U.S. patent application number 13/953964 was filed with the patent office on 2014-02-20 for substrate processing device and substrate processing method for carrying out chemical treatment for substrate.
This patent application is currently assigned to DAINIPPON SCREEN MFG. CO., LTD.. The applicant listed for this patent is DAINIPPON SCREEN MFG. CO., LTD.. Invention is credited to Nobuyuki SHIBAYAMA.
Application Number | 20140051259 13/953964 |
Document ID | / |
Family ID | 50100322 |
Filed Date | 2014-02-20 |
United States Patent
Application |
20140051259 |
Kind Code |
A1 |
SHIBAYAMA; Nobuyuki |
February 20, 2014 |
SUBSTRATE PROCESSING DEVICE AND SUBSTRATE PROCESSING METHOD FOR
CARRYING OUT CHEMICAL TREATMENT FOR SUBSTRATE
Abstract
It is an object to reduce a chemical treating width in a
peripheral edge part of a substrate while suppressing deterioration
in each of uniformity of the chemical treating width and processing
efficiency. In order to achieve the object, a substrate processing
device for carrying out a chemical treatment for a substrate using
a processing liquid having a reaction rate increased with a rise in
temperature includes a substrate holding portion, a rotating
portion for rotating the substrate held in the substrate holding
portion in a substantially horizontal plane, a heating portion for
injecting heating steam to a central part of a lower surface of the
substrate to entirely heat the substrate, and a peripheral edge
processing portion for supplying the processing liquid from above
to a peripheral edge part of the substrate heated by the heating
portion, thereby carrying out a chemical treatment for the
peripheral edge part.
Inventors: |
SHIBAYAMA; Nobuyuki;
(Kyoto-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DAINIPPON SCREEN MFG. CO., LTD. |
Kyoto |
|
JP |
|
|
Assignee: |
DAINIPPON SCREEN MFG. CO.,
LTD.
Kyoto
JP
|
Family ID: |
50100322 |
Appl. No.: |
13/953964 |
Filed: |
July 30, 2013 |
Current U.S.
Class: |
438/748 ;
156/345.23 |
Current CPC
Class: |
H01L 21/6708 20130101;
H01L 21/30604 20130101; H01L 21/67109 20130101; H01L 21/02087
20130101; H01L 21/02035 20130101; H01L 21/68792 20130101; H01L
21/67028 20130101; H01L 21/0209 20130101; H01L 21/32134
20130101 |
Class at
Publication: |
438/748 ;
156/345.23 |
International
Class: |
H01L 21/306 20060101
H01L021/306; H01L 21/67 20060101 H01L021/67 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 20, 2012 |
JP |
JP2012-181540 |
Claims
1. A substrate processing device for carrying out a chemical
treatment for a substrate by using a processing liquid having a
reaction rate increased with a rise in temperature, the device
comprising: a substrate holding portion for holding a substrate in
a substantially horizontal posture; a rotating portion for rotating
said substrate held in said substrate holding portion in a
substantially horizontal plane; a heating portion for injecting
heating steam into a central part of a lower surface of said
substrate to entirely heat said substrate; and a peripheral edge
processing portion for supplying a processing liquid from above to
a peripheral edge part of said substrate which is heated by said
heating portion, thereby carrying out a chemical treatment for said
peripheral edge part.
2. The substrate processing device according to claim 1, wherein
said heating portion injects said steam to the lower surface of
said substrate via a supply tube inserted into a rotating support
shaft of said substrate holding portion.
3. The substrate processing device according to claim 1, wherein
said steam is superheated steam.
4. The substrate processing device according to claim 1, wherein
said peripheral edge processing portion regulates a width in a
radial direction of said substrate in a portion in which said
processing liquid collides with said peripheral edge part.
5. A substrate processing method for carrying out a chemical
treatment for a substrate by using a processing liquid having a
reaction rate increased with a rise in temperature, the method
comprising the steps of: holding a substrate in a substantially
horizontal posture and rotating said substrate in a substantially
horizontal plane; injecting heating steam into a central part of a
lower surface of said substrate to heat said substrate entirely, in
parallel with said rotating step; and supplying a processing liquid
to a peripheral edge part of said substrate from above said
peripheral edge part, thereby carrying out a chemical treatment for
said peripheral edge part, in parallel with said heating step.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a substrate processing
device and a substrate processing method for supplying a processing
liquid to a substrate to carry out a chemical treatment such as
etching while rotating the substrate. The substrate to be processed
includes substrates, for example, a semiconductor wafer, a
substrate for an optical disk, a substrate for a magnetic disk, a
substrate for a magneto-optical disk, a substrate for a photomask,
a substrate for a solar cell, and the like.
[0003] 2. Description of the Background Art
[0004] Although a series of processing steps for a substrate such
as a semiconductor wafer have a plurality of film forming steps for
forming a thin film of a metal, a photoresist or the like on a
front surface ("an upper surface") of the substrate, a film is also
formed on a back surface ("a lower surface") of the substrate or a
peripheral edge part of the upper surface of the substrate at the
film forming step in some cases. In general, however, the film
formation is required for only a circuit formation region in a
central part of the upper surface of the substrate in the
substrate. In cases where the film is formed on the back surface of
the substrate or the peripheral edge part of the upper surface of
the substrate, a thin film formed on the peripheral edge part of
the upper surface of the substrate may be peeled by contact with
another device at a subsequent step to the film forming step, and
may cause reduction in yield or a trouble of a substrate processing
device itself.
[0005] Therefore, there is proposed a substrate processing device
for carrying out so-called bevel etching, that is, supplying a
processing liquid having its temperature previously controlled to a
peripheral edge part of a substrate held in a substantially
horizontal condition while rotating the substrate, thereby removing
a thin film formed on the peripheral edge part of an upper surface
of the substrate.
[0006] For example, the substrate processing device described in
Japanese Patent Application Laid-Open No. 2004-6672 serves to
supply the etchant from the nozzle taking an opposed shape to the
central part in the lower surface of the substrate held in a
substantially horizontal condition to the lower surface of the
substrate while rotating the substrate, and to cause the etchant
spreading toward the peripheral edge part by the action of
centrifugal force to go around the peripheral edge part of the
upper surface of the substrate, thereby etching the peripheral edge
part of the upper surface of the substrate.
