U.S. patent application number 14/799677 was filed with the patent office on 2015-11-05 for substrate processing apparatus.
The applicant listed for this patent is Hitachi Kokusai Electric Inc.. Invention is credited to Taketoshi SATO, Tsuyoshi TAKEDA, Daigo YAMAGUCHI, Hidenari YOSHIDA.
Application Number | 20150315702 14/799677 |
Document ID | / |
Family ID | 50339253 |
Filed Date | 2015-11-05 |
United States Patent
Application |
20150315702 |
Kind Code |
A1 |
YAMAGUCHI; Daigo ; et
al. |
November 5, 2015 |
Substrate Processing Apparatus
Abstract
A substrate processing apparatus includes a process container, a
process gas supply system, an exhaust system, and a control unit.
The process container has inner and outer reaction tubes and a
communication section connecting the insides of the reaction tubes.
The inner reaction tube has a flat top inner surface at an upper
end that covers at least part of a top surface of a substrate
support. The process gas supply system supplies a process gas into
the process container, and the exhaust system exhausts the process
gas from the process container via the communication section and a
space between the reaction tubes. The control unit controls a
repeated cycle that includes: supplying the process gas into the
process container; confining the process gas in the process
container; and exhausting the process gas from the process
container via the communication section and the space between the
reaction tubes.
Inventors: |
YAMAGUCHI; Daigo; (Toyama,
JP) ; TAKEDA; Tsuyoshi; (Toyama, JP) ; SATO;
Taketoshi; (Toyama, JP) ; YOSHIDA; Hidenari;
(Toyama, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hitachi Kokusai Electric Inc. |
Tokyo |
|
JP |
|
|
Family ID: |
50339253 |
Appl. No.: |
14/799677 |
Filed: |
July 15, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14036836 |
Sep 25, 2013 |
9111748 |
|
|
14799677 |
|
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Current U.S.
Class: |
118/704 |
Current CPC
Class: |
C23C 16/45517 20130101;
C23C 16/45523 20130101; C23C 16/54 20130101; C23C 16/4401 20130101;
H01L 21/02167 20130101; H01L 21/67109 20130101; H01L 21/02126
20130101; H01L 21/02211 20130101; H01L 21/02104 20130101; H01L
21/02271 20130101; C23C 16/45561 20130101; H01L 21/67017 20130101;
C23C 16/52 20130101 |
International
Class: |
C23C 16/455 20060101
C23C016/455; C23C 16/52 20060101 C23C016/52 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 26, 2012 |
JP |
2012-212461 |
Aug 1, 2013 |
JP |
2013-160345 |
Claims
1. A substrate processing apparatus comprising: a process container
comprising: an outer reaction tube; and an inner reaction tube
disposed in the outer reaction tube, the inner reaction tube having
a flat top inner surface at an upper end portion thereof covering
at least a portion of a top surface of a support arranging and
supporting a plurality of substrates in the inner reaction tube and
including a communication section connecting an inside of the inner
reaction tube to an inside of the outer reaction tube, wherein the
communication section is disposed at a region other than a region
horizontally encompassing a substrate arrangement region where the
plurality of substrates are arranged; a process gas supply system
configured to supply a process gas into the process container; an
exhaust system configured to exhaust the process gas from the
process container via the communication section and a space between
the inner reaction tube and the outer reaction tube; and a control
unit configured to control the process gas supply system and the
exhaust system to form thin films on the plurality of substrates by
performing a cycle a predetermined number of times, the cycle
comprising: (a) supplying the process gas into the process
container and confining the process gas in the process container
with the plurality of substrates arranged and supported by the
support being accommodated in the process container; (b)
maintaining a state where the process gas is confined in the
process container; and (c) exhausting the process gas from the
process container via the communication section and the space
between the inner reaction tube and the outer reaction tube.
2. The substrate processing apparatus of claim 1, wherein the
communication section is disposed above or below a portion of the
region horizontally encompassing the substrate arrangement region
of the inner reaction tube.
3. The substrate processing apparatus of claim 1, wherein the
communication section is disposed at one of the upper end portion
of the inner reaction tube and a sidewall portion of the inner
reaction tube.
4. The substrate processing apparatus of claim 1, wherein the
communication section is disposed at a central portion of the upper
end portion of the inner reaction tube.
5. The substrate processing apparatus of claim 1, wherein the
communication section comprises a plurality of communication
portions disposed at the upper end portion of the inner reaction
tube.
6. The substrate processing apparatus of claim 1, wherein the
support comprises a plate-shaped member disposed at the top surface
thereof, and the plate-shaped member faces the communication
section.
7. The substrate processing apparatus of claim 1, wherein the
support comprises a plate-shaped member disposed at the top surface
thereof, and the plate-shaped member covers a surface of an
uppermost one of the plurality of substrates supported by the
support.
8. The substrate processing apparatus of claim 1, wherein the
support comprises a plate-shaped member disposed at the top surface
thereof, and the plate-shaped member faces the communication
section and a surface of an uppermost one of the plurality of
substrates supported by the support.
9. The substrate processing apparatus of claim 1, wherein at least
a top inner surface at an upper end portion of the outer reaction
tube is flat.
10. The substrate processing apparatus of claim 1, wherein the
upper end portion of the inner reaction tube is parallel to an
upper end portion of the outer reaction tube.
11. The substrate processing apparatus of claim 1, wherein an upper
end portion of the outer reaction tube, the upper end portion of
the inner reaction tube and the top surface of the support are
parallel to one another.
12. The substrate processing apparatus of claim 1, wherein an upper
end portion of the outer reaction tube, the upper end portion of
the inner reaction tube, the top surface of the support and
surfaces of the plurality of substrates are parallel to one
another.
13. The substrate processing apparatus of claim 1, wherein the
support arranges and supports a plurality of insulating plates, and
the communication section is disposed in a portion of a region
horizontally encompassing an insulating plate arrangement region of
the inner reaction tube where the plurality of insulating plates
are arranged.
14. The substrate processing apparatus of claim 1, further
comprising a heater, wherein the control unit is further configured
to control the heater to heat an inside of the process container to
a thermal decomposition temperature of the process gas while the
thin films are formed.
15. The substrate processing apparatus of claim 1, wherein thin
films are formed in a non-plasma atmosphere.
16. A substrate processing apparatus comprising: a process
container comprising: an outer reaction tube having an upper end
portion thicker than a sidewall portion thereof; and an inner
reaction tube disposed in the outer reaction tube, the inner
reaction tube having a flat top inner surface at an upper end
portion thereof covering at least a portion of a top surface of a
support arranging and supporting a plurality of substrates in the
inner reaction tube and including a communication section
connecting an inside of the inner reaction tube to an inside of the
outer reaction tube, wherein the communication section is disposed
at a region other than a region horizontally encompassing a
substrate arrangement region where the plurality of substrates are
arranged; a process gas supply system configured to supply a
process gas into the process container; an exhaust system
configured to exhaust the process gas from the process container
via the communication section and a space between the inner
reaction tube and the outer reaction tube; and a control unit
configured to control the process gas supply system and the exhaust
system to form thin films on the plurality of substrates by
performing a cycle a predetermined number of times, the cycle
comprising: (a) supplying the process gas into the process
container and confining the process gas in the process container
with the plurality of substrates arranged and supported by the
support being accommodated in the process container; (b)
maintaining a state where the process gas is confined in the
process container; and (c) exhausting the process gas from the
process container via the communication section and the space
between the inner reaction tube and the outer reaction tube.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/036,836 filed Sep. 25, 2013, which claims
foreign priority under 35 U.S.C. .sctn.119(a)-(d) to Application
No. JP 2012-212461 filed on Sep. 26, 2012, and Application No. JP
2013-160345 filed on Aug. 1, 2013, the entire contents of each of
which are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a method of manufacturing a
semiconductor device, a substrate processing apparatus and a
non-transitory computer readable recording medium, and more
particularly, to a method of manufacturing a semiconductor device,
which includes a process of forming a thin film by chemical vapor
deposition (CVD), a substrate processing apparatus and a
non-transitory computer readable recording medium that is
preferably used for the process.
BACKGROUND
[0003] A substrate processing process in which a thin film is
formed by chemical vapor deposition (CVD) is performed using, for
example, a substrate processing apparatus that includes a process
chamber configured to accommodate and process a plurality of
substrates therein, a process gas supply line via which a process
gas is supplied into the process chamber, and an exhaust line via
which the inside of the process chamber is exhausted. In this case,
a thin film is formed on the plurality of substrates by supplying
the process gas into the process chamber via the process gas supply
line while the inside of the process chamber in which the plurality
of substrates are accommodated is exhausted using the exhaust line,
and causing the process gas to pass between the plurality of
substrates.
