the lower position. The
electric motor 23 then changes the rotational speed of the spin
base 21 to a predetermined residue removing speed. The residue
removing speed is, for example, 300 rpm.
[0205] The second DIW valve 55 is then closed and in its place, the
IPA valve 56 is opened. Thereby, the supply of DIW from the central
nozzle 12 is stopped and in its place, IPA is supplied from the
central nozzle 12 toward the upper surface of the substrate Win the
rotating state. The processing fluid valve 59 and the medium
temperature DIW valve 124 are then closed. The supply of the medium
temperature DIW from the lower surface nozzle 13 to the lower
surface of the substrate W is thereby stopped.
[0206] The IPA supplied to the upper surface of the substrate W
spreads across the entire upper surface of the substrate W due to
the centrifugal force and replaces the DIW on the substrate W. The
IPA supplied to the upper surface of the substrate W is eliminated
radially outward from the substrate W due to the centrifugal force.
The DIW and the IPA eliminated from the substrate W are received by
the second guard 71B.
[0207] Referring to FIG. 7H, after the particle holding layer 150
is removed from the substrate W (after the residue removing step),
the liquid film forming step of supplying the second processing
liquid to the upper surface of the substrate W to form a liquid
film of the second processing liquid (second processing liquid film
160) covering the upper surface of the substrate W is executed
(S7). The liquid film forming step is executed in a period, for
example, of 30 seconds.
[0208] In the liquid film forming step, the facing member
elevating/lowering unit 61 disposes the facing member 6 at a second
processing position lower than the first processing position. When
the facing member 6 is positioned at the second processing
position, the facing surface 6a of the facing member 6 is separated
from the upper surface of the substrate W by just a predetermined
distance (for example, 10 mm). The electric motor 23 then changes
the rotational speed of the spin base 21 to a predetermined liquid
film forming speed. The liquid film forming speed is, for example,
300 rpm.
[0209] The second processing liquid valve 54 is then opened. The
second processing liquid is thereby fed via the second processing
liquid piping 44 toward the discharge port 12a of the central
nozzle 12 (liquid feeding step). The second processing liquid is
then discharged (supplied) from the discharge port 12a of the
central nozzle 12 toward the upper surface of the substrate W
(discharging step). The second processing liquid supplied to the
upper surface of the substrate W spreads across the entire upper
surface of the substrate W due to the centrifugal force and the IPA
on the substrate W is replaced.
[0210] The processing fluid valve 59 and the medium temperature DIW
valve 124 are then opened. Supply of the medium temperature DIW
(third heat medium) from the lower surface nozzle 13 to the lower
surface of the substrate W is thereby started. Since the
temperature of the medium temperature DIW is, for example,
25.degree. C., the temperature of the second processing liquid film
160 is held within a liquid film holding temperature range of not
less than the melting point of the sublimable substance in the
second processing liquid (for example, 20.5.degree. C.) and less
than the boiling point of the sublimable substance (for example,
82.5.degree. C.).
[0211] The second processing liquid supplied to the upper surface
of the substrate W and the DIW supplied to the lower surface of the
substrate W are eliminated radially outward from the substrate W
due to the centrifugal force. The IPA, DIW, and the second
processing liquid eliminated from the substrate W are received by
the second guard 71B.
[0212] Referring to FIG. 7I, while the temperature of the second
processing liquid film 160 is within the temperature range of not
less than the melting point of the sublimable substance in the
second processing liquid and less than the boiling point of the
sublimable substance, the film thinning step of removing a portion
of the second processing liquid that constitutes the second
processing liquid film 160 from the upper surface of the substrate
W to thin the second processing liquid film 160 is executed (S8).
The film thinning step is continued, for example, for 6 seconds. In
the film thinning step, the facing member 6 is maintained at the
second processing position and the second guard 71B is maintained
at the lower position.
[0213] In the film thinning step, the second processing liquid
valve 54 is closed. The discharge (supply) of the second processing
liquid from the discharge port 12a of the central nozzle 12 to the
upper surface of the substrate W is thereby stopped. That is, the
discharging step is ended. On the other hand, the supply of the
medium temperature DIW (third heat medium) from the lower surface
nozzle 13 to the lower surface of the substrate W is continued. The
temperature of the second processing liquid film 160 is thus held
within the liquid film holding temperature range mentioned above
after the supply of the second processing liquid in the liquid film
forming step is stopped (temperature holding step).
[0214] The electric motor 23 then sets the rotational speed of the
spin base 21 to a predetermined film thinning speed. The film
thinning speed is, for example, 300 rpm. By rotating the substrate
W while continuing the supply of the medium temperature DIW from
the lower surface nozzle 13, the second processing liquid film 160
can be thinned by removing the second processing liquid from the
upper surface of the substrate W while the temperature of the
second processing liquid film 160 is within the liquid film holding
temperature range. That is, the electric motor 23 functions as a
removing unit that removes the second processing liquid on the
substrate W.
[0215] The second processing liquid supplied to the upper surface
of the substrate W and the DIW supplied to the lower surface of the
substrate W are eliminated radially outward from the substrate W
due to the centrifugal force. The DIW and the second processing
liquid eliminated from the substrate W are received by the second
guard 71B.
[0216] After the end of the discharging step, the second processing
liquid remains in the second processing liquid piping 44 and the
discharge port 12a. Thus, after the end of the above-stated
discharging step, the suction valve 97 may be opened and the second
processing liquid inside the second processing liquid piping 44 may
be suctioned by the suction unit 98 (suctioning step).
[0217] By making the suction unit 98 suction the second processing
liquid inside the second processing liquid piping 44, the second
processing liquid can be removed from the second processing liquid
piping 44 and the discharge port 12a before the second processing
liquid solidifies.
