U.S. patent application number 10/163453 was filed with the patent office on 2003-06-12 for semiconductor substrate cleaning apparatus, method of cleaning semiconductor substrate and method of manufacturing semiconductor device.
This patent application is currently assigned to Mitsubishi Denki Kabushiki Kaisha. Invention is credited to Anabuki, Kazutoshi, Higashi, Masahiko, Tanaka, Hiroshi, Yokoi, Naoki.
Application Number | 20030106567 10/163453 |
Document ID | / |
Family ID | 19182552 |
Filed Date | 2003-06-12 |
United States Patent
Application |
20030106567 |
Kind Code |
A1 |
Anabuki, Kazutoshi ; et
al. |
June 12, 2003 |
Semiconductor substrate cleaning apparatus, method of cleaning
semiconductor substrate and method of manufacturing semiconductor
device
Abstract
A semiconductor substrate cleaning apparatus, a method of
cleaning a semiconductor substrate and a method of manufacturing a
semiconductor device are obtained, in which reduction of production
yield of a semiconductor device can be prevented. The semiconductor
substrate cleaning apparatus includes a holding member holding a
semiconductor substrate and a cleaning member allowing a cleaning
medium to be supplied only to a part of a surface of the
semiconductor substrate while the semiconductor substrate held by
the holding member is fixed. In such a manner, the cleaning medium
is supplied to the semiconductor substrate while the semiconductor
substrate is not rotated but fixed, whereby only a part of the
surface of the semiconductor substrate can be cleaned.
Inventors: |
Anabuki, Kazutoshi; (Hyogo,
JP) ; Tanaka, Hiroshi; (Hyogo, JP) ; Yokoi,
Naoki; (Hyogo, JP) ; Higashi, Masahiko;
(Hyogo, JP) |
Correspondence
Address: |
McDERMOTT, WILL & EMERY
600 13th Street, N.W.
Washington
DC
20005-3096
US
|
Assignee: |
Mitsubishi Denki Kabushiki
Kaisha
|
Family ID: |
19182552 |
Appl. No.: |
10/163453 |
Filed: |
June 7, 2002 |
Current U.S.
Class: |
134/1.3 ;
134/184; 134/198; 134/26; 134/99.1 |
Current CPC
Class: |
H01L 21/67051 20130101;
H01L 21/67057 20130101 |
Class at
Publication: |
134/1.3 ; 134/26;
134/184; 134/198; 134/99.1 |
International
Class: |
C25F 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 7, 2001 |
JP |
2001-373912(P) |
Claims
What is claimed is:
1. A semiconductor substrate cleaning apparatus, comprising: a
holding member holding a semiconductor substrate; and a cleaning
member allowing a cleaning medium to be supplied only to a part of
a surface of said semiconductor substrate while said semiconductor
substrate held by said holding member is fixed.
2. The semiconductor substrate cleaning apparatus according to
claim 1, wherein said cleaning medium includes at least one
selected from the group consisting of cleaning chemicals and pure
water.
3. The semiconductor substrate cleaning apparatus according to
claim 1, wherein said cleaning member includes at least one
selected from the group consisting of means for supplying
ultrasonically vibrated said cleaning medium and means for
supplying pressurized said cleaning medium, to the part of the
surface of said semiconductor substrate.
4. The semiconductor substrate cleaning apparatus according to
claim 1, wherein said cleaning member includes a nozzle for
supplying said cleaning medium to the surface of said semiconductor
substrate, and position determining means for determining a
relative position of said nozzle to the surface of said
semiconductor substrate based on coordinate data of said part to be
supplied with said cleaning medium, of the surface of said
semiconductor substrate.
5. The semiconductor substrate cleaning apparatus according to
claim 1, further comprising rinsing means for washing said cleaning
medium away from the surface of said semiconductor substrate.
6. The semiconductor substrate cleaning apparatus according to
claim 5, wherein said rinsing means includes means for supplying a
rinsing medium to the surface of said semiconductor substrate, and
said cleaning member supplies said cleaning medium only to the part
of the surface of said semiconductor substrate while the surface of
said semiconductor substrate is supplied with the rinsing
medium.
7. A method of cleaning a semiconductor substrate, comprising the
steps of: providing a semiconductor substrate; and cleaning by
supplying a cleaning medium only to a part of a surface of said
semiconductor substrate while supplying a rinsing medium to the
surface of said semiconductor substrate with said semiconductor
substrate being fixed.
8. The method of cleaning a semiconductor substrate according to
claim 7, wherein said cleaning medium includes at least one
selected from the group consisting of cleaning chemicals and pure
water.
