U.S. patent application number 14/268394 was filed with the patent office on 2014-10-09 for apparatus and method for drying substrates.
This patent application is currently assigned to SEMES CO., LTD.. The applicant listed for this patent is SEMES CO., LTD.. Invention is credited to Jeong-Yong Bae, Sun-Kyu Hwang, Young-Ju Jeong, Bok-Kyu Lee, Soo-Bin Yong.
Application Number | 20140298669 14/268394 |
Document ID | / |
Family ID | 40032113 |
Filed Date | 2014-10-09 |
United States Patent
Application |
20140298669 |
Kind Code |
A1 |
Jeong; Young-Ju ; et
al. |
October 9, 2014 |
APPARATUS AND METHOD FOR DRYING SUBSTRATES
Abstract
A method for drying substrates using isopropyl alcohol (IPA)
includes: a pre-stage in which heated fluid is injected to a bottom
surface of a substrate to raise a temperature of the substrate
simultaneously to injection of an organic solvent to a top surface
of the substrate and injection of a dry gas to the top surface
thereof to improve a vaporization power of the organic solvent; and
a final stage in which the injection of the heated fluid is stopped
and the organic solvent and the dry gas are injected to the top
surface of the substrate.
Inventors: |
Jeong; Young-Ju;
(Chungcheongnam-do, KR) ; Lee; Bok-Kyu;
(Chungcheongnam-do, KR) ; Hwang; Sun-Kyu;
(Chungcheongnam-do, KR) ; Bae; Jeong-Yong;
(Chungcheongnam-do, KR) ; Yong; Soo-Bin;
(Chungcheongnam-do, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SEMES CO., LTD. |
Chungcheongnam-do |
|
KR |
|
|
Assignee: |
SEMES CO., LTD.
Chungcheongnam-do
KR
|
Family ID: |
40032113 |
Appl. No.: |
14/268394 |
Filed: |
May 2, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13586250 |
Nov 2, 2012 |
|
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14268394 |
|
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|
12600550 |
Nov 17, 2009 |
8793898 |
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PCT/KR08/02875 |
May 22, 2008 |
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13586250 |
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Current U.S.
Class: |
34/60 ;
34/218 |
Current CPC
Class: |
H01L 21/02057 20130101;
F26B 3/00 20130101; H01L 21/67051 20130101; F26B 21/14 20130101;
H01L 21/67034 20130101 |
Class at
Publication: |
34/60 ;
34/218 |
International
Class: |
F26B 21/14 20060101
F26B021/14 |
Foreign Application Data
Date |
Code |
Application Number |
May 23, 2007 |
KR |
10-2007-0050356 |
Mar 11, 2008 |
KR |
10-2008-0022470 |
Claims
1. An apparatus for drying substrates, comprising: a support unit
including a spin head rotating a substrate; a bowl configured to
accommodate the spin head of the support unit and provide a space
where a process is performed; an upper nozzle part configured to
supply a dry fluid to a top surface of the substrate while the spin
head rotates the substrate; a lower nozzle part installed at a top
surface of the spin head and configured to inject heated fluid to
the bottom surface of the substrate simultaneously with the upper
nozzle part supplying the dry fluid; a first fluid supply part
configured to supply the heated fluid to the lower nozzle part; and
a heater installed at the first fluid supply part and configured to
heat fluid to be supplied to the lower nozzle part.
2. The apparatus of claim 1, wherein the upper nozzle part
includes: a first nozzle configured to inject an organic solvent to
dry the top surface of the substrate; and a second nozzle
configured to inject a dry gas to improve vaporization power of the
organic solvent.
3. The apparatus of claim 1, further comprising a moving part
configured to move the upper nozzle part such that the upper nozzle
part injects fluid while moving from the center to the edge of a
top surface of the substrate.
4. The apparatus of claim 1, further comprising a lift configured
to move up or down the bowl so that a height of the bowl is
adjusted to a height of the spin head when the substrate is loaded
on the spin head.
5. The apparatus of claim 4, wherein the lift moves down the bowl
so that the spin head protrudes over the bowl when the substrate is
unloaded from the spin head.
6. The apparatus of claim 1, wherein the lower nozzle part
includes: a rinsing injection hole configured to inject a rinsing
fluid; and a drying injection hole configured to inject a drying
fluid.
