U.S. patent application number 14/298304 was filed with the patent office on 2014-09-25 for substrate processing method and substrate processing system for performing the same.
The applicant listed for this patent is SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Sang-Won BAE, Yong-Jhin CHO, Jung-Min HO, Young-Hoo KIM, Hyo-San LEE, Jung-Won LEE, Kun-Tack LEE.
Application Number | 20140283886 14/298304 |
Document ID | / |
Family ID | 46233021 |
Filed Date | 2014-09-25 |
United States Patent
Application |
20140283886 |
Kind Code |
A1 |
CHO; Yong-Jhin ; et
al. |
September 25, 2014 |
SUBSTRATE PROCESSING METHOD AND SUBSTRATE PROCESSING SYSTEM FOR
PERFORMING THE SAME
Abstract
In a supercritical fluid method a supercritical fluid is
supplied into a process chamber. The supercritical fluid is
discharged from the process chamber as a supercritical fluid
process proceeds. A concentration of a target material included in
the supercritical fluid discharged from the process chamber is
detected during the supercritical fluid process. An end point of
the supercritical fluid process may be determined based on a
detected concentration of the target material.
Inventors: |
CHO; Yong-Jhin; (Suwon-si,
KR) ; LEE; Kun-Tack; (Suwon-si, KR) ; LEE;
Hyo-San; (Suwon-si, KR) ; KIM; Young-Hoo;
(Hwaseong-si, KR) ; LEE; Jung-Won; (Gunpo-si,
KR) ; BAE; Sang-Won; (Incheon, KR) ; HO;
Jung-Min; (Hwaseong-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG ELECTRONICS CO., LTD. |
Suwon-si |
|
KR |
|
|
Family ID: |
46233021 |
Appl. No.: |
14/298304 |
Filed: |
June 6, 2014 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
13314791 |
Dec 8, 2011 |
8795541 |
|
|
14298304 |
|
|
|
|
Current U.S.
Class: |
134/56R ;
134/107; 134/113 |
Current CPC
Class: |
H01L 21/02104 20130101;
H01L 28/90 20130101; H01L 22/00 20130101; B08B 7/0021 20130101;
H01L 21/31111 20130101; H01L 27/10852 20130101; H01L 21/67023
20130101; H01L 22/26 20130101; H01L 21/0206 20130101 |
Class at
Publication: |
134/56.R ;
134/113; 134/107 |
International
Class: |
H01L 21/67 20060101
H01L021/67 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 16, 2010 |
KR |
10-2010-0128776 |
Claims
1. A processing system comprising: a process chamber; a supply unit
configured to supply a supercritical fluid to the process chamber;
a discharge unit configured to discharge the supercritical fluid
from the process chamber; and a detection unit provided in the
discharge unit, and configured to detect a concentration of a
target material included in the supercritical fluid discharged from
the process chamber during a supercritical fluid process.
2. The processing system of claim 1, wherein the detection unit is
configured to determine an end point of the supercritical fluid
process based on a detected concentration of the target
material.
3. The processing system of claim 1, wherein the detection unit
comprises a heater for heating the supercritical fluid discharged
from the process chamber to maintain a gas phase and a detector for
detecting the concentration of a target material in the gas phase
included in the supercritical fluid discharged from the process
chamber.
4. The processing system of claim 1, wherein the detection unit
comprises a condenser for condensing the supercritical fluid
discharged from the process chamber to a liquid phase and a
detector for detecting the concentration of a target material in
the liquid phase included in the supercritical fluid discharged
from the process chamber.
5. The processing system of claim 4, wherein the detection unit
further comprises a mixer for mixing the supercritical fluid
discharged from the process chamber with a reference liquid, and
the detector detects a relative concentration of the target
material in the liquid phase with respect to the reference
liquid.
6. The processing system of claim 2, further comprising a control
unit connected to the process chamber, the supply unit, and the
discharge unit, to determine the end point of the supercritical
fluid process and control operations of the processing system.
7. The processing system of claim 1, further comprising a valve to
control a flow rate of the supercritical fluid to the detection
unit.
8. The processing system of claim 1, further comprising a chamber
detector to detect a concentration of the target material in the
process chamber.
9. The processing system of claim 1, wherein the discharge unit
further comprises at least two discharge pipes, wherein at least
one of the two discharge pipes is connected to the detection unit.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of co-pending
U.S. application Ser. No. 13/314,791 filed Dec. 8, 2011, which
claims priority under 35 U.S.C. .sctn.119 to Korean Patent
Application No. 10-2010-0128776, filed on Dec. 16, 2010 in the
Korean Intellectual Property Office (KIPO), the disclosures of
which are each hereby incorporated by reference in their
entireties.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates to a substrate processing
method and a substrate processing system for performing the same,
and more particularly to a method of processing a substrate using a
supercritical fluid and a substrate processing system for
performing the same.
[0004] 2. Description of Related Art
[0005] In the field of integrated semiconductor device manufacture,
a supercritical fluid may be used to physically and chemically
process fine semiconductor patterns.