9. The method of cleaning a semiconductor substrate according to
claim 7, wherein said step of cleaning includes at least one
selected from the group consisting of the step of supplying
ultrasonically vibrated said cleaning medium and the step of
supplying pressurized said cleaning medium, to the part of the
surface of said semiconductor substrate.
10. A method of manufacturing a semiconductor device using the
method of cleaning a semiconductor substrate according to claim
7.
11. A method of cleaning a semiconductor substrate, comprising the
steps of: providing a semiconductor substrate; providing a medium
tank holding a cleaning medium for cleaning a surface of the
semiconductor substrate; and dipping only an end portion of said
semiconductor substrate into said cleaning medium held in said
medium tank.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a semiconductor substrate
cleaning apparatus, a method of cleaning a semiconductor substrate
and a method of manufacturing a semiconductor device. More
particularly, the present invention relates to a semiconductor
substrate cleaning apparatus, a method of cleaning a semiconductor
substrate, in which only a particular position of the semiconductor
substrate can be cleaned, and a method of manufacturing a
semiconductor device.
[0003] 2. Description of the Background Art
[0004] Conventionally, a prescribed semiconductor device is formed
by performing film deposition, etching and the like on the surface
of a semiconductor substrate in a manufacturing process of a
semiconductor device. Furthermore, before and after the steps of
film deposition and etching, a cleaning step is performed for
removing particles from the surface of the semiconductor
substrate.
[0005] An example of a cleaning method conventionally utilized in
the cleaning step includes a method shown in FIG. 10. FIG. 10 is a
schematic view illustrating one example of a conventional method of
cleaning a semiconductor substrate. As shown in FIG. 10, in the
conventional method of cleaning a semiconductor substrate, a
semiconductor substrate 101 is fixed on a base 102, and then base
102 and semiconductor substrate 101 are rotated as represented by
an arrow 130. Then, while semiconductor substrate 101 is rotated,
cleaning liquid 105 is supplied from chemicals nozzle 103 onto the
surface of semiconductor substrate 101. At this point, by supplying
cleaning liquid 105 to approximately the center portion of
semiconductor substrate 101, cleaning liquid 105 is flown from the
center portion toward the outer periphery portion on the surface of
the semiconductor substrate, because the semiconductor substrate
101 is rotated. As a result, the entire surface of semiconductor
substrate 101 can be cleaned almost uniformly.
[0006] Furthermore, another example of a cleaning method
conventionally utilized in the cleaning step includes a method as
shown in FIG. 11. FIG. 11 is a schematic view illustrating another
example of a conventional method of cleaning a semiconductor
substrate. As shown in FIG. 11, in another example of a
conventional method of cleaning a semiconductor substrate, a
chemicals tank containing cleaning liquid 105 is provided. Then,
semiconductor substrate 101 is dipped in cleaning liquid 105 held
in this chemicals tank 118, as represented by an arrow 131. In this
way also, the entire surface of semiconductor substrate 101 can be
cleaned almost uniformly.
[0007] Now, an identification label for individually identifying
semiconductor substrate 101 is formed on the surface of
semiconductor substrate 101 in a manufacturing process of a
semiconductor device. A laser-printed portion 106 is formed as this
identification label by printing the substrate with a prescribed
character or sign using a laser beam as shown, for example, in FIG.
11. More specifically, the surface layer of semiconductor substrate
101 is irradiated with a laser beam and thus partially removed to
form a groove. The irradiation energy or irradiation position of
the laser beam is controlled such that the planar shape of this
groove has a prescribed character or sign. As a result, a
prescribed character or sign can be formed in laser-printed portion
106. It is noted that such laser-printed portion 106 is formed at a
position different from a chip-formed region 119 that will be a
semiconductor device. For example, it is formed at the end portion
of semiconductor substrate 101.
[0008] A character or sign formed in laser-printed portion 106
needs to be recognized even after CMP (Chemical Mechanical
Polishing) is performed to planarize a surface of an interlayer
insulating film or the like in the subsequent process. Therefore, a
groove that represents a character or the like formed in
laser-printed portion 106, is formed to have a depth sufficient to
be recognized even after the CMP described above is performed.
[0009] In forming such laser-printed portion 106, particles
resulting from the laser print step remain on the surface of
semiconductor substrate 101 or within the groove formed at the time
of the laser print step. In order to remove such particles from the
surface of semiconductor substrate 101, the cleaning step as
described above has conventionally been carried out.
