U.S. patent application number 16/993442 was filed with the patent office on 2021-02-18 for method and apparatus for treating substrate.
This patent application is currently assigned to SEMES CO., LTD.. The applicant listed for this patent is SEMES CO., LTD.. Invention is credited to Dongok AHN, Jungsuk GOH, Pil Kyun HEO, Byeong Geun KIM, Doyeon KIM, Choonghyun LEE, Jaeseong LEE, Yoonki SA, Yong-Jun SEO, Youngje UM, Yerim YEON, Hyun YOON.
Application Number | 20210050210 16/993442 |
Document ID | / |
Family ID | 1000005072519 |
Filed Date | 2021-02-18 |
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United States Patent
Application |
20210050210 |
Kind Code |
A1 |
SEO; Yong-Jun ; et
al. |
February 18, 2021 |
METHOD AND APPARATUS FOR TREATING SUBSTRATE
Abstract
The inventive concept provides a method for treating a
substrate. In an embodiment, the substrate treating method includes
a treatment step of treating a residue on the substrate with a
first fluid in a supercritical state and a second fluid in a
supercritical state in a process space of a chamber, and the first
fluid in the supercritical state and the second fluid in the
supercritical state have different densities.
Inventors: |
SEO; Yong-Jun; (Hwaseong-si,
KR) ; YOON; Hyun; (Hwaseong-si, KR) ; GOH;
Jungsuk; (Hwaseong-si, KR) ; KIM; Byeong Geun;
(Incheon, KR) ; SA; Yoonki; (Seoul, KR) ;
KIM; Doyeon; (Yongin-si, KR) ; YEON; Yerim;
(Hwaseong-si, KR) ; LEE; Choonghyun; (Hwaseong-si,
KR) ; HEO; Pil Kyun; (Hwaseong-si, KR) ; UM;
Youngje; (Busan, KR) ; LEE; Jaeseong;
(Hwaseong-si, KR) ; AHN; Dongok; (Anyang-si,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SEMES CO., LTD. |
Cheonan-si |
|
KR |
|
|
Assignee: |
SEMES CO., LTD.
Cheonan-si
KR
|
Family ID: |
1000005072519 |
Appl. No.: |
16/993442 |
Filed: |
August 14, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 21/02101 20130101;
H01L 21/6715 20130101 |
International
Class: |
H01L 21/02 20060101
H01L021/02; H01L 21/67 20060101 H01L021/67 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 14, 2019 |
KR |
10-2019-0099686 |
Claims
1. A method for treating a substrate, the method comprising: a
treatment step of treating a residue on the substrate with a first
fluid in a supercritical state and a second fluid in a
supercritical state in a process space of a chamber, wherein the
first fluid in the supercritical state and the second fluid in the
supercritical state have different densities.
2. The method of claim 1, wherein a supply step of supplying the
first fluid into the process space and an exhaust step of
evacuating the process space are sequentially repeated a plurality
of times in the treatment step, and wherein the second fluid is
supplied in the supply step.
3. The method of claim 1, wherein a supply step of supplying the
first fluid into the process space and an exhaust step of
evacuating the process space are sequentially repeated a plurality
of times in the treatment step, and wherein the second fluid is
supplied in the supply step and the exhaust step.
4. The method of claim 1, wherein the method further comprises a
depressurization step of reducing pressure in the process space by
evacuating the process space after the treatment step, and wherein
the second fluid is supplied into the process space during the
depressurization step.
5. The method of claim 1, wherein the method further comprises an
opening step of opening the chamber after the depressurization
step, and wherein the second fluid in a gaseous state is supplied
into the process space during the opening step.
6. The method of claim 1, wherein a supply step of supplying the
first fluid or the second fluid and an exhaust step of evacuating
the process space after the supply step are alternately performed a
plurality of times in the treatment step, and wherein the supply
step includes a first supply step of supplying only the first fluid
and a second supply step of supplying only the second fluid.
7. The method of claim 6, wherein an amount of the first fluid
supplied per unit time in the first supply step is the same as an
amount of the second fluid supplied per unit time in the second
supply step.
8. The method of claim 7, wherein the first supply step is
continuously performed N times, and the second supply step is
continuously performed M times, N being a number larger than M.
9. The method of claim 8, wherein as the number of times that the
supply step is repeated increases, N gradually decreases and M
gradually increases.
10. The method of claim 6, wherein the first supply step and the
second supply step are alternately performed, and wherein an amount
of the first fluid supplied per unit time in the first supply step
is larger than an amount of the second fluid supplied per unit time
in the second supply step.
11. The method of claim 10, wherein as the number of times that the
supply step is repeated increases, the amount of the first fluid
supplied per unit time in the first supply step decreases, and the
amount of the second fluid supplied per unit time increases.
12. The method of claim 6, wherein a total amount of the first
fluid supplied is larger than a total amount of the second fluid
supplied.
13. The method of claim 1, wherein the treatment of the substrate
is a process of removing an organic solvent on the substrate by
dissolving the organic solvent on the substrate in the first fluid
or the second fluid.
14. The method of claim 1, wherein the first fluid has a higher
density than the second fluid, and the second fluid has a higher
diffusivity than the first fluid.
15. The method of claim 1, wherein the first fluid is a fluid
configured to dissolve the residue better than the second
fluid.
16. The method of claim 1, wherein the second fluid is a fluid
configured to experience a phase change into a supercritical state
at a lower temperature and a lower pressure than the first
fluid.
17. The method of claim 1, wherein the second fluid is supplied at
a temperature and pressure above a temperature and pressure at
which the first fluid experiences a phase change into a
supercritical state.
18. The method of claim 1, wherein the first fluid is carbon
dioxide, and the second fluid is an inert gas.
19. The method of claim 1, wherein the second fluid is an argon
gas, a nitrogen gas, or a helium gas.
20. The method of claim 1, wherein the first fluid and the second
fluid are the same types of fluids having different densities.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] A claim for priority under 35 U.S.C. .sctn. 119 is made to
Korean Patent Application No. 10-2019-0099686 filed on Aug. 14,
2019, in the Korean Intellectual Property Office, the entire
contents of which are hereby incorporated by reference.