[0218] The second processing liquid remaining inside the second
processing liquid piping 44 and at the discharge port 12a can thus
be suppressed or prevented from solidifying due to a heat amount of
the second processing liquid remaining inside the second processing
liquid piping 44 and at the discharge port 12a being lost due to
heat of vaporization. Clogging of the second processing liquid
piping 44 can thus be suppressed or prevented.
[0219] Further, at least in an interval from start of the liquid
feeding step to end of the suctioning step, the heater 99 may be
energized to hold a temperature inside the second processing liquid
piping 44 within a control temperature range of not less than the
melting point of the sublimable substance and less than the boiling
point of the sublimable substance (processing liquid piping control
temperature holding step).
[0220] The second processing liquid remaining inside the second
processing liquid piping 44 can thereby be heated. Further, by heat
of the heater 99 being transmitted from the second processing
liquid piping 44 to the discharge port 12a of the central nozzle
12, the discharge port 12a is heated.
[0221] The heat amount of the second processing liquid remaining
inside the second processing liquid piping 44 and at the discharge
port 12a can thus be compensated. Solidification of the second
processing liquid remaining inside the second processing liquid
piping 44 and at the discharge port 12a can thus be suppressed or
prevented. The heater 99 thus functions as a second processing
liquid piping temperature holding unit that holds the temperature
inside the second processing liquid piping 44 within the control
temperature range.
[0222] Referring to FIG. 7J, after the second processing liquid
film 160 is thinned, a solidifying step of supplying the low
temperature DIW (second heat medium) to the lower surface of the
substrate W to cool the second processing liquid film 160 via the
substrate W to a temperature not more than the melting point of the
sublimating substance to make the second processing liquid film 160
solidify on the substrate W is executed (S9). In the solidifying
step, the second processing liquid film 160 solidifies and a solid
film 165 of the sublimable substance is formed. The solidifying
step is continued, for example, for a period of 2 seconds. In the
solidifying step, the facing member 6 is maintained at the second
processing position. In the solidifying step, the first guard 71A
is maintained at the upper position and the second guard 71B is
maintained at the lower position.
[0223] The electric motor 23 then sets the rotational speed of the
spin base 21 to a predetermined solidifying speed. The solidifying
speed is, for example, 300 rpm. Then, the medium temperature DIW
valve 124 is closed and the low temperature DIW valve 123 is
opened. The low temperature DIW (second heat medium) is thereby
supplied to the lower surface of the substrate W in place of the
medium temperature DIW (third heat medium).
[0224] The temperature of the second processing liquid film 160 on
the substrate W is thus made to approach the temperature (for
example, 4.degree. C. to 19.degree. C.) of the low temperature DIW
via the substrate W. Eventually, the temperature of the second
processing liquid film 160 on the substrate W becomes not more than
the melting point (for example, 20.5.degree. C.) of the sublimable
substance and the second processing liquid film 160 thus
solidifies.
[0225] A length of the film thinning step (film thinning period)
can be adjusted by adjusting a timing at which the heat medium
discharged from the lower surface nozzle 13 is switched from the
medium temperature DIW to the low temperature DIW. By adjusting the
length of the film thinning step, a film thickness of the solid
film 165 of the second processing liquid can be adjusted. For
example, the film thickness of the solid film 165 can be made
smaller by making the film thinning period longer.
[0226] Referring to FIG. 7K, a sublimating step of sublimating the
solid film 165 formed on the substrate W to remove the solid film
165 from the upper surface of the substrate W is executed
(S10).
[0227] In the sublimating step, the facing member
elevating/lowering unit 61 disposes the facing member 6 at a second
proximity position. When positioned at the second proximity
position, the facing member 6 is positioned just a predetermined
distance (for example, 1.5 mm) above the upper surface of the
substrate W. The electric motor 23 then sets the rotational speed
of the spin base 21 to a predetermined sublimating speed. The
sublimating speed is, for example, 1500 rpm. The processing fluid
supplying valve 59 and the low temperature DIW valve 123 are then
closed.
[0228] The first gas valve 57 is then opened. The gas is thereby
supplied from the central nozzle 12 to the upper surface of the
substrate W. By the supplied gas, the atmosphere between the facing
surface 6a of the facing member 6 and the upper surface of the
substrate W is dehumidified and dew condensation is prevented (dew
condensation preventing step). Sublimation of the solid film 165 is
promoted by the gas being made to flow above a front surface of the
solid film 165 (sublimation promoting step). The central nozzle 12
functions as a sublimating unit that sublimates the solid film
165.
[0229] Further, an interior of the processing cup 7 is
depressurized from a bottom portion of the processing cup 7 by the
downflow formed by the FFU 29 and the exhaust apparatus 28.
Thereby, the sublimation of the solid film 165 is promoted and dew
condensation is prevented (dew condensation preventing step,
sublimation promoting step). The FFU 29 and the exhaust apparatus
28 function as the sublimating unit that sublimates the solid film
165.
[0230] Then, referring to FIG. 7L, after the solid film 165 is
removed from the upper surface of the substrate W, the drying step
is executed to further dry the upper surface of the substrate W
(S11).
[0231] In the drying step, the facing member 6 is maintained at the
second proximity position. The electric motor 23 then sets the
rotational speed of the spin base 21 to a predetermined drying
speed. The drying speed is, for example, 1500 rpm. The first gas
valve 57 is then closed. Supply of the gas from the central nozzle
12 is thereby stopped.
[0232] After the drying step, the rotation of the spin base 21 is
stopped and the second gas valve 77 is closed to stop the supply of
gas from the fifth tube 95. The facing member elevating/lowering
unit 61 then disposes the facing member 6 at the upper position.
Thereafter, the substrate carry-out step, in which the transfer
robot CR enters into the processing unit 2, lifts up the processed
substrate W from the spin chuck 5, and carries it outside the
processing unit 2, is executed (S12). The substrate W is
transferred from the transfer robot CR to the transfer robot IR and
is housed in a carrier C by the transfer robot IR.