[0010] Particles, however, often remain within the groove even
after the cleaning step, because the groove representing the
character or the like of laser-printed portion 106 is formed
relatively deep as described above. When particles remain in the
groove in such a manner, the particles remaining within the groove
adheres on chip-formed portion 119 or the like on the surface of
semiconductor substrate 101, in a subsequent hydrofluoric acid
treatment step. The presence of such particles may cause a short
circuit of interconnection or a structural defect in the
semiconductor device formed on the surface of semiconductor
substrate 101. Therefore, it may possibly reduce production yield
of the finished semiconductor device.
[0011] On the other hand, cleaning liquid or a cleaning technique
with a high cleaning capability may be used to completely remove
the particles from the inside of the groove after forming the
laser-printed portion. In the conventional cleaning method,
however, the entire surface of semiconductor substrate 101 is
cleaned. Therefore, when a cleaning method with a high cleaning
capability is used, the cleaning step may cause a damage in the
structure of chip-formed region 119. Accordingly, it has been
difficult to use a cleaning method with such a high cleaning
capability that can completely remove the particles within the
groove.
[0012] As described above, it has been conventionally difficult to
prevent reduction in production yield of the semiconductor device,
which results from the particles remaining in the groove of
laser-printed portion 106.
SUMMARY OF THE INVENTION
[0013] An object of the present invention is to provide a
semiconductor substrate cleaning apparatus, a method of cleaning a
semiconductor substrate and a method of manufacturing a
semiconductor device, in which reduction in production yield of the
semiconductor device can be prevented.
[0014] A semiconductor substrate cleaning apparatus in accordance
with a one aspect of the present invention includes a holding
member holding a semiconductor substrate and a cleaning member
allowing a cleaning medium to be supplied only to a part of the
surface of the semiconductor substrate while the semiconductor
substrate held by the holding member is fixed.
[0015] Accordingly, the cleaning medium is supplied to the
semiconductor substrate with the semiconductor substrate fixed
without rotation, so that only a part of the surface of the
semiconductor substrate can be cleaned. Therefore, when particles
are present in a groove that represents a character or the like
formed in a laser-printed portion, only this laser-printed portion
can be cleaned. Furthermore, by using chemicals with a high
cleaning capability as a cleaning medium, the particles existing
within the groove can be removed.
[0016] In addition, since the cleaning medium is supplied only to a
part of the surface of the semiconductor substrate (a laser-printed
portion), the possibility that the region other than the above part
of the surface of the semiconductor substrate (for example, a
chip-formed region) is damaged by the cleaning medium, can be
reduced. In other words, only a part of the surface of the
semiconductor substrate, such as a laser-printed portion can surely
be cleaned without damaging the chip-formed region of the
semiconductor substrate. This can prevent the particles from
remaining in the groove positioned on a part of the surface of the
semiconductor substrate (for example a laser-printed potion).
Therefore, in a semiconductor device formed on the surface of the
semiconductor substrate, a defect resulting from the cleaning step
can be prevented and the possibility of a defect resulting from the
particles can be reduced. As a result, reduction of production
yield of the semiconductor device can be prevented.
[0017] In the semiconductor substrate cleaning apparatus in
accordance with the one aspect above, the cleaning member may
include at least one selected from the group consisting of a member
supplying an ultrasonically vibrated cleaning medium and a member
supplying a pressurized cleaning medium, to the part of the surface
of the semiconductor substrate.
[0018] In this case, the cleaning capability in cleaning the part
of the surface of the semiconductor substrate can be improved.
Therefore, the possibility that the particles remain in the above
part can effectively be reduced.
[0019] In the semiconductor substrate cleaning apparatus in
accordance with the one aspect above, the cleaning member may
include a nozzle for supplying the cleaning medium to the surface
of the semiconductor substrate, and a position determining member
determining a relative position of the nozzle to the surface of the
semiconductor substrate based on coordinate data of that part on
the surface of the semiconductor substrate which is supplied with
the cleaning medium.
[0020] In this case, a position of the nozzle relative to the part
to be cleaned can accurately be determined. Therefore, the cleaning
medium can be supplied only to a part of the surface of the
semiconductor substrate at high accuracy. Accordingly, only a part
of the surface of the semiconductor substrate can surely be
cleaned.
[0021] In the semiconductor substrate cleaning apparatus in
accordance with the one aspect above, the rinsing member may
include a member supplying a rinsing medium to the surface of the
semiconductor substrate. The cleaning member may supply the
cleaning medium only to a part of the surface of the semiconductor
substrate while the rinsing medium is supplied to the surface of
the semiconductor substrate.