SUMMARY
[0004] In a general thermal process, when a process gas is supplied
into a heated process chamber, the process gas supplied into the
process chamber is pyrolyzed and active species are thus generated
in a radical state and deposited on a substrate to form a film. In
a structure of a general process chamber, since a region in which
the process gas is pyrolyzed is large, a plurality of types of
active species that cause undesirable results involving non-uniform
film thickness and non-uniform film quality within or between
planes of substrates may be present among active species.
[0005] It is an object of the present invention to limit a region
in which a process gas is to be decomposed, to suppress generation
of a plurality of types of active species, and to prevent
undesirable active species from contributing to substrate
processing when a thin film is formed on a substrate using a
thermal process.
[0006] According to one aspect of the present invention, there is
provided a substrate processing apparatus including: a process
container including: an outer reaction tube; and an inner reaction
tube disposed in the outer reaction tube, the inner reaction tube
having a flat top inner surface at an upper end portion thereof
covering at least a portion of a top surface of a support arranging
and supporting a plurality of substrates in the inner reaction tube
and including a communication section connecting an inside of the
inner reaction tube to an inside of the outer reaction tube,
wherein the communication section is disposed at a region other
than a region horizontally encompassing a substrate arrangement
region where the plurality of substrates are arranged; a process
gas supply system configured to supply a process gas into the
process container; an exhaust system configured to exhaust the
process gas from the process container via the communication
section and a space between the inner reaction tube and the outer
reaction tube; and a control unit configured to control the process
gas supply system and the exhaust system to form thin films on the
plurality of substrates by performing a cycle a predetermined
number of times, the cycle including: (a) supplying the process gas
into the process container and confining the process gas in the
process container with the plurality of substrates arranged and
supported by the support being accommodated in the process
container; (b) maintaining a state where the process gas is
confined in the process container; and (c) exhausting the process
gas from the process container via the communication section and
the space between the inner reaction tube and the outer reaction
tube.
[0007] According to another aspect of the present invention, there
is provided a substrate processing apparatus including: a process
container including: an outer reaction tube having an upper end
portion thicker than a sidewall portion thereof; and an inner
reaction tube disposed in the outer reaction tube, the inner
reaction tube having a flat top inner surface at an upper end
portion thereof covering at least a portion of a top surface of a
support arranging and supporting a plurality of substrates in the
inner reaction tube and including a communication section
connecting an inside of the inner reaction tube to an inside of the
outer reaction tube, wherein the communication section is disposed
at a region other than a region horizontally encompassing a
substrate arrangement region where the plurality of substrates are
arranged; a process gas supply system configured to supply a
process gas into the process container; an exhaust system
configured to exhaust the process gas from the process container
via the communication section and a space between the inner
reaction tube and the outer reaction tube; and a control unit
configured to control the process gas supply system and the exhaust
system to form thin films on the plurality of substrates by
performing a cycle a predetermined number of times, the cycle
including: (a) supplying the process gas into the process container
and confining the process gas in the process container with the
plurality of substrates arranged and supported by the support being
accommodated in the process container; (b) maintaining a state
where the process gas is confined in the process container; and (c)
exhausting the process gas from the process container via the
communication section and the space between the inner reaction tube
and the outer reaction tube.
[0008] According to still another aspect of the present invention,
there is provided a non-transitory computer readable recording
medium storing a program that causes a computer to perform a
process of forming thin films on a plurality of substrates by
performing a cycle a predetermined number of times, the cycle
including: (a) supplying a process gas into a process container and
confining the process gas in the process container in a state where
the plurality of substrates arranged and supported by a support are
accommodated in the process container, the process container
including an outer reaction tube and an inner reaction tube
disposed in the outer reaction tube, the inner reaction tube having
a flat top inner surface at an upper end portion thereof covering
at least a portion of a top surface of the support arranging and
supporting the plurality of substrates in the inner reaction tube
and including a communication section connecting an inside of the
inner reaction tube to an inside of the outer reaction tube,
wherein the communication section is disposed at a region other
than a region horizontally encompassing a substrate arrangement
region where the plurality of substrates are arranged; (b)
maintaining a state where the process gas is confined in the
process container; and (c) exhausting the process gas from the
process container via the communication section and a space between
the inner reaction tube and the outer reaction tube.
[0009] According to the present invention, when a thin film is
formed on substrates using a thermal process, uniform thickness and
quality of the thin film may be achieved between and within planes
of the substrates.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic configuration diagram of a vertical
process furnace of a substrate processing apparatus according to an
embodiment of the present invention, in which a longitudinal
cross-sectional view of a portion of the process furnace is
illustrated.
[0011] FIG. 2 is a cross-sectional view of the vertical process
furnace of the substrate processing apparatus according to an
embodiment of the present invention, taken along line A-A of FIG.
1.
[0012] FIG. 3 is a schematic configuration diagram of a controller
of the substrate processing apparatus according to an embodiment of
the present invention, in which a block diagram of a control system
of the controller is illustrated.
[0013] FIG. 4 is a diagram illustrating a sequence of a
film-forming process according to an embodiment of the present
invention.
[0014] FIG. 5 is a diagram illustrating a sequence of a
film-forming process according to another embodiment of the present
invention.
[0015] FIG. 6 is a diagram illustrating a sequence of a
film-forming process according to still another embodiment of the
present invention.
[0016] FIG. 7 is a diagram illustrating a sequence of a
film-forming process according to yet another embodiment of the
present invention.
[0017] FIGS. 8A to 8L are diagrams illustrating structures of an
inner tube according to various embodiments of the present
invention.
[0018] FIGS. 9A to 9H are diagrams illustrating structures of an
inner tube according to other various embodiments of the present
invention.
[0019] FIGS. 10A and 10B are diagrams illustrating structures of an
inner tube according to other various embodiments of the present
invention.
[0020] FIGS. 11A to 11J are diagrams illustrating structures of an
outer tube according to various embodiments of the present
invention.
[0021] FIGS. 12A and 12B are diagrams illustrating structures of an
outer tube according to other various embodiments of the present
invention.
[0022] FIG. 13 is a diagram illustrating a structure of an inner
tube according to other embodiments of the present invention.
[0023] FIG. 14 is a diagram illustrating a structure of an inner
tube according to other embodiments of the present invention.
[0024] FIG. 15A is an enlarged view of portions of vertical process
furnaces of substrate processing apparatuses according to Example
and Comparative Example of the present invention.
[0025] FIG. 15B is a graph illustrating a result of measuring the
thicknesses of SiC films according to Example and Comparative
Example of the present invention.
DETAILED DESCRIPTION
[0026] Hereinafter, exemplary embodiments of the present invention
will be described with reference to the accompanying drawings.
[0027] FIG. 1 is a schematic configuration diagram of a vertical
process furnace 202 of a substrate processing apparatus according
to an embodiment of the present invention, in which a longitudinal
cross-sectional view of a portion of the process furnace 202 is
illustrated. FIG. 2 is a cross-sectional view of the vertical
process furnace 202 of the substrate processing apparatus according
to an embodiment of the present invention, taken along line A-A of
FIG. 1. Specifically, FIG. 2 illustrates only an inner tube 203b, a
boat 217 included in the process furnace 202 (which will be
described below), and a wafer 200 supported by the boat 217.
[0028] As illustrated in FIG. 1, the process furnace 202 includes a
heater 207 serving as a heating member (heating device). The heater
207 has a cylindrical shape and is vertically installed by being
supported by a heater base (not shown) serving as a support plate.
The heater 207 may also function as an activating mechanism
(exciting unit) configured to activate (excite) a gas by
decomposing the gas by heat, as will be described below.
[0029] At an inner side of the heater 207, a process tube 203 is
provided as a reaction tube that forms a reaction container
(process container) to be concentrically formed with the heater
207. The process tube 203 includes an inner tube 203b serving as an
inner reaction tube, and an outer tube 203a serving as an outer
reaction tube installed at an outer side of the inner tube
203b.
[0030] The inner tube 203b is formed of, for example, a
heat-resistant material such as quartz (SiO.sub.2), silicon carbide
(SiC), etc., and has a disk shape, the upper end (upper end
portion) and lower end (lower end portion) of which are open. In a
hollow tubular portion of the inner tube 203b, a plurality of
wafers 200 are accommodated as substrates which are targets on
which a thin film is to be formed. Hereinafter, in the inner tube
203b, a region accommodating the wafers 200 is also referred to as
a wafer region (substrate arrangement region).