[0233] Thereafter, the plurality of first gripping pins 20A and the
plurality of second gripping pins 20B may be cleaned before the
next substrate W is carried into the processing unit 2 (gripping
pin cleaning step). Specifically, the electric motor 23 rotates the
spin base 21. Then, the second SC1 liquid valve 58 is opened to
discharge the SC1 liquid from the side nozzle 14 toward the
plurality of first gripping pins 20A and the plurality of second
gripping pins 20B in the rotating state. Contaminants attached to
the plurality of first gripping pins 20A and the plurality of
second gripping pins 20B are thereby washed away before the next
substrate W is carried into the processing unit 2. Attachment of
particles to the substrate W that is subsequently held by the spin
chuck 5 can thereby be suppressed.
[0234] After ending the cooling of the substrate W in the
solidifying step, the processing fluid common piping 101 of the
processing fluid supply piping 49 (heat medium supply piping) may
be heated by the high temperature DIW (first heat medium) until the
heating step of the next substrate W is started (heat medium supply
piping heating step).
[0235] Specifically, in the state where the processing fluid supply
valve 59 is closed, the high temperature DIW valve 122 and the
liquid draw-off valve 127 are opened. An interior of the processing
fluid common piping 101 is thereby heated by the high temperature
DIW. By heating the processing fluid common piping 101 of the
processing fluid supply piping 49 with the high temperature DIW in
advance after the solidifying step, it is made possible, in the
holding layer forming step of the substrate processing of the next
substrate W, to heat the first processing liquid on the substrate W
to the desired temperature.
[0236] With the present preferred embodiment, the first processing
liquid supplying step, the holding layer forming step, the holding
layer removing step, the liquid film forming step, the solidifying
step, and the sublimating step are executed. The first processing
liquid on the substrate W is heated by the high temperature DIW
(first heat medium) via the substrate W in the holding layer
forming step. By the first processing liquid thereby being
solidified or cured, the particle holding layer 150 is formed on
the upper surface of the substrate W. When the first processing
liquid is being solidified or cured, the particles 151 are pulled
away from the substrate W. The particles 151 that are pulled away
become held inside the particle holding layer 150. Therefore, by
supplying the peeling liquid to the upper surface of the substrate
W in the holding layer removing step, the particle holding layer
150 can be peeled and removed, together with the held particles
151, from the upper surface of the substrate W.
[0237] Also, with the present method, the second processing liquid
film 160 that covers the entirety of the upper surface of the
substrate W is formed in the liquid film forming step. Then, in the
solidifying step, the second processing liquid film 160 is cooled
to the temperature (for example, 4.degree. C. to 19.degree. C.) not
more than the melting point (20.5.degree. C.) of the sublimable
substance by supplying the low temperature DIW (second heat medium)
and the solid film 165 is formed. The solid film 165 is removed by
sublimation. Therefore, the second processing liquid can be removed
from the substrate W and the upper surface of the substrate W can
be dried without letting surface tension of the second processing
liquid act on the upper surface of the substrate W. Collapse of the
pattern formed on the upper surface of the substrate W can thus be
suppressed or prevented.
[0238] By the above, the particles 151 can be removed
satisfactorily from the upper surface of the substrate W and the
upper surface of the substrate can be dried satisfactorily.
[0239] In the present preferred embodiment, the solute contained in
the first processing liquid is the thermosensitive water-soluble
resin. In the holding layer forming step, the substrate W is heated
such that the temperature of the first processing liquid, supplied
to the upper surface of the substrate W, becomes a temperature less
than the alteration temperature and the particle holding layer 150
is formed.
[0240] Although the particle holding layer 150 is thus poorly
soluble or insoluble in each peeling liquid, it can be peeled by
the peeling liquid. Therefore, in the holding layer removing step,
the particle holding layer 150 formed on the upper surface of the
substrate W can be peeled and removed, without dissolving the
particle holding layer 150 and with the particle holding layer 150
being in the state of holding the particles 151, from the upper
surface of the substrate W.
[0241] Consequently, by peeling the particle holding layer 150, in
the state of holding the particles 151, from the upper surface of
the substrate W, the particles 151 can be removed at a high removal
rate. Further, a residue, resulting from dissolution of the
particle holding layer 150 in the peeling liquid, can be suppressed
from remaining on or reattaching to the upper surface of the
substrate W.
[0242] With the present preferred embodiment, in the holding layer
forming step, the substrate W is heated such that the temperature
of the first processing liquid supplied to the upper surface of the
substrate W becomes less than the boiling point of the solvent. The
solvent can thus be made to remain in the particle holding layer
150 after the heating in the holding layer forming step. The
particle holding layer 150 can thus be made easily peelable from
the upper surface of the substrate W in the subsequent holding
layer removing step by interaction of the solvent remaining in the
particle holding layer 150 and the peeling liquid that is supplied.
That is, by making the peeling liquid permeate into the particle
holding layer 150 and making the peeling liquid reach an interface
between the particle holding layer 150 and the substrate W, the
particle holding layer 150 can be lifted and peeled from the upper
surface of the substrate W.
[0243] With the present preferred embodiment, the peeling liquid is
the SC1 liquid or DIW, the solvent of the first processing liquid
is PGEE, and the peeling liquid thus has compatibility with the
solvent of the first processing liquid. When the solvent is made to
remain appropriately in the particle holding layer 150 in the
holding layer forming step, the peeling liquid that is compatible
with the solvent can permeate into the particle holding layer 150
and reach the interface between the particle holding layer 150 and
the substrate W. The particle holding layer 150 can thereby be
lifted and peeled from the upper surface of the substrate W.