BACKGROUND
[0002] Embodiments of the inventive concept described herein relate
to a method and apparatus for treating a substrate, and more
particularly, relate to a method and apparatus for treating a
substrate using a supercritical fluid.
[0003] In general, semiconductor elements are manufactured from a
substrate such as a wafer. Specifically, the semiconductor elements
are manufactured by forming fine circuit patterns on an upper
surface of the substrate through a deposition process, a
photolithography process, an etching process, and the like.
[0004] Various types of foreign substances adhere to the upper
surface of the substrate, on which the circuit patterns are formed,
during the processes. Therefore, a cleaning process of removing the
foreign substances on the substrate is performed between the
processes.
[0005] The cleaning process generally includes a chemical
processing process of removing the foreign substances on the
substrate by dispensing a chemical onto the substrate, a rinsing
process of removing the chemical remaining on the substrate by
dispensing deionized water onto the substrate, and a drying process
of removing the deionized remaining on the substrate.
[0006] A supercritical fluid is used to dry the substrate. For
example, the deionized water on the substrate is replaced by an
organic solvent, and thereafter the supercritical fluid is supplied
to the upper surface of the substrate in a high-pressure chamber
and dissolves the organic solvent remaining on the substrate to
remove the organic solvent from the substrate. In a case where
isopropyl alcohol (hereinafter, referred to as the IPA) is used as
the organic solvent, carbon dioxide (CO.sub.2) that has a
relatively low critical temperature and pressure and in which the
IPA is dissolved well is used as the supercritical fluid.
[0007] The substrate is treated using the supercritical fluid as
follows. FIG. 1 represents the pressure P and the temperature T in
the chamber when the substrate is treated by using the
supercritical fluid. When the substrate is loaded into the
high-pressure chamber, the carbon dioxide in a supercritical state
is supplied into the high-pressure chamber to pressurize the inside
of the high-pressure chamber (S10), and thereafter the substrate is
treated with the supercritical fluid while the supply of the
supercritical fluid and evacuation of the high-pressure chamber are
repeated (S20). After the substrate is completely treated, the
pressure in the high-pressure chamber is reduced by evacuating the
inside of the high-pressure chamber.
[0008] As illustrated in FIG. 2, the solubility of the IPA in the
carbon dioxide is lowered as temperature is lowered. Accordingly,
the temperature in the chamber is lowered by adiabatic expansion
when the inside of the chamber is evacuated while the substrate is
treated by repeating the supply of the carbon dioxide and the
evacuation of the chamber. Although the temperature in the chamber
is not lower than the critical temperature of the carbon dioxide,
the solubility of the IPA in the carbon dioxide is lowered as
illustrated in FIG. 2 as the temperature in the chamber is lowered.
As the solubility is lowered, the IPA in the chamber is left in the
form of mist and falls on the substrate to cause a defect in
cleaning.
[0009] While the pressure in the high-pressure chamber is reduced
by evacuating the inside of the high-pressure chamber (S30), the
pressure in the chamber is lowered, and the temperature in the
chamber is lowered to less than 31 degrees Celsius, which is the
critical temperature of the carbon dioxide, by adiabatic expansion.
Due to this, a supercritical mixture in the chamber is condensed
and falls on the substrate after time t1 elapses.
[0010] IPA that is not dissolved in the supercritical fluid and a
carbon dioxide mixture adhere to the substrate to cause a pattern
leaning phenomenon. In a case of increasing process time to
decrease the IPA remaining on the substrate, semiconductor prices
may be raised, and yields may be lowered.
[0011] In the supercritical process using the carbon dioxide in the
supercritical state, the carbon dioxide may experience a phase
change due to a change in the pressure or temperature in the
chamber. Therefore, the solubility of the IPA in the supercritical
fluid may be changed, and the IPA that is not dissolved in the
supercritical fluid may still remain on the substrate. In
particular, as the high-temperature and high-pressure chamber is
opened immediately after the substrate is completely treated, the
supercritical fluid may experience a rapid phase change, and the
temperature in the chamber may be rapidly changed.
[0012] Furthermore, because the supercritical fluid and the IPA are
not smoothly released, the supercritical fluid infiltrating deep
into the space between the patterns or the IPA dissolved in the
supercritical fluid may remain without being released even after
the process is completed.
SUMMARY
[0013] Embodiments of the inventive concept provide a substrate
treating apparatus and method for improving efficiency in treating
a substrate using a supercritical fluid.
[0014] Embodiments of the inventive concept provide a substrate
treating apparatus and method for preventing a rapid phase change
of a supercritical fluid by using different types of supercritical
fluids when drying a substrate.
[0015] The technical problems to be solved by the inventive concept
are not limited to the aforementioned problems, and any other
technical problems not mentioned herein will be clearly understood
from the following description by those skilled in the art to which
the inventive concept pertains.
[0016] According to an exemplary embodiment, a method for treating
a substrate includes a treatment step of treating a residue on the
substrate with a first fluid in a supercritical state and a second
fluid in a supercritical state in a process space of a chamber, and
the first fluid in the supercritical state and the second fluid in
the supercritical state have different densities.
[0017] In an embodiment, a supply step of supplying the first fluid
into the process space and an exhaust step of evacuating the
process space may be sequentially repeated a plurality of times in
the treatment step, and the second fluid may be supplied in the
supply step.
[0018] In an embodiment, a supply step of supplying the first fluid
into the process space and an exhaust step of evacuating the
process space may be sequentially repeated a plurality of times in
the treatment step, and the second fluid may be supplied in the
supply step and the exhaust step.
[0019] In an embodiment, the method may further include a
depressurization step of reducing pressure in the process space by
evacuating the process space after the treatment step, and the
second fluid may be supplied into the process space during the
depressurization step.
[0020] In an embodiment, an amount of the second fluid supplied
into the process space per unit time may be smaller than amounts of
the first fluid and the second fluid discharged from the process
space per unit time.
[0021] In an embodiment, the method may further include an opening
step of opening the chamber after the depressurization step, and
the second fluid in a gaseous state may be supplied into the
process space during the opening step.