[0007] Moreover, the substrate processing device described in
Japanese Patent Application Laid-Open No. 2008-47629 has the
blocking member which is opposed to the upper surface of the
substrate above the substrate and serves to supply the processing
liquid from the nozzle disposed on the peripheral edge part of the
blocking member toward the peripheral edge part of the upper
surface of the substrate while rotating the substrate in the
substantially horizontal plane, thereby etching the peripheral edge
part of the upper surface of the substrate.
[0008] In the technique of this type, it is demanded to reduce an
etching width in the peripheral edge part ("end") of the upper
surface of the substrate as greatly and evenly as possible in order
to effectively utilize, as a device, an area over the substrate
which is as large as possible. In the technical field of
manufacture of a semiconductor device, particularly, it is desired
to decrease an etching width of 2 to 3 mm in the related art down
to 1 mm or less in order to reduce a loss in a peripheral edge part
of a wafer which is increased with increase in diameter of a
semiconductor wafer, for example.
[0009] As a method for reducing the etching width by the substrate
processing device described in the Japanese Patent Application
Laid-Open No. 2004-6672, it is supposed to decrease an amount of
supply of the processing liquid and to increase the rotating speed
of the substrate in order to reduce an amount of wraparound of the
processing liquid toward the upper surface of the substrate.
According to the method, although an average etching width can be
reduced, uniformity of the etching width is deteriorated, for
example, the amount of wraparound of the processing liquid to the
peripheral edge part is controlled with difficulty so that a
portion to be etched locally and greatly appears. Furthermore,
there is also a problem in that the temperatures of the peripheral
edge part and the processing liquid in the peripheral edge part are
lowered, resulting in reduction in an etching rate.
[0010] In order to decrease the etching width by the substrate
processing device described in the Japanese Patent Application
Laid-Open No. 2008-47629, it is necessary to decrease the amount of
supply of the processing liquid to be supplied to the peripheral
edge part of the substrate. However, there is a problem in that the
etching rate in the peripheral edge part of the substrate is
reduced due to decrease in the amount of the processing liquid and
reduction in the temperature of the processing liquid in a pipe due
to the decrease.
[0011] These are problems which are not limited to the etching
using the etchant, but are caused in general processing for
carrying out a chemical treatment for a substrate by using a
processing liquid having a reaction rate increased with a rise in a
temperature.
SUMMARY OF THE INVENTION
[0012] The present invention is directed to a substrate processing
device for carrying out a chemical treatment for a substrate by
using a processing liquid having a reaction rate increased with a
rise in temperature.
[0013] According to the present invention, the substrate processing
device includes a substrate holding portion for holding a substrate
in a substantially horizontal posture; a rotating portion for
rotating the substrate held in the substrate holding portion in a
substantially horizontal plane; a heating portion for injecting
heating steam into a central part of a lower surface of the
substrate to entirely heat the substrate; and a peripheral edge
processing portion for supplying a processing liquid from above to
a peripheral edge part of the substrate which is heated by the
heating portion, thereby carrying out a chemical treatment for the
peripheral edge part.
[0014] The heating steam is injected to the central part of the
lower surface of the substrate so that the substrate is entirely
heated, and the processing liquid is supplied to the peripheral
edge part from above so that even if an amount of the processing
liquid to be supplied is small, it is possible to enhance
reactivity of the processing liquid in the peripheral edge part by
sufficiently heating the peripheral edge part. Accordingly, if the
processing liquid is supplied from above to a desirable region
having a small width at the substrate end side in the peripheral
edge part, it is possible to reduce a chemical treating width while
suppressing deterioration in each of uniformity of the chemical
treating width (an etching width or the like) and chemical treating
efficiency (an etching rate or the like). Moreover, the heating
steam is injected to the lower surface of the substrate. Therefore,
even if a water droplet is generated by condensation of the steam
over the lower surface, it is possible to suppress wraparound of
the water droplet onto an upper surface of the substrate.
Accordingly, it is possible to prevent deterioration in a
non-processed region from being caused by adhering of the water
droplet or the like to the non-processed region on the upper
surface of the substrate.
[0015] Preferably, the heating portion injects the steam to the
lower surface of the substrate via a supply tube inserted into a
rotating support shaft of the substrate holding portion.
[0016] Preferably, the steam is superheated steam.
[0017] Preferably, the peripheral edge processing portion regulates
a width in a radial direction of the substrate in a portion in
which the processing liquid collides with the peripheral edge
part.
[0018] Moreover, the present invention is also directed to a
substrate processing method for carrying out a chemical treatment
for a substrate by using a processing liquid having a reaction rate
increased with a rise in temperature.
[0019] Therefore, it is an object of the present invention to
provide a technique capable of reducing a chemical treating width
while suppressing deterioration in each of uniformity of a chemical
treating width (an etching width or the like) and chemical treating
efficiency (an etching rate or the like).
[0020] These and other objects, features, aspects and advantages of
the present invention will become more apparent from the following
detailed description of the present invention when taken in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a view schematically showing an example of a
schematic structure of a substrate processing device according to a
preferred embodiment;
[0022] FIG. 2 is a top view schematically showing an arrangement of
a nozzle unit with respect to an upper surface of a substrate;
[0023] FIGS. 3 and 4 are side views each illustrating an example of
a structure of the nozzle unit;
[0024] FIG. 5 is a view illustrating, in a graph, a difference in
temperature distribution over the substrate depending on presence
or absence of a steam injection nozzle;
[0025] FIG. 6 is a view illustrating a difference in etching width
over the substrate depending on the presence or absence of the
steam injection nozzle;
[0026] FIG. 7 is a view showing an example of a sectional view of
the substrate;
[0027] FIG. 8 is a view showing an example of the sectional view
obtained after etching for the substrate of FIG. 7;
[0028] FIG. 9 is a view showing a comparative technique; and
[0029] FIGS. 10 and 11 are flow charts each illustrating an example
of a flow of substrate processing according to the preferred
embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] A preferred embodiment according to the present invention
will be described below with reference to the drawings. Portions
having the same structures and functions have the same reference
numerals in the drawings, and repetitive description will be
omitted in the following explanation. Moreover, each of the
drawings is shown schematically, and for example, a size, a
positional relationship and the like of an illustrated member in
the drawing are not always shown accurately.