[0244] With the present preferred embodiment, after the holding
layer removing step and before the liquid film forming step, the
residue removing liquid, such as IPA, etc., is supplied to the
upper surface of the substrate W to remove the residue remaining on
the upper surface of the substrate W after the particle holding
layer 150 is removed (residue removing step). The residue removing
liquid has a property of dissolving the solute component that forms
the particle holding layer. The residue of the particle holding
layer 150 (the particle holding layer 150 that was not peeled by
the peeling liquid) can thus be dissolved in the residue removing
liquid to remove the residue from the upper surface of the
substrate W before supplying the second processing liquid to the
upper surface of the substrate W. The upper surface of the
substrate W can thereby be dried in a state where an amount of
particles on the upper surface of the substrate W is reduced
further.
[0245] When volatilizing the solvent of the first processing liquid
in the holding layer forming step, particles, resulting from the
solvent, may become attached to the facing member 6 (member
positioned in a vicinity of the substrate W). As an amount of the
volatilized solvent increases, an amount of the particles attaching
to the facing member 6 increases. After the holding layer removing
step, the particles attaching to the facing member 6 may drift in
the atmosphere inside the chamber 4 and become reattached to the
substrate W. Especially when the facing member 6 is disposed at the
second proximity position in the drying step, there is a high
possibility for the particles attaching to the facing member 6 to
separate from the facing member 6 and drift in the atmosphere
inside the chamber 4. The amount of the particles attaching to the
facing member 6 increases as the amount of the volatilized solvent
increases.
[0246] Thus, in the present preferred embodiment, the rotation
elimination step and the substrate heating step are executed in the
holding layer forming step. In detail, after the first processing
liquid is eliminated appropriately from the substrate by the
rotation of the substrate W, the high temperature DIW (first heat
medium) is supplied to the lower surface of the substrate to heat
the first processing liquid on the substrate W. An amount of the
solvent that volatilizes can thereby be reduced and an amount of
the solvent attaching to the facing member 6 can thus be reduced.
Reattachment of particles to the substrate W after the holding
layer removing step can thus be suppressed.
[0247] With the present preferred embodiment, the temperature
holding step and the film thinning step are executed. By holding
the temperature of the second processing liquid film 160 within the
liquid film holding temperature range in the temperature holding
step, solidification of the second processing liquid film 160 can
be suppressed and the second processing liquid on the substrate W
can be maintained in a liquid phase before the solidifying step.
For example, even if the second processing liquid film 160
undergoes partial solidification in the liquid film forming step,
it can be remelted and put in liquid form in the temperature
holding step.
[0248] In the film thinning step, by removing excess second
processing liquid while the temperature of the liquid film of the
second processing liquid is within the liquid film holding
temperature range and the solidification of the second processing
liquid film 160 does not occur, the film thickness of the solid
film 165 formed in the solidifying step can be reduced
appropriately. By reducing the film thickness of the solid film
165, an internal stress that remains in the solid film 165 can be
reduced. A force that acts on the upper surface of the substrate W
due to the internal stress can thus be reduced and pattern collapse
can thus be suppressed further. Therefore, by sublimating and
removing the solid film 165 in the subsequent sublimating step, the
upper surface of the substrate W can be dried while further
suppressing pattern collapse.
[0249] With the present preferred embodiment, the state in which
the substrate W is held by the spin chuck 5 is continued until the
sublimating step ends. The steps from the first processing liquid
supplying step (S2) to the drying step (S11) can thus be executed
inside the single chamber 4 without having to transfer the
substrate W to another chamber in the middle of the substrate
processing. Time necessary for processing the single substrate W
(throughput) can thus be reduced.
[0250] Although, unlike in the present preferred embodiment, use of
a heater, which can be elevated and lowered between the spin base
21 and the substrate W, as a heat medium may also be considered,
when such a heater is used, it is difficult to adjust the
temperature of the second processing liquid on the substrate W to a
temperature lower than the melting point of the sublimable
substance.
[0251] In detail, even when such a heater is separated maximally
from the substrate W, the heater can only be lowered to a position
of contacting the upper surface of the spin base 21. A temperature
of a typical heater is 150.degree. C. to 200.degree. C. and, in
many cases, the heater is constantly energized from a standpoint of
throughput. Therefore, even if the heater is separated maximally
from the substrate W, the substrate W would be heated by radiant
heat from the heater and the temperature of the second processing
liquid on the substrate W may become higher than the melting point
(for example, 20.5.degree. C.) of the sublimable substance. Even if
the heater and the low temperature DIW are used in combination, the
low temperature DIW may become heated by the heater and the
temperature of the second processing liquid on the substrate W may
become higher than the melting point of the sublimable
substance.
[0252] With the present preferred embodiment, a timing for starting
the substrate heating step may be determined by the imaging unit 9.
FIG. 9A and FIG. 9B are schematic views for describing the timing
for starting the heating of the substrate W in the holding layer
forming step (S3 of FIG. 6).
[0253] As shown in FIG. 9A, interference fringes 142 form on a
front surface of a first processing liquid film 140. On the other
hand, as shown in FIG. 9B, when the first processing liquid on the
substrate W is eliminated by a centrifugal force to a degree such
that the first processing liquid remains slightly across the entire
upper surface of the substrate W (to a degree such that the first
processing liquid 140 becomes extremely thin), the interference
fringes 142 disappear from the upper surface of the substrate W. It
is known that if the solvent of the first processing liquid is
volatilized to form the particle holding layer 150 after the
interference fringes 142 disappear, attachment of particles to the
upper surface of the substrate W after the holding layer forming
step can be suppressed.
[0254] Therefore, if, in the rotation elimination step, the imaging
unit 9 detects the interference fringes 142 on the front surface of
the first processing liquid film 140 (detecting step) and the lower
surface nozzle 13 discharges the high temperature DIW to start the
heating of the substrate W at a timing at which the interference
fringes 142 are no longer detected (first heating starting step),
an amount of the solvent of the first processing liquid to be
volatilized can be reduced appropriately. Consequently, the forming
of particles can be suppressed further.
[0255] The imaging unit 9 is thus an example of a detecting unit
that detects the interference fringes 142. As the detecting unit, a
light sensor, detecting a change in detected wavelength due to the
forming of the interference fringes 142, etc., may be used besides
the imaging unit 9.