7. The apparatus of claim 6, wherein the rinsing fluid is deionized
water and the drying fluid is isopropyl alcohol or nitrogen
gas.
8. The apparatus of claim 2, wherein the organic solution is
isopropyl alcohol and the dry gas is nitrogen gas.
9. The apparatus of claim 2, wherein the first nozzle is closer to
the center of the substrate than the second nozzle.
10. The apparatus of claim 2, wherein the first and second nozzles
are arranged in a moving direction of the upper nozzle part.
11. The apparatus of claim 2, wherein the first and second nozzles
are arranged tangentially to a moving direction of the upper nozzle
part.
12. The apparatus of claim 1, wherein the first fluid supply part
includes: a supply line configured to provide the heated fluid from
the heater to the lower nozzle part; and a value configured to
drain the heated fluid in the supply line for a predetermined time
before the first fluid supply part supplies the heated fluid to the
lower nozzle part.
13. The apparatus of claim 1, wherein the heater heats the fluid at
a temperature ranging from 60 to 80 degrees centigrade, and
14. The apparatus of claim 1, wherein the bowl includes a plurality
of recovery containers which recover different kinds of fluids,
respectively.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 13/586,250 filed Nov. 2, 2012, which is a divisional of
U.S. patent application Ser. No. 12/600,550 filed Nov. 17, 2009,
which claims the benefit of and priority to PCT/KR2008/002875 filed
May 22, 2008, which claims the benefit of and priority to Korean
Patent Application No. 10-2007-0050356 filed May 23, 2007, and
Korean Patent No. 10-2008-0022470 filed Mar. 11, 2008, the entire
contents of each of which are hereby incorporated in their
entirety.
TECHNICAL FIELD
[0002] The present invention relates to apparatuses and methods for
drying substrates. More specifically, the present invention relates
to an apparatus and a method for drying substrates using isopropyl
alcohol (IPA).
BACKGROUND ART
[0003] Semiconductor manufacturing processes include a wafer
fabrication process. Generally, a wafer fabrication process
includes a photoresist coating process, a developing and baking
process, an etching process, a chemical vapor deposition process,
an ashing process and so forth. In addition, a wet cleaning process
is performed using chemicals or deionized water (DI water) to
remove various contaminants attached to a surface of a substrate
during these processes.
[0004] After a cleaning process is performed, a drying process is
performed to dry chemicals or DI water remaining on the surface of
the substrate. A spin dryer and an isopropyl alcohol (IPA) dryer
are used as apparatuses for drying substrates. The spin dryer uses
a mechanodynamical rotatory force to dry semiconductor substrates,
and the IPA dryer uses a chemical reaction of IPA to dry
semiconductor substrates.
[0005] A typical spin dryer uses the rotation operation of a spin
head to dry substrates. Considering impurity particles with the
trends toward higher integration density of semiconductor devices
and larger diameter of substrates, the spin dryer cannot evade
disadvantages such as watermarks formed on a dried semiconductor
substrate.
[0006] For this reason, the IPA dryers are widely being used. As
mentioned above, the IPA dryer uses a chemical reaction of IPA to
dry substrates. That is, the IPA dryer vaporizes an IPA solution
and substitutes DI water with the vaporized IPA solution to perform
a drying process.
[0007] Unfortunately, a conventional substrate drying apparatus
suffers from problems set forth below.
[0008] When an IPA solution is vaporized, a surface temperature of
a substrate is rapidly reduced to increase time required for
performing a drying process. Thus, the consumed amount of IPA also
increases. Moreover, watermarks may be formed or particles may be
generated by lack of drying.
SUMMARY
[0009] Exemplary embodiments of the present invention are directed
to methods for drying substrates. In an exemplary embodiment, the
method may include: a pre-stage in which heated fluid is injected
to a bottom surface of a substrate to raise a temperature of the
substrate simultaneously to injection of an organic solvent to a
top surface of a rotating substrate.
[0010] In this embodiment, the method further includes: a final
stage in which the injection of the heated fluid is stopped and the
organic solvent is injected to a top surface of the substrate.
[0011] In this embodiment, during the pre-stage and the final
stage, a dry gas is injected with the organic solvent to improve a
vaporization power of the organic solvent.
[0012] In this embodiment, a substrate rotation speed in the final
stage is higher than that in the pre-stage.