[0006] A supercritical fluid is any substance at a temperature and
pressure above its critical point, where distinct liquid and gas
phases do not exist. The supercritical fluid may have unique
properties as compared to a gas and a liquid, including low surface
tension, low viscosity, high solvency, and high diffusion
coefficient with applications in the field of integrated
semiconductor device manufacture.
SUMMARY
[0007] According to an exemplary embodiment of the present
disclosure, in a supercritical fluid method a supercritical fluid
is supplied into a process chamber. The supercritical fluid is
discharged from the process chamber as a supercritical fluid
process proceeds. A concentration of a target material included in
the supercritical fluid discharged from the process chamber is
detected during the supercritical fluid process.
[0008] In an exemplary embodiment, an end point of the
supercritical fluid process is determined based on a detected
concentration of the target material.
[0009] In an exemplary embodiment, detecting the concentration of
the target material may include heating the supercritical fluid
discharged from the process chamber to maintain the supercritical
fluid in a gas phase and detecting the concentration of the target
material in the gas phase included in the supercritical fluid
discharged from the process chamber.
[0010] In an exemplary embodiment, detecting the concentration of
the target material may include condensing the supercritical fluid
discharged from the process chamber to liquid phase and detecting
the concentration of the target material in the liquid phase
included in the supercritical fluid discharged from the process
chamber.
[0011] In an exemplary embodiment, detecting the concentration of
the target material in the liquid phase may include mixing the
target material in the liquid phase with a reference liquid and
detecting a relative concentration of the target material in the
liquid phase with respect to the reference liquid.
[0012] In an exemplary embodiment, the method may further include
controlling a system including the process chamber to complete the
supercritical fluid process after determining the end point of the
supercritical fluid process.
[0013] In an exemplary embodiment, the method may further include
loading a substrate into the process chamber.
[0014] In an exemplary embodiment, the method may further include
controlling a flow rate of the supercritical fluid to a detection
unit detecting the concentration of the target material.
[0015] In an exemplary embodiment, the method may further include
detecting a concentration of the target material in the process
chamber during the supercritical fluid process.
[0016] According to an exemplary embodiment of the present
disclosure, a processing system includes a process chamber, a
supply unit configured to supply a supercritical fluid to the
process chamber, a discharge unit configured to discharge the
supercritical fluid from the process chamber, and a detection unit
provided in the discharge unit, and configured to detect a
concentration of a target material included in the supercritical
fluid discharged from the process chamber during a supercritical
fluid process.
[0017] In an exemplary embodiment, the detection unit is configured
to determine an end point of the supercritical fluid process based
on a detected concentration of the target material.
[0018] In an exemplary embodiment, the detection unit may include a
heater for heating the supercritical fluid discharged from the
process chamber to maintain in a gas phase and a detector for
detecting the concentration of the target material in the gas phase
included in the supercritical fluid discharged from the process
chamber.
[0019] In an exemplary embodiment, the detection unit may include a
condenser for condensing the supercritical fluid discharged from
the process chamber to a liquid phase and a detector for detecting
the concentration of the target material in the liquid phase
included in the supercritical fluid discharged from the process
chamber.
[0020] In an exemplary embodiment, the detection unit may further
include a mixer for mixing the supercritical fluid discharged from
the process chamber with a reference liquid, and the detector may
detect a relative concentration of the target material in the
liquid phase with respect to the reference liquid.
[0021] In an exemplary embodiment, the processing system may
further include a control unit connected to the process chamber,
the supply unit and the discharge unit, to determine the end point
of the supercritical fluid process and control operations of the
processing system.
[0022] In an exemplary embodiment, the processing system may
further include a valve to control a flow rate of the supercritical
fluid to the detection unit.
[0023] In an exemplary embodiment, the processing system may
further include a chamber detector to detect a concentration of the
target material in the process chamber.
[0024] In an exemplary embodiment, wherein the discharge unit
further comprises at least two discharge pipes, wherein at least
one of the two discharge pipes is connected to the detection
unit.
[0025] Accordingly, a concentration of a target material in the
discharged fluid may be detected and analyzed to check the progress
of the process and determine the end point of the supercritical
fluid process. After determining the end point of the supercritical
fluid process, a system including the process chamber may be
controlled to complete the supercritical fluid process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Embodiments of the present disclosure will be more clearly
understood from the following detailed description taken in
conjunction with the accompanying drawings. FIGS. 1 to 13 represent
non-limiting, exemplary embodiments as described herein.
[0027] FIG. 1 is a flowchart illustrating a substrate processing
method in accordance with exemplary embodiments of the present
disclosure.
[0028] FIG. 2 is a block diagram illustrating a substrate
processing system in accordance with an exemplary embodiment of the
present disclosure.
[0029] FIGS. 3A and 3B are graphs illustrating concentration
changes of a target material versus a process time detected by the
detection unit in FIG. 2.
[0030] FIG. 4 is a block diagram illustrating a substrate
processing system in accordance with an exemplary embodiment of the
present disclosure.