[0031] At least a portion of a top surface 217a (ceiling plate) of
the boat 217 serving as a support (which will be described below)
is covered with an upper end portion 203c (ceiling portion) of the
inner tube 203b. The upper end portion 203c of the inner tube 203b
may also be considered as a structure that covers at least a
portion of a surface of the wafer 200. The upper end portion 203c
of the inner tube 203b is installed in parallel with the top
surface 217a having a flat shape of the boat 217 and a surface of
the wafer 200, and has at least flat inner surfaces. An outer
surface of the upper end portion 203c of the inner tube 203b is
also flat. The upper end portion 203c of the inner tube 203b
extends from upper ends of sidewalls of the inner tube 203b toward
inner sides of the inner tube 203b, and may be thus referred to as
an extension unit. A communication section (opening) 270 is formed
in a central portion (center portion) of the upper end portion 203c
of the inner tube 203b, through which the inside of the inner tube
203b and the inside of the outer tube 203a which will be described
below communicate with each other. That is, the upper end portion
203c of the inner tube 203b includes a donut-shaped (ring-shaped)
plate-shaped member (plate) having an opening in a central portion
thereof. Due to this shape, the upper end portion 203c of the inner
tube 203b may be referred to as an orifice-shaped member (or simply
`orifice`). The communication section 270 may be formed in portion
of the upper end portion 203c of the inner tube 203b other than the
central portion of the upper end portion 203c, e.g., a
circumferential portion of the upper end portion 203c or the like,
or may be formed in a sidewall portion of the inner tube 203b.
However, when the communication section 270 is formed in the
sidewall portion of the inner tube 203b, the communication section
270 may be formed in a region above the wafer region and near the
upper end portion 203c, or may be formed in a region that is
located below the wafer region and that horizontally encompasses an
insulating plate arrangement region in which a plurality of
insulating plates 218 (which will be described below) are
arranged.
[0032] The outer tube 203a is formed of, for example, a
heat-resistant material such as quartz or SiC, has a cylindrical
shape, the internal diameter of which is greater than the external
diameter of the inner tube 203b, the upper end portion of which is
closed, and the lower end (lower end portion) of which is open, and
is formed concentrically with the inner tube 203b. The upper end
portion 203c of the inner tube 203b (ceiling portion) is covered
with the upper end portion (ceiling portion) of the outer tube
203a.
[0033] The upper end portion of the outer tube 203a is installed in
parallel with the upper end portion 203c of the inner tube 203b,
the top surface (ceiling plate) 217a of the boat 217, and a surface
of the wafer 200, and has at least flat inner surfaces. That is,
the inner surfaces of the upper end portion of the outer tube 203a
are composed of planes. Similarly, outer surfaces of the upper end
portion of the outer tube 203a have a flat shape and are composed
of planes. The upper end portion of the outer tube 203a is formed
to be thicker than the sidewall portion of the outer tube 203a, and
is configured to maintain hardness of the outer tube 203a even when
the inside of the outer tube 203a is set to a predetermined vacuum
degree. The upper end portion of the outer tube 203a is thicker
than the upper end portion 203c of the inner tube 203b or a
sidewall portion of the inner tube 203b.
[0034] The process chamber 201 is mainly configured by the outer
tube 203a and the inner tube 203b. The process chamber 201 is
configured to accommodate wafers 200 such that the wafers 200 are
arranged in a horizontal posture and vertically in a multistage
manner by the boat 217 which will be described below.
[0035] Due to the structures of the outer tube 203a and the inner
tube 203b described above, an actual volume (capacity) of the
process chamber 201 may be reduced, and a region in which a process
gas is pyrolyzed to generate active species is limited (minimized),
thereby enabling a plurality of types of active species to be
generated.
[0036] In other words, the volume (capacity) of the space between
the ceiling portions of the outer tube 203a and the inner tube 203b
may be set to be small by forming a flat-flat structure in which an
inner surface of the upper end portion (ceiling portion) of the
outer tube 203a and an outer surface of the upper end portion
(ceiling portion) 203c of the inner tube 203b are formed to be
flat. Thus, the actual volume (capacity) of the process chamber 201
may be set to be small and a region in which a process gas is
pyrolyzed to generate active species is limited (reduced), thereby
suppressing generation of a plurality of types of active species.
Also, the volume (capacity) of the space between the inner surface
of the upper end portion 203c of the inner tube 203b and the top
surface 271a of the boat 217 may be reduced to be small by forming
a flat-flat structure in which an inner surface of the upper end
portion 203c of the inner tube 203b is formed to be flat and at
least a portion of the flat top surface of the boat 217 is covered
with the upper end portion 203c of the inner tube 203b. Thus, the
actual volume (capacity) of the process chamber 201 may be reduced
to be smaller, and the region in which the process gas is pyrolyzed
to generate active species is more limited (reduced), thereby
further suppressing generation of a plurality of types of active
species.
[0037] Also, active species produced in the space between the inner
surface of the upper end portion (ceiling portion) of the outer
tube 203a and the outer surface of the upper end portion (ceiling
portion) 203c of the inner tube 203b and the space between the
inner surface of the upper end portion 203c of the inner tube 203b
and the top surface 217a of the boat 217 may be easily consumed to
be exhausted by reducing the volumes of the spaces. As a result,
the concentration of the active species in the spaces may be
appropriately reduced.
[0038] That is, the ratio of "the amount of active species consumed
by contacting the surface of the space between the inner surface of
the ceiling portion of the outer tube 203a and the outer surface of
the ceiling portion of the inner tube 203b, such as the outer tube
203a or the inner tube 203b" to "the amount of active species
produced in the space," i.e., (consumption rate/production rate),
may be increased by increasing the ratio of the surface area of the
space between the inner surface of the ceiling portion of the outer
tube 203a and the outer surface of the ceiling portion of the inner
tube 203b to the volume thereof, i.e., (surface area/volume).
Similarly, the ratio of "the amount of active species consumed by
contacting a surface of the space between the upper end portion
203c of the inner tube 203b and the top surface 217a of the boat
217, i.e., the surface of the inner tube 203b or the boat 217" to
"the amount of active species produced in the space between the
upper end portion 203c of the inner tube 203b and the top surface
217a of the boat 217," i.e., (consumption rate/production rate),
may be increased by increasing the ratio of the surface area of the
space between the upper end portion 203c of the inner tube 203b and
the top surface 217a of the boat 217 to the volume thereof, i.e.,
(surface area/volume). That is, the active species produced in
these spaces may be easily consumed by increasing the ratio of the
surface area of each of the spaces to the volume thereof.
Accordingly, the concentration of the active species in these
spaces may be appropriately reduced.
[0039] Also, the distance from active species (generated as
reactive species at an upper portion of the wafer 200 or between
the outer tube 203a and the inner tube 203b) to the wafer 200 may
be increased and the active species may be suppressed from
contacting the wafer 200 by covering at least a portion of the top
surface 217a (ceiling plate) of the boat 217, i.e., the upper
portion of the wafer 200, with the upper end portion 203c of the
inner tube 203b and forming the communication section 270 on the
upper end portion 203c of the inner tube 203b.
[0040] That is, through the above configuration, active species
generated in the space between the inner surface of the upper end
portion 203c of the inner tube 203b and the top surface 217a of the
boat 217 cannot arrive at the wafer 200 unless the active species
bypasses an edge of the top surface 217a of the boat 217. Also,
through the above configuration, the communication section 270
formed at the upper end portion 203c of the inner tube 203b is
disposed facing the top surface 217a of the boat 217 so that the
communication section 270 may be blocked by the top surface 217a of
the boat 217. Thus, active species generated in the space between
the outer tube 203a and the inner tube 203b cannot arrive at the
wafer 200 unless the active species move along the space, pass
through the communication section 270, and bypass the edge of the
top surface 217a of the boat 217. As described above, the distance
(path) from the active species to the wafer 200 may be increased,
and the active species may be consumed to be exhausted before
arriving at the wafer 200 by bypassing the active species generated
at the upper portion of the wafer 200 or between the outer tube
203a and the inner tube 203b. In other words, the active species
generated around these elements may be suppressed from contacting
the wafer 200. In particular, when the communication section 270 is
formed at a central portion of the upper end portion 203c of the
inner tube 203b, a distance from the active species passing through
the communication section 270 to the wafer 200 may be increased to
a maximum level and the active species are easily suppressed from
contacting the wafer 200.
[0041] Using the above configuration, the distribution of the
concentration of active species in the process chamber 201
(particularly, in the wafer region) may be uniformized. Also, film
thickness and quality may be suppressed from being influenced by
active species generated at the upper portion of the wafer 200 or
in the space between the outer tube 203a and the inner tube 203b.
As a result, the uniformity of the thickness and quality of a thin
film formed on the wafers 200 within and between planes of the
wafer 200 may be improved.
[0042] Also, in the above configuration, the distance between an
inner wall of a sidewall of the inner tube 203b (hereinafter
referred to simply as an inner wall of the inner tube 203b) and an
end portion of the wafer 200 is preferably short. For example, the
distance between the inner wall of the inner tube 203b and the end
portion of the wafer 200 is preferably less than or equal to the
distance between adjacent wafers 200 (wafer arrangement pitch).