[0013] In this embodiment, during the final stage, the organic
solvent is injected from the center to the edge of the substrate
only once.
[0014] In this embodiment, the pre-stage includes: a scan step in
which scan injection of the organic solvent is conducted from the
center to the edge of the substrate and from the edge to the center
thereof; and a fixing step in which the organic solvent is fixedly
injected at the center of the substrate, wherein the heated fluid
is injected to the bottom surface of the substrate only in the
fixing step.
[0015] In this embodiment, the method further include: a final
stage in which the injection of the heated fluid is stopped and an
organic solvent is injected only to the center of the top surface
of the substrate.
[0016] In this embodiment, a substrate rotation speed in the final
stage is higher than that in the pre-stage.
[0017] In this embodiment, a substrate rotation speed in the final
stage is 1400 to 1600 rpm, and a temperature of the heated fluid
injected to the bottom surface of the substrate is 60 to 80 degrees
centigrade.
[0018] In this embodiment, in the pre-stage, the heated fluid is
injected to the bottom surface of the substrate after fluid
accumulated in a pipe is drained for a determined time.
[0019] In this embodiment, the heated fluid is deionized water (DI
water), and the organic solvent is isopropyl alcohol (IPA).
[0020] In another exemplary embodiment, the method may include: a
pre-stage in which heated fluid is injected to a bottom surface of
a substrate to raise a temperature of the substrate simultaneously
to injection of an organic solvent to a top surface of the
substrate and injection of a dry gas to the top surface thereof to
improve a vaporization power of the organic solvent; and a final
stage in which the injection of the heated fluid is stopped and the
organic solvent and the dry gas are injected to the top surface of
the substrate.
[0021] In this embodiment, a substrate rotation speed in the final
stage is 600 to 800 rpm which is higher than that in the pre-stage,
and the organic solvent is injected from the center to the edge of
the substrate only once.
[0022] In another exemplary embodiment, the method may include: a
pre-stage in which after scan injection of an organic solvent is
conducted from the center to the edge of a substrate and from the
edge to the center thereof, heated fluid is injected to a bottom
surface of the substrate to raise a temperature of the substrate
simultaneously to fixedly injection of the organic solvent at the
center of the substrate; and a final stage in which the injection
of the heated fluid is stopped and the organic solvent is injected
only at the center of the top surface of the substrate.
[0023] In this embodiment, a substrate rotation speed in the final
stage is 1400 to 1600 rpm which is higher than that in the
pre-stage.
[0024] Exemplary embodiments of the present invention are directed
to an apparatus for drying substrates. In an exemplary embodiment,
the apparatus may include: a support unit including a spin head on
which a substrate is loaded; a bowl adapted to accommodate the spin
head of the support unit and provide a space where a process is
performed; an upper nozzle part configured to supply a dry fluid to
a top surface of the substrate loaded on the spin head; a lower
nozzle part installed at a top surface of the spin head and
configured to inject heated fluid to the bottom surface of the
substrate; a first fluid supply part configured to supply heated
fluid to the lower nozzle part; and a heater installed at the first
fluid supply part and configured to heat fluid to be supplied to
the lower nozzle part.
[0025] In this embodiment, the upper nozzle part includes: a first
nozzle configured to inject an organic solvent to dry a top surface
of a substrate; and a second nozzle configured to inject a dry gas
to improve a vaporization power of the organic solvent.
[0026] In this embodiment, the apparatus further includes: a moving
part configured to moving the upper nozzle part such that the upper
nozzle part injects fluid while moving from the center to the edge
of a top surface of the substrate.
[0027] In this embodiment, the heater heats deionized water (DI
water) at a temperature ranging from 60 to 80 degrees
centigrade.
[0028] According to the present invention, there are advantages and
effects set forth below.
[0029] Firstly, DI water of a regular temperature is supplied to a
bottom surface of a substrate to prevent a temperature of a
substrate surface from increasing rapidly and suppress generation
of particles resulting from watermarks or lack of drying.
[0030] Secondly, a temperature of a substrate is regularly
maintained during a drying process to reduce time required for the
drying process and the consumed amount of an IPA solution.
[0031] Thirdly, while a substrate rotates at a high speed, an IPA
solution is injected at the center of a substrate to reduce the
amount of a dry gas used. Further, a rebound phenomenon of the IPA
solution is suppressed to reduce particles.