[0031] FIG. 5 is a graph illustrating concentration changes of a
target material versus a process time detected by the detection
unit in FIG. 4.
[0032] FIG. 6 is a block diagram illustrating a substrate
processing system in accordance with an exemplary embodiment of the
present disclosure.
[0033] FIG. 7 is a block diagram illustrating a substrate
processing system in accordance with an exemplary embodiment of the
present disclosure.
[0034] FIGS. 8 to 13 are cross-sectional views illustrating a
method of manufacturing a semiconductor device using a substrate
process method in accordance with an exemplary embodiment of the
present disclosure.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0035] Various exemplary embodiments will be described more fully
hereinafter with reference to the accompanying drawings, in which
exemplary embodiments are shown. Embodiments of the present
disclosure may, however, be embodied in many different forms and
should not be construed as limited to exemplary embodiments set
forth herein. Rather, exemplary embodiments are provided so that
this disclosure will be thorough and complete, and will fully
convey the scope of exemplary embodiments to those skilled in the
art. In the drawings, the sizes and relative sizes of layers and
regions may be exaggerated for clarity.
[0036] It will be understood that when an element or layer is
referred to as being "on," "connected to" or "coupled to" another
element or layer, it can be directly on, connected or coupled to
the other element or layer or intervening elements or layers may be
present. In contrast, when an element is referred to as being
"directly on," "directly connected to" or "directly coupled to"
another element or layer, there are no intervening elements or
layers present. Like numerals refer to like elements throughout. As
used herein, the term "and/or" includes any and all combinations of
one or more of the associated listed items.
[0037] It will be understood that, although the terms first,
second, third, etc. may be used herein to describe various
elements, components, regions, layers and/or sections, these
elements, components, regions, layers and/or sections should not be
limited by these terms. These terms are only used to distinguish
one element, component, region, layer or section from another
region, layer or section. Thus, a first element, component, region,
layer or section discussed below could be termed a second element,
component, region, layer or section without departing from the
teachings of exemplary embodiments.
[0038] Spatially relative terms, such as "beneath," "below,"
"lower," "above," "upper" and the like, may be used herein for ease
of description to describe one element or feature's relationship to
another element(s) or feature(s) as illustrated in the figures. It
will be understood that the spatially relative terms are intended
to encompass different orientations of the device in use or
operation in addition to the orientation depicted in the figures.
For example, if the device in the figures is turned over, elements
described as "below" or "beneath" other elements or features would
then be oriented "above" the other elements or features. Thus, the
exemplary term "below" can encompass both an orientation of above
and below. The device may be otherwise oriented (rotated 90 degrees
or at other orientations) and the spatially relative descriptors
used herein interpreted accordingly.
[0039] The terminology used herein is for the purpose of describing
particular exemplary embodiments only and is not intended to be
limiting of exemplary embodiments. As used herein, the singular
forms "a," "an" and "the" are intended to include the plural forms
as well, unless the context clearly indicates otherwise. It will be
further understood that the terms "comprises" and/or "comprising,"
when used in this specification, specify the presence of stated
features, integers, steps, operations, elements, and/or components,
but do not preclude the presence or addition of one or more other
features, integers, steps, operations, elements, components, and/or
groups thereof.
[0040] Exemplary embodiments are described herein with reference to
cross-sectional illustrations that are schematic illustrations of
idealized exemplary embodiments (and intermediate structures). As
such, variations from the shapes of the illustrations as a result,
for example, of manufacturing techniques and/or tolerances, are to
be expected. Thus, exemplary embodiments should not be construed as
limited to the particular shapes of regions illustrated herein but
are to include deviations in shapes that result, for example, from
manufacturing. For example, an implanted region illustrated as a
rectangle will, typically, have rounded or curved features and/or a
gradient of implant concentration at its edges rather than a binary
change from implanted to non-implanted region. Likewise, a buried
region formed by implantation may result in some implantation in
the region between the buried region and the surface through which
the implantation takes place. Thus, the regions illustrated in the
figures are schematic in nature and their shapes are not intended
to illustrate the actual shape of a region of a device and are not
intended to limit the scope of exemplary embodiments.
[0041] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which exemplary
embodiments belong. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and will not be
interpreted in an idealized or overly formal sense unless expressly
so defined herein.
[0042] Hereinafter, exemplary embodiments will be explained in
detail with reference to the accompanying drawings.
[0043] FIG. 1 is a flowchart illustrating a substrate processing
method in accordance with exemplary embodiments of the present
disclosure.
[0044] Referring to FIG. 1, a substrate may be loaded into a
process chamber (S100). The process chamber may provide a space for
performing a supercritical fluid process on the substrate.
[0045] In exemplary embodiments, the process chamber may include a
temperature and pressure control device for controlling a
temperature and a pressure inside the process chamber to provide a
supercritical condition for a supercritical fluid process.
Accordingly, the substrate may be loaded into the process chamber
such that a supercritical fluid process is performed on a material
layer formed on the substrate.