Preferred Embodiment
<1. Structure of Substrate Processing Device>
[0031] FIG. 1 is a view schematically showing an example of a
schematic structure of a substrate processing device 100 according
to a preferred embodiment. The substrate processing device 100
carries out a chemical treatment for a substrate by using a
processing liquid having a reaction rate increased with a rise in
temperature. More specifically, the substrate processing device 100
performs etching for a peripheral edge part (also referred to as an
"upper surface peripheral edge part") S3 of a substrate W such as a
semiconductor wafer in a front surface (also referred to as an
"upper surface") S1 of the substrate W by using an etchant as a
processing liquid for a chemical treatment, thereby removing a thin
film (an unnecessary object) formed on the upper surface peripheral
edge part S3. The upper surface peripheral edge part S3 is a
ring-shaped region having a width of 0.5 to 3.0 mm from a
peripheral edge of the substrate W in the upper surface S1 of the
substrate W, for example. A back surface S2 at a side opposite to
the upper surface S1 is also referred to as a "lower surface". An
upper surface shape of the substrate W is substantially circular,
and the upper surface S1 of the substrate W implies a device
formation surface on which a device pattern is to be formed.
[0032] In addition to the etchant to be used in the etching, most
of chemical treating solutions conform to the general Arrhenius
equation in which a reaction rate is increased with a rise in
temperature. In other words, most of treating solutions belong to
"a processing liquid having a reaction rate increased with a rise
in temperature".
[0033] FIG. 7 is a view showing an example of a sectional view of
the substrate W. As shown in FIG. 7, a central layer 11 of the
substrate W is constituted by silicon (Si). An insulating film
which does not conduct electricity, for example, a thermal oxide
film (Th--SiO.sub.2), Hf (hafnium), Hf oxide, or the like is formed
on the central layer 11 as a lower film 12. Then, a barrier metal
film such as a TiN film or a TaN film, or a metal film such as an
Al film, a W film, a NiSi film, or a Cu film is formed on the lower
film 12 as an upper film 13. In the substrate W, the upper film 13
in a region (a processed region) at a peripheral edge side in the
upper surface peripheral edge part S3 is removed by etching. For
example, a substrate having only the lower film 12 formed on the
central layer 11 may be employed as the substrate W, and the lower
film 12 in the processed region of the upper surface peripheral
edge part may be removed.
[0034] As shown in FIG. 1, the substrate processing device 100
includes a spin chuck ("a substrate holding portion") 111 for
holding and rotating the substrate W in a substantially horizontal
posture with the upper surface S1 facing upward. The spin chuck 111
has a cylindrical rotating support shaft 113 coupled to a rotating
axis of a chuck rotating mechanism ("a rotating portion") 154
including a motor, and is rotatable around a rotating axis a1 (a
vertical axis), that is, in a substantially horizontal plane by a
driving operation of the chuck rotating mechanism 154.
[0035] A disk-shaped spin base 115 is integrally coupled to an
upper end of the rotating support shaft 113 by means of a fastening
component such as a screw. Accordingly, the chuck rotating
mechanism 154 is operated in response to an operation command sent
from a control portion 151 for controlling the entire device so
that the spin base 115 is rotated around the rotating axis a1.
Moreover, the control portion 151 controls the chuck rotating
mechanism 154 to regulate a rotating speed. The control portion 151
is implemented through execution of a program stored in a memory by
a CPU or the like, for example.
[0036] A plurality of chuck pins 117 for gripping the peripheral
edge part of the substrate W is erected in the vicinity of the
peripheral edge part of the spin base 115. It is sufficient that at
least three chuck pins 117 are provided in order to reliably hold
the circular substrate W, and the chuck pins 117 are disposed at an
equal angle interval along the peripheral edge part of the spin
base 115. Each of the chuck pins 117 includes a substrate
supporting portion for supporting the peripheral edge part of the
substrate W from below and a substrate holding portion for pressing
an outer peripheral end face of the substrate W supported on the
substrate supporting portion to hold the substrate W. Each of the
chuck pins 117 is configured to be switchable between a pressing
state in which the substrate holding portion presses the outer
peripheral end face of the substrate W and a releasing state in
which the substrate holding portion is released from the outer
peripheral end face of the substrate W.
[0037] The plurality of chuck pins 117 are brought into the
releasing state when the substrate W is transferred to the spin
base 115, and the plurality of chuck pins 117 are brought into the
pressing state when etching is carried out over the substrate W. By
setting the pressing state, the plurality of chuck pins 117 can
grip the peripheral edge part of the substrate W, thereby holding
the substrate W in a substantially horizontal posture at a
predetermined interval from the spin base 115. Consequently, the
substrate W is supported with the upper surface (pattern formation
surface) S1 facing upward and the back surface S2 facing
downward.
[0038] The spin chuck 111 thus holding the substrate W is
rotationally driven by the chuck rotating mechanism 154 to rotate
the substrate W at a predetermined rotating speed, and at the same
time, a processing liquid is supplied to the upper surface
peripheral edge part S3 of the upper surface S1 and the back
surface S2 in the substrate W through a nozzle unit 120 and a lower
nozzle 141, respectively. Consequently, a predetermined chemical
treatment (etching) is performed.
[0039] FIG. 2 is a top view schematically showing the arrangement
of the nozzle unit 120 with respect to the upper surface S1 of the
substrate W. For convenience of illustration, a size of the nozzle
unit 120 is set to be larger than an actual size with respect to
the substrate W. FIGS. 3 and 4 are side views each showing an
example of a structure of the nozzle unit 120.
[0040] A nozzle rotating mechanism 155 including a motor is
provided on the side of the substrate W held on the spin chuck 111
as shown in FIGS. 1 and 2, and an operation of the nozzle rotating
mechanism 155 is controlled by the control portion 151. A rigid
tubular piping arm 180 is attached to the nozzle rotating mechanism
155 pivotably in a substantially horizontal plane with the nozzle
rotating mechanism 155 set to be a rotating center.