[0022] In this case, even if the cleaning medium scatters over the
region other than the part of the surface of the semiconductor
substrate, the cleaning medium is immediately washed away by the
rinsing medium. Therefore, the possibility of a damage caused by
the cleaning medium in the region other than the part of the
surface of the semiconductor substrate can be reduced.
[0023] A method of cleaning a semiconductor substrate in accordance
with another aspect of the present invention includes the steps of
providing a semiconductor substrate, and cleaning by supplying a
cleaning medium only to a part of a surface of the semiconductor
substrate while supplying a rinsing medium to the surface of the
semiconductor substrate with the semiconductor substrate being
fixed.
[0024] A method of cleaning a semiconductor substrate in accordance
with a further aspect of the present invention includes the steps
of providing a semiconductor substrate, cleaning by supplying a
cleaning medium only to a part of a surface of the semiconductor
substrate while fixing the semiconductor substrate, and supplying a
rinsing medium to the surface of the semiconductor substrate after
the cleaning step.
[0025] In the method of cleaning a semiconductor substrate in
accordance with the another aspect above or the further aspect
above of the present invention, the cleaning step may include at
least one selected from the group consisting of the step of
supplying an ultrasonically vibrated cleaning medium and the step
of supplying a pressurized cleaning medium, to the part of the
surface of the semiconductor substrate.
[0026] A method of cleaning a semiconductor substrate in accordance
with a still further aspect of the present invention includes the
steps of providing a semiconductor substrate, providing a medium
tank containing a cleaning medium therein for cleaning the surface
of the semiconductor substrate, and dipping only an end portion of
the semiconductor substrate into the cleaning medium held in the
medium tank.
[0027] In such a manner, only the end portion of the semiconductor
substrate can be cleaned in a simple step as described above. Since
a semiconductor substrate often has a laser-printed portion formed
on its end portion, only such a printed portion formed at the end
portion can surely be cleaned.
[0028] Furthermore, since the region other than the end portion of
the semiconductor substrate is not in contact with the cleaning
liquid, the possibility that the cleaning liquid damages the region
other than the end portion can significantly be reduced.
[0029] A method of manufacturing a semiconductor device in
accordance with other aspect of the present invention uses the
method of cleaning a semiconductor substrate in accordance with the
another aspect above or further or still further aspects of the
present invention.
[0030] Accordingly, particles can surely be removed from a part of
the surface of the semiconductor substrate such as a laser-printed
portion, so that reduction of production yield of the semiconductor
device, which results from such particles, can be prevented.
[0031] The foregoing 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
[0032] FIG. 1 is a schematic view illustrating a first embodiment
of a cleaning apparatus in accordance with the present
invention.
[0033] FIG. 2 is a block diagram illustrating a configuration of
the cleaning apparatus shown in FIG. 1.
[0034] FIG. 3 is a flow chart illustrating a method of cleaning a
semiconductor substrate using the cleaning apparatus shown in FIG.
1.
[0035] FIG. 4 is a flow chart illustrating the cleaning steps shown
in FIG. 3 in more detail.
[0036] FIG. 5 is a flow chart illustrating a modification of the
first embodiment of the method of cleaning a semiconductor
substrate in accordance with the present invention.
[0037] FIG. 6 is a schematic view illustrating a second embodiment
of the cleaning apparatus in accordance with the present
invention.
[0038] FIG. 7 is a flow chart illustrating a cleaning method using
the cleaning apparatus shown in FIG. 6.
[0039] FIG. 8 is a schematic view showing a third embodiment of the
cleaning apparatus in accordance with the present invention.
[0040] FIG. 9 is a flow chart illustrating the method of cleaning a
semiconductor substrate using the cleaning apparatus shown in FIG.
8.
[0041] FIG. 10 is a schematic view illustrating an example of a
conventional method of cleaning a semiconductor substrate.
[0042] FIG. 11 is a schematic view illustrating another example of
a conventional method of cleaning a semiconductor substrate.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] In the followings, embodiments of the present invention will
be described with reference to the figures. It is noted that the
same or corresponding parts will be denoted with the same reference
numerals in the figures and the description thereof will not be
repeated.
First Embodiment
[0044] Referring to FIGS. 1 to 4, a first embodiment of a method of
cleaning a semiconductor substrate using a cleaning apparatus in
accordance with the present invention will be described.