[0046] It should be noted that the present disclosure is not
limited to methods wherein a substrate is loaded into the process
chamber. For example, a supercritical fluid process may be
performed to clean a process chamber without a substrate being
disposed therein.
[0047] A supercritical fluid may be supplied to the process chamber
to perform a supercritical fluid process (S110), and the
supercritical fluid may be subsequently discharged from the process
chamber (S120).
[0048] A supercritical fluid is any substance at a temperature and
pressure above its critical point, where distinct liquid and gas
phases do not exist. A supercritical fluid may have unique
properties as compared to a gas and a liquid including low surface
tension, low viscosity, high solvency and high diffusion
coefficient. According to an exemplary embodiment of the present
disclosure, a supercritical fluid process may be applied to
manufactures of semiconductor devices using a supercritical
fluid.
[0049] Table. 1 shows the critical properties for some substances,
which may be used as supercritical fluids.
TABLE-US-00001 TABLE 1 Critical properties of various solvents.
critical boiling freezing temper- critical chemical point point
ature pressure Density solvent formula (.degree. C.) (.degree. C.)
(.degree. C.) (atm) (g/cm.sup.3) ammonia NH.sub.3 -33.4 -77.7 132
111.3 0.24 carbon CO.sub.2 -56.6 -78.5 31 72.8 0.47 dioxide ethane
C.sub.2H.sub.6 -88.6 -183.3 32 48.2 0.20 propane C.sub.3H.sub.8
-42.1 -189.7 97 41.9 0.22 sulfur SF.sub.6 -50.5 -63.8 45 37.1 0.74
hexafluo- ride water H.sub.2O 100.0 0.0 374 217.7 0.32
[0050] In an exemplary embodiment, the supercritical fluid process
may be a drying process for drying the substrate using a
supercritical fluid. For example, after a material layer on a
substrate is etched using an etching mask and is cleaned using a
cleaning solution, the substrate may be dried using a supercritical
fluid. In one example the material layer may include a silicon
oxide such as BPSG (boro-phospho silicate glass), TEOS (tetraethyl
orthosilicate). The cleaning solution may include DI water or
alcohol such as IPA (iso propyl alcohol). The supercritical fluid
may include supercritical carbon dioxide. Different material layers
may be used and the present disclosure is not limited to those
described herein. The cleaning solution may be selected based on
the material layer.
[0051] In an exemplary embodiment, supercritical carbon dioxide may
be supplied onto the substrate to perform a supercritical drying
process for drying the substrate. As the drying process proceeds,
the supercritical fluid may be used and discharged from the process
chamber. The discharged fluid may include IPA as a target material
(e.g., a material used in a current process), and the discharged
fluid may be discharged with the supercritical fluid from the
process chamber.
[0052] In another exemplary embodiment, the supercritical fluid
process may be a cleaning process that cleans the substrate using a
supercritical fluid. For example, after a material layer on a
substrate is etched using an etching mask, the substrate may be
cleaned using a supercritical fluid including a cleaning solution.
In one example, supercritical carbon dioxide with surfactant
dissolved therein may be supplied onto the substrate to perform a
supercritical cleaning process for cleaning the substrate. As the
cleaning process proceeds, the supercritical fluid may be used and
discharged from the process chamber. The discharged fluid may
include a target material (e.g., a cleaning solution and a material
removed by the etching process), and the target material may be
discharged with the supercritical fluid from the process
chamber.
[0053] In still another exemplary embodiment, the supercritical
fluid process may be an etching process that etches a material
layer on the substrate using a supercritical fluid. For example,
supercritical carbon dioxide with fluoride, such as hydrogen
fluoride (HF), included therein may be supplied onto the substrate
to perform a supercritical etching process for etching the material
layer on the substrate. As the etching process proceeds, the
supercritical fluid may be used and discharged from the process
chamber. The discharged fluid may include a target material (e.g.,
an etchant), and the target material may be discharged with the
supercritical fluid from the process chamber.
[0054] A real-time concentration of a target material included in
the fluid discharged from the process chamber may be detected
(S130), and an end point (EP) of the supercritical fluid process
may be determined based on a detected concentration of the target
material (S140).
[0055] In exemplary embodiments, the fluid discharged from the
process chamber may include a target material indicative of the
progress of the supercritical fluid process. Accordingly, a
real-time concentration of the target material included in the
fluid discharged from the process chamber may be detected to
determine an end point of the supercritical fluid process based on
the detected concentration.
[0056] For example, the discharged fluid may be heated to be in a
gas phase and a concentration of the target material of a gas phase
(target gas) included in the discharged fluid may be detected.
[0057] Alternatively, the discharged fluid may be condensed to be
in a liquid phase and a concentration of the target material of a
liquid phase (target liquid) included in the discharged fluid may
be detected. In this case, the target liquid may be mixed with a
reference liquid and a relative concentration of the target liquid
with respect to the reference liquid may be detected.
[0058] In exemplary embodiments, a concentration of a target
material in the discharged fluid may be detected and analyzed in
real time, to check the progress of the process and determine the
end point of the supercritical fluid process. After determining the
end point of the supercritical fluid process, a system including
the process chamber may be controlled to complete the supercritical
fluid process, to thereby improve reliability of the process.