[0022] In an embodiment, a supply step of supplying the first fluid
or the second fluid and an exhaust step of evacuating the process
space after the supply step may be alternately performed a
plurality of times in the treatment step, and the supply step may
include a first supply step of supplying only the first fluid and a
second supply step of supplying only the second fluid.
[0023] In an embodiment, the first supply step may be continuously
performed N times, and the second supply step may be continuously
performed M times, N being a number larger than M.
[0024] In an embodiment, as the number of times that the supply
step is repeated increases, N may gradually decrease and M may
gradually increase.
[0025] In an embodiment, as the number of times that the supply
step is repeated increases, the amount of the first fluid supplied
per unit time in the first supply step may decrease, and the amount
of the second fluid supplied per unit time may increase.
[0026] In an embodiment, the treatment of the substrate may be a
process of removing an organic solvent on the substrate by
dissolving the organic solvent on the substrate in the first fluid
or the second fluid.
[0027] In an embodiment, the first fluid may have a higher density
than the second fluid, and the second fluid may have a higher
diffusivity than the first fluid.
[0028] In an embodiment, the first fluid may be a fluid that
dissolves the residue better than the second fluid.
[0029] In an embodiment, the second fluid may be a fluid that
experiences a phase change into a supercritical state at a lower
temperature and a lower pressure than the first fluid.
[0030] In an embodiment, the first fluid may be carbon dioxide, and
the second fluid may be an inert gas.
[0031] In an embodiment, the second fluid may be an argon gas, a
nitrogen gas, or a helium gas.
[0032] In an embodiment, the first fluid and the second fluid may
be the same types of fluids having different densities.
[0033] In an embodiment, the first fluid and the second fluid may
be carbon dioxide.
[0034] In an embodiment, a substrate having patterns formed thereon
may be disposed in the process space, the first fluid in the
supercritical state may be supplied into the process space to
dissolve the residue remaining on the substrate in the first fluid,
and the second fluid in the supercritical state may be supplied
into the process space to discharge, from the patterns, the first
fluid that remains between the patterns and in which the residue is
dissolved. The first fluid may have a higher density than the
second fluid, and the second fluid may have a higher diffusivity
than the first fluid.
[0035] In an embodiment, a supply step of supplying the first fluid
into the process space and an exhaust step of evacuating the
process space may be sequentially repeated a plurality of times,
and the evacuation may be performed in a lower direction from the
process space.
[0036] In an embodiment, the first fluid and the second fluid may
be simultaneously supplied into the process space.
[0037] In an embodiment, the first fluid and the second fluid may
be alternately supplied into the process space.
[0038] In an embodiment, the treatment of the substrate may be
performed by sequentially repeating the supply of the first fluid
into the process space and the evacuation of the process space a
plurality of times, and as the number of repetitions increases, an
amount of the first fluid supplied per unit time may decrease, and
an amount of the second fluid supplied per unit time may
increase.
[0039] In an embodiment, the treatment of the substrate may be a
process of removing an organic solvent on the substrate by
dissolving the organic solvent on the substrate in the first fluid
or the second fluid.
[0040] In an embodiment, the first fluid may have a higher density
than the second fluid, and the second fluid may have a higher
diffusivity than the first fluid.
[0041] In an embodiment, the first fluid may be a fluid that
dissolves the residue better than the second fluid.
[0042] In an embodiment, the second fluid may be a fluid that
experiences a phase change into a supercritical state at a lower
temperature and a lower pressure than the first fluid.
[0043] In an embodiment, the first fluid and the second fluid may
be the same types of fluids having different densities.
[0044] According to an exemplary embodiment, an apparatus for
treating a substrate includes a chamber having a process space
therein, a support unit that supports the substrate in the process
space, a first supply unit that supplies a first fluid in a
supercritical state into the process space, a second supply unit
that supplies a second fluid in a supercritical state into the
process space, and an exhaust unit that evacuates the process
space. The second fluid may be a fluid that experiences a phase
change into a supercritical state at a lower temperature and a
lower pressure than the first fluid.
[0045] In an embodiment, the apparatus may further include a third
supply unit that supplies the second fluid in a gaseous state into
the process space.
[0046] In an embodiment, the apparatus may further include a
controller that controls the first supply unit and the second
supply unit. The controller may control the first supply unit and
the second supply unit such that a supply step of supplying the
first fluid into the process space and an exhaust step of
evacuating the process space are sequentially repeated a plurality
of times in a treatment step of treating a residue on the substrate
with the first fluid in the supercritical state and the second
fluid in the supercritical state in the process space and the
second fluid is supplied in the supply step.
[0047] In an embodiment, the controller may control the first
supply unit and the second supply unit such that the second fluid
is supplied in the supply step and the exhaust step.
[0048] In an embodiment, the apparatus may further include a
controller that controls the first supply unit and the second
supply unit. The controller may control the first supply unit and
the second supply unit such that a depressurization step of
reducing pressure in the process space by evacuating the process
space after a treatment step is further included and the second
fluid is supplied into the process space during the
depressurization step.
[0049] In an embodiment, the apparatus may further include a
controller that controls the third supply unit. The controller may
control the first supply unit, the second supply unit, and the
third supply unit such that a treatment step of treating a residue
on the substrate with the first fluid in the supercritical state
and the second fluid in the supercritical state in the process
space, a depressurization step of evacuating the process space, and
an opening step of opening the chamber after the depressurization
step are included and the second fluid in a gaseous state is
supplied into the process space during the opening step.
[0050] In an embodiment, the treatment of the substrate may be a
process of removing an organic solvent on the substrate by
dissolving the organic solvent on the substrate in the first fluid
or the second fluid.
[0051] In an embodiment, the first fluid may have a higher density
than the second fluid, and the second fluid may have a higher
diffusivity than the first fluid.