[0045] As can be seen from FIG. 1, in the method of cleaning a
semiconductor substrate in accordance with the present invention,
only a particular portion of a substrate 1, which is a
semiconductor substrate, that is, a part of substrate 1, for
example, a laser-printed portion 6 is cleaned. A cleaning apparatus
10 as a semiconductor substrate cleaning apparatus which performs
such a cleaning method includes a control unit 11, a substrate
operating unit 14, a chemicals nozzle operating unit 12, and pure
water nozzle operating unit 13, as shown in FIG. 2. Control unit 11
controls chemicals nozzle operating unit 12, pure water nozzle
operating unit 13 and substrate operating unit 14.
[0046] Substrate operating unit 14 controls a manipulator (not
shown) for mounting substrate 1 onto a base 2 as a holding member,
a position of base 2, and the like. Base 2 holds substrate 1 to be
fixed without rotation. Chemicals nozzle operating unit 12 controls
a position of a chemicals nozzle 3 which sprays cleaning liquid 5
as a cleaning medium only to a particular part of substrate 1, as
well as a discharge pressure, a discharge flow rate and the like of
cleaning liquid 5 in chemicals nozzle 3. It is noted that chemicals
nozzle 3 is connected to a pump and a chemicals tank (not shown)
through a hose 4. Cleaning liquid 5 is discharged from chemicals
nozzle 3 with substrate 1 fixed without rotation, as described
later. Furthermore, pure water nozzle operating unit 13 as a
rinsing member controls the rinsing conditions such as a position
of a pure water nozzle 7 which discharges pure water 9 as a rinsing
medium for washing cleaning liquid 5 away from the surface of
substrate 1, a discharge flow rate of pure water 9, and the like.
Note that pure water nozzle 7 is connected to a pump and a pure
water tank (not shown) through a hose 8.
[0047] In this way, only laser-printed portion 6 that is a part of
the surface of substrate 1 can be cleaned, since cleaning liquid 5
is supplied to substrate 1 with substrate 1 fixed without rotation.
Therefore, when particles exist within a groove representing a
character or the like formed in laser-printed portion 6, the
particles existing within the groove can be removed by using
chemicals with a high cleaning capability as cleaning liquid 5.
[0048] Furthermore, since cleaning liquid 5 is supplied only to
laser-printed portion 6 that is the part of the surface of
substrate 1, the possibility that the region other than
laser-printed portion 6 of the surface of substrate 1 (for example
a chip-formed region) is damaged by cleaning liquid 5 can be
reduced. In other words, only laser-printed portion 6 can surely be
cleaned without causing a damage in the chip-formed region or the
like of substrate 1. Therefore, in the semiconductor device formed
on the surface of the semiconductor substrate, a defect resulting
from the cleaning step can be prevented, and in addition the
possibility of a defect resulting from the particles can be
reduced. As a result, reduction of production yield of the
semiconductor device can be prevented.
[0049] Furthermore, when chemicals for cleaning are used as
cleaning liquid 5, the particles can surely be removed from
laser-printed portion 6 of substrate 1 by adjusting conditions such
as a type or a concentration of chemicals in accordance with the
type of particles to be removed from the surface of substrate
1.
[0050] Alternatively, pure water may be used as cleaning liquid 5,
as described later. When pure water is used as cleaning liquid 5, a
technique such as of spraying pure water onto substrate 1 at high
pressure can be used to remove the particles from laser-printed
portion 6 of substrate 1. Furthermore, even if pure water as this
cleaning medium scatters over the surface region other than
laser-printed portion 6 of substrate 1, a damage resulting from the
cleaning medium is scarcely caused in this region, because pure
water is used as cleaning liquid 5.
[0051] Additionally, chemicals nozzle operating unit 12 as a
cleaning member may include an ultrasonic generator for applying an
ultrasonic vibration to cleaning liquid 5 such that cleaning liquid
5 as ultrasonically vibrated can be supplied to a part of the
surface of substrate 1. Alternatively, chemicals nozzle operating
unit 12 may be configured to supply pressurized cleaning liquid 5
to substrate 1.
[0052] In this case, the cleaning capability in cleaning a part of
the surface of substrate 1 can be improved.
[0053] Furthermore, even if washing liquid 5 scatters and adheres
onto the surface region of substrate 1 other than laser-printed
portion 6 to be cleaned, that adhered cleaning liquid 5 can be
washed away by pure water 9, as pure water nozzle 7 is installed.
Therefore, the possibility that the region other than laser-printed
portion 6 of substrate 1 (for example a chip-formed region) is
damaged by the scattered cleaning liquid 5 can be reduced.