[0059] Hereinafter, a substrate processing system for performing a
substrate processing method of FIG. 1 will be explained in
detail.
[0060] FIG. 2 is a block diagram illustrating a substrate
processing system 10 in accordance with an exemplary embodiment of
the present disclosure.
[0061] Referring to FIG. 2, a substrate processing system 10
according to a first exemplary embodiment includes a supply unit
20, a process chamber 30, a discharge unit 40, a detection unit 50
and a control unit 60.
[0062] The process chamber 30 may provide a space for processing a
substrate. The process chamber 30 may include a temperature and
pressure control device for controlling a temperature and a
pressure inside the process chamber 30 to provide a supercritical
condition for a supercritical fluid process. A substrate including
a material layer formed thereon may be loaded into the process
chamber 30. The supply unit 20 and the discharge unit 40 may be
connected to the process chamber 30 by a plurality of pipes 24, 32,
38.
[0063] The supply unit 20 may supply a supercritical fluid source
to the process chamber 30. A supercritical fluid may be supplied
onto the substrate in the process chamber 30 to perform a
supercritical fluid process. The supercritical fluid may be
discharged from the process chamber 30 to the discharge unit
40.
[0064] The supply unit 20 may include at least one container 22 for
storing a solvent. The supply unit 20 may include one or more
additional containers (not illustrated) for storing a co-solvent
such as an etching material or a cleaning material corresponding to
a desired process. The etching material may include, for example,
fluoride such as hydrogen fluoride (HF), and the cleaning material
may include DI (de-ionized) water, surfactant, alcohol, etc.
[0065] The supply unit 20 may include a pressure pump 28 configured
to pressurize a solvent from the container 22 and to supply the
supercritical fluid source to the process chamber 30. The
supercritical fluid may be supplied in a supercritical state from
the supply unit 20 into the process chamber 30 through a plurality
of temperature control jackets 34a and 34b and may be transferred
from the process chamber 30 to the discharge unit 40 through a
another temperature control jacket 34c. A plurality of valves 26,
36, and 46 may be provided to control the flow rate of the fluid
through the pipes.
[0066] The detection unit 50 may be provided in the discharge unit
40 to detect a concentration of a target material included in the
fluid discharged from the process chamber 30. The detection may be
performed in real time during a process in the process chamber.
[0067] In an exemplary embodiment of the present disclosure, the
discharge unit 40 may include a main discharge pipe 42 and an
auxiliary discharge pipe 44. A portion of the fluid may be
discharged from the process chamber 30 through the main discharge
pipe 42 and another portion of fluid may be discharged from the
process chamber 30 through the auxiliary discharge pipe 44.
[0068] The detection unit 50 may be disposed at the auxiliary
discharge pipe 44 to detect a real-time concentration of a target
material included in the discharged fluid. A discharge valve 46 may
be provided at the auxiliary discharge pipe 44 to control the flow
rate of the fluid to the detection unit 50.
[0069] The discharge unit 40 may include a separator (not
illustrated) that separates specific chemicals from the solvent of
the discharged fluid. The fluid may be circulated from the
separator to the system through a circulation pipe (not
illustrated).
[0070] The detection unit 50 may include a heater 52 for heating
the discharged fluid to maintain a gas phase thereof and a detector
54 for detecting a concentration of a target material of the gas
phase (target gas) included in the discharged fluid. Accordingly,
the detection unit 50 may detect a real-time concentration of a
target gas included in the discharged fluid.
[0071] The detector 54 may have various analyzers corresponding to
a target material. Examples of the detector 54 may include an RGA
(residual gas analyzer), an HF detector, an IPA detector, a
hygrometer, etc.
[0072] The control unit 60 may be connected to the process chamber
30, the supply unit 20, and the discharge unit 40, to determine an
end point of the supercritical fluid process and control operations
of the system.
[0073] FIGS. 3A and 3B are graphs illustrating exemplary
concentration changes of a target material versus a process time
detected by the detection unit in FIG. 2.
[0074] Referring to FIG. 3A, a concentration of the target material
detected by the detection unit in FIG. 2 may decrease with time.
For example, as the process proceeds, a discharged reactant (target
material) may decrease. Accordingly, a time when a normalized
concentration of the target material decreases to a predetermined
concentration (for example, 0.05%) may be determined as an end
point (EP) of the process.
[0075] Referring to FIG. 3B, a concentration of the target material
detected by the detection unit in FIG. 2 may increase with time.
For example, as the process proceeds, a discharged supercritical
fluid (e.g., gas supplied to the process chamber) as a target
material may increase while a discharged reactant decreases.
Accordingly, a time when a normalized concentration of the target
material increases to a predetermined concentration (for example,
0.95%) may be determined as an end point of the process.
[0076] Thus, a concentration of a target material in the discharged
fluid may be detected and analyzed in real time, to check the
progress of the process and determine the end point of the
supercritical fluid process. After determining the end point of the
supercritical fluid process, the system including the process
chamber may be controlled to complete the supercritical fluid
process.