BRIEF DESCRIPTION OF THE FIGURES
[0052] The above and other objects and features will become
apparent from the following description with reference to the
following figures, wherein like reference numerals refer to like
parts throughout the various figures unless otherwise specified,
and wherein:
[0053] FIG. 1 is a graph illustrating a general supercritical
drying process;
[0054] FIG. 2 is a view illustrating the solubility of isopropyl
alcohol in carbon dioxide depending on temperature;
[0055] FIG. 3 is a schematic plan view illustrating a substrate
treating apparatus according to an embodiment of the inventive
concept;
[0056] FIG. 4 is a schematic view illustrating one embodiment of
liquid treatment apparatuses of FIG. 3;
[0057] FIG. 5 is a schematic view illustrating one embodiment of
supercritical apparatuses of FIG. 3;
[0058] FIG. 6 is a schematic view illustrating one embodiment of a
fluid supply unit for supplying a supercritical fluid;
[0059] FIG. 7 is a flowchart illustrating a substrate treating
method according to an embodiment of the inventive concept;
[0060] FIG. 8 is a graph depicting a pressure change in a chamber
over time;
[0061] FIGS. 9 to 12 illustrate behaviors of a first fluid F1 and a
second fluid F2 between patterns formed on a substrate; and
[0062] FIGS. 13 and 14 illustrate phase diagrams of argon and
nitrogen gases, respectively.
DETAILED DESCRIPTION
[0063] Hereinafter, embodiments of the inventive concept will be
described in more detail with reference to the accompanying
drawings. The inventive concept may, however, be embodied in
different forms and should not be construed as limited to the
embodiments set forth herein. Rather, these embodiments are
provided so that the inventive concept will be thorough and
complete, and will fully convey the scope of the inventive concept
to those skilled in the art. In the drawings, the dimensions of
components are exaggerated for clarity of illustration.
[0064] FIG. 3 is a schematic plan view illustrating a substrate
treating apparatus according to an embodiment of the inventive
concept. Referring to FIG. 3, the substrate treating apparatus
includes an index module 10, a process module 20, and a controller
(not illustrated). According to an embodiment, the index module 10
and the process module 20 are disposed along one direction.
Hereinafter, the direction in which the index module 10 and the
process module 20 are disposed is referred to as a first direction
92, a direction perpendicular to the first direction 92 when viewed
from above is referred to as a second direction 94, and a direction
perpendicular to both the first direction 92 and the second
direction 94 is referred to as a third direction 96.
[0065] The index module 10 transfers substrates W from carriers 80,
in which the substrates W are received, to the process module 20
and places, in the carriers 80, the substrates W completely treated
in the process module 20. The lengthwise direction of the index
module 10 is parallel to the second direction 94. The index module
10 has load ports 12 and an index frame 14. The load ports 12 are
located on the opposite side to the process module 20 with respect
to the index frame 14. The carriers 80 having the substrates W
received therein are placed on the load ports 12. The plurality of
load ports 12 may be disposed along the second direction 94.
[0066] Airtight carriers, such as front open unified pods (FOUPs),
may be used as the carriers 80. The carriers 80 may be placed on
the load ports 12 by a transfer unit (not illustrated) such as an
overhead transfer, an overhead conveyor, or an automatic guided
vehicle, or by an operator.
[0067] An index robot 120 is provided in the index frame 14. A
guide rail 140, the lengthwise direction of which is parallel to
the second direction 94, is provided in the index frame 14 and the
index robot 120 is movable on the guide rail 140. The index robot
120 includes hands 122 on which the substrates W are placed, and
the hands 122 are movable forward and backward, rotatable about an
axis facing in the third direction 96, and movable along the third
direction 96. The hands 122 may be spaced apart from each other in
the vertical direction. The hands 122 may independently move
forward and backward.
[0068] The process module 20 includes a buffer unit 200, a transfer
apparatus 300, liquid treatment apparatuses 400, and supercritical
apparatuses 500. The buffer unit 200 provides a space in which the
substrates W to be loaded into the process module 20 and the
substrates W to be unloaded from the process module 20 temporarily
stay. Each of the liquid treatment apparatuses 400 performs a
liquid treatment process of treating the substrate W by dispensing
a liquid onto the substrate W. Each of the supercritical
apparatuses 500 performs a drying process of removing the liquid
remaining on the substrate W. The transfer apparatus 300 transfers
the substrates W between the buffer unit 200, the liquid treatment
apparatuses 400, and the supercritical apparatuses 500.
[0069] The transfer apparatus 300 may be disposed such that the
lengthwise direction thereof is parallel to the first direction 92.
The buffer unit 200 may be disposed between the index module 10 and
the transfer apparatus 300. The liquid treatment apparatuses 400
and the supercritical apparatuses 500 may be disposed on opposite
sides of the transfer apparatus 300. The liquid treatment
apparatuses 400 and the transfer apparatus 300 may be disposed
along the second direction 94. The supercritical apparatuses 500
and the transfer apparatus 300 may be disposed along the second
direction 94. The buffer unit 200 may be located at one end of the
transfer apparatus 300.
[0070] According to an embodiment, the liquid treatment apparatuses
400 may be disposed on the opposite sides of the transfer apparatus
300. The supercritical apparatuses 500 may be disposed on the
opposite sides of the transfer apparatus 300. The liquid treatment
apparatuses 400 may be disposed closer to the buffer unit 200 than
the supercritical apparatuses 500. On one side of the transfer
apparatus 300, the liquid treatment apparatuses 400 may be provided
in an A.times.B array (A and B being natural numbers of 1 or
larger) along the first direction 92 and the third direction 96.
Furthermore, on the one side of the transfer apparatus 300, the
supercritical apparatuses 500 may be provided in a C.times.D array
(C and D being natural numbers of 1 or larger) along the first
direction 92 and the third direction 96. Alternatively, only the
liquid treatment apparatuses 400 may be provided on the one side of
the transfer apparatus 300, and only the supercritical apparatuses
500 may be provided on the opposite side of the transfer apparatus
300.
[0071] The transfer apparatus 300 has a transfer robot 320. A guide
rail 340, the lengthwise direction of which is parallel to the
first direction 92, may be provided in the transfer apparatus 300,
and the transfer robot 320 is movable on the guide rail 340. The
transfer robot 320 includes hands 322 on which the substrates W are
placed. The hands 322 are movable forward and backward, rotatable
about an axis facing in the third direction 96, and movable along
the third direction 96. The hands 322 may be spaced apart from each
other in the vertical direction. The hands 322 may independently
move forward and backward.