[0256] The controller 3 may be programmed to judge that the
interference fringes 142 are no longer detected when, for example,
a state of the front surface of the first processing liquid film
140 does not change for a fixed time after the discharge of the
first processing liquid from the discharge port 10a of the first
moving nozzle 10 is stopped.
[0257] The present invention is not restricted to the preferred
embodiment described above and may be implemented in yet other
modes.
[0258] For example, with the preferred embodiment described above,
it is described that, in the rotation elimination step, the imaging
unit 9 detects the interference fringes 142 on the front surface of
the first processing liquid film 140 (detecting step) and the
heating of the substrate W is started at the timing at which the
interference fringes 142 are no longer detected (first heating
starting step). However, unlike in the preferred embodiment
described above, the heating of the substrate in the holding layer
forming step may be started after elapse of a predetermined time
from the stopping of the supply of the first processing liquid
(second heating starting step).
[0259] FIG. 10A is a graph showing times required until
disappearance of the interference fringes 142 from the stopping of
the supply of the first processing liquid (disappearance
requirement times) at respective rotational speeds in cases, in
each of which the substrate W is rotated at a fixed rotational
speed in the rotation elimination step. In the graph of FIG. 10A,
the solvent of the first processing liquid is PGEE. The abscissa of
FIG. 10A is the rotational speed (rpm) of the substrate W and the
ordinate of FIG. 10A is the disappearance requirement time
(sec).
[0260] FIG. 10B is a graph showing products of the rotational speed
and the disappearance requirement time (required integrated numbers
of rotations) at respective rotational speeds in cases, in each of
which the substrate W is rotated at a fixed rotational speed in the
rotation elimination step. The abscissa of FIG. 10B is the
rotational speed (rpm) of the substrate W and the ordinate of FIG.
10B is the required integrated number of rotations (rpmmin).
[0261] As shown in FIG. 10A, the disappearance requirement time
changes with the rotational speed of the substrate W. Also, the
disappearance requirement time also changes with the type of the
solvent of the first processing liquid. Therefore, if the heating
of the substrate W is started after the disappearance requirement
time that is in accordance with the rotational speed of the
substrate W elapses from the stopping of the supply of the first
processing liquid, the amount of the solvent of the first
processing liquid to be volatilized can be reduced appropriately.
Consequently, the forming of particles can be suppressed
further.
[0262] As shown in FIG. 10B, the required integrated number of
rotations was substantially fixed and not dependent on the
rotational speed of the substrate W. Therefore, the required
integrated number of rotations corresponding to PGEE may be
acquired in advance. If the solvent of the first processing liquid
is PGEE, the required integrated number of rotations is preferably
set to not less than 300 rpmmin. If the solvent of the first
processing liquid is PGEE, the required integrated number of
rotations is more preferably set to 400 rpmmin. Even when the
solvent of the first processing liquid is a substance besides PGEE,
the required integrated number of rotations can be acquired by
evaluating a relationship of the required integrated number of
rotations at respective rotational speeds.
[0263] The disappearance requirement time can be calculated from
the rotational speed of the substrate W and the required integrated
number of rotations acquired in advance. By arranging such that the
heating of the substrate W is started after the calculated
disappearance requirement time elapses from the stopping of the
supply of the first processing liquid, the amount of the solvent of
the first processing liquid to be volatilized can be reduced
appropriately. Consequently, the forming of particles can be
suppressed further.
[0264] With the modification example illustrated with FIG. 10A and
FIG. 10B, an example where the rotational speed of the substrate W
is fixed in the rotation elimination step is described. However,
the rotational speed of the substrate W may be changed during the
rotation elimination step. Even when the rotational speed of the
substrate W is changed during the rotation elimination step, by
setting a rotation elimination time such that a product of the
rotation elimination time and the rotational speed of the substrate
W (integrated number of rotations) becomes the required integrated
number of rotations, the substrate heating step can be started in a
state where the interference fringes 142 have been made to
disappear. For example, if the solvent of the first processing
liquid is PGEE, by setting the rotation elimination time such that
the integrated number of rotations becomes not less than 300 rpmmin
(preferably 400 rpmmin), the substrate heating step can be started
in the state where the interference fringes 142 have been made to
disappear.
[0265] Also, with the preferred embodiment described above, it is
described that a thermosensitive water-soluble resin is used as the
solute of the first processing liquid. However, the resin used as
the solute of the first processing liquid may be a resin other than
a thermosensitive water-soluble resin.
[0266] As examples of a resin, other than a thermosensitive
water-soluble resin, to be used as the solute contained in the
first processing liquid, acrylic resins, phenol resins, epoxy
resins, melamine resins, urea resins, unsaturated polyester resins,
alkyd resins, polyurethane, polyimide, polyethylene, polypropylene,
polyvinyl chloride, polystyrene, polyvinyl acetate,
polytetrafluoroethylene, acrylonitrile-butadiene-styrene resins,
acrylonitrile-styrene resins, polyamide, polyacetal, polycarbonate,
polyvinyl alcohol, modified polyphenylene ether, polybutylene
terephthalate, polyethylene terephthalate, polyphenylene sulfide,
polysulfone, polyether ether ketone, polyamide-imide, etc., can be
cited. When any of these resins is used in the first processing
liquid, any solvent that can dissolve the resin used as the solute
may be used.
[0267] As the solute of the first processing liquid, a resin, other
than a thermosensitive water-soluble resin, does not have an
alteration temperature, and therefore in the substrate heating step
in the particle holding layer forming step, there is no need, as in
the case of using a thermosensitive water-soluble resin as the
solute of the first processing liquid, for the temperature of the
first processing liquid to be less than the alteration temperature
of the thermosensitive water-soluble resin and it suffices to heat
the substrate W such that the temperature of the first processing
liquid on the substrate W is less than the boiling point of the
solvent.