However, as illustrated in FIG. 2, the boat 217 which will be
described in detail below includes boat pillars (boat supports)
217c in which locking grooves 217b are formed to support the wafer
200. The boat pillars 217c are located outside of the wafer 200.
Thus, when the distance between the inner wall of the inner tube
203b and the end portion of the wafer 200 is short, the inner wall
of the inner tube 203b and the boat pillars 217c contact one
another. For this reason, the distance between the inner wall of
the inner tube 203b and the end portion of the wafer 200 should not
be shortened any further. That is, the boat pillars 217c prevent
the distance between the inner wall of the inner tube 203b and the
end portion of the wafer 200 from being shortened. Thus, in order
to further reduce the distance between the inner wall of the inner
tube 203b and the end portion of the wafer 200, boat pillar grooves
203d serving as spaces (concavities) for avoiding the boat pillars
217c are preferably formed in locations corresponding to the boat
pillars 217c on the inner wall of the inner tube 203b as
illustrated in, for example, FIG. 2. FIG. 2 illustrates only the
inner tube 203b, the boat 217, and the wafer 200 supported by the
boat 217, for convenience of explanation.
[0043] Using this configuration, i.e., the configuration in which a
concave portion for avoiding a member forming the boat 217 is
formed on the inner tube 203b, the distance between the inner wall
of the inner tube 203b and the end portion of the wafer 200 may be
reduced to a minimum level.
[0044] As described above, by minimizing the distance between the
inner wall of the inner tube 203b and the end portion of the wafer
200, an actual volume of the process chamber 201 may be reduced and
a region in which active species are generated may be reduced to
suppress generation of a plurality of types of active species. Due
to this configuration, the thickness and quality of a film may be
suppressed from being influenced more by the active species, and
may be more uniformized within and between planes of the wafers
200.
[0045] The shape of the inner tube 203b including the upper end
portion 203c and the sidewall portion described above may be
referred to as a roughly cylindrical shape as compared with a pure
cylindrical shape.
[0046] Below the outer tube 203a, a manifold 209 is provided to be
formed concentrically with the outer tube 203a. The manifold 209 is
formed of, for example, stainless steel (SUS) and has a cylindrical
shape, the top and bottom ends of which are open. The manifold 209
is engaged with the inner tube 203b and the outer tube 203a and
installed to support the inner tube 203b and the outer tube 203a.
An O-ring 220a is installed as a seal member between the manifold
209 and the outer tube 203a. The process tube 203 is vertically
installed since the manifold 209 is supported by the heater base. A
reaction container (process container) is mainly configured by the
process tube 203 and the manifold 209.
[0047] Nozzles 249a to 249d serving as gas introduction units are
connected to the manifold 209 to pass through a sidewall of the
manifold 209 and to communicate with the inside of the process
chamber 201. Gas supply pipes 232a to 232d are connected to the
nozzles 249a to 249d, respectively. As described above, four
nozzles 249a to 249d and four gas supply pipes 232a to 232d are
installed at the process tube 203, and configured to supply a
plurality of types of process gases (here, four types of process
gases) into the process chamber 201.
[0048] At the gas supply pipes 232a to 232d, mass flow controllers
(MFCs) 241a to 241d which are flow rate controllers (flow rate
control units) and valves 243a to 243d which are opening/closing
valves are sequentially installed in an upstream direction. Also,
gas supply pipes 232e to 232h configured to supply an inert gas are
connected to the gas supply pipes 232a to 232d at downstream sides
of the valves 243a to 243d, respectively. MFCs 241e to 241h which
are flow rate controllers (flow rate control unit) and valves 243e
to 243h which are opening/closing valves are sequentially installed
at the gas supply pipes 232e to 232h in the upstream direction,
respectively. Also, the nozzles 249a to 249d described above are
connected to front ends of the gas supply pipes 232a to 232d,
respectively.
[0049] A silicon-based gas, i.e., a silane-based gas, is supplied
as a process gas into the process chamber 201 from the gas supply
pipe 232a via the MFC 241a, the valve 243a, and the nozzle
249a.
[0050] An amine-based gas is supplied as a process gas into the
process chamber 201 from the gas supply pipe 232b via the MFC 241b,
the valve 243b, and the nozzle 249b.
[0051] An oxidizing gas, i.e., an oxygen-containing gas, is
supplied as a process gas into the process chamber 201 from the gas
supply pipe 232c via the MFC 241c, the valve 243c, and the nozzle
249c.
[0052] A nitriding gas, i.e., a nitrogen-containing gas, is
supplied as a process gas into the process chamber 201 from the gas
supply pipe 232d via the MFC 241d, the valve 243d, and the nozzle
249d.
[0053] For example, nitrogen (N.sub.2) gas is supplied as an inert
gas into the process chamber 201 from the gas supply pipes 232e to
232h via the MFCs 241e to 241h, the valves 243e to 243h, the gas
supply pipes 232a to 232d, and the nozzles 249a to 249d.
[0054] When the gases described above are supplied from these gas
supply pipes, a silane-based gas supply system which is a
silicon-based gas supply system is mainly configured by the gas
supply pipe 232a, the MFC 241a, and the valve 243a. The nozzle 249a
may further be included in the silane-based gas supply system.
Also, an amine-based gas supply system is configured by the gas
supply pipe 232b, the MFC 241b, and the valve 243b. The nozzle 249b
may further be included in the amine-based gas supply system. Also,
an oxygen-containing gas supply system is configured as an
oxidizing gas supply system by the gas supply pipe 232c, the MFC
241c, and the valve 243c. The nozzle 249c may further be included
in the oxygen-containing gas supply system. Also, a
nitrogen-containing gas supply system is configured as a nitriding
gas supply system is configured by the gas supply pipe 232d, the
MFC 241d, and the valve 243d. The nozzle 249d may further be
included in the nitrogen-containing gas supply system. Also, an
inert gas supply system is configured by the gas supply pipes 232e
to 232h, the MFCs 241e to 232h, and the valves 243e to 243h. The
inert gas supply system may also act a purge gas supply system.
[0055] At least one among the silicon-based gas supply system
(silane-based gas supply system), the amine-based gas supply
system, the oxidizing gas supply system (oxygen-containing gas
supply system), and the nitriding gas supply system
(nitrogen-containing gas supply system) may be referred to simply
as a process gas supply system. For example, the silicon-based gas
supply system may be referred to as a process gas supply system,
and the silicon-based gas supply system and the amine-based gas
supply system may be referred to as a process gas supply
system.
[0056] At the manifold 209, an exhaust pipe 231 configured to
exhaust an atmosphere in the process chamber 201 is installed. The
exhaust pipe 231 is disposed below a container-shaped space 250
formed by a gap between the inner tube 203b and the outer tube
203a, and communicates with the container-shaped space 250. A
vacuum pump 246 serving as a vacuum exhaust device is connected to
a downstream side opposite to a side of the exhaust pipe 231
connected to the manifold 209, via a pressure sensor 245 serving as
a pressure detector (pressure detection unit) configured to detect
pressure in the process chamber 201 and an auto pressure controller
(APC) valve 244 serving as a pressure adjustor (pressure adjustment
unit). The APC valve 244 is a valve configured to perform or
suspend vacuum exhaust in the process chamber 201 by
opening/closing the APC valve 244 and to adjust the pressure in the
process chamber 201 by controlling the degree of opening the APC
valve 244 based on pressure information detected by the pressure
sensor 245, while the vacuum pump 246 is operated. An exhaust
system is mainly configured by the exhaust pipe 231, the APC valve
244, and the pressure sensor 245. The vacuum pump 246 may be
further included in the exhaust system.
[0057] A seal cap 219 serving as a furnace port lid is installed
below the manifold 209 to air-tightly seal a low end opening in the
manifold 209. The seal cap 219 abuts a lower end of the manifold
209 from a lower side in a vertical direction. The seal cap 219 is
formed of a metal such as stainless steel (SUS), and has a disk
shape. An `O-ring` 220 serving as a sealing member that abuts the
lower end of the manifold 209 is installed on a top surface of the
seal cap 219. A rotation mechanism 267 configured to rotate the
boat 217 (which will be described below) is installed at a side of
the seal cap 219 opposite to the process chamber 201. A rotary
shaft 255 of the rotation mechanism 267 is connected to the boat
217 (which will be described below) while passing through the seal
cap 219. The rotation mechanism 267 is configured to rotate the
wafers 200 by rotating the boat 217. The seal cap 219 is vertically
moved by a boat elevator 115 which is a lifting mechanism
vertically installed outside the reaction tube 203. The boat
elevator 115 is configured to vertically move the seal cap 219 so
that the boat 217 may be loaded into/unloaded from the process
chamber 201. The boat elevator 115 is configured as a transfer
device (transfer mechanism) that transfers the boat 217, i.e., the
wafers 200, inside/outside the process chamber 201.