[0077] FIG. 4 is a block diagram illustrating a substrate
processing system 11 in accordance with an exemplary embodiment of
the present disclosure. FIG. 4 is substantially the same as FIG. 2
with the exception of the detection unit. Thus, the same reference
numerals will be used to refer to the same or like elements as
those described with reference to FIG. 2 and any further
explanation thereof will be omitted.
[0078] Referring to FIG. 4, a detection unit 50 of a substrate
processing system 11 according to an exemplary embodiment of the
present disclosure may include a condenser 51 for condensing the
discharged fluid to a liquid phase and a detector 54 for detecting
a concentration of a target material (target liquid) included in
the discharged fluid in the liquid phase.
[0079] The condenser 51 may be disposed at the auxiliary discharge
pipe 44 to condense the fluid discharged from the process chamber
30 to a liquid phase. The fluid of a liquid phase may be circulated
from the condenser 51 to the supply unit 20 of the system through a
circulation pipe 48.
[0080] In an exemplary embodiment, the detection unit 50 may
further include a mixer 57 for mixing a reference liquid with the
target liquid discharged from the condenser 51. The mixer 57 may be
provided between the condenser 51 and a detector 54.
[0081] A reference liquid supply unit 56 may supply the reference
liquid to the mixer 57. A first flowmeter 53 may be disposed
between the condenser 51 and the mixer 57 to detect a flow rate of
the target liquid. A second flowmeter 55 may be disposed between
the reference liquid supply unit 56 and the mixer 57 to detect a
flow rate of the reference liquid. For example, as a supercritical
fluid process proceeds, a flow rate of the reference fluid may be
kept constant while a flow rate of the target liquid may decrease.
Accordingly, the detector 54 may detect a relative concentration of
the target liquid with respect to the reference liquid.
[0082] FIG. 5 is a graph illustrating concentration changes of a
target material detected by the detection unit in FIG. 4 versus a
process time.
[0083] Referring to FIG. 5, a relative concentration of the target
material detected by the detection unit in FIG. 4 may decrease over
time. Accordingly, a time when a relative concentration of the
target material decreases to a predetermined concentration (for
example, 0.05%) may be determined as an end point (EP) of the
process.
[0084] Thus, even though a concentration of a target material in a
discharged fluid is too small to detect, a relative concentration
of a target liquid with respect to a reference liquid may be
detected, to check the progress of the process and determine the
end point of the supercritical fluid process.
[0085] Referring to FIG. 3B, a concentration of the target material
detected by the detection unit in FIG. 2 may increase with time.
For example, as the process proceeds, a discharged supercritical
fluid (e.g., a gas supplied to the process chamber) as a target
material may increase while a discharged reactant decreases.
Accordingly, a time when a normalized concentration of the target
material increases to a predetermined concentration (for example,
0.95%) may be determined as an end point of the process.
[0086] Thus, a concentration of a target material in the discharged
fluid may be detected and analyzed in real time, to check the
progress of the process and determine the end point of the
supercritical fluid process.
[0087] FIG. 6 is a block diagram illustrating a substrate
processing system 12 in accordance with an exemplary embodiment of
the present disclosure. FIG. 6 is substantially the same as FIG. 4,
with the exception of the detection unit. Thus, the same reference
numerals will be used to refer to the same or like elements as
those described with reference to FIG. 4 and any further
explanation thereof will be omitted.
[0088] Referring to FIG. 6, a detection unit 50 of a substrate
processing system 12 according to an exemplary embodiment may
include a condenser 51 for condensing the discharged fluid to a
liquid phase and a photodetector 58 for detecting a concentration
of a target material (target liquid) included in the discharged
fluid in a liquid phase.
[0089] The condenser 51 may be disposed at the auxiliary discharge
pipe 44 to condense the fluid discharged from the process chamber
30 to a liquid phase. The fluid of a liquid phase may be circulated
from the condenser 51 to the supply unit 20 of the system through a
circulation pipe 48.
[0090] In an exemplary embodiment, the photodetector 58 may detect
a concentration of a target liquid discharged from the condenser
51. The photodetector may include a light source 59a and a light
receiving sensor 59b.
[0091] In particular, the light source 59a may emit a light, which
may pass through the target liquid discharged from the condenser
51, and then may be incident on the light receiving sensor 59b. The
intensity of the light incident on the light receiving sensor 59b
may vary according to the progress of the process. For example, as
the process proceeds, a concentration of the target material in the
discharged fluid may decrease and thus the intensity of the light
incident on the light receiving sensor 59b may increase.
Accordingly, a time when the intensity of the light increases to a
predetermined intensity may be determined as an end point of the
process.
[0092] Thus, a concentration of a target material in the discharged
fluid may be detected in real time using a photodetector, to check
the progress of the process and determine the end point of the
supercritical fluid process.