[0032] Although the present invention has been described in
connection with the embodiment of the present invention illustrated
in the accompanying drawings, it is not limited thereto. It will be
apparent to those skilled in the art that various substitutions,
modifications and changes may be made without departing from the
scope and spirit of the invention.
DESCRIPTION OF DRAWINGS
[0033] FIG. 1 is a cross-sectional view of a substrate drying
apparatus using IPA according to an embodiment of the present
invention.
[0034] FIG. 2 shows an upper nozzle part operating in rotation
movement.
[0035] FIG. 3 shows an upper nozzle part operating in straight line
movement.
[0036] FIG. 4 is a flowchart illustrating a drying method according
to a first embodiment of the present invention.
[0037] FIG. 5 illustrates steps of the drying method according to
the first embodiment of the present invention.
[0038] FIG. 6 is a flowchart illustrating a drying method according
to a second embodiment of the present invention.
[0039] FIG. 7 illustrates steps of the drying method according to
the second embodiment of the present invention.
DETAILED DESCRIPTION
[0040] The present invention will now be described more fully
hereinafter with reference to the accompanying drawings, in which
preferred embodiments of the invention are shown. This invention,
however, may be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein. Rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. Like numbers refer to like
elements throughout.
[0041] FIG. 1 shows a substrate drying apparatus 10 using IPA
according to an embodiment of the present invention.
[0042] The substrate drying apparatus 10 includes a bowl 100, a
lift unit 200, a support unit 300, an upper nozzle part 400, and a
lower nozzle part 500.
[0043] <Bowl>
[0044] As shown in FIG. 1, the bowl 100 has an open top and is
configured to surround a spin head 310. Also the bowl 100 collects
and discharge treatment fluid dispersed over a rotating substrate.
A rinsing nozzle, fixed to the bowl 100 to inject deionized water
(DI water) to a substrate, etc. is omitted for the convenience of
drawing this figure. The bowl 100 may have a variety of shapes and
be a one-stage bowl.
[0045] In the bowl 100, annular ducts are arranged on multi-stages
to intake or suck treatment fluid dispersed on a substrate. More
specifically, a top-open space "A" is defined inside the bowl 100.
In the space "A", a substrate W is treated and the spin head 310 is
disposed. A spindle 320 is fixedly coupled with the bottom of the
spin head 310 to support and rotate the spin head 320. The spindle
320 protrudes to the exterior of the bowl 100 through an opening
formed at the bottom surface of the bowl 100. A rotation member
330, such as a motor, is coupled with the spindle 320 to provide a
rotation force. The bowl 100 is configured to separate and recover
chemicals used in a process, which makes it possible to reuse the
chemicals. The bowl 100 includes a plurality of recovery containers
110a, 110b, and 110c in which different kinds of treatment
solutions used in a process are recovered, respectively. In this
embodiment, the bowl 100 includes three recovery containers, which
are named an inner recovery container 110a, an intermediate
recovery container 110b, and an outer recovery container 110c,
respectively.
[0046] The inner recovery container 110a is provided with a ring
shape to surround the spin head 310, and the intermediate recovery
container 110b is provided with a ring shape to surround the inner
recovery container 110a. The outer recovery container 110c is
provided with a ring shape to surround the intermediate recovery
container 110b. The recovery containers 110a, 110b, and 110c have
inlets 111a, 111b, and 111c communicating with the space "A"
defined inside the bowl 110, respectively. Each of the inlets 111a,
111b, and 111c is provided at the circumference of the spin head
310 with a ring shape. The chemicals injected to the substrate W to
be used in the process flows into the recovery containers 110a,
110b, and 110c through the inlets 111a, 111b, and 111c by a
centrifugal force caused by rotation of the substrate W. The
chemicals flowing into the recovery containers 110a, 110b, and 110c
are drained to the outside through their drain lines 115a, 115b,
and 115c.
[0047] <Lift Unit>
[0048] The lift unit 200 allows the bowl 100 to straightly move up
and down. Due to the up-and-down movement of the bowl 100, a
relative height of the bowl 100 to the spin head 310 is altered.
The lift unit 200 includes a bracket 210, a movable shaft 220, and
a driver 230. The bracket 210 is fixedly installed at the outer
wall of the bowl 100. The movable shaft 220 is fixedly coupled with
the bracket 210 and raised and lowered by means of the driver 230.