[0054] In addition, in cleaning apparatus 10, chemicals nozzle
operating unit 12 is configured such that cleaning liquid 5 can be
supplied to laser-printed portion 6 while pure water 9 is supplied
to substrate 1. Therefore, even if cleaning liquid 5 scatters over
the region other than laser-printed portion 6 of the surface of
substrate 1, that cleaning liquid 5 can immediately be washed away
by pure water 9 as a rinsing medium.
[0055] A method of cleaning a semiconductor substrate using the
cleaning apparatus shown in FIGS. 1 and 2 will now be described. It
is noted that a method of cleaning a semiconductor substrate
described below is performed as a step of a method of manufacturing
a semiconductor device.
[0056] As shown in FIG. 3, a step of providing a substrate (S110)
is first performed. In this substrate provision step (S110),
substrate 1 to be cleaned is arranged on the mounting surface of
base 2 using a manipulator or the like. Substrate 1 is fixed on
base 2 preferably by such a method as vacuum suction, electrostatic
suction or the like.
[0057] A positioning step (S120) is then performed. In this
positioning step (S120), a relative position between substrate 1,
chemicals nozzle 3 and pure water nozzle 7 is determined. Chemicals
nozzle 3 is arranged at such a position that allows cleaning liquid
5 to be sprayed onto laser-printed portion 6 that is a region to be
cleaned, of the surface of substrate 1. Furthermore, pure water
nozzle 7 is arranged at such a position that allows scattered
cleaning liquid to be washed away from the surface of substrate 1
if cleaning liquid 5 which is sprayed onto laser-printed portion 6
scatters therearound. Pure water nozzle 7 may be arranged, for
example, approximately at the center of substrate 1, to supply pure
water 9 to the entire surface of substrate 1.
[0058] A cleaning step (S130) is then performed. Specifically, this
cleaning step (S130) includes the following steps. First, as shown
in FIG. 4, a step of starting discharge of pure water from pure
water nozzle 7 (S131) is performed in order to supply pure water 9
as a rinsing medium to the surface of substrate 1 beforehand.
Thereafter, a step of cleaning a particular part by discharging
chemicals while flowing pure water (S132) is performed. More
specifically, cleaning liquid 5 of chemicals is discharged toward
laser-printed portion 6 from chemicals nozzle 3. At this point,
substrate 1 is fixed and not rotated.
[0059] As a result, laser-printed portion 6 as a particular part
can be cleaned by directly spraying cleaning liquid 5.
[0060] Since cleaning liquid 5 is supplied only to a part of the
surface of substrate 1 (laser-printed portion 6), the possibility
that the region other than laser-printed portion 6 of the surface
of substrate 1 (for example a chip-formed region) is damaged by
cleaning liquid 5 can be reduced.
[0061] Furthermore, even if cleaning liquid 5 scatters over the
region other than the part of the surface of substrate 1, that
cleaning liquid 5 is immediately washed away by pure water 9 as a
rinsing medium. Therefore, the possibility of a damage caused by
cleaning liquid 5 in the region other than laser-printed portion 6
of substrate 1 can surely be reduced.
[0062] As a result, only a part of the surface of substrate 1 such
as laser-printed portion 6 can surely be cleaned without causing a
damage in the chip-formed region or the like of substrate 1.
Accordingly, the possibility that particles or the like remain in
laser-printed portion 6 can be reduced. Therefore, reduction of
production yield of a semiconductor device, which results from such
particles, can be prevented by applying the cleaning apparatus and
method in accordance with the present invention as described above
in forming a semiconductor device such as a semiconductor memory
device on the surface of substrate 1.
[0063] It is noted that in the cleaning step (S130) chemicals
nozzle 3 may appropriately be moved to correspond to the shape of
laser-printed portion 6 or the shape of the character or sign
forming the identification label formed in the laser-printed
portion. Furthermore, such a technique may be used for cleaning
liquid 5 in that megasonic pure water (ultrasonically vibrated pure
water) in place of chemicals is sprayed to laser-printed portion 6,
ultrasonically vibrated chemicals are sprayed to laser-printed
portion 6, and chemicals or pure water at high pressure
(pressurized) is sprayed to laser-printed portion 6. Application of
such a technique can increase the cleaning capability of cleaning
liquid 5.
[0064] Additionally, the different cleaning techniques above may be
combined for cleaning. Different cleaning methods may be performed
successively, for example, by first spraying chemicals to
laser-printed portion 6, then spraying megasonic pure water, and
thereafter further spraying pressurized pure water or chemicals
(high pressure Jet).