[0268] When a resin, other than a thermosensitive water-soluble
resin, is used as the solute of the first processing liquid, any
liquid having a dissolving ability with respect to any of the
resins may be used as the residue removing liquid. When a resin,
other than a thermosensitive water-soluble resin, is used as the
solute of the first processing liquid, for example, an organic
solvent, such as a thinner, toluene, an acetate ester, an alcohol,
a glycol, etc., or an acidic liquid, such as acetic acid, formic
acid, hydroxyacetic acid, etc., may be used as the residue removing
liquid.
[0269] Besides the various resins mentioned above, for example, an
organic compound other than a resin or a mixture of an organic
compound and another substance may be used as the solute of the
first processing liquid. Or, the solute may be a compound other
than an organic compound.
[0270] As the peeling liquid, another peeling liquid that is not
water-based may be used. In this case, a solute, which forms a
particle holding layer 150 that is poorly soluble or insoluble in
the peeling liquid, a solvent, which has compatibility with the
peeling liquid and has a dissolving ability with respect to the
solute, a residue removing liquid, having compatibility with the
peeling liquid and has a dissolving ability with respect to the
solute, etc., should be combined as appropriate.
[0271] As the second processing liquid used in the preferred
embodiment above and the modifications thereof, that which contains
the sublimable substance in the molten state, such as the melt of
the sublimable substance, etc., or a solution, having the
sublimable substance dissolved as a solute in a solvent, etc., may
be used as described above.
[0272] As the sublimable substance, for example,
hexamethylenetetramine, 1,3,5-trioxane, ammonium 1-pyrrolidine
carbodithioate, metaldehyde, paraffin with approximately 20 to 48
carbon atoms, t-butanol, para-dichlorobenzene, naphthalene,
L-menthol, or a fluorohydrocarbon compound, etc., is used. In
particular, a fluorohydrocarbon compound may be used as the
sublimable substance. As the sublimable substance,
1,1,2,2,3,3,4-heptafluorocyclopentane, used in the above
description of the preferred embodiment, is especially
preferable.
[0273] As specific examples of the fluorohydrocarbon compound, for
example, one type or two or more types of the following compounds
(A) to (E) may be used.
[0274] Compound (A): A fluoroalkane with 3 to 6 carbon atoms or a
derivative thereof.
[0275] Compound (B): A fluorocycloalkane with 3 to 6 carbon atoms
or a derivative thereof.
[0276] Compound (C): A fluorobicycloalkane with 10 carbon atoms or
a derivative thereof.
[0277] Compound (D): Fluorotetracyanoquinodimethane or a derivative
thereof.
[0278] Compound (E): A fluorocyclophosphazene with 3 or more
phosphazene units or a derivative thereof.
[0279] <Compound A>
[0280] As the compound (A), a fluoroalkane with 3 to 6 carbon
atoms, expressed by formula (1):
C.sub.mH.sub.nF.sub.2m+2-n (1)
(In the formula, m indicates a number from 3 to 6 and n indicates a
number such that 0.ltoreq.n.ltoreq.2m+1.) or a derivative thereof
can be cited.
[0281] Specifically, as examples of the fluoroalkane with 3 carbon
atoms, CF.sub.3CF.sub.2CF.sub.3, CHF.sub.2CF.sub.2CF.sub.3,
CH.sub.2FCF.sub.2CF.sub.3, CH.sub.3CF.sub.2CH.sub.3,
CHF.sub.2CF.sub.2CH.sub.3, CH.sub.2FCF.sub.2CH.sub.3,
CH.sub.2FCF.sub.2CH.sub.2F, CHF.sub.2CF.sub.2CHF.sub.2,
CF.sub.3CHFCF.sub.3, CH.sub.2FCHFCF.sub.3, CHF.sub.2CHFCF.sub.3,
CH.sub.2FCHFCH.sub.2F, CHF.sub.2CHFCHF.sub.2, CH.sub.3CHFCH.sub.3,
CH.sub.2FCHFCH.sub.3, CHF.sub.2CHFCH.sub.3,
CF.sub.3CH.sub.2CF.sub.3, CH.sub.2FCH.sub.2CF.sub.3,
CHF.sub.2CH.sub.2CF.sub.3, CH.sub.2FCH.sub.2CH.sub.2F,
CH.sub.2FCH.sub.2CHF.sub.2, CHF.sub.2CH.sub.2CHF.sub.2,
CH.sub.3CH.sub.2CH.sub.2F, CH.sub.3CH.sub.2CHF.sub.2, etc., can be
cited.
[0282] As examples of the fluoroalkane with 4 carbon atoms,
CF.sub.3(CF.sub.2).sub.2CF.sub.3,
CF.sub.3(CF.sub.2).sub.2CH.sub.2F,
CF.sub.3CF.sub.2CH.sub.2CF.sub.3, CHF.sub.2
(CF.sub.2).sub.2CHF.sub.2, CHF.sub.2CHFCF.sub.2CHF.sub.2,
CF.sub.3CH.sub.2CF.sub.2CHF.sub.2, CF.sub.3CHFCH.sub.2CF.sub.3,
CHF.sub.2CHFCHFCHF.sub.2, CF.sub.3CH.sub.2CF.sub.2CH.sub.3,
CF.sub.3CF.sub.2CH.sub.2CH.sub.3, CF.sub.3CHFCF.sub.2CH.sub.3,
CHF.sub.2CH.sub.2CF.sub.2CH.sub.3, etc., can be cited.