When a substrate W is loaded on the spin head 310 or unloaded
therefrom, the bowl 100 is lowered to protrude the spin head 310
over the bowl 100. While a process is carried out, a height of the
bowl 100 is adjusted to enable a treatment solution supplied to a
substrate W to flow into preset recovery containers 110a, 110b, and
110c according to the kind of the treatment solution. The contrary
to the above-stated method, the lift unit 200 allows the spin head
310 to move up and down.
[0049] <Support Unit>
[0050] The support unit 300 is configured to support a substrate W
during a treatment process and includes the spin head 310, the
spindle 320, and a rotation member 330.
[0051] The spin head 310 is disposed at the inner space defined
inside the bowl 100. The spin head 310 includes a top surface 312a
on which a substrate W is loaded, support pins 314 to support the
substrate W while being spaced apart from the top surface 312a of
the spin head 310, and chucking pins 316 to chuck a portion of the
edge of the substrate W when a process is carried out.
[0052] The spindle 320 is coupled with the central bottom of the
spin head 310 and has a hollow-shaft shape to transmit a rotation
force to the spin head 310. Although not illustrated in detail, the
rotation member 330 may have a conventional structure including a
driving part such as a motor to generate a rotation force, a belt
to transmit the rotation force generated from the driver to a
spindle, and a power transmission part such as a chain.
[0053] <Lower Nozzle Part>
[0054] The lower nozzle part 500 is configured to inject heated
fluid to a bottom surface of a substrate W. The heated fluid is
heated deionized water (DI water) and may be heated nitrogen gas or
the like.
[0055] The lower nozzle part 500 includes a lower nozzle 510
installed at the center of the top surface of the spin head 310.
The lower nozzle 510 is connected to a DI water supply line to be
disposed at the center of the spin head 310. The lower nozzle 510
includes a heating injection hole 512 provided to inject the heated
DI water to a bottom surface of a substrate. The substrate is
heated by the heated DI water injected through the heating
injection hole 512. The heated DI water, injected to the center of
the bottom surface of the substrate through the lower nozzle 510,
is easily injected to the edge of the substrate due to the rotation
of the substrate to uniformly raise a temperature of the
substrate.
[0056] A first fluid supply part 520 includes a DI water supply
source 522, a heater 524, a DI water supply line 526, and a drain
line 528. The heater 524 heats the DI water stored in the DI water
supply source 522 to a temperature ranging from 60 to 80 degrees
centigrade. The DI water supply line 526 has one end connected to
the DI water supply source 522 and the other end connected to the
lower nozzle 510. The DI water supply line 526 functions as a flow
path of the heated DI water passing a hollow section of the spindle
320. The drain line 528 branches from the DI water supply line 526.
A first valve 527a functioning as an on/off valve and a suckback
valve 527b are installed at the DI water supply line 526, and a
second valve 527c functioning as an on/off valve is installed at
the drain line 528. The suckback valve 527b allows the heated DI
water remaining in a nozzle to flow backward shortly after
discharging the heated DI water. The DI water supply line 526
includes a predetermined pipe. Also the DI water supply line 526
may be defined as a pipe-type (hollow) space inside the spindle
320. The drain line 528 is adapted to achieve process
reproducibility of the heated DI water injected to the bottom
surface of the substrate. A temperature of the heated DI water
accumulated on the DI water supply line 526 decreases with the
lapse of time. For this reason, the DI water accumulated on the DI
water supply line 526 is drained through the drain line 528 by
closing the first valve 527a and opening the second valve 527c in
order not to be injected to the bottom surface of the substrate
through the lower nozzle 510. That is, the DI water accumulated on
the DI water supply line 526 is drained for a determined time
before supplying the heated DI water to the bottom surface of the
substrate. Afterwards, the DI water heated by the heater 524 is
supplied to the lower nozzle 510.
[0057] The heated DI water serves to prevent a surface temperature
of a substrate W from rapidly decreasing with condensation cooling
caused by vaporization of an isopropyl alcohol (IPA) solution when
a process of drying the substrate W is carried out. That is, while
the IPA solution and an N.sub.2 gas are injected to a surface of
the substrate W to dry the substrate W, the heated DI water is
injected to a bottom surface of the substrate W to maintain the
entire temperature of the substrate W at a temperature between 60
and 80 degrees centigrade. Although a temperature of the heated DI
water is 60 to 80 degrees centigrade, it may vary with a proceeding
state of the drying process.