[0072] The buffer unit 200 includes a plurality of buffers 220 in
which the substrates W are placed. The buffers 220 may be spaced
apart from each other along the third direction 96. A front face
and a rear face of the buffer unit 200 are open. The front face is
a face that faces the index module 10, and the rear face is a face
that faces the transfer apparatus 300. The index robot 120 may
approach the buffer unit 200 through the front face, and the
transfer robot 320 may approach the buffer unit 200 through the
rear face.
[0073] FIG. 4 is a schematic view illustrating one embodiment of
the liquid treatment apparatuses 400 of FIG. 3. Referring to FIG.
4, the liquid treatment apparatus 400 has a housing 410, a cup 420,
a support unit 440, a liquid dispensing unit 460, a lifting unit
480, and a controller 40. The controller 40 controls operations of
the liquid dispensing unit 460, the support unit 440, and the
lifting unit 480. The housing 410 has a substantially rectangular
parallelepiped shape. The cup 420, the support unit 440, and the
liquid dispensing unit 460 are disposed in the housing 410.
[0074] The cup 420 has a process space that is open at the top, and
the substrate W is treated with a liquid in the process space. The
support unit 440 supports the substrate W in the process space. The
liquid dispensing unit 460 dispenses the liquid onto the substrate
W supported on the support unit 440. A plurality of types of
liquids may be sequentially dispensed onto the substrate W. The
lifting unit 480 adjusts the relative height between the cup 420
and the support unit 440.
[0075] According to an embodiment, the cup 420 has a plurality of
recovery bowls 422, 424, and 426. The recovery bowls 422, 424, and
426 have recovery spaces for recovering the liquids used to treat
the substrate W. The recovery bowls 422, 424, and 426 are provided
in a ring shape that surrounds the support unit 440. The treatment
liquids scattered by rotation of the substrate W during a liquid
treatment process are introduced into the recovery spaces through
inlets 422a, 424a, and 426a of the respective recovery bowls 422,
424, and 426. According to an embodiment, the cup 420 has the first
recovery bowl 422, the second recovery bowl 424, and the third
recovery bowl 426. The first recovery bowl 422 is disposed to
surround the support unit 440, the second recovery bowl 424 is
disposed to surround the first recovery bowl 422, and the third
recovery bowl 426 is disposed to surround the second recovery bowl
424. The second inlet 424a through which a liquid is introduced
into the second recovery bowl 424 may be located in a higher
position than the first inlet 422a through which a liquid is
introduced into the first recovery bowl 422, and the third inlet
426a through which a liquid is introduced into the third recovery
bowl 426 may be located in a higher position than the second inlet
424a.
[0076] The support unit 440 has a support plate 442 and a drive
shaft 444. An upper surface of the support plate 442 may have a
substantially circular shape and may have a larger diameter than
the substrate W. Support pins 442a are provided on a central
portion of the support plate 442 to support the backside of the
substrate W. The support pins 442a protrude upward from the support
plate 442 to space the substrate W apart from the support plate 442
by a predetermined distance. Chuck pins 442b are provided on a
peripheral portion of the support plate 442.
[0077] The chuck pins 442b protrude upward from the support plate
442 and support the side of the substrate W to prevent the
substrate W from escaping from the support unit 440 when being
rotated. The drive shaft 444 is driven by an actuator 446. The
drive shaft 444 is connected to the center of a bottom surface of
the support plate 442 and rotates the support plate 442 about the
central axis thereof.
[0078] According to an embodiment, the liquid dispensing unit 460
has a first nozzle 462, a second nozzle 464, and a third nozzle
466. The first nozzle 462 dispenses a first liquid onto the
substrate W. The first liquid may be a liquid for removing a film
or foreign matter remaining on the substrate W. The second nozzle
464 dispenses a second liquid onto the substrate W. The second
liquid may be a liquid that dissolves well in a third liquid. For
example, the second liquid may be a liquid that dissolves better in
the third liquid than the first liquid. The second liquid may be a
liquid for neutralizing the first liquid dispensed onto the
substrate W. Furthermore, the second liquid may be a liquid that
neutralizes the first liquid and that dissolves better in the third
liquid than the first liquid.
[0079] According to an embodiment, the second liquid may be water.
The third nozzle 466 dispenses the third liquid onto the substrate
W. The third liquid may be a liquid that dissolves well in a
supercritical fluid that is used in the supercritical apparatuses
500. For example, the third liquid may be a liquid that dissolves
better in the supercritical fluid used in the cleaning apparatuses
500 than the second liquid. According to an embodiment, the third
liquid may be an organic solvent. The organic solvent may be
isopropyl alcohol (IPA). According to an embodiment, the
supercritical fluid may be carbon dioxide.
[0080] The first nozzle 462, the second nozzle 464, and the third
nozzle 466 may be supported on different arms 461. The arms 461 may
be independently moved. Selectively, the first nozzle 462, the
second nozzle 464, and the third nozzle 466 may be mounted on the
same arm and may be simultaneously moved.
[0081] The lifting unit 480 moves the cup 420 in the vertical
direction. The relative height between the cup 420 and the
substrate W is changed by the vertical movement of the cup 420.
Accordingly, the recovery bowls 422, 424, and 426 for recovering
the treatment liquids may be changed depending on the types of
liquids dispensed onto the substrate W, thereby separating and
recovering the liquids. Alternatively, the cup 420 may be fixed,
and the lifting unit 480 may move the support unit 440 in the
vertical direction.
[0082] FIG. 5 is a schematic view illustrating one embodiment of
the supercritical apparatuses 500 of FIG. 3. According to an
embodiment, the supercritical apparatus 500 removes a liquid on the
substrate W using a supercritical fluid. According to an
embodiment, the liquid on the substrate W is IPA. The supercritical
fluid may be supplied into the supercritical apparatus 500 to
dissolve the IPA on the substrate W and evaporate the IPA from the
substrate W, thereby drying the substrate W.
[0083] The supercritical apparatus 500 removes the liquid on the
substrate W using the supercritical fluid. According to an
embodiment, the liquid on the substrate W is isopropyl alcohol
(IPA). The supercritical apparatus 500 supplies the supercritical
fluid to the substrate W to dissolve the IPA on the substrate W in
the supercritical fluid, thereby removing the IPA from the
substrate W.