[0058] The boat 217 serving as a support is formed of, for example,
quartz or SiC, and supports a plurality of wafers 200 in a
multi-stage manner such that the plurality of wafers 200 are
arranged in a horizontal posture to be concentrically formed with
one another. As illustrated in FIGS. 1 and 2, the boat 217 includes
the ceiling plate 217a forming the top surface of the boat 217, and
a plurality of boat pillars 217c (four boat pillars 217c in the
present embodiment).
[0059] The ceiling plate 217a is configured as a flat plate type
member and to entirely cover an upper portion of the wafer 200,
i.e., an upper portion of the wafer 200 disposed on an uppermost
portion (top portion) of the wafer region. Thus, the length of a
path in which active species generated on an upper portion of the
wafer 200 arrive at the wafer 200 may be increased. Also, the
ceiling plate 217a is formed to face the communication section 270
installed on the upper end portion 203c of the inner tube 203b,
i.e., to close the communication section 270, when the boat 217 is
loaded into the process chamber 201. Thus, the length of a path in
which active species generated between the outer tube 203a and the
inner tube 203b arrive at the wafers 200 after the active species
pass through the communication section 270 may be increased and the
active species may be suppressed from contacting the wafers 200. As
a result, the uniformity of the thickness and quality of a thin
film formed on the wafers 200 within and between planes of the
wafers 200 may be improved.
[0060] On each of the boat pillars 217c, a plurality of locking
grooves (slots) 217b are formed to support a plurality of wafers
200 (e.g., 25 to 200 wafers 200). The boat pillars 217c are each
formed to be accommodated into the boat pillar grooves 203d formed
in the inner wall of the inner tube 203b not to be in contact with
the boat pillar grooves 203d. When the wafers 200 are loaded into
all the locking grooves 217b, the distance between the wafer 200
disposed on the uppermost portion of the wafer region and the
ceiling plate 217a is equal to the distance between adjacent wafers
200 (wafer arrangement pitch). Thus, when the boat 217 is loaded
into the process chamber 201, an actual volume (capacity) of the
process chamber 201 may be reduced and a region in which a process
gas is pyrolyzed to generate active species is limited (reduced to
a minimum), thereby suppressing generation of a plurality of types
of active species. Also, a film thickness and quality may be
suppressed from being influenced by the active species, and uniform
film thickness and quality within and between planes of the wafers
200 may be achieved.
[0061] Below the boat 217, the insulating plates 218 formed of, for
example, quartz or SiC are configured to be supported in a
horizontal posture and a multi-stage manner, and to prevent heat
generated from the heater 207 from being delivered to the seal cap
219. Otherwise, an insulating container configured as a
container-shaped member formed of a heat-resistant material such as
quartz or SiC may be installed below the boat 217, instead of the
insulating plate 218. In the process chamber 201 (the inner tube
203b), a region configured to accommodate the insulating plates 218
is also referred to as an insulating plate arrangement region.
[0062] In the process tube 203, a temperature sensor 263 is
installed as a temperature detector. A temperature in the process
chamber 201 may have a desired temperature distribution by causing
the temperature sensor 263 to control an amount of electric power
to be supplied to the heater 207 based on temperature information
detected by the temperature sensor 263. The temperature sensor 263
is configured in an L shape, and has a horizontal portion installed
to pass through the manifold 209 and a vertical portion installed
to move upward from at least one end side of the wafer region
toward another end side of the wafer region.
[0063] As illustrated in FIG. 3, a controller 121 which is a
control unit (control member) is configured as a computer that
includes a central processing unit (CPU) 121a, a random access
memory (RAM) 121b, a memory device 121c, and an input/output (I/O)
port 121d. The RAM 121b, the memory device 121c, and the I/O port
121d are configured to exchange data with the CPU 121a via an
internal bus 121e. An I/O device 122 configured by, for example, a
touch panel, etc., is connected to the controller 121.
[0064] The memory device 121c is configured by, for example, a
flash memory, a hard disk drive (HDD), etc. In the memory device
121c, a control program controlling an operation of a substrate
processing apparatus or a process recipe instructing an order or
conditions of processing a substrate (which will be described
below) are stored to be readable. The process recipe is obtained by
combining operations of a substrate processing process (which will
be described below) such that a desired result is obtained when the
operations are performed by the controller 121, and acts as a
program. Hereinafter, such a process recipe and a control program
will be referred to collectively simply as a `program.` Also, when
the term `program` is used in the present disclosure, it can be
understood as including only a program recipe, only a control
program, or both the program recipe and the control program. The
RAM 121b is configured as a work area for temporarily storing a
program or data read by the CPU 121a.
[0065] The I/O port 121d is connected to the MFCs 241a to 241h, the
valves 243a to 243h, the pressure sensor 245, the APC valve 244,
the vacuum pump 246, the heater 207, the temperature sensor 263,
the rotation mechanism 267, the boat elevator 115, etc., which were
described above.
[0066] The CPU 121a is configured to read and execute the control
program stored in the memory device 121c, and read the process
recipe from the memory device 121c according to a manipulation
command received via the I/O device 122. Also, according to the
read process recipe, the CPU 121a is configured to control the MFCs
241a to 241h to adjust the flow rates of various gases, control the
valves 243a to 243h to be opened/closed, control the APC valve 244
to be opened/closed and to adjust pressure based on the pressure
sensor 245, control the heater 207 to adjust temperature based on
the temperature sensor 263, control the vacuum pump 246 to be
started and stopped, control the rotation mechanism 267 to rotate
the boat 217 and adjust a rotation speed of the boat 217, and
control the boat elevator 115 to move the boat 217
upward/downward.
[0067] The controller 121 is not limited to a dedicated computer
and may be configured as a general-purpose computer. For example,
the controller 121 according to the present embodiment may be
configured by preparing an external memory device 123 storing such
programs, e.g., a magnetic disk (a magnetic tape, a flexible disk,
a hard disk, etc.), an optical disc (a Compact Disc (CD), a Digital
Versatile Disc (DVD), etc.), a magneto-optical disc (MO), or a
semiconductor memory (a Universal Serial Bus (USB) memory, a memory
card, etc.), and then installing the programs in a general-purpose
computer using the external memory device 123. However, a method of
supplying a program to a computer is not limited to using the
external memory device 123. For example, a communication unit, such
as the Internet or an exclusive line, may be used to supply a
program to a computer without using the external memory device 123.
The memory device 121c or the external memory device 123 may be
configured as a non-transitory computer-readable recording medium.
Hereinafter, the memory device 121c or the external memory device
123 may also be referred to collectively as simply a `recording
medium.` When the term `recording medium` is used in the present
disclosure, it may be understood as including only the memory
device 121c, only the external memory device 123, or both the
memory device 121c and the external memory device 123.
[0068] Next, a method of forming a thin film on a substrate using
the substrate processing apparatus described above, which is a
process included in a semiconductor manufacturing process, will now
be described.
[0069] For example, a method of forming a film containing silicon
and carbon, i.e., a SiC-based film, on the wafer 200 serving as a
substrate by supplying a silicon-based gas and an amine-based gas
into the process chamber 201 will now be described. Specifically, a
case in which disilane (Si.sub.2H.sub.6) gas is used as the
silicon-based gas, triethyl amine [(C.sub.2H.sub.5).sub.3N,
abbreviated to: TEA] gas is used as the amine-based gas, and a SiC
film is formed as the SiC-based film is formed will now be
described. In the present embodiment, the SiC-based film is formed
under a non-plasma atmosphere. Also, in the present embodiment, a
semiconductor silicon wafer is used as the wafer 200, and the
formation of the SiC-based film is performed as a process included
in a semiconductor device manufacturing process. The SiC-based film
such as a SiC film is an insulating film having high etching and
oxidation resistances and is preferably used around a transistor
gate or in a wire structure.
[0070] In the present disclosure, the term `SiC-based film` means a
film including at least silicon (Si) and carbon (C), and may be a
silicon carbide (SiC) film. However, examples of the SiC-based film
may further include a silicon oxycarbide (SiOC) film, a silicon
carbonitride (SiCN) film, a silicon oxycarbonitride film (SiOCN)
film, etc.
[0071] When the term `wafer` is used in the present disclosure, it
should be understood as either the wafer itself, or a stacked
structure (assembly) including the wafer and a layer/film formed on
the wafer (i.e., the wafer having the layer/film formed thereon).
Also, when the expression `surface of the wafer` is used in the
present disclosure, it should be understood as either a surface
(exposed surface) of the wafer itself, or a surface of a layer/film
formed on the wafer, i.e., an uppermost surface of the wafer which
is a stacked structure.