[0041] One of ends of the piping arm 180 penetrates the nozzle
rotating mechanism 155 to reach a lower surface thereof, and the
other end can be positioned above the upper surface peripheral edge
part S3 of the substrate W by swinging of the piping arm 180 by the
nozzle rotating mechanism 155. The nozzle unit 120 is attached to
the other end. In the transfer of the substrate W to the spin base
115 or the like, the piping arm 180 is swung so that the nozzle
unit 120 is moved backward from a delivery-in path for the
substrate W. Moreover, a position (a processing position) of the
nozzle unit 120 in execution of etching, rinsing, or the like is
accurately adjusted by servo control so that the etching width of
the upper surface peripheral edge part S3 is regulated. The servo
control is carried out by the control portion 151. Therefore, it is
possible to regulate the etching width of the upper surface
peripheral edge part S3 in accordance with a command sent from the
control portion 151.
[0042] As shown in FIGS. 2 to 4, the nozzle unit 120 is configured
to include a processing liquid discharging portion ("a peripheral
edge processing portion") 122 having a processing liquid supply
nozzle 126 and a rinsing liquid supply nozzle 127, and a nitrogen
gas injecting portion 124 having a nitrogen gas injection nozzle
128. Pipes 182 to 184 are connected to the processing liquid supply
nozzle 126, the rinsing liquid supply nozzle 127, and the nitrogen
gas injection nozzle 128, respectively. The pipes 182 to 184 are
disposed to pass through an inner part of the piping arm 180 via an
inner part of the nozzle unit 120 and to reach a portion provided
below the lower surface of the nozzle rotating mechanism 155,
respectively.
[0043] As shown in FIG. 1, furthermore, the substrate processing
device 100 is also provided with a processing liquid supply source
132 for supplying an etchant (a processing liquid) which is stored
therein and a rinsing liquid supply source 133 for supplying a
rinsing liquid which is stored therein. For example, SC1
(ammonia-hydrogen peroxide mixture), SC2 (hydrochloric
acid/hydrogen peroxide mixture), HF (hydrofluoric acid) or the like
is employed for the etchant. Note that contamination is caused if a
metal component such as Mo or Co adheres onto a contact part with a
wafer in another manufacturing apparatus or a delivery system, an
inside of FOUP/FOSB holding a wafer or the like. For this reason,
the SC2 is used for washing a bevel portion or a back surface of
the wafer in order to remove the adhering metal component, for
example. Thus, in some cases, the processing liquid stored in the
processing liquid supply source 132 is supplied to the wafer for
the purpose other than etching.
[0044] Pure water (DIW: deionized water) or the like is employed
for the rinsing liquid to be supplied by the rinsing liquid supply
source 133. Functional water or warm water may be employed for the
rinsing liquid.
[0045] The pipe 182 connected to the processing liquid supply
nozzle 126 of the processing liquid discharging portion 122 is
connected in communication with a pipe 383 provided out of the
processing liquid supply source 132, and an on-off valve 173 is
provided in a middle part of the pipe 383. The pipe 183 connected
to the rinsing liquid supply nozzle 127 of the processing liquid
discharging portion 122 is connected in communication with a pipe
384 provided out of the rinsing liquid supply source 133. An on-off
valve 174 is provided in a middle part of the pipe 384.
[0046] The on-off valves 173 and 174 are on-off controlled by means
of a valve control mechanism 152 which is controlled by the control
portion 151, and the valve control mechanism 152 selectively opens
the on-off valve 173 and the on-off valve 174 as necessary.
[0047] If the on-off valve 173 is opened, a processing liquid 52
(FIG. 3) supplied from the processing liquid supply source 132 is
discharged from the processing liquid supply nozzle 126 of the
processing liquid discharging portion 122 and is thus supplied to
the upper surface peripheral edge part S3. The processing liquid
discharging portion 122 supplies the processing liquid 52 from
above to the peripheral edge part of the substrate W heated by the
lower nozzle 141 which will be described below, thereby carrying
out a chemical treatment (etching) for the peripheral edge part. A
flow rate of the processing liquid to be supplied to the upper
surface peripheral edge part S3 is set to be small, for example,
approximately 10 ml to 100 ml per minute. As described above,
moreover, the rotating angle of the piping arm 180 connected to the
nozzle unit 120 is accurately regulated by the nozzle rotating
mechanism 155. Consequently, the processing liquid discharging
portion 122 can precisely regulate a width in a radial direction of
the substrate W in a portion in which the processing liquid to be
discharged collides with the upper surface peripheral edge part S3
of the substrate W.
[0048] In the case where an etchant (a processing liquid) having a
reaction rate increased with a rise in temperature is used, it is
possible to reduce an etching width (a chemical treating width) by
supplying the processing liquid to a desirable region having a
small width at the peripheral edge side of the upper surface
peripheral edge part S3 of the substrate W having the entire upper
surface S1 heated. More specifically, the etching width can be
reduced to be approximately 0.5 mm to 1 mm, for example.
[0049] Furthermore, it is preferable that the processing liquid
discharging portion 122 supply the processing liquid to the upper
surface peripheral edge part S3 of the substrate W along a path in
an obliquely downward direction from an inside of the substrate W
toward an outside thereof. Consequently, the supplied processing
liquid can be prevented from adhering onto a non-processed region
of the substrate W.
[0050] In addition, if the on-off valve 174 is opened, a rinsing
liquid 53 (FIG. 4) supplied from the rinsing liquid supply source
133 is discharged from the rinsing liquid supply nozzle 127 of the
processing liquid discharging portion 122 and is thus supplied to
the upper surface peripheral edge part S3. Consequently, rinsing
for the peripheral edge part of the substrate W is carried out.
[0051] As shown in FIG. 1, a through hole connected to a through
hole of the rotating support shaft 113 is formed on a central part
of the spin base 115. A cylindrical portion 143 is inserted into
these through holes. The substantially disk-shaped lower nozzle 141
is fixed to an upper end of the cylindrical portion 143. A diameter
of the lower nozzle 141 is set to be smaller than a diameter of a
rotating track of the chuck pin 117 in such a manner that the chuck
pin 117 erected on the rotating spin base 115 does not interfere
with the lower nozzle 141.