[0093] FIG. 7 is a block diagram illustrating a substrate
processing system 13 in accordance with an exemplary embodiment of
the present disclosure. FIG. 7 is substantially the same as FIG. 2,
with the exception of the detection unit. Thus, the same reference
numerals will be used to refer to the same or like elements as
those described with reference to FIG. 4 and any further
explanation thereof will be omitted.
[0094] Referring to FIG. 7, a substrate processing system 13
according to an exemplary embodiment of the present disclosure may
further include a chamber detector 70 to directly detect a
concentration of a target material in the process chamber 30.
[0095] Accordingly, the chamber detector 70 may be used together
with the detection unit 50 disposed in the discharge unit 40 to
check the progress of the process and determine the end point of
the supercritical fluid process.
[0096] Hereinafter, an exemplary method of manufacturing a
semiconductor device using the substrate processing method in FIG.
1 will be explained in detail.
[0097] FIGS. 8 to 13 are cross-sectional views illustrating a
method of manufacturing a semiconductor device using a substrate
process method in accordance with an exemplary embodiment of the
present disclosure.
[0098] Referring to FIG. 8, an isolation process may be performed
on a semiconductor substrate 100 to form an isolation layer 103
defining an active region and a field region in the semiconductor
substrate 100.
[0099] A thermal oxidation process or a chemical vapor deposition
process may be performed on the semiconductor substrate 100
including the isolation layer 103 formed therein, to form a gate
oxide layer 106 of a gate structure 115. The gate structure 115 may
further include a gate conductive layer pattern 109 and a first
hard mask pattern 112 formed on the gate oxide layer 106. The gate
structure 115 may have a linear shape extending in a first
direction.
[0100] After a silicon nitride layer is formed on the semiconductor
substrate 100 including gate structures 115 formed thereon, the
silicon nitride layer may be anisotropically etched to form a gate
spacer 118 on a sidewall of each of the gate structures 115.
[0101] Impurities may be doped into the semiconductor substrate 100
using the gate structures 115 as an ion implantation mask, and the
substrate 100 may be thermally treated to form source/drain regions
124, 121 in the semiconductor substrate 100.
[0102] These processes may be performed to form transistors in the
semiconductor substrate 100. A gate electrode having a linear shape
may be used as a word line. The source/drain region 124, 121 may be
defined by an operation mode of the transistor. However,
hereinafter, a first region electrically connected to a bit line
may be referred to as a source region 124 and a second region
electrically connected to a capacitor may be referred to as a drain
region 121.
[0103] A first insulation interlayer 130 may be formed on the
transistors on the semiconductor substrate 100. The first
insulation interlayer 130 may include silicon oxide. The first
insulation interlayer 130 may be partially etched to form first
contact holes (not illustrated) that expose the source/drain
regions. Then, the first contact holes may be filled with
conductive material to form pad contacts 133, 136.
[0104] A second insulation interlayer 139 may be formed on the
first insulation interlayer 130. The second insulation interlayer
139 may be partially etched to form second contact hole (not
illustrated) exposing the pad contact 136 connected to the source
region 124. A conducive layer may be formed on the second
insulation interlayer 139 to fill the second contact hole to form a
bit line (not illustrated) and a bit line contact (not
illustrated).
[0105] A third insulation interlayer 154 may be formed on the
second insulation interlayer 139 to fill the bit line. The third
insulation interlayer 154 and the second insulation interlayer 139
may be partially etched to form third contact holes (not
illustrated) exposing the pad contact 133 connected to the drain
region 121. The third contact holes may be filled with conductive
material to form a storage node contact 157. Then, although it is
not illustrated, a pad pattern may be further formed on the storage
node contact 157 to define a storage node electrode forming
region.
[0106] Next, an etch stop layer 163 may be formed on the storage
node contact 157 and the third insulation layer 154. The etch stop
layer 163 may include silicon nitride.
[0107] Referring to FIG. 9, a mold layer 170 may be formed on the
etch stop layer 163. The mold layer 170 may be formed using silicon
oxide. For example, the mold layer 170 may include BPSG or
TEOS.
[0108] The mold layer 170 may be used to mold a cylindrical storage
electrode. The height of the cylindrical storage electrode may
depend on the thickness of the mold layer 170. Accordingly, the
thickness of the mold layer 170 may be determined according to a
desired capacitance.
[0109] A second hard mask pattern 172 may be formed on the mold
layer 170 to expose a region for a storage electrode to be formed.
The second hard mask pattern 172 may be formed using a material
having an etch selectivity with respect to the mold layer. For
example, the second hard mask pattern 178 may include
polysilicon.
[0110] Referring to FIG. 10, the mold layer 170 may be etched using
the second hard mask pattern 172 as an etching mask, to form a
preliminary opening (not illustrated) that exposes an upper surface
of the storage node contact 157.
[0111] The preliminary opening may be cleaned to form an opening
180 that is used to form a cylindrical storage electrode. A
cleaning process may be performed using a cleaning solution.
[0112] Referring to FIG. 11, a conductive layer (not illustrated)
for a storage node electrode may be formed on sidewalls and a lower
face of the opening 180 and an upper surface of the second hard
mask pattern (not illustrated). The conductive layer for a storage
node electrode may include polysilicon doped with impurities.