[0072] Thus, in the present disclosure, the expression `specific
gas is supplied to a wafer` should be understood to mean that the
specific gas is directly supplied onto a surface (exposed surface)
of the wafer or that the specific gas is supplied onto a surface of
a layer/film on the wafer, i.e., the uppermost surface of the wafer
which is a stacked structure. Also, in the present disclosure, the
expression `a layer (or film) is formed on the wafer` should be
understood to mean that the layer (or film) is directly formed on a
surface (exposed surface) of the wafer itself, or that the layer
(or film) is formed on a layer/film on the wafer, i.e., on the
uppermost surface of the wafer which is the stacked structure.
[0073] Also, in the present disclosure, the term `substrate` has
the same meaning as the term `wafer.` Thus, the term `wafer` may be
interchangeable with the term `substrate.`
[0074] An example of a method of forming a SiC-based film will now
be described in detail.
[0075] A plurality of wafers 200 are placed on the boat 217 (wafer
charging). In this case, the plurality of wafers 200 are placed
such that unoccupied slots are not present in all regions of a
wafer region. Thus, during substrate processing, an actual volume
(capacity) of the process chamber 201 may be reduced and a region
in which a process gas is pyrolyzed to generate active species may
be limited (minimized), thereby suppressing generation of a
plurality of types of active species. Also, the thickness and
quality of a film may be suppressed from being influenced by the
active species, and may be uniformly achieved within and between
planes of the plurality of wafers 200. In particular, when the
plurality of wafers 200 are placed such that unoccupied slots are
not present in at least a portion adjacent to the communication
section 270 of the wafer region (a top portion of the wafer region
in the present embodiment), the volume (capacity) of the region
adjacent to the communication section 270 may be reduced and active
species may be suppressed from being generated in the vicinity of
the communication section 270. As a result, the thickness and
quality of a film formed on a wafer 200 disposed adjacent to the
communication section 270 may be appropriately suppressed from
being influenced by the active species.
[0076] Then, as illustrated in FIG. 1, the boat 217 supporting the
plurality of wafers 200 is lifted by the boat elevator 115 to be
loaded into the process chamber 201 (boat loading), and the
plurality of wafers 200 are thus accommodated in the process
chamber 201. In this state, the seal cap 219 air-tightly seals a
lower end of a process container, i.e., the manifold 209, via the
O-ring 220.
[0077] Then, while the vacuum pump 246 is operated, the APC valve
244 is gradually opened to a full extent, and the inside of the
process chamber 201 is vacuum-exhausted by the vacuum pump 246 such
that a base pressure (degree of vacuum) in the process chamber 201
becomes 1 Pa or less. The vacuum pump 246 is continuously operated
at least until processing of the wafers 200 is completed. By
rotating the boat 217 using the rotation mechanism 267, the wafers
200 are rotated (wafer rotation), and are preferably rotated such
that the number of rotations thereof is maintained constant, for
example, within a range of 1 rpm to 10 rpm. The boat 217 and the
wafer 200 are continuously rotated by the rotation mechanism 267 at
least until processing of the wafers 200 is completed. The inside
of the process chamber 201 is set to a desired temperature by
heating the inside of the process chamber 201 by the heater 207 so
that the wafers 200 may be maintained at a desired temperature (and
preferably, at a temperature that falls within, for example, a
range of 350.degree. C. to 450.degree. C.). In this case, the state
of supplying electric power to the heater 207 is
feedback-controlled based on temperature information detected by
the temperature sensor 263 so that the inside of the process
chamber 201 may have a desired temperature distribution
(temperature adjustment). The inside of the process chamber 201 is
continuously heated by the heater 207 at least until processing of
the wafers 200 is completed.
[0078] Then, nitrogen purging is performed for several minutes
under an arbitrary pressure by preferably supplying several liters
of nitrogen (N.sub.2) gas per minute into the process chamber 201
from the gas supply pipes 232e and 232f via the MFCs 241e and 241f,
the valves 243e and 243f, the gas supply pipes 232a and 232b, and
the nozzles 249a and 249b. Then, the supply of the nitrogen
(N.sub.2) gas is suspended and the nitrogen purging is
completed.
[0079] Then, the inside of the process chamber 201 is
vacuum-exhausted by the vacuum pump 246 while the APC valve 244 is
fully opened, in which a base pressure in the process chamber 201
is preferably set to, for example, 1 Pa or less. When the pressure
in the process chamber 201 becomes 1 Pa or less, the APC valve 244
is completely closed and gas confining is started. In this case,
the APC valve 244 may not be completely closed and may be slightly
opened.
[0080] The wafers 200 are maintained at a desired temperature (and
preferably, a desired temperature that falls within a range, for
example, of 350.degree. C. to 450.degree. C.), are continuously
rotated at a desired speed of rotation (and preferably, a desired
speed of rotation that falls within a range of, for example, 1 rpm
to 10 rpm), the APC valve 244 is completely closed, and disilane
(Si.sub.2H.sub.6) gas is introduced as a silicon-based gas into the
process chamber 201 from the gas supply pipe 232a via the MFC 241a,
the valve 243a, and the nozzle 249a. At the same time,
triethylamine (TEA) gas is introduced as an amine-based gas into
the process chamber 201 from the gas supply pipe 232b via the MFC
241b, the valve 243b, and the nozzle 249b. Through the above
manipulation, confining of the Si.sub.2H.sub.6 gas and the TEA gas
in the process chamber 201 is started (process A). The TEA gas is
preferably introduced at a desired flow rate that falls within a
range, for example, of 0.1 slm to 2 slm, and the Si.sub.2H.sub.6
gas is preferably introduced at a desired flow rate that falls
within a range, for example, of 0.05 slm to 0.5 slm. The duration
for which the TEA gas is supplied is preferably a time period that
falls within a range, for example, of 1 to 60 seconds, and the
duration for which the Si.sub.2H.sub.6 gas is supplied is
preferably a time period that falls within a range, for example, of
1 to 60 seconds. Also, the Si.sub.2H.sub.6 gas and the TEA gas are
confined in the process chamber 201 preferably under a desired
pressure that falls within a range, for example, of 100 to 2,000
Pa.
[0081] Then, the supply of the Si.sub.2H.sub.6 gas and the TEA gas
into the process chamber 201 is suspended, and the state in which
the Si.sub.2H.sub.6 gas and the TEA gas are confined in the inside
of the process chamber 201 is maintained while the APC valve 244 is
completely closed (process B).
[0082] In this case, in the process chamber 201, the
Si.sub.2H.sub.6 gas and the TEA gas are pyrolyzed to generate
active species. However, as described above, the volume (capacity)
of the space between the ceiling portions of the outer tube 203a
and the inner tube 203b is reduced using the flat-flat structure in
which the inner surface of the ceiling portion of the outer tube
203a and the outer surface of the ceiling portion of the inner tube
203b are formed to be flat. Thus, the actual volume (capacity) of
the process chamber 201 may be small, and a region in which the
Si.sub.2H.sub.6 gas and the TEA gas are pyrolyzed to generate
active species may be limited (reduced). As a result, a plurality
of types of active species may be suppressed from being generated.
Also, when the space between these ceiling portions is formed such
that the ratio of the surface area to the volume is high, active
species generated in this space are easily consumed in the space,
and the concentration of the active species in the space may be
appropriately lowered. Accordingly, the active species may have a
uniform concentration distribution in the inside of the process
chamber 201, and particularly, in the wafer region.
[0083] Also, as described above, the volume (capacity) of the space
between the upper end portion 203c of the inner tube 203b and the
top surface 217a of the boat 217 is reduced by using the flat-flat
structure in which the inner surface of the upper end portion 203c
of the inner tube 203b is formed to be flat and at least a portion
of the flat top surface 217a of the boat 217 is covered with the
upper end portion 203c of the inner tube 203b. Thus, the actual
volume (capacity) of the process chamber 201 may be set to be
lower, and the region in which the Si.sub.2H.sub.6 gas and the TEA
gas are pyrolyzed to generate active species may be more limited
(reduced). As a result, generation of a plurality of types of
active species may be more suppressed. Furthermore, when the space
between the upper end portion 203c of the inner tube 203b and the
top surface 217a of the boat 217 is set such that the ratio of the
surface area to the volume is high, active species generated in the
space are easily consumed in the space and the concentration of the
active species in the space may be appropriately reduced. As a
result, the concentration distribution of the active species in the
process chamber 201, and particularly in the wafer region, may be
more uniformized.