[0084] Referring to FIG. 5, the supercritical apparatus 500
includes a process chamber 520, a fluid supply unit 560, a support
apparatus 580, and an exhaust line 550.
[0085] The process chamber 520 provides a process space 502 in
which a cleaning process is performed. The process chamber 520 has
an upper housing 522 and a lower housing 524. The upper housing 522
and the lower housing 524 are combined with each other to provide
the process space 502 described above. The upper housing 522 is
provided over the lower housing 524.
[0086] The upper housing 522 may be fixed in position, and the
lower housing 524 may be raised or lowered by a drive member 590
such as a cylinder. When the lower housing 524 is spaced apart from
the upper housing 522, the process space 502 is opened. At this
time, the substrate W is loaded into or out of the process space
502.
[0087] During a process, the lower housing 524 is brought into
close contact with the upper housing 522 and seals the process
space 502 from the outside. A heater 570 is provided inside a wall
of the process chamber 520. The heater 570 heats the process space
502 of the process chamber 520 such that the fluid supplied into
the inner space of the process chamber 520 is maintained in a
supercritical state. An atmosphere by the supercritical fluid is
formed in the process space 502.
[0088] The support apparatus 580 supports the substrate W in the
process space 502 of the process chamber 520. The substrate W
loaded into the process space 502 of the process chamber 520 is
placed on the support apparatus 580. According to an embodiment,
the substrate W is supported by the support apparatus 580 such that
a patterned surface faces upward.
[0089] The fluid supply unit 560 supplies the supercritical fluid
for substrate treatment into the process space 502 of the process
chamber 520. According to an embodiment, the fluid supply unit 560
has a main supply line 562, an upper supply line 564, and a lower
supply line 566. The upper supply line 564 and the lower supply
line 566 branch off from the main supply line 562. The upper supply
line 564 may be connected to the center of the upper housing 522.
According to an embodiment, the lower supply line 566 may be
coupled to the lower housing 524. Furthermore, the exhaust line 550
is coupled to the lower housing 524. The fluid in the process space
502 of the process chamber 520 is discharged outside the process
chamber 520 through the exhaust line 550.
[0090] FIG. 6 is a view illustrating an apparatus for treating a
substrate according to an embodiment of the inventive concept.
Referring to FIG. 6, the substrate treating apparatus of the
inventive concept may include a first supply unit 610, a second
supply unit 620, a third supply unit 630, and a controller (not
illustrated). The controller controls the first supply unit 610,
the second supply unit 620, and the third supply unit 630.
[0091] The first supply unit 610 supplies a first fluid in a
supercritical state into the process space 502. The second supply
unit 620 supplies a second fluid in a supercritical state into the
process space 502. The third supply unit 630 supplies the second
fluid in a gaseous state into the process space 502.
[0092] The first supply unit 610 includes a first supply line 611,
and a first pump 612, a first front valve 614, a first rear valve
616, a first heater 618, a first filter 619, and a first adjustment
valve 617 that are provided on the first supply line 611. The first
pump 612 is provided in front of a first reservoir 615 and supplies
the first fluid to the first reservoir 615. The first front valve
614 adjusts the flow rate of the first fluid that is supplied from
the first pump 612 to the first reservoir 615. The first rear valve
616 adjusts the flow rate of the first fluid that is supplied from
the first reservoir 615 to the first heater 618. The first filter
619 is provided downstream of the first heater 618 and removes
impurities flowing in the first supply line 611. The first
adjustment valve 617 adjusts the flow rate of the first fluid that
is supplied from the first supply line 611 into the process space
502.
[0093] The second supply unit 620 includes a second supply line
621, a second pump 622, a second front valve 624, a second rear
valve 626, a second heater 628, a second filter 629, and a second
adjustment valve 627. The second pump 622 is provided in front of a
second reservoir 625 and supplies the second fluid to the second
reservoir 625. The second front valve 624 adjusts the flow rate of
the second fluid that is supplied from the second pump 622 to the
second reservoir 625. The second rear valve 626 adjusts the flow
rate of the second fluid that is supplied from the second reservoir
625 to the second heater 628. The second filter 629 is provided
downstream of the second heater 628 and removes impurities flowing
in the second supply line 621. The second adjustment valve 627
adjusts the flow rate of the second fluid that is supplied from the
second supply line 621 into the process space 502.
[0094] The third supply unit 630 includes a third supply line 631,
a third pump 632, a third front valve 634, a third rear valve 636,
a third filter 639, and a third adjustment valve 637. The third
pump 632 is provided in front of a third reservoir 635 and supplies
the second fluid to the third reservoir 635. The third front valve
634 adjusts the flow rate of the second fluid that is supplied from
the third pump 632 to the third reservoir 635. The third rear valve
636 adjusts the flow rate of the second fluid that is supplied from
the third reservoir 635. The third filter 636 is provided
downstream of the third rear valve 636 and removes impurities
flowing in the third supply line 631. The third adjustment valve
637 adjusts the flow rate of the second fluid that is supplied from
the third supply line 631 into the process space 502.
[0095] Hereinabove, it has been described that the third supply
unit 630 in FIG. 6 does not include a heater. However, in another
embodiment, the third supply unit 630 may include a heater under a
condition that the second fluid is supplied at a temperature lower
than the critical temperature at which the second fluid is changed
into a supercritical state.
[0096] In an embodiment, the first supply unit 610, the second
supply unit 620, and the third supply unit 630 may be connected to
the main supply line 562 of the fluid supply unit 560.
[0097] FIG. 7 is a flowchart illustrating a method for treating a
substrate according to the inventive concept, and FIG. 8 is a graph
depicting a pressure change in the process chamber 520 of the
inventive concept. Referring to FIGS. 7 and 8, the method for
treating the substrate may include a pressurization step S100, a
treatment step S200, a depressurization step S300, and an opening
step S400.
[0098] The pressurization step S100 is performed when the substrate
is loaded into the process space 502. In the pressurization step
S100, the first fluid in the supercritical state is supplied into
the process space 502 to pressurize the process space 502. The
pressurization is performed until the pressure in the process space
502 reaches more than the critical pressure at which the first
fluid is changed into a supercritical fluid.