[0052] The processing liquid is supplied from the processing liquid
supply source 132 through a pipe 386 to a supply tube 147 connected
to a processing liquid discharging port 148 of the lower nozzle
141, and furthermore, a rinsing liquid is supplied thereto from the
rinsing liquid supply source 133 through a pipe 388. On-off valves
176 and 178 are provided in the middle parts of the pipes 386 and
388, respectively. The on-off valves 176 and 178 are on-off
controlled by means of the valve control mechanism 152. The valve
control mechanism 152 selectively opens the on-off valve 176 and
the on-off valve 178 so that the processing liquid and the rinsing
liquid are selectively supplied to the supply tube 147 and are
selectively discharged from the processing liquid discharging port
148 on an upper surface 145 of the lower nozzle 141 toward the back
surface S2 of the substrate W. The processing liquid and the
rinsing liquid which are discharged spread over the entire region
of the back surface S2 by the action of centrifugal force generated
by the rotation of the substrate W. Consequently, the lower nozzle
141 performs the etching and rinsing for the back surface S2.
[0053] Moreover, the processing liquid discharging port 148 is
formed on the lower nozzle 141. The processing liquid discharging
port 148 has an opening on the central part of the upper surface
145 and penetrates the lower nozzle 141. The processing liquid
discharging port 148 is connected in communication with the supply
tube 147 to be a through hole formed by an internal wall of the
cylindrical portion 143.
[0054] Furthermore, a supply tube 181 penetrating the supply tube
147 and the processing liquid discharging port 148 is inserted into
the supply tube 147 and the processing liquid discharging port 148.
In other words, the supply tube 181 is inserted through the inner
part of the rotating support shaft 113 which supports the spin base
115 and is rotated integrally with the spin base 115. At an upper
end of the supply tube 181 protruded to the upper surface 145 of
the lower nozzle 141, a steam injection nozzle 125 (also referred
to as a "heating portion") is connected in communication with the
supply tube 181. Moreover, a lower end of the supply tube 181 is
connected to a steam supply source 131 at an outside of the
substrate processing device 100 by means of a pipe 385. Heating
steam 51 to be supplied from the steam supply source 131 is fed to
the steam injection nozzle 125 via the pipe 385 and the supply tube
181. Then, the steam injection nozzle 125 injects the supplied
heating steam 51 into the central part of the back surface S2 of
the substrate W, thereby entirely heating the substrate W.
[0055] A heater 139 and an on-off valve 175 are provided in a
middle part of the pipe 385 connecting the steam supply source 131
and the supply tube 181 in the substrate processing device 100.
[0056] The heater 139 heats steam supplied from the steam supply
source 131 depending on the control of the control portion 151. In
the steam supply source 131, pure water or the like is heated so
that steam for entirely heating the substrate W is generated. The
heating steam thus generated is heated by the heater 139 and is
then supplied as superheated steam having a higher temperature than
100.degree. C., for example.
[0057] The on-off valve 175 is on-off controlled by the valve
control mechanism 152 which is controlled by means of the control
portion 151. The valve control mechanism 152 opens the on-off valve
175 as necessary so that heating steam 51 supplied from the steam
supply source 131 is injected from the supply tube 181 of the lower
nozzle 141 to the central part of the back surface S2 of the
substrate W.
[0058] The steam 51 injected from the steam injection nozzle 125 to
the central part of the back surface S2 is rotated in a reverse
rotating direction to a rotating direction of the substrate W
relatively with the back surface S2 of the substrate W, and at the
same time, spreads toward the peripheral edge part of the back
surface S2 by centrifugal force and a supply pressure which are
generated by the rotation of the substrate W. Consequently, the
entire region of the back surface S2 is heated, and furthermore,
the entire region of the upper surface S1 is also heated by thermal
conduction from the back surface S2 to the upper surface S1.
[0059] The steam 51 injected to the central part of the back
surface S2 is cooled by taking heat through the substrate W in a
process of spreading toward the peripheral edge part of the back
surface S2. For this reason, the steam 51 is condensed over the
back surface S2 so that a water droplet is generated in some cases.
The water droplet thus generated is shaken off from the peripheral
edge part of the back surface S2 to the outside of the substrate W
by the action of centrifugal force through high-speed rotation of
the substrate W and does not adhere onto the non-processed region
of the upper surface S1.
[0060] The superheated steam at 110.degree. C. is supplied from the
steam supply source 131 to the heater 139, for example, and a
temperature of the superheated steam obtained immediately after
heating by the heater 139 is preferably set to be 140.degree. C. to
160.degree. C. or the like, for example. The superheated steam
having a high temperature is injected to the central part of the
back surface S2 of the rotated substrate W to heat the substrate W,
and at the same time, can also be maintained at a high temperature
after reaching the peripheral edge part along the back surface S2.
Accordingly, the water droplet obtained by the condensation of the
steam 51 or the like can be further prevented from adhering onto
the non-processed region of the upper surface S1 of the substrate
W. Moreover, if the superheated steam having the high temperature
is used, it is possible to cause the upper surface peripheral edge
part S3 of the substrate W to have a higher temperature, thereby
increasing an etching rate more greatly as compared with the case
where saturated steam having a temperature of 100.degree. C. or
less is discharged from the lower nozzle 141, for example.
[0061] FIG. 5 is a view illustrating, in a graph, a difference in
temperature distribution on the substrate W depending on presence
or absence of the steam injection nozzle 125 for heating the back
surface S2 of the substrate W. A graph 83 shows an example of a
temperature distribution on the upper surface S1 of the substrate W
in the case where the processing liquid is discharged from the
lower nozzle 141 provided on the back surface S2 side of the
substrate W toward the back surface S2 of the substrate W which is
being rotated at a predetermined rotating speed. The back surface
S2 is not heated by the steam injection nozzle 125. The processing
liquid to be discharged to the back surface S2 has a temperature
regulated to 70.degree. C. or the like, for example, and is
supplied to the peripheral edge part of the substrate W by the
action of centrifugal force. The upper surface 51 is heated with
the processing liquid supplied to the back surface S2. Moreover, a
graph 84 shows an example of a temperature distribution on the
upper surface S1 of the substrate W in the case where the heating
steam is injected from the steam injection nozzle 125 onto the back
surface S2.
[0062] As shown in each of the graphs in FIG. 5, the temperature of
the processing liquid or the steam is gradually reduced depending
on the rotation of the substrate W apart from the central part of
the substrate W so that the temperature on the upper surface S1 is
also reduced. However, in the case where the back surface S2 of the
substrate W is heated by the steam injection nozzle 125, it is
possible to increase a temperature in the upper surface peripheral
edge part S3 portion as compared with the case where the heating is
not carried out by the steam injection nozzle 125 as shown in the
graph 84. Moreover, in the case where etching is carried out over
the back surface S2, it is possible to carry out processing with
the substrate W having a high temperature (that is, a high etching
rate) by supplying the processing liquid and the steam at the same
time.