[0084] Also, as described above, the length of a path in which
active species generated on the upper portion of the wafer 200 or
between the outer tube 203a and the inner tube 203b arrive at the
wafer 200 may be increased using a structure in which the upper end
portion 203c of the inner tube 203b covers at least a portion of
the top surface (ceiling plate) 217a of the boat 217, i.e., an
upper portion of the wafer 200, and the communication section 270
is formed on the upper end portion 203c of the inner tube 203b. As
a result, the active species generated on the upper portion of the
wafer 200 or between the outer tube 203a and the inner tube 203b
may be suppressed from contacting the wafer 200. In particular,
when the communication section 270 is formed on a central portion
of the upper end portion 203c of the inner tube 203b, the length of
a path in which the active species passing through the
communication section 270 arrive at the wafer 200 may be maximized
and the active species are easily suppressed from contacting the
wafer 200.
[0085] Also, as described above, by forming a sidewall portion of
the inner tube 203b not to be in contact with the members that
constitute the boat 217, the distance between the inner wall of the
sidewall portion of the inner tube 203b and an end portion of the
wafer 200 is reduced to a lower limit and an actual volume
(capacity) of the process chamber 201 is more reduced. Thus, a
region in which the Si.sub.2H.sub.6 gas and the TEA gas are
pyrolyzed to generate active species may be more limited (reduced).
Accordingly, generation of a plurality of types of active species
may be further suppressed.
[0086] As described above, when a film is formed while process
gases such as the Si.sub.2H.sub.6 gas and the TEA gas are confined
in the process chamber 201, the thickness and quality of the film
may be suppressed from being influenced by active species and may
be uniformized within and between planes of the wafers 200 by using
the process chamber 201 including the outer tube 203a and the inner
tube 203b having the structures described above. It has been
revealed that the above effects obtained when the outer tube 203a
and the inner tube 203b described above are used are remarkably
high particularly when a film forming process including a process
of maintaining the state in which process gases are confined in the
process chamber 201 for a predetermined time is performed as in the
present embodiment.
[0087] In order to reduce a region in which a process gas is
decomposed, only the outer tube 203a may be used as the process
tube 203 without using the inner tube 203b and a volume (capacity)
of the outer tube 203a may be set to a necessary minimum level.
That is, both the distances between a sidewall portion of the outer
tube 203a and a sidewall portion of the boat 217 and between an
upper end portion of the outer tube 203a and an upper end portion
of the boat 217 may be reduced to necessary minimum levels. Here,
the necessary minimum level means a range that does not cause
difficulties in performing manufacture of a semiconductor device
and substrate processing and in handling a substrate processing
apparatus. Also, the region in which a process gas is decomposed
may be reduced by forming capacities such as convex portions (e.g.,
projections or ribs), grooves, or holes in an inner surface of the
outer tube 203a or the inner tube 203b so that the inner surface of
the outer tube 203a or the inner tube 203b may have a
concave-convex structure.
[0088] In the process A or both the processes A and B, the APC
valve 244 may not be completely closed (i.e., may be slightly
opened) to slightly exhaust the Si.sub.2H.sub.6 gas and the TEA gas
so that a slight flow of the gases may be formed. In this case, in
the process A or both the processes A and B, the Si.sub.2H.sub.6
gas and the TEA gas are exhausted from the process chamber 201
while the Si.sub.2H.sub.6 gas and the TEA gas are supplied into the
process chamber 201. In this case, the exhaust rate of the
Si.sub.2H.sub.6 gas and the TEA gas from the process chamber 201
may be maintained to be lower than the supply rate of the
Si.sub.2H.sub.6 gas and the TEA gas into the process chamber 201 so
that the Si.sub.2H.sub.6 gas and the TEA gas may be slightly
exhausted. In other words, in the process A of both the processes A
and B, the Si.sub.2H.sub.6 gas and the TEA gas may be slightly
exhausted in a state in which a total exhaust rate of the gases
exhausted from the process chamber 201 [a total gas exhaust rate
(exhaust flow rate or volume flow rate) per unit time under a
predetermined pressure] is maintained to be lower than a total
supply rate of the gases supplied into the process chamber 201 [a
total gas supply rate (supply flow rate or volume flow rate) per
unit time under the predetermined pressure]. In this case, in the
process A, the Si.sub.2H.sub.6 gas and the TEA gas are exhausted
from the process chamber 201 while the Si.sub.2H.sub.6 gas and the
TEA gas are supplied into the process chamber 201, and the exhaust
rate of the Si.sub.2H.sub.6 gas and the TEA gas from the process
chamber 201 is set to be lower than the supply rate of the
Si.sub.2H.sub.6 gas and the TEA gas into the process chamber 201,
and this state is maintained in the process B.
[0089] As described above, even if gases supplied into the process
chamber 201 are slightly exhausted, a gas confining state may
actually be formed similar to when the APC valve 244 is completely
closed. Thus, in the present disclosure, a state in which gases
supplied into the process chamber 201 are slightly exhausted is
considered as being included in the gas confining state. That is,
in the present disclosure, the term `gas confining` should be
understood as including not only a case in which the APC valve 244
is completely closed and exhausting of the inside of the process
chamber 201 is suspended but also a case in which the APC valve 244
is not completely closed and is slightly opened to maintain a state
in which an exhaust rate of gases supplied into the process chamber
201 from the process chamber 201 is lower than a supply rate of
gases supplied into the process chamber 201 and the gases supplied
into the process chamber 201 are slightly exhausted.
[0090] After the processes A and B are performed a predetermined
number of times, the APC valve 244 is completely opened to rapidly
exhaust the inside of the process chamber 201 (process C). In this
case, the Si.sub.2H.sub.6 gas or the TEA gas (that does not react
or contributes when a film is formed) or byproducts remaining in
the process chamber 201 are exhausted from the exhaust pipe 231
starting from the process chamber 201, via the communication
section 270 (opening) in the upper end portion 203c of the inner
tube 203b and the container-shaped space 250 between the inner tube
203b and the outer tube 203a.
[0091] A cycle including the processes A, B, and C, i.e., a cycle
including a process (process D) of performing the processes A and B
a predetermined number of times and the process C, is performed a
predetermined number of times until a SiC film is formed to a
desired thickness on the wafer 200. An example of a sequence of the
cycle according to the present embodiment is illustrated in FIG.
4.
[0092] Then, for example, several liters of nitrogen (N.sub.2) gas
per minute is preferably supplied into the process chamber 201 from
the gas supply pipes 232e and 232f via the MFCs 241e and 241f, the
valves 243e and 243f, the gas supply pipes 232a and 232b, and the
nozzles 249a and 249b, nitrogen purging is preferably performed,
for example, for several minutes under an arbitrary pressure, the
supply of the nitrogen gas is suspended, and the nitrogen purging
is then completed.
[0093] Then, the rotation of the boat 217 by the rotation mechanism
267 is suspended, the APC valve 244 is closed, and for example,
several liters of nitrogen (N.sub.2) gas is preferably supplied
into the process chamber 201 from the gas supply pipes 232e and
232f via the MFCs 241e and 241f, the valves 243e and 243f, the gas
supply pipes 232a and 232b, and the nozzles 249a and 249b, until
the pressure in the process chamber 201 becomes equal to
atmospheric pressure (atmospheric pressure recovery).
[0094] The boat 217 supporting the wafers 200 on which forming of a
film is completed is unloaded from the process chamber 201 by the
boat elevator 115 (boat unloading). Thereafter, the plurality of
processed wafers 200 are picked out of the boat 217.
[0095] In the present embodiment described above, as illustrated in
FIG. 4, the process of alternately performing the process of
supplying the Si.sub.2H.sub.6 gas and the TEA gas into the process
chamber 201 and confining these gases in the gas process chamber
201 (process A) and the process of maintaining the state in which
the Si.sub.2H.sub.6 gas and the TEA gas are confined in the process
chamber 201 (process B) a plurality of times (for example, three
times) (process D), and the process of exhausting the inside of the
process chamber 201 (process C) are alternately and repeatedly
performed a plurality of times. That is, in the present embodiment,
a cycle including the process D of performing a cycle including the
process A and the process B in a plurality of cycles (for example,
three cycles), and the process C is repeatedly performed in a
plurality of cycles.
[0096] Although in the present embodiment, the process C is
performed once whenever the cycle including the process A and the
process B is performed in three cycles, the process C may be
performed whenever the cycle of the process A and the process B is
performed in one cycle. That is, a process of alternately
performing the process A and the process B once and the process C
may be alternately and repeatedly performed a plurality of times.
In this case, the cycle including the processes A, B, and C is
repeatedly performed a plurality of times.