[0099] In the treatment step S200, the substrate is treated by
supplying the first fluid in the supercritical state into the
process space 502. The treatment step S200 includes a supply step
S201 and an exhaust step S203. The supply step S201 and the exhaust
step S203 are sequentially repeated a plurality of times. In the
supply step S201, the first fluid is supplied into the process
space 502, and in the exhaust step S203, the process space 502 is
evacuated.
[0100] In the depressurization step S300, the process space 502 is
evacuated after the substrate is completely treated. According to
an embodiment, the depressurization is performed until the pressure
in the process space 502 reaches the atmospheric pressure or a
pressure similar thereto. After the depressurization step S300 is
completed, the opening step S400 of opening the chamber is
performed, and when the chamber is open, the substrate is unloaded
from the process space 502.
[0101] As described above, in the pressurization step S100 and the
treatment step S200, the first fluid in the supercritical state is
supplied into the process space 502. In at least one of the
treatment step S200, the depressurization step S300, or the opening
step S400, the second fluid is supplied into the process space 502.
The first fluid and the second fluid may be alternately
supplied.
[0102] The second fluid supplied into the process space 502 has a
different density from the first fluid. The first fluid may have a
higher density than the second fluid, and the second fluid may have
a higher diffusivity than the first fluid. The first fluid may
dissolve a residue better than the second fluid. For example, the
residue is IPA that is an organic solvent.
[0103] Hereinafter, it will be exemplified that the first fluid is
carbon dioxide and the second fluid is nitrogen. After the
pressurization step S100 is performed, nitrogen in a supercritical
state, together with carbon dioxide in a supercritical state, is
supplied into the process space 502 in the supply step S201.
[0104] The supply step S201 includes a first supply step S211 and a
second supply step S221. In the first supply step S211, only the
carbon dioxide is supplied into the process space 502, and the
nitrogen is not supplied. In the second supply step S221, only the
nitrogen is supplied into the process space 502, and the carbon
dioxide is not supplied. In an embodiment, the amount of the first
fluid supplied into the process space 502 per unit time in the
first supply step S211 is the same as the amount of the second
fluid supplied into the process space 502 per unit time in the
second supply step S221.
[0105] The first supply step S211 may be continuously performed N
times, and the second supply step S221 may be continuously
performed M times. N may be a number larger than M. In an
embodiment, in the supply step S201, the carbon dioxide is
continuously supplied into the process space 502 five times, and in
the following supply step S201, the nitrogen is supplied into the
process space 502 once. A process in which in the following supply
step S201, the carbon dioxide is supplied into the process space
502 five times and in the following supply step S201, the nitrogen
is supplied into the process space 502 once may be repeated.
[0106] With an increase in the number of times that the supply unit
S201 is repeated, N may gradually decrease, and M may gradually
increase. In an embodiment, in the supply step S201, the carbon
dioxide is continuously supplied into the process space 502 five
times, and in the following supply step S201, the nitrogen is
supplied into the process space 502 once. In the following supply
step S201, the carbon dioxide is supplied into the process space
502 four times, and in the following supply step S201, the nitrogen
is supplied into the process space 502 twice.
[0107] As the number of times that the supply step S201 is repeated
increases, N gradually decreases, and M gradually increases.
However, N remains larger than M such that the total amount of the
carbon dioxide supplied in the supply step S201 is larger than the
total amount of the nitrogen.
[0108] FIGS. 9 to 12 illustrate behaviors of the first fluid F1 and
the second fluid F2 between patterns formed on the substrate.
Referring to FIG. 9, when the first fluid F1 is supplied into the
process space 502, the first fluid F1 having a relatively high
density sinks between the patterns. At this time, IPA dissolved in
the first fluid F1 exists between the patterns.
[0109] The second fluid F2 is supplied into the process space 502.
Referring to FIG. 10, the second fluid F2 pushes the first fluid F1
between the patterns because the second fluid F2 has a lower
density and a higher diffusivity than the first fluid F1. At this
time, the IPA dissolved in the first fluid F1, together with the
first fluid F1, is pushed from between the patterns. Referring to
FIG. 11, only the second fluid F2 having a high diffusivity exists
between the patterns.
[0110] The first fluid F1 is supplied into the process space 502
again. Referring to FIG. 12, due to a difference in density between
the first fluid F1 and the second fluid F2, the first fluid F1
having a higher density sinks while pushing the second fluid F2
remaining between the patterns.
[0111] By repeating the process of FIGS. 9 to 12, the first fluid
and the second fluid may be briskly moved, and thus a stirring
effect of stirring the process space 502 may be obtained. The IPA
dissolved in the first fluid between the patterns may be
effectively released while the process space 501 is agitated by the
first fluid and the second fluid.
[0112] Furthermore, due to the density difference between the first
fluid and the second fluid, the second fluid may infiltrate deep
into the space between the patterns and thereafter may be pushed
from between the patterns. Accordingly, the IPA may be effectively
discharged even in a case where a pattern having a relatively large
height is formed.
[0113] The second fluid may experience a phase change into a
supercritical state at a lower temperature and a lower pressure
than the first fluid. The second fluid is supplied into the process
space 502 at a temperature and pressure above the temperature and
pressure at which the first fluid is changed into a supercritical
state. Accordingly, the second fluid in the gaseous state that is
introduced into the process space 502 exists in a supercritical
state in the process space 502.
[0114] In an embodiment, the first fluid may be carbon dioxide, and
the second fluid may be an inert gas. FIGS. 13 and 14 illustrate
phase diagrams of argon and nitrogen gases, respectively. Referring
to FIGS. 13 and 14, the argon and nitrogen gases experience a phase
change into a supercritical state at a lower temperature and a
lower pressure than the carbon dioxide. Accordingly, in a case of
supplying the argon gas or the nitrogen gas into the process space
502 at a temperature and pressure above the temperature and
pressure at which the carbon dioxide is changed into a
supercritical state and maintaining the temperature and pressure of
the process space 502 such that the carbon dioxide is changed into
a supercritical state, the fluid in the process space 502 remains
in a supercritical state.
[0115] In an embodiment, the second fluid may be an argon gas or a
nitrogen gas, or may be a helium gas that experiences a phase
change into a supercritical state at a lower temperature and a
lower pressure than carbon dioxide, similarly to the argon gas or
the nitrogen gas.