[0063] FIG. 6 is a view showing a difference in an etching width
over the upper surface S1 of the substrate W illustrated in FIG. 7
depending on presence or absence of an operation for supplying the
heating steam through the steam injection nozzle 125. For
convenience of illustration, each etching width is described to be
larger than an actual width.
[0064] A substantially circular boundary 41 indicates an example of
a boundary between an etched region and a non-processed region
which is not subjected to the etching at the rotating axis a1 side
in the case where the back surface S2 is heated by the steam
injection nozzle 125, and at the same time, the processing liquid
is supplied from the processing liquid supply nozzle 126 to the
upper surface peripheral edge part S3. Moreover, FIG. 8 is a view
showing an example of a sectional view of the substrate W obtained
after the etching in this case. A width 21 (FIGS. 6 and 8)
indicates an etching width at one point on the boundary 41. The
etching width 21 is approximately 0.5 to 1.0 mm, for example, and a
variation thereof is reduced to be approximately 1/10 or less of a
mean value of the etching width 21, for example.
[0065] A boundary 42 indicates an example of a boundary between an
etched region in the upper surface S1 of the substrate W and a
non-processed region in the case where the etching for the upper
surface peripheral edge part S3 is carried out with the processing
liquid discharged from the lower nozzle 141 provided on the back
surface S2 side of the substrate W to the back surface S2 of the
rotating substrate W. FIG. 9 is a view showing an example of the
sectional view of the substrate W obtained after the etching in
this case. The centrifugal force acts on the processing liquid
discharged to the back surface S2 so that the processing liquid
spreads toward the peripheral edge part of the substrate W, and
furthermore, goes around the upper surface peripheral edge part S3.
Thus, the upper surface peripheral edge part S3 is etched. The
rotating speed of the substrate W is regulated in such a manner
that the processing liquid can go around the upper surface
peripheral edge part S3 from the back surface S2. There are carried
out neither the heating for the back surface S2 through the steam
injection nozzle 125 nor the supply of the processing liquid to the
upper surface peripheral edge part S3 through the processing liquid
discharging portion 122.
[0066] A width 22 indicates an etching width at one point on the
boundary 42. It is difficult to control an amount of the processing
liquid going around the upper surface peripheral edge part S3 by
the action of the centrifugal force. For this reason, a shape of
the boundary 42 is more wavy than the boundary 41 taking the
substantially circular shape, and the etching width 22 is
approximately 2 to 3 mm, for example, and is larger than the
etching width 21. Moreover, a variation in the etching width 22 is
greater than that in the etching width 21.
[0067] As shown in FIGS. 6, 8 and 9, in the case where there are
carried out the heating for the back surface S2 of the substrate W
through the steam injection nozzle 125 and the supply of the
processing liquid to a region having a small width at the
peripheral edge side of the upper surface peripheral edge part S3
through the processing liquid discharging portion 122, the etching
width in the upper surface peripheral edge part S3 is smaller and
the variation in the etching width is also reduced as compared with
the case where the etching is carried out by the wraparound of the
processing liquid from the back surface S2 side.
[0068] Returning to FIG. 1, a nitrogen gas supply source 134 is
provided on the outside of the substrate processing device 100. As
shown in FIGS. 3 and 4, a nitrogen gas is supplied from the
nitrogen gas supply source 134 through a pipe 381 to the pipe 184
connected to the nitrogen gas injecting portion 124 in the
substrate processing device 100. An on-off valve 171 to be on-off
controlled by the valve control mechanism 152 is provided in a
middle part of the pipe 381 in the substrate processing device
100.
[0069] When the control portion 151 opens the on-off valve 171
through the valve control mechanism 152, the nitrogen gas is
supplied from the nitrogen gas supply source 134 to the nitrogen
gas injecting portion 124.
[0070] The nitrogen gas injecting portion 124 is configured to have
a slender arcuate sectional shape in a circumferential direction of
the substrate W, for example. The nitrogen gas injection nozzle 128
is configured by an injection nozzle having a slender arc-shaped
opening in the circumferential direction of the substrate W on a
lower surface of the nitrogen gas injecting portion 124, a
plurality of cylindrical injection nozzles provided at a
predetermined interval on the lower surface of the nitrogen gas
injecting portion 124 or the like. The nitrogen gas supplied to the
nitrogen gas injecting portion 124 is injected as a nitrogen gas G1
(a gas for purge) from the nitrogen gas injection nozzle 128 to the
upper surface S1 of the rotating substrate W.
[0071] In more detail, the nitrogen gas G1 is injected from the
nitrogen gas injection nozzle 128 provided above the substrate W
toward a predetermined injection target region defined within a
range surrounded by the rotating track of the upper surface
peripheral edge part S3 in the upper surface S1 of the substrate W.
The nitrogen gas G1 injected onto the upper surface 51 forms a gas
flow which flows from the injection target region toward the upper
surface peripheral edge part S3 of the substrate W. With the air
flow formed by the nitrogen gas G1, mist obtained by the
condensation of the steam 51 injected from the steam injection
nozzle 125 to the back surface S2 and the processing liquid 52
discharged from the processing liquid supply nozzle 126 of the
processing liquid discharging portion 122 or the like can be
prevented from adhering onto the non-processed region in the upper
surface S1 of the substrate W where the etching is not carried
out.
[0072] Moreover, also in a drying treatment for the upper surface
S1 of the substrate W after the end of the rinsing, the substrate W
is promoted to be dried with the nitrogen gas G1 supplied from the
nitrogen gas injection nozzle 128, and furthermore, the rinsing
liquid shaken off from the upper surface peripheral edge part S3
toward the outside of the substrate W by the centrifugal force
acting through the high-speed rotation of the substrate W can be
prevented from returning to the substrate W and adhering onto the
non-processed region of the upper surface S1.