[0058] Due to the heated DI water, the temperature of the substrate
W may be maintained regularly during the drying process to prevent
generation of particles caused by watermarks and lack of drying.
Moreover, the entire substrate W is regularly maintained without
rapid decrease in temperature to reduce time required for
performing a drying process using an IPA solution. Thus, the
consumed amount of the IPA solution decreases.
[0059] Although not shown in the figure, the lower nozzle 510 may
further include a rinsing injection hole provided to inject a
rinsing solution (e.g., DI water) during a rinsing process and a
drying injection hole provided to inject IPA vapor or dry gas
(e.g., nitrogen gas) during a substrate drying process.
[0060] <Upper Nozzle Part>
[0061] The upper nozzle part 400 includes a plurality of nozzles
configured to treat a substrate W loaded on the spin head 310. The
upper nozzle part 400 injects an organic solvent, a dry gas, etc.
to a top surface (to-be-treated surface) of a substrate W loaded on
the spin head 310.
[0062] While traveling from the center to the edge of a substrate W
and vice versa or at the center of the substrate W, the upper
nozzle part 400 injects an organic solvent or a dry gas to the
surface of the substrate W. The upper nozzle part 400 is connected
to a moving part 420, described later, to be movable.
[0063] The upper nozzle part 400 includes a plurality of nozzles
412 and 414 and an injection head 410 where the plurality of
nozzles 412 and 414 are installed. The injection head 410 is
connected to an arm 422 of the moving part 420. The plurality of
nozzles 412 and 414 are installed at a surface of the injection
head 410 facing the substrate W, and include a first nozzle 412 and
a second nozzle 414 injecting different fluids. Specifically, the
injection head 410 includes the first nozzle 412 configured to
inject an IPA solution and the second nozzle 414 configured to
inject N2 gas.
[0064] Isopropyl alcohol (IPA) is a chemical used to dry a
substrate W using its volatility. While passing the surface of the
substrate W, the IPA solution makes a substitution reaction with
hydrogen of the DI water remaining at the surface of the substrate
W after a cleaning process to remove moisture from the remaining DI
water. The N.sub.2 gas serves to activate vaporization
(vaporization power) of the IPA solution. That is, the N.sub.2 gas
increases a vaporization temperature of the IPA solution to enhance
a drying effect of the substrate W. Further, it is possible to
prevent a temperature of the IPA solution from decreasing with
N.sub.2 gas of a normal temperature.
[0065] The upper nozzle part 400 may further include a nozzle
configured to inject an etchant such as hydrofluoric acid (HF)
solution for etching and a nozzle configured to inject DI water for
cleaning. In another embodiment, another upper nozzle part may be
provided with a nozzle configured to inject an etchant or a nozzle
configured to inject DI water for cleaning. Although two nozzles
are provided in this embodiment, three or more nozzles may be
provided according to the kind of fluids required in a substrate
treating process.
[0066] A second fluid supply part 430 supplies various fluids for a
drying process to the injection head 410. The second fluid supply
part 430 includes an IPA supply source 432, a nitrogen gas supply
source 434, a first supply line 435 to connect the IPA supply
source 432 with the first nozzle 412, and a second supply line 436
to connect the nitrogen gas supply source 434 with the second
nozzle 414.
[0067] For example, the upper nozzle part 400 may be configured to
sequentially inject fluids for etching, cleaning, and drying to the
surface of the substrate W to sequentially remove oxide and
contaminants, clean and dry the substrate W. Accordingly, if
necessary, the top nozzle part 400 may include a plurality of
nozzles.
[0068] The moving part 420 moves the upper nozzle part 400 to
uniformly inject the fluid, injected from the upper nozzle part
400, to the edge from the center of the substrate W. The moving
part 420 includes an arm 422, a support shaft 424, and a driving
motor 426. The injection head 410 is connected to one end of the
arm 422 to support the injection head 410, and the support shaft
424 is connected to the other end of the arm 422. The support shaft
424 receives a rotation force from the driving motor 426 and moves
the injection head 410 connected to the arm 422 by means of the
received rotation force. The driving motor is connected to a
controller (not shown).