[0113] A sacrificial layer 184 may be formed on the conductive
layer for a storage node electrode to completely fill the opening
180. The sacrificial layer 184 may be formed using silicon
oxide.
[0114] A planarization process may be performed to remove the
conductive layer for the storage node electrode 157 and the second
hard mask pattern on the upper surface of the mold layer 170, to
form a storage electrode 182 in the opening 180.
[0115] Referring to FIG. 12, after forming the storage electrode
182, an etching process may be performed to remove the mold layer
170 and the sacrificial layer 184 (see FIG. 11).
[0116] In an exemplary embodiment, after the mold layer 170 and the
sacrificial layer 184 are removed by the etching process to expose
the storage electrode 182, a cleaning process and/or a drying
process may be performed to remove byproducts of the etching
process.
[0117] In an exemplary embodiment, after a material layer such as
the mold layer and the sacrificial layer are etched and cleaned,
the semiconductor substrate may be dried using a supercritical
fluid.
[0118] For example, after the etching process is performed,
byproducts of the etching process may be removed using a cleaning
solution such as DI water or alcohol such as IPA. After the
cleaning process is performed, a drying process may be performed to
remove residual IPA. After the substrate is loaded into a process
chamber of a substrate process chamber according to an exemplary
embodiment, the substrate may be dried using supercritical carbon
dioxide.
[0119] As the drying process proceeds, the supercritical carbon
dioxide with IPA may be discharged from the process chamber. The
IPA may be a target material indicative of the progress of the
supercritical drying process. Accordingly, a real-time
concentration of the target material included in the fluid
discharged from the process chamber may be detected to determine an
end point of the supercritical drying process based on the detected
concentration.
[0120] In another exemplary embodiment, after a material layer such
as the mold layer and the sacrificial layer are etched, the
semiconductor substrate may be cleaned using a supercritical fluid.
For example, the semiconductor substrate may be cleaned using a
supercritical carbon dioxide with surfactant dissolved therein.
[0121] As the cleaning process proceeds, the supercritical carbon
dioxide with surfactant may be discharged from the process chamber.
The surfactant may be a target material indicative of the progress
of the supercritical cleaning process. Accordingly, a real-time
concentration of the target material included in the fluid
discharged from the process chamber may be detected to determine an
end point of the supercritical cleaning process based on the
detected concentration.
[0122] In still another exemplary embodiment, a material layer such
as the mold layer and the sacrificial layer may be etched by a
supercritical etching process. For example, the material layer may
be etched using a supercritical fluid with hydrogen fluoride (HF)
included therein.
[0123] As the etching process proceeds, the supercritical fluid
with byproducts of the etching process may be discharged from the
process chamber. The byproduct of the etching process may include a
target material indicative of the progress of the supercritical
cleaning process. Accordingly, a real-time concentration of the
target material included in the fluid discharged from the process
chamber may be detected to determine an end point of the
supercritical etching process based on the detected
concentration.
[0124] Alternatively, the supercritical fluid itself may be a
target material. As the etching process proceeds, a concentration
of supercritical carbon dioxide may increase. Accordingly, a
real-time concentration of the discharged fluid from the process
chamber may be detected to determine an end point of the
supercritical fluid process based on the detected
concentration.
[0125] Referring to FIG. 13, a dielectric layer 190 may be formed
on a surface of the storage electrode 182. A plate electrode 192
may be formed on the dielectric layer 190. The above-mentioned
processes may be performed to manufacture a semiconductor device
including a storage electrode.
[0126] As mentioned above, in a method of processing a substrate in
accordance with exemplary embodiments of the present disclosure, a
supercritical fluid process may be performed on a substrate using a
supercritical fluid in a process chamber. As the supercritical
fluid process proceeds, the supercritical fluid may be discharged
from the process chamber. A real-time concentration of a target
material included in the fluid discharged from the process chamber
may be detected to determine an end point of the supercritical
fluid process based on the detected concentration of the target
material.
[0127] Accordingly, a concentration of a target material in the
discharged fluid may be detected and analyzed in real time, to
check the progress of the process and determine the end point of
the supercritical fluid process. After determining the end point of
the supercritical fluid process, a system including the process
chamber may be controlled to complete the supercritical fluid
process.
[0128] The foregoing description is illustrative of exemplary
embodiments and is not to be construed as limiting thereof.
Although a few exemplary embodiments have been described, those
skilled in the art will readily appreciate that many modifications
are possible without materially departing from the novel teachings
and advantages of the present disclosure. Accordingly, all such
modifications are intended to be included within the scope of
exemplary embodiments as defined in the claims. In the claims,
means-plus-function clauses are intended to cover the structures
described herein as performing the recited function and structural
equivalents. Therefore, it is to be understood that the foregoing
is illustrative of various exemplary embodiments and is not to be
construed as limited to specific exemplary embodiments disclosed,
and that modifications to exemplary embodiments are intended to be
included within the scope of the appended claims.
* * * * *