[0116] In the depressurization step S300, nitrogen in a
supercritical state may be supplied into the process space 502. The
amount of the nitrogen supplied into the process space 502 per unit
time in the depressurization step S300 may be smaller than the
amount of fluid discharged from the process space 502 per unit
time. Accordingly, in the depressurization step S300, the pressure
in the process space 502 may be lowered. In an embodiment, the
nitrogen may be continually supplied while the depressurization
step S300 is performed.
[0117] In the depressurization step S300, the temperature and
pressure of the nitrogen supplied may be lowered as time passes,
and the nitrogen may be changed into a gaseous state prior to the
opening step S400. In a case of supplying the nitrogen in a gaseous
state prior to the opening step S400, efficiency in drying the
substrate may be improved, and particles may be easily removed.
[0118] When the process space 502 is evacuated, the pressure in the
process space 502 may be rapidly lowered. Accordingly, the
temperature T1 in a conventional process chamber may be rapidly
lowered by adiabatic expansion. As the temperature in the process
space 502 is lowered, the solubility of IPA in carbon dioxide may
be decreased. In a case where the temperature in the process space
502 is lowered to 31 degrees Celsius or less, carbon dioxide in a
supercritical state may be changed into a subcritical state. The
carbon dioxide in the subcritical state may form a mixture and may
contaminate the substrate.
[0119] In the depressurization step S300 in which pressure is
lowered, different types of supercritical fluids having a
temperature and pressure above the critical temperature and
pressure of carbon dioxide may be supplied to stably maintain the
supercritical environment of the carbon dioxide and maintain the
solubility of IPA in the carbon dioxide. Accordingly, the
solubility of the IPA in the carbon dioxide may be conserved, and
when the pressure in the process space 502 is reduced, the IPA
dissolved in the carbon dioxide in the supercritical state may be
discharged outside the chamber.
[0120] In the opening step S400 after the depressurization step
S300, nitrogen in a supercritical state may be supplied into the
process space 502. In an embodiment, the nitrogen may be
continually supplied while the opening step S400 is performed. In
the opening step S400, the nitrogen may be continually supplied to
help release of IPA remaining in the process space 502.
[0121] Hereinabove, it has been described that the second fluid is
supplied in the supply step S201, in which the first supply step
S211 is continuously performed N times and the second supply step
S221 is continuously performed M times, N being a number larger
than M. Alternatively, the first fluid and the second fluid may be
alternately supplied. At this time, the amount of the first fluid
supplied per unit time may be set to be larger than the amount of
the second fluid supplied per unit time. As the supply step S201 is
repeated a plurality of times, the amount of the first fluid
supplied per unit time may gradually decrease, and the amount of
the second fluid supplied per unit time may gradually increase. The
amount of the second fluid supplied per unit time may be set so as
not to exceed the amount of the first fluid supplied per unit
time.
[0122] Although it has been described that in the treatment step
S200, the second fluid in the supercritical state is supplied in
the supply step S201, the second fluid in the supercritical state
may be supplied in the exhaust step S203. Selectively, the second
fluid in the supercritical state may be continually supplied
without a break during the treatment step S200. As time passes, the
amount of the second fluid supplied per unit time may increase, the
amount of the first fluid supplied per unit time may decrease, and
the total amount of carbon dioxide supplied in the treatment step
S200 may be larger than the total amount of nitrogen.
[0123] Although it has been described that the first fluid is
continually supplied while the depressurization step S300 is
performed, the first fluid may be intermittently supplied as in the
supply step S200.
[0124] Although it has been described that the first fluid is
continually supplied while the opening step S400 is performed, the
first fluid may be intermittently supplied as in the supply step
S200.
[0125] Although it has been described that the second fluid is
supplied in the supply step S201, the depressurization step S300,
and the opening step S400, the second fluid may be supplied in at
least one of the aforementioned steps.
[0126] Although it has been described that the first fluid and the
second fluid are of different types, the first fluid and the second
fluid may be the same types of fluids having different densities.
In an embodiment, the first fluid and the second fluid may be
carbon dioxide.
[0127] According to the embodiments of the inventive concept, the
substrate treating method and apparatus may improve efficiency in
treating a substrate using a supercritical fluid.
[0128] According to the embodiments of the inventive concept, the
substrate treating method and apparatus may prevent contamination
of a substrate by a supercritical fluid mixture condensed in a
subcritical state as the temperature in the process space is
lowered when the process space in the chamber is evacuated.
[0129] According to the embodiments of the inventive concept, the
substrate treating method and apparatus may prevent a reduction in
the solubility of an organic solvent in a supercritical fluid due
to a decrease in the temperature of the process space when
supplying the supercritical fluid into the process space of the
chamber or releasing the supercritical fluid from the process space
of the chamber.
[0130] According to the embodiments of the inventive concept, the
substrate treating method and apparatus may minimize IPA remaining
on a substrate when drying the substrate using a supercritical
fluid.
[0131] Effects of the inventive concept are not limited to the
above-described effects, and any other effects not mentioned herein
may be clearly understood from this specification and the
accompanying drawings by those skilled in the art to which the
inventive concept pertains.
[0132] The above description exemplifies the inventive concept.
Furthermore, the above-mentioned contents describe exemplary
embodiments of the inventive concept, and the inventive concept may
be used in various other combinations, changes, and environments.
That is, variations or modifications can be made to the inventive
concept without departing from the scope of the inventive concept
that is disclosed in the specification, the equivalent scope to the
written disclosures, and/or the technical or knowledge range of
those skilled in the art. The written embodiments describe the best
state for implementing the technical spirit of the inventive
concept, and various changes required in specific applications and
purposes of the inventive concept can be made. Accordingly, the
detailed description of the inventive concept is not intended to
restrict the inventive concept in the disclosed embodiment state.
In addition, it should be construed that the attached claims
include other embodiments.
[0133] While the inventive concept has been described with
reference to exemplary embodiments, it will be apparent to those
skilled in the art that various changes and modifications may be
made without departing from the spirit and scope of the inventive
concept. Therefore, it should be understood that the above
embodiments are not limiting, but illustrative.
* * * * *