[0065] Here, if chemicals for cleaning are used as cleaning liquid
5, particles can surely be removed from laser-printed portion 6 of
substrate 1 by adjusting conditions such as a type or concentration
of chemicals for cleaning in accordance with the type of substrate
1 to be cleaned or particles to be removed, as previously
mentioned.
[0066] On the other hand, in case pure water is used as cleaning
liquid 5, even if this pure water as cleaning liquid 5 scatters
over a surface region other than laser-printed portion 6 of
substrate 1, a damage is scarcely caused by cleaning liquid 5 on
this surface region.
[0067] Furthermore, in case pure water is used as the cleaning
medium, the cleaning step may be performed without supplying pure
water as a rinsing medium from pure water nozzle 7 to the surface
of substrate 1.
[0068] In the cleaning step (S130), such a method as shown in FIG.
5 may also be used instead of cleaning using cleaning liquid 5 of
chemicals with pure water 9 previously supplied to the surface of
substrate 1. Referring to FIG. 5, a modification to the first
embodiment of the method of cleaning a semiconductor substrate in
accordance with the present invention will be described.
[0069] As shown in FIG. 5, in the cleaning step (S130) (see FIG.
3), a step of discharging chemicals to clean a particular part
(S133) is first performed. Specifically, cleaning liquid 5 of
chemicals is discharged from chemicals nozzle 3 only to
laser-printed portion 6. Here, the entire region of laser-printed
portion 6 may surely be cleaned by moving chemicals nozzle 3 as
previously mentioned. At this point, substrate 1 is not rotated but
fixed.
[0070] A step of washing the entire surface of the substrate with
pure water (S134) is then performed after completion of cleaning.
Specifically, the surface of substrate 1 is washed with water by
supplying pure water 9 as a rinsing medium from pure water nozzle 7
to the surface of substrate 1. As a result, cleaning liquid 5
remaining on the surface of substrate 1 is washed away.
[0071] In this way also, the effect similar to the cleaning method
shown in FIGS. 1 to 4 can result.
[0072] It is noted that in the cleaning step (S133) shown in FIG.
5, such a technique may be used in that megasonic pure water is
sprayed to laser-printed portion 6 in place of chemicals,
ultrasonically vibrated chemicals are sprayed to laser-printed
portion 6, or pressurized chemicals or pure water is sprayed to
laser-printed portion 6. Additionally, the different cleaning
methods as described above may be combined for cleaning.
Second Embodiment
[0073] Referring to FIGS. 6 and 7, a second embodiment of the
cleaning apparatus and a method of cleaning a semiconductor
substrate using the cleaning apparatus in accordance with the
present invention will be described.
[0074] As shown in FIG. 6, the cleaning apparatus basically has a
configuration similar to the first embodiment of the cleaning
apparatus in accordance with the present invention, except for the
configuration in chemicals nozzle operation unit 12 (see FIG. 2).
More specifically, in the cleaning apparatus shown in FIG. 6, the
chemicals nozzle operating unit includes chemicals nozzle 3 and
nozzle movement controller 16. Nozzle movement controller 16 is
connected to chemicals nozzle 3 through arm 15. As nozzle movement
controller 16 moves, chemicals nozzle 3 can freely move within a
plane substantially parallel to the surface of substrate 1 as
represented by an arrow 17.
[0075] Furthermore, coordinate data of a region to be cleaned in
substrate 1 is transmitted through a conductive line from control
unit 11 to nozzle movement controller 16. Nozzle movement
controller 16 can move chemicals nozzle 3 based on the coordinate
data. More specifically, it can move chemicals nozzle 3 onto
laser-printed portion 6 to be cleaned (see FIG. 1) based on the
coordinate data. As a result, the position of chemicals nozzle 3
can be determined accurately. Therefore, cleaning liquid 5 such as
chemicals can be supplied only to the region to be cleaned with
high accuracy.
[0076] A method of cleaning a semiconductor substrate using the
cleaning apparatus shown in FIG. 6 will now be described. The
method of cleaning a semiconductor substrate using the cleaning
apparatus shown in FIG. 6 basically includes the step (shown in
FIG. 3) similar to the first embodiment of the method of cleaning a
semiconductor substrate in accordance with the present invention,
but differs in the positioning step (S120). Specifically, in the
method of cleaning a semiconductor substrate using the cleaning
apparatus shown in FIG. 6, a step of acquiring coordinate data of a
region to be cleaned within substrate 1 (S121), as shown in FIG. 7,
is performed in the positioning step (S120) after performing the
step of providing a substrate (S110) shown in FIG. 3. More
specifically, coordinate data of laser-printed portion 6, that is a
region to be cleaned of the surface of substrate 1, for example, is
input into control unit 11, and that data is transmitted from
control unit 11 to nozzle movement controller 16.