[0069] There are two methods of moving the top nozzle part 400 by
means of the moving part 420. One is a straight-line movement
method, and the other is a rotation movement method. These two
methods may be used individually or together.
[0070] As shown in FIG. 2, an upper nozzle part 400 may
rotationally move on a support shaft 424. At this point, the upper
nozzle part 400 draws an arc "a" passing the center "c" of a
substrate W, and first and second nozzles 412 and 414 are disposed
on the arc "a". In the moving direction (arrow direction) of the
upper nozzle part 400, the first nozzle 412 may be disposed ahead
of the second nozzle 414, i.e., the second nozzle 414 may be
disposed behind the first nozzle 412.
[0071] As shown in FIG. 3, an upper nozzle part 400a may straightly
move over an arm 422 of a moving part 420. At this point, the upper
nozzle part 400a is disposed on a straight line passing the center
"c" of a substrate. In the moving direction (arrow direction) of
the upper nozzle part 400a, the first nozzle 412 may be disposed
ahead of the second nozzle 414, i.e., the second nozzle 414 may be
disposed behind the first nozzle 412.
[0072] As shown in FIGS. 2 and 3, the first nozzle 412 and the
second nozzle 414 are disposed in a row in a moving direction of
the upper nozzle part 400 or relative to a tangent line of the
moving direction thereof. Thus, although any one of the foregoing
two methods is used, the second nozzle 414 injects N.sub.2 gas
while moving along the track of the first nozzle 412 during the
injection of an IPA solution from the first nozzle 412.
[0073] The effect of the above-structured substrate drying
apparatus using IPA will now be described below.
[0074] First, a substrate W is transferred to be loaded on a spin
head 310. The loaded substrate W is held by a chucking pin 316 and
a rotation member 330 rotates the spin head 310.
[0075] If the substrate W rotates, an etching process is performed
using an etchant. Generally, hydrofluoric acid (HF) solution is
used as an etchant for etching a silicon layer on a substrate
during a wet etching process. The HF solution is injected into a
process chamber to etch a silicon layer on a surface of a rotating
substrate W. An injection hole formed to inject an etchant may be
provided at an upper nozzle part 400 or another nozzle except the
upper nozzle part 400.
[0076] After the etching process is performed, etching residues on
the surface of the substrate W are removed. While a substrate W
continues to rotate, DI water is injected to clean or rinse the
substrate W. An injection hole formed to inject cleaning DI water
is provided at the upper nozzle part 400 or another nozzle except
the upper nozzle part 400.
[0077] After the cleaning process is completed, a drying process is
performed to dry a surface of a substrate W.
[0078] FIG. 4 is a flowchart illustrating a drying method according
to a first embodiment of the present invention, and FIG. 5
illustrates steps of the drying method according to the first
embodiment of the present invention.
[0079] As illustrated in FIGS. 4 and 5, a drying process may
include a pre-stage S610 and a final stage S620. A substrate
rotation speed in the pre-stage S610 is 400 to 500 rpm, which is
lower than that in the final stage S620 (600 to 800 rpm).
[0080] In the pre-stage S610, heated DI water is injected from a
lower nozzle part 500 simultaneously to injection of an IPA
solution and N.sub.2 gas from an upper nozzle part 400. The upper
nozzle part 400 injects the IPA solution and N.sub.2 gas while
taking a round scan between the center and the edge of a substrate
surface. The IPA solution is injected to dry a substrate W using
volatility of the IPA solution. While passing the surface of the
substrate W, the IPA solution makes a substitution reaction with
hydrogen of the DI water remaining at the surface of the substrate
W after a cleaning process to remove moisture from the remaining DI
water. During the drying process using the IPA solution, a second
nozzle 414 of the upper nozzle part 400 injects the N.sub.2 gas
while moving along the track of a first nozzle 412 to dry the
surface of the substrate W. The N.sub.2 gas serves to activate
vaporization of the IPA solution.
[0081] As described above, while the surface of the substrate W is
dried using the IPA solution and the N.sub.2 gas, the lower nozzle
part 500 injects heated DI water to a bottom surface of the
substrate W. A temperature of the heated DI water is 60 to 80
degrees centigrade. The supply of the heated DI water makes a
temperature distribution of the entire substrate W uniform,
preventing formation of watermarks or generation of particles
resulting from lack of drying. Moreover, the entire temperature of
the substrate W is raised to make rapid drying (improvement of
vaporization power) possible due to the IPA solution. Thus, drying
time is reduced, i.e., the consumed amount of the IPA solution
decreases.