[0283] As examples of the fluoroalkane with 5 carbon atoms,
CF.sub.3(CF.sub.2).sub.3CF.sub.3,
CF.sub.3CF.sub.2CF.sub.2CHFCF.sub.3, CHF.sub.2
(CF.sub.2).sub.3CF.sub.3, CHF.sub.2 (CF.sub.2).sub.3CHF.sub.2,
CF.sub.3CH(CF.sub.3) CH.sub.2CF.sub.3,
CF.sub.3CHFCF.sub.2CH.sub.2CF.sub.3, CF.sub.3CF(CF.sub.3)
CH.sub.2CHF.sub.2, CHF.sub.2CHFCF.sub.2CHFCHF.sub.2,
CF.sub.3CH.sub.2CF.sub.2CH.sub.2CF.sub.3,
CHF.sub.2(CF.sub.2).sub.2CHFCH.sub.3,
CHF.sub.2CH.sub.2CF.sub.2CH.sub.2CHF.sub.2, CF.sub.3
(CH.sub.2).sub.3CF.sub.3, CF.sub.3CHFCHFCF.sub.2CF.sub.3, etc., can
be cited.
[0284] As examples of the fluoroalkane with 6 carbon atoms,
CF.sub.3 (CF.sub.2).sub.4CF.sub.3, CF.sub.3
(CF.sub.2).sub.4CHF.sub.2, CF.sub.3 (CF.sub.2).sub.4CH.sub.2F,
CF.sub.3CH(CF.sub.3) CHFCF.sub.2CF.sub.3, CHF.sub.2
(CF.sub.2).sub.4CHF.sub.2, CF.sub.3CF.sub.2CH.sub.2CH(CF.sub.3)
CF.sub.3, CF.sub.3CF.sub.2(CH.sub.2).sub.2CF.sub.2CF.sub.3,
CF.sub.3CH.sub.2 (CF.sub.2).sub.2CH.sub.2CF.sub.3, CF.sub.3
(CF.sub.2).sub.3CH.sub.2CF.sub.3,
CF.sub.3CH(CF.sub.3)(CH.sub.2).sub.2CF.sub.3, CHF.sub.2CF.sub.2
(CH.sub.2).sub.2CF.sub.2CHF.sub.2, CF.sub.3 (CF.sub.2).sub.2
(CH.sub.2).sub.2CH.sub.3, etc., can be cited.
[0285] Also, as the derivative of the fluoroalkane with 3 to 6
carbon atoms, a compound, with which at least one type of
substituent, selected from the group consisting of halogens other
than fluorine (specifically, chlorine, bromine, and iodine), a
hydroxyl group, an oxygen atom, alkyl groups, a carboxyl group, and
perfluoroalkyl groups, is substituted in any of the fluoroalkanes
mentioned above, etc., can be cited.
[0286] As examples of the alkyl group, a methyl group, ethyl group,
n-propyl group, isopropyl group, n-butyl group, t-butyl group,
etc., can be cited.
[0287] As examples of the perfluoroalkyl group, saturated
perfluoroalkyl groups and unsaturated perfluoroalkyl groups can be
cited. Also, the perfluoroalkyl group may be of either a
straight-chain structure or a branched structure. As examples of
the perfluoroalkyl group, for example, a trifluoromethyl group,
perfluoroethyl group, perfluoro-n-propyl group, perfluoroisopropyl
group, perfluoro-n-butyl group, perfluoro-sec-butyl group,
perfluoro-tert-butyl group, perfluoro-n-amyl group,
perfluoro-sec-amyl group, perfluoro-tert-amyl group,
perfluoroisoamyl group, perfluoro-n-hexyl group, perfluoroisohexyl
group, perfluoroneohexyl group, perfluoro-n-heptyl group,
perfluoroisoheptyl group, perfluoroneoheptyl group,
perfluoro-n-octyl group, perfluoroisooctyl group, perfluoroneooctyl
group, perfluoro-n-nonyl group, perfluoroneononyl group,
perfluoroisononyl group, perfluoro-n-decyl group, perfluoroisodecyl
group, perfluoroneodecyl group, perfluoro-sec-decyl group,
perfluoro-tert-decyl group, etc., can be cited.
[0288] <Compound B>
[0289] As the compound (B), a fluorocycloalkane with 3 to 6 carbon
atoms, expressed by formula (2):
C.sub.mH.sub.nF.sub.2m-n (2)
(In the formula, m indicates a number from 3 to 6 and n indicates a
number such that 0.ltoreq.n.ltoreq.2m-1.) or a derivative thereof
can be cited.
[0290] Specifically, as examples of the fluorocycloalkane with 3 to
6 carbon atoms, monofluorocyclohexane, dodecafluorocyclohexane,
1,1,4-trifluorocyclohexane, 1,1,2,2-tetrafluorocyclobutane,
1,1,2,2,3-pentafluorocyclobutane,
1,2,2,3,3,4-hexafluorocyclobutane,
1,1,2,2,3,3-hexafluorocyclobutane,
1,1,2,2,3,4-hexafluorocyclobutane,
1,1,2,2,3,3-hexafluorocyclopentane,
1,1,2,2,3,4-hexafluorocyclopentane,
1,1,2,2,3,3,4-heptafluorocyclopentane,
1,1,2,2,3,4,5-heptafluorocyclopentane,
1,1,2,2,3,3,4,4-octafluorocyclopentane,
1,1,2,2,3,3,4,5-octafluorocyclopentane,
1,1,2,2,3,4,5,6-octafluorocyclohexane,
1,1,2,2,3,3,4,4-octafluorocyclohexane,
1,1,2,2,3,3,4,5-octafluorocyclohexane,
1,1,2,2,3,4,4,5,6-nonafluorocyclohexane,
1,1,2,2,3,3,4,4,5-nonafluorocyclohexane,
1,1,2,2,3,3,4,5,6-nonafluorocyclohexane,
1,1,2,2,3,3,4,5,5,6-decafluorocyclohexane,
1,1,2,2,3,3,4,4,5,6-decafluorocyclohexane,
1,1,2,2,3,3,4,4,5,5-decafluorocyclohexane,
1,1,2,2,3,3,4,4,5,6-decafluorocyclohexane, perfluorocyclopropane,
perfluorocyclobutane, perfluorocyclopentane, perfluorocyclohexane,
etc., can be cited.