[0073] Furthermore, as shown in FIG. 1, the nitrogen gas is
supplied from the nitrogen gas supply source 134 through a pipe 387
to the supply tube 147 connected to the lower nozzle 141. An on-off
valve 177 to be on-off controlled by the valve control mechanism
152 is provided in a middle part of the pipe 387. The control
portion 151 opens the on-off valve 177 through the valve control
mechanism 152 after the end of the rinsing for the back surface S2
so that the nitrogen gas is supplied from the processing liquid
discharging port 148 of the lower nozzle 141 to the back surface S2
of the rotating substrate W.
[0074] Great centrifugal force acts on the rinsing liquid adhering
to the back surface S2 by the high-speed rotation of the substrate
W so that the rinsing liquid is shaken off around the substrate W
and the drying treatment for the back surface S2 is carried out.
Moreover, drying of the back surface S2 is also promoted with the
nitrogen gas supplied from the lower nozzle 141 to the back surface
S2.
[0075] Even if the substrate processing device 100 includes neither
the nitrogen gas supply source 134 nor the nitrogen gas injecting
portion 124, it is possible to reduce the etching width while
suppressing deterioration in each of the uniformity of the etching
width and the etching rate. Therefore, the usefulness of the
present invention is not lost.
<2. Operation of Substrate Processing Device>
[0076] FIGS. 10 and 11 are flow charts showing an example of a flow
of substrate processing to be carried out by the substrate
processing device 100 according to the preferred embodiment. Before
the start of the processing, each of the on-off valves is closed
and the spin chuck 111 is stationary. Moreover, the nozzle unit 120
is placed in a standby position other than the delivery-in path for
the substrate W. First of all, a single substrate W is delivered by
a substrate delivery robot (not shown) into a processing chamber
(chamber) (not shown) in which the spin chuck 111 is disposed, and
is mounted on the spin chuck 111 to be held by the chuck pin 117
(step S110).
[0077] Subsequently, the nozzle unit 120 is placed in a
predetermined position above the upper surface peripheral edge part
S3 of the substrate W. Then, the on-off valve 171 is opened and the
nitrogen gas is started to be supplied from the nitrogen gas supply
source 134 in a flow rate of 30 L to 100 L per minute, for example.
The nitrogen gas is heated to 120.degree. C. to 150.degree. C. by a
nitrogen gas heater 138, for example, and is then injected as the
nitrogen gas G1 (a gas for purge) from the nitrogen gas injecting
portion 124 toward the upper surface peripheral edge part S3 of the
substrate W (step S120). In the case where the nitrogen gas having
an ordinary temperature that is supplied from the nitrogen gas
supply source 134 is not heated but injected as the gas for purge
from the nitrogen gas injecting portion 124, the temperature is
reduced in the substrate W so that the etching rate is decreased.
However, if the nitrogen gas heated by the nitrogen gas heater 138
is supplied as the gas for purge to the upper surface peripheral
edge part S3 of the substrate W, the etching rate can be prevented
from being decreased.
[0078] Next, the control portion 151 controls the chuck rotating
mechanism 154 so that the rotation of the spin chuck 111 is started
in such a manner that the rotating speed of the spin chuck 111
becomes a predetermined high rotating speed of 50 rpm to 1000 rpm,
for example (step S130). Then, the on-off valve 175 is opened so
that the heating steam generated by the steam supply source 131 and
heated by the heater 139 is supplied to the steam injection nozzle
125 via the supply tube 181. Thereafter, the steam injection nozzle
125 starts to inject the heating steam toward the central part of
the back surface S2 of the substrate W (step S140), thereby
starting to entirely heat the substrate W through thermal
conduction from the central part of the back surface S2.
[0079] Subsequently, the etching for the upper surface peripheral
edge part S3 of the substrate W is carried out (step S150). More
specifically, the on-off valve 173 is opened so that the processing
liquid is supplied from the processing liquid supply source 132 to
the processing liquid discharging portion 122 of the nozzle unit
120 and discharged from the processing liquid supply nozzle 126 to
a narrow width region at the peripheral edge side of the upper
surface peripheral edge part S3 which is heated. Then, the etching
for the upper surface peripheral edge part S3 of the substrate W is
carried out with the processing liquid thus discharged.
[0080] When a predetermined time elapsed and the etching for the
upper surface peripheral edge part S3 is completed, the on-off
valve 175 is closed so that the supply of the processing liquid to
the substrate W is stopped.
[0081] Subsequently, the rinsing for the upper surface peripheral
edge part S3 of the substrate W is carried out (step S160). More
specifically, the on-off valve 174 is opened and the rinsing liquid
is started to be supplied from the rinsing liquid supply source
133. Then, the rinsing liquid is discharged from the rinsing liquid
supply nozzle 127 of the processing liquid discharging portion 122
to the upper surface peripheral edge part S3 so that the rinsing
for the upper surface peripheral edge part S3 is carried out. When
a predetermined time elapsed and the rinsing for the upper surface
peripheral edge part S3 is completed, the on-off valve 174 is
closed so that the supply of the rinsing liquid is stopped.
[0082] Next, the etching for the back surface S2 of the substrate W
is carried out (step S170). More specifically, the on-off valve 176
is opened so that the processing liquid is supplied from the
processing liquid supply source 132 to the lower nozzle 141 and
discharged to the heated back surface S2. Thereafter, the etching
for the back surface S2 of the substrate W is carried out with the
discharged processing liquid. In the etching for the back surface
S2, it is preferable that pure water or DIW should be supplied from
above to the upper surface peripheral edge part S3 through the
rinsing liquid supply nozzle 127, thereby preventing the processing
liquid from going around the upper surface peripheral edge part S3
from the back surface S2.
[0083] When a predetermined time elapsed and the etching for the
back surface S2 is completed, the on-off valve 176 is closed so
that the supply of the processing liquid to the back surface S2 is
stopped. Then, the on-off valve 175 is closed so that the injection
of the heating steam to the back surface S2 is stopped (step S180).
The injection of the heating steam to the back surface S2 may be
once stopped before the start of step S160 and may be started again
before the start of step S170, for example.
[0084] Subsequently to the processing of the step S180, the rinsing
for the back surface S2 of the substrate W is carried out (step
S190). More specifically, the on-off valve 178 is opened and the
rinsing liquid is started to be supplied from the rinsing liquid
supply source 133. Then, the rinsing liquid is discharged from the
processing liquid discharging port 148 of the lower nozzle 141 to
the back surface S2 of the substrate W so that the rinsing for the
back surface S2 is carried out. When a predetermined time elapsed
and the rinsing for the back surface S2 is completed, the on-off
valve 178 is closed and the supply of the rinsing liquid is
stopped.