[0082] In the final stage S620, the IPA solution and N.sub.2 gas
are injected to the top surface of the substrate W to dry the top
surface thereof while rotating the substrate W at a higher speed
than in the pre-stage S610 without injection of the heated DI
water. The final stage S620 is completed by taking one scan from
the center to the edge of the substrate W. Meanwhile, the final
stage S620 may include a step of injecting N.sub.2 gas to the
bottom of the substrate W to remove DI water which may remain at
the bottom thereof. Thus, the lower nozzle part 500 may have an
injection hole (not shown) for injecting the N.sub.2 gas to dry the
remaining DI water.
[0083] After the drying process is completed, the rotation member
330 stops operating. Thus, rotation of the spin head 310 pauses and
the substrate W is transferred or another process is performed.
[0084] FIG. 6 is a flowchart illustrating a drying method according
to a second embodiment of the present invention, and FIG. 7
illustrates steps of the drying method according to the second
embodiment of the present invention.
[0085] As illustrated in FIGS. 6 and 7, a drying process may
include a pre-stage S710 and a final stage S720. A substrate
rotation speed in the pre-stage S710 is 400 to 500 rpm, which is
lower than that in the final stage S710 (1400 to 1600 rpm).
[0086] The pre-stage S710 includes a first step S712 in which an
upper nozzle part 400 injects an IPA solution to a top surface of a
substrate while taking four to six round scan (from the center to
the edge of the substrate) and a second step S714 in which a lower
nozzle part 500 injects heated DI water simultaneously to injection
of the IPA solution to the center of the top surface of the
substrate while the upper nozzle part 400 is fixed to the center of
the substrate.
[0087] That is, the upper nozzle part 400 injects the IPA solution
while taking four to six round scan from the top surface to the
edge of the substrate (taking 10-13 seconds). Thereafter, the upper
nozzle part 400 injects IPA solution while being fixed to the
center of the top surface of the substrate (taking 9-11 seconds).
The lower nozzle part 500 injects heated DI water to the bottom of
the substrate to heat the substrate only during the injection of
the IPA solution while the upper nozzle part 400 is fixed to the
center of the top surface of the substrate.
[0088] In the final stage S720, while the substrate rotates at a
higher speed than in the pre-stage S710, the IPA solution is
injected to the top surface of the substrate to dry the top surface
thereof without injection of the heated DI water (taking 14-16
seconds). The final stage S720 is to inject the IPA solution while
the upper nozzle part 400 is fixed to the center of the substrate.
In the final stage S720, a centrifugal force caused by high-speed
rotation of the substrate is replaced with dry gas effect without
use of N.sub.2 gas. Especially because the upper nozzle part 400
injects the IPA solution while being fixed to the center of the
substrate, generation of particles resulting from a rebound
phenomenon may be suppressed.
[0089] After the drying process is completed, the rotation member
330 stops operating. Thus, rotation of the spin head 310 pauses and
the substrate W is transferred or another process is performed.
[0090] The substrate W is not limited to a wafer for use in
fabrication of semiconductor chips and may be applied to all
substrates corresponding to flat panel displays such as liquid
crystal displays (LCDs), plasma display panels (PDPs), vacuum
fluorescence displays (VFDs), field emission displays (FEDs) or
electroluminescence displays (ELDs).
[0091] According to the present invention, there are advantages and
effects set forth below.
[0092] Firstly, DI water of a regular temperature is supplied to a
bottom surface of a substrate to prevent a temperature of a
substrate surface from increasing rapidly and suppress generation
of particles resulting from watermarks or lack of drying.
[0093] Secondly, a temperature of a substrate is regularly
maintained during a drying process to reduce time required for the
drying process and the consumed amount of an IPA solution.
[0094] Thirdly, while a substrate rotates at a high speed, an IPA
solution is injected at the center of a substrate to reduce the
amount of a dry gas used. Further, a rebound phenomenon of the IPA
solution is suppressed to reduce particles.
[0095] Although the present invention has been described in
connection with the embodiment of the present invention illustrated
in the accompanying drawings, it is not limited thereto. It will be
apparent to those skilled in the art that various substitutions,
modifications and changes may be made without departing from the
scope and spirit of the invention.
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