[0291] Also, as the derivative of the fluorocycloalkane with 3 to 6
carbon atoms, a compound, with which at least one type of
substituent, disclosed for the compound (A), is substituted in any
of the fluorocycloalkanes mentioned above, etc., can be cited.
[0292] As specific examples of the derivative of the
fluorocycloalkane with 3 to 6 carbon atoms, for example,
1,2,2,3,3-tetrafluoro-1-trifluoromethylcyclobutane,
1,2,4,4-tetrafluoro-1-trifluoromethylcyclobutane,
2,2,3,3-tetrafluoro-1-trifluoromethylcyclobutane,
1,2,2-trifluoro-1-trimethylcyclobutane,
1,4,4,5,5-pentafluoro-1,2,2,3,3-pentamethylcyclopentane,
1,2,5,5-tetrafluoro-1,2-dimethylcyclopentane,
3,3,4,4,5,5,6,6-octafluoro-1,2-dimethylcyclohexane,
1,1,2,2-tetrachloro-3,3,4,4-tetrafluorocyclobutane,
2-fluorocyclohexanol, 4,4-difluorocyclohexanone,
4,4-difluorocyclohexanecarboxylic acid,
1,2,2,3,3,4,4,5,5,6,6-undecafluoro-1-(nonafluorobutyl)cyclohexane,
perfluoromethylcyclopropane, perfluorodimethylcyclopropane,
perfluorotrimethylcyclopropane, perfluoromethylcyclobutane,
perfluorodimethylcyclobutane, perfluorotrimethylcyclobutane,
perfluoromethylcyclopentane, perfluorodimethylcyclopentane,
perfluorotrimethylcyclopentane, perfluoromethylcyclohexane,
perfluorodimethylcyclohexane, perfluorotrimethylcyclohexane, etc.,
can be cited.
[0293] <Compound (C)>
[0294] As the fluorobicycloalkane with 10 carbon atoms of the
compound (C), for example, fluorobicyclo[4.4.0]decane,
fluorobicyclo[3.3.2]decane, perfluorobicyclo[4.4.0]decane,
perfluorobicyclo[3.3.2]decane, etc., can be cited.
[0295] Also, as the compound (C), a derivative with which a
substituent is bonded to the fluorobicycloalkane with 10 carbon
atoms can be cited. As the substituent, a halogen other than
fluorine (specifically, chlorine, bromine, or iodine), a cycloalkyl
group that may have a halogen atom, or an alkyl group having a
cycloalkyl group that may have a halogen atom can be cited.
[0296] In the cycloalkyl group that may have a halogen atom,
fluorine, chlorine, bromine, or iodine can be cited as the halogen
atom. Also, as the cycloalkyl group that may have a halogen atom, a
cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl
group, cycloheptyl group, perfluorocyclopropyl group,
perfluorocyclobutyl group, perfluorocyclopentyl group,
perfluorocyclohexyl group, perfluorocycloheptyl group, etc., can be
cited.
[0297] In the alkyl group having a cycloalkyl group that may have a
halogen atom, fluorine, chlorine, bromine, or iodine can be cited
as the halogen atom. Also, in the alkyl group having a cycloalkyl
group that may have a halogen atom, a cyclopropyl group, cyclobutyl
group, cyclopentyl group, cyclohexyl group, cycloheptyl group,
perfluorocyclopropyl group, perfluorocyclobutyl group,
perfluorocyclopentyl group, perfluorocyclohexyl group,
perfluorocycloheptyl group, etc., can be cited as the cycloalkyl
group that may have a halogen atom. As a specific example of the
alkyl group having a cycloalkyl group that may have a halogen atom,
for example, a difluoro(undecafluorocyclohexyl)methyl group, etc.,
can be cited.
[0298] As specific examples of the compound (C) with which a
substituent is bonded to the fluorobicycloalkane with 10 carbon
atoms, for example,
2-[difluoro(undecafluorocyclohexyl)methyl]-1,1,2,3,3,4,4,4a,5,5,6,6,7,7,8-
,8,8a-heptadecafluorodecahydronaphthalene, etc., can be cited.
[0299] <Compound (D)>
[0300] As the fluorotetracyanoquinodimethane of the compound (D),
for example, tetrafluorotetracyanoquinodimethane, etc., can be
cited.
[0301] Also, as the compound (D), a derivative with which at least
one halogen other than fluorine (specifically, chlorine, bromine,
or iodine) is bonded to the fluorotetracyanoquinodimethane can be
cited.
[0302] <Compound (E)>
[0303] As the fluorocyclophosphazene of the compound (E),
hexafluorocyclotriphosphazene, octafluorocyclotetraphosphazene,
decafluorocyclopentaphosphazene, dodecafluorocyclohexaphosphazene,
etc., can be cited.
[0304] Also, as the compound (E), a derivative with which a
substituent is bonded to the fluorocyclophosphazene can be cited.
As the substituent, a halogen other than fluorine (specifically,
chlorine, bromine, or iodine), phenoxy group, alkoxy group (--OR
group), etc., can be cited. As the R of the alkoxy group, for
example, an alkyl group, such as a methyl group, ethyl group, etc.,
a fluoroalkyl group, such as a trifluoromethyl group, etc., an
aromatic group, such as a phenyl group, etc., etc., can be
cited.
[0305] As examples of the compound (E) with which a substituent is
bonded to the fluorocyclophosphazene,
hexachlorocyclotriphosphazene, octachlorocyclotetraphosphazene,
decachlorocyclopentaphosphazene, dodecachlorocyclohexaphosphazene,
hexaphenoxycyclotriphosphazene, etc., can be cited.
[0306] While preferred embodiments of the present invention have
been described above, it is to be understood that variations and
modifications will be apparent to those skilled in the art without
departing from the scope and spirit of the present invention. The
scope of the present invention, therefore, is to be determined
solely by the following claims.
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