[0077] A step of determining a relative position between the
chemicals nozzle and the substrate based on the above coordinate
data (S122) is then performed. Specifically, chemicals nozzle 3 is
moved based on the input coordinate data by operating nozzle
movement controller 16. Chemicals nozzle 3 is then arranged on a
region to be cleaned such as laser-printed portion 6 that is
indicated by that coordinate.
[0078] Thereafter, the cleaning step (S130) is performed in a
manner similar to the cleaning method in accordance with the first
embodiment of the present invention. Thus, only a particular region
within the surface of substrate 1 can be cleaned at high
accuracy.
[0079] It is noted that in the step of determining a relative
position between the chemicals nozzle and the substrate based on
coordinate data (S122), substrate 1 may be moved rather than moving
chemicals nozzle 3. Specifically, base 2 having substrate 1 mounted
thereon is configured to be movable within a plane extending in a
direction approximately parallel to the surface of substrate 1. For
example, an XY stage movable within a plane approximately parallel
to the surface of substrate 1 may be used as base 2. Base 2 may
then be moved such that the region to be cleaned (laser-printed
portion 6) is arranged under chemicals nozzle 3, based on the
coordinate data of the region to be cleaned within the substrate.
In this example, the coordinate data of a region to be cleaned is
transmitted to a controller which controls the operation of base 2
utilizing an XY stage or the like.
Third Embodiment
[0080] Referring to FIGS. 8 and 9, a third embodiment of the
cleaning apparatus and a method of cleaning a semiconductor
substrate using the cleaning apparatus in accordance with the
present invention will be described.
[0081] As shown in FIG. 8, the third embodiment of the cleaning
apparatus in accordance with the present invention includes a
chemicals tank 18 for holding chemicals 5, and a substrate holding
portion (not shown) for holding and moving substrate 1 to dip
substrate 1 into chemicals 5.
[0082] A method of cleaning a semiconductor substrate using the
cleaning apparatus shown in FIG. 8 will now be described. A step of
providing substrate 1 to be cleaned and a step of providing
chemicals tank 18 as a medium tank containing cleaning liquid 5 of
chemicals as a cleaning medium are first performed. As shown in
FIG. 9, a step of determining the position of the substrate (S210)
is then performed. Specifically, as shown in FIG. 8, laser-printed
portion 6 that is a region to be cleaned within substrate 1 is
arranged to be lower. Substrate 1 is then arranged above chemicals
tank 18.
[0083] A step of dipping only a portion of substrate 1 into
chemicals tank 18 (S220) is then performed. Specifically, substrate
1 is moved in a direction represented by an arrow 20 in FIG. 8. At
this point, the substrate holding portion which holds substrate 1
is moved to come close to the side of chemicals tank 18. It is
noted that chemicals tank 18 may be moved upward in a direction
represented by an arrow 21 with the position of the substrate
holding portion and substrate 1 being fixed. Then, as shown in FIG.
8, only laser-printed portion 6 arranged at the end portion of
substrate 1 is dipped in chemicals 5 held in chemicals tank 18.
[0084] A step of keeping the substrate dipped in the chemicals for
a prescribed period of time (S230) is then performed. The dipping
time is determined depending on the characteristics or size of an
object of cleaning in the region to be cleaned such as
laser-printed portion 6, or the temperature or composition of
chemicals 5.
[0085] A step of pulling the substrate out of chemicals layer
(S240) is then performed. Specifically, substrate 1 is pulled out
of chemicals tank 18 in the direction represented by arrow 21 in
FIG. 8. It is noted that at this point chemicals tank 18 may be
moved in the direction represented by arrow 20 with substrate 1
being fixed.
[0086] Thereafter, rinsing or washing with water for removing
chemicals remaining on the surface of substrate 1 is performed. In
this way, only a partial region in which laser-printed portion 6 of
substrate 1 is formed can be cleaned. Furthermore, chip-formed
portion 19 is not in contact with cleaning liquid 5 and therefore
this chip-formed portion 19 is not damaged by cleaning liquid
5.
[0087] Although the present invention has been described and
illustrated in detail, it is clearly understood that the same is by
way of illustration and example only and is not to be taken by way
of limitation, the spirit and scope of the present invention being
limited only by the terms of the appended claims.
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