[0085] Next, the rotation of the spin chuck 111 is continuously
carried out for a predetermined time in a state in which the
rotating speed of the spin chuck 111 is set to be a high rotating
speed of 1000 rpm to 1500 rpm. Consequently, the rinsing liquid
remaining in the upper surface peripheral edge part S3 is shaken
off toward the outside of the substrate W by the action of
centrifugal force so that a drying treatment (spin drying) for the
upper surface S1 of the substrate W is carried out (step S200). In
the spin drying, the nitrogen gas G1 is continuously supplied from
the nitrogen gas injection nozzle 128 of the nitrogen gas injecting
portion 124 to the upper surface peripheral edge part S3.
Consequently, drying of the rinsing liquid adhering onto the upper
surface peripheral edge part S3 is promoted, and furthermore, the
shaken-off rinsing liquid can be prevented from returning to the
substrate W side and adhering onto the non-processed region of the
upper surface S1. Moreover, the nitrogen gas is injected from the
processing liquid discharging port 148 of the lower nozzle 141
toward the back surface S2 so that the drying of the back surface
S2 is promoted.
[0086] When a predetermined time elapsed since the start of the
drying treatment, the rotation of the spin chuck 111 is stopped so
that the drying treatment is ended (step S210). Subsequently, the
on-off valve 171 and the on-off valve 177 are closed so that the
injection of the nitrogen gas for purge from the nitrogen gas
injecting portion 124 and the lower nozzle 141 is stopped (step
S220).
[0087] When the injection of the gas from the nitrogen gas
injecting portion 124 and the lower nozzle 141 is stopped, the
control portion 151 controls the nozzle rotating mechanism 155 to
move the nozzle unit 120 to the standby position. Then, the
processed substrate W is removed from the spin chuck 111 and
delivered to the outside of the processing chamber by means of a
delivery robot (not shown) (step S230) so that the substrate
processing to be carried out by the substrate processing device 100
is ended.
[0088] According to the substrate processing device in accordance
with the present preferred embodiment configured as described
above, the heating steam is injected to the central part of the
back surface S2 of the substrate W so that the substrate W is
entirely heated and the processing liquid is supplied to the
peripheral edge part from above. Also in the case where the amount
of the processing liquid to be supplied is small, consequently, it
is possible to enhance reactivity of the processing liquid in the
peripheral edge part by sufficiently heating the peripheral edge
part. Accordingly, if the processing liquid is supplied from above
to a desirable region having a small width at the substrate end
side (the peripheral edge side) in the peripheral edge part, it is
possible to reduce the etching width while suppressing
deterioration in each of the uniformity of the etching width and
the etching rate. Moreover, the heating steam is injected to the
lower surface of the substrate W. Therefore, even if a water
droplet is generated by the condensation of the steam, it is
possible to suppress wraparound of the water droplet onto the upper
surface of the substrate W. Accordingly, it is possible to prevent
deterioration in the non-processed region from being caused by the
adhering of the water droplet to the non-processed region on the
upper surface of the substrate W. Moreover, since the non-processed
region is hardly deteriorated due to the supply of the heating
steam, it is possible to supply, to the back surface S2, the steam
in an amount sufficient for heating the upper surface peripheral
edge part S3 of the substrate W.
[0089] Moreover, according to the substrate processing device in
accordance with the present preferred embodiment configured as
described above, the steam injection nozzle 125 injects the heating
steam to the back surface S2 of the substrate W via the supply tube
181 inserted into the inner part of the rotating support shaft 113
of the spin chuck 111. Consequently, it is possible to supply the
heating steam to the back surface S2 while preventing the contact
of the rotating chuck pin 117 and the steam injection nozzle 125
with a simple structure.
[0090] Furthermore, according to the substrate processing device in
accordance with the present preferred embodiment configured as
described above, the superheated steam having a high temperature is
used as the heating steam. For this reason, it is possible to cause
the upper surface peripheral edge part of the substrate W to have a
higher temperature and to increase the etching rate more greatly as
compared with the case where saturated steam having a temperature
of 100.degree. C. or less is used for the heat treatment, for
example. It is also possible to save the processing liquid.
[0091] Furthermore, according to the substrate processing device in
accordance with the present preferred embodiment configured as
described above, the processing liquid discharging portion 122 can
regulate the width in the radial direction of the substrate W in
the portion in which the processing liquid collides with the upper
surface peripheral edge part S3 by the control of the nozzle
rotating mechanism 155. Consequently, it is possible to supply the
processing liquid from above to the desirable region having a small
width in the upper surface peripheral edge part S3 of the substrate
W having the upper surface S1 heated. Therefore, it is possible to
control the etching width with high precision irrespective of the
rotating speed of the substrate W.
[0092] Although the present invention has been shown and described
in detail, the description is illustrative in all aspects and is
not restrictive. Therefore, the preferred embodiment according to
the present invention can be appropriately changed and omitted
within the scope of the present invention. For example, the
nitrogen gas supply source 134 and the steam supply source 131 may
be provided in the substrate processing device 100. It is also
possible to employ a structure in which a dry gas such as dry air
or an inert gas other than the nitrogen gas is supplied in place of
the supply of the nitrogen gas through the nitrogen gas supply
source 134. Moreover, although the respective nozzles or the like
in the nozzle unit 120 are moved integrally with the substrate W,
it is also possible to employ a structure in which they can be
individually moved, respectively. Furthermore, among the back
surface S2 and the upper surface peripheral edge part S3, even if
the substrate processing device 100 supplies the processing liquid
to only the upper surface peripheral edge part S3 to carry out the
etching for only the upper surface peripheral edge part S3, the
usefulness of the present invention is not lost. Moreover, even if
the substrate processing device 100 is not provided with the
nitrogen gas heater 138, the usefulness of the present invention is
not lost.
[0093] While the invention has been shown and described in detail,
the foregoing description is in all aspects illustrative and not
restrictive. It is therefore understood that numerous modifications
and variations can be devised without departing from the scope of
the invention.
* * * * *