[0097] Also, the process C may be performed whenever the cycle
including the process A and the process B is performed once, and a
supply rate of the Si.sub.2H.sub.6 gas and the TEA gas supplied
once in the process A may be set to be higher than a supply rate of
the Si.sub.2H.sub.6 gas and the TEA gas supplied once in the
present embodiment (for example, to be three times the supply rate
of the Si.sub.2H.sub.6 gas and the TEA gas supplied once in the
process A in the present embodiment or to be the same as when the
cycle including the process A and the process B is performed in
three cycles). However, in this case, since large amounts of gases
are supplied when the gases are supplied once, a film forming speed
increases but the pressure in the process chamber 201 may sharply
increase, thereby degrading uniformity of the thickness of a film
formed within planes of the wafers 200 or degrading step
coverage.
[0098] Thus, when the process C is performed whenever the cycle
including the process A and the process B is performed once and the
supply rate of the Si.sub.2H.sub.6 gas and the TEA gas supplied
once in the process A is set to be low (e.g., to be less than or
equal to the supply rate of the Si.sub.2H.sub.6 gas and the TEA gas
supplied once in the process A in the present embodiment), the
uniformity of the thickness of the film within the planes of the
wafers 200 or the step coverage may be improved but the film
forming speed decreases.
[0099] In the present embodiment, the process C is performed once
whenever the cycle including the process A and the process B is
performed in three cycles. That is, since each of the
Si.sub.2H.sub.6 gas and the TEA gas is divided and supplied a
plurality of times (e.g., three times) while the APC valve 244 is
completely closed, the pressure in the process chamber 201 is
gradually increased in a multistage manner (three-step manner in
this case). In the first step (first cycle), the pressure in the
process chamber 201 and a film forming rate may be lower than in
the other steps but the uniformity of the thickness of a film
formed within the planes of the wafers 200 or step coverage may be
better than in the other steps. In contrast, in the third step
(third cycle), the pressure in the process chamber 201 and the film
forming rate may be better than in the other steps but the
uniformity of the thickness of the film formed within the planes of
the wafers 200 or step coverage may be lower than in the other
steps. Properties in the second step (second cycle) are in the
middle of those of the first step (first cycle) and those of the
third step (third cycle).
[0100] However, when the pressure in the process chamber 201 is
increased in the multistage manner (e.g., three steps) as in the
present embodiment, a film having a uniform thickness within the
planes of the wafers 200 or having high step coverage is formed in
the first step (first cycle) and films are formed in the second and
third steps using the film having the uniform thickness or the high
step coverage as an underlying film. When the films are formed in
the second and third steps, they are influenced by the underlying
film. Thereafter, films having a uniform thickness within the
planes of the wafers 200 or having high step coverage may be
formed. As described above, when the pressure in the process
chamber 201 is increased in the multistage manner, an initial layer
having a uniform thickness within the planes of the wafers 200 or
having high step coverage may be formed in an initial stage, and
the film forming rate may then be increased while securing either
thickness uniformity of a film within the planes of the wafers 200
or high step coverage.
[0101] In the present embodiment, although the duration of
supplying the TEA gas is set to be longer than the duration of
supplying the Si.sub.2H.sub.6 gas as illustrated in FIG. 4, the
duration of supplying the TEA gas may be set to be less than or
equal to the duration of supplying the Si.sub.2H.sub.6 gas.
However, it is preferable that the duration of supplying the TEA
gas be set to be equal to the duration of supplying the
Si.sub.2H.sub.6 gas.
[0102] According to the present embodiment, in the process A in
which the Si.sub.2H.sub.6 gas and the TEA gas are supplied and
confined in the process chamber 201, the Si.sub.2H.sub.6 gas and
the TEA gas are supplied into the heated process chamber 201 so
that the Si.sub.2H.sub.6 gas and the TEA gas may be thermally
decomposed in the heated process chamber 201. That is, a thermal
gas-phase decomposition reaction is caused. In the process B as in
the process A, the Si.sub.2H.sub.6 gas and the TEA gas supplied
into the process chamber 201 is thermally decomposed.
[0103] By thermally decomposing the Si.sub.2H.sub.6 gas, a material
including active species, e.g., (SiH.sub.3+SiH.sub.3),
(Si.sub.2H.sub.4+H.sub.2), or (SiH.sub.4+SiH.sub.2), is generated.
Also, by thermally decomposing the TEA [(C.sub.2H.sub.5).sub.3N]
gas, a material including active species, e.g.,
((C.sub.2H.sub.5).sub.2N+C.sub.2H.sub.5),
(C.sub.2H.sub.5N+2C.sub.2H.sub.5), (N+3C.sub.2H.sub.5), is
generated. These materials are representative examples of materials
that mainly contribute to a reaction occurring when a SiC film is
formed on the wafer 200.
[0104] In order to thermally decompose the Si.sub.2H.sub.6 gas and
the TEA gas, in the process A in which the Si.sub.2H.sub.6 gas and
the TEA gas are supplied and confined in the process chamber 201,
the pressure in the process chamber 201 is preferably set to fall
within a range of 100 to 2,000 Pa by supplying the Si.sub.2H.sub.6
gas and the TEA gas into the process chamber 201. Also, the
temperature of the heater 207 is preferably set such that the
temperature of the wafer 200 falls within a range of 350 to
450.degree. C. N.sub.2 gas may be supplied as an inert gas into the
process chamber 201 from the gas supply pipes 232e and 232f. A rare
gas such as Ar gas, He gas, Ne gas, or Xe gas may be used as the
inert gas, instead of the N.sub.2 gas.
[0105] When the temperature of the wafer 200 is less than
350.degree. C., the Si.sub.2H.sub.6 gas is not thermally decomposed
and the TEA gas does not react with a thermally decomposed
material, and the SiC film is not thus formed. When the temperature
of the wafer 200 is greater than 450.degree. C., the content of
nitrogen (N) remaining in the SiC film becomes greater than that of
impurities and the nitrogen (N) thus acts as a component to form a
film. Thus, the SiC film is prevented from being formed (that is, a
SiCN film is formed rather than the SiC film). Also, when the
temperature of the wafer 200 is greater than 450.degree. C., a
gas-phase reaction becomes excessively strong, thereby preventing
the uniformity of the thickness of a film within the planes of the
wafers 200 from being secured. Accordingly, the temperature of the
wafer 200 is preferably set to fall within a range of 350 to
450.degree. C.
[0106] When the pressure in the process chamber 201 is less than
100 Pa, a material obtained by thermally decomposing the
Si.sub.2H.sub.6 gas and a material obtained by thermally
decomposing the TEA gas are difficult to react with each other.
When the pressure in the process chamber 201 is greater than 2,000
Pa, the duration of exhausting the process chamber 201 increases in
the process C, thereby lowering the throughput. Also, when the
pressure in the process chamber 201 is greater than 2,000 Pa, the
content of nitrogen (N) remaining in the SiC film becomes greater
than that of impurities therein and the nitrogen (N) thus acts as a
component to form a film. Thus, the SiC film is prevented from
being formed (that is, a SiCN film is formed rather than the SiC
film). Also, a gas-phase reaction becomes excessively strong,
thereby preventing the uniformity of the thickness of a film within
the planes of the wafers 200 from being secured. Accordingly, the
pressure in the wafer 200 is preferably set to fall within a range
of 100 to 2,000 Pa.
[0107] When the supply flow rate of the Si.sub.2H.sub.6 gas into
the process chamber 201 is less than 50 sccm under such an
atmosphere (condition), the film forming rate is extremely
degraded. When the supply flow rate of the Si.sub.2H.sub.6 gas into
the process chamber 201 is greater than 500 sccm, the content of
carbon (C) in the SiC film decreases. Thus, the supply flow rate of
the Si.sub.2H.sub.6 gas is preferably set to fall within a range of
50 to 500 sccm (0.05 to 0.5 slm).
[0108] Also, it is preferable that the duration of supplying the
Si.sub.2H.sub.6 gas be set to be as short as possible and a
reaction continuation time thereof (the duration of suspending the
Si.sub.2H.sub.6 gas) be set to be as long as possible. That is, an
appropriate amount of the Si.sub.2H.sub.6 gas is preferably
supplied for a short time. However, when the duration of supplying
the Si.sub.2H.sub.6 gas is set to be less than one second, valve
control is difficult. Thus, the duration of supplying the
Si.sub.2H.sub.6 gas is preferably set to fall within a range of 1
to 60 seconds.
[0109] When the supply flow rate of the TEA gas into the process
chamber 201 is less than 100 sccm under such an atmosphere
(condition), the content of carbon (C) in the SiC film extremely
decreases. Also, when the supply flow rate of the TEA gas into the
process chamber 201 is greater than 2,000 sccm, the amount of the
TEA gas that does not contribute to a reaction increases and is
thus wasted. Thus, the supply flow rate of the TEA gas is
preferably set to fall within a range of 100 to 2,000 sccm (0.1 to
2 slm).
[0110] It is preferable that the duration of supplying the TEA gas
be set to be as short as possible and a reaction continuation time
thereof be set to be as long as possible. That is, an appropriate
amount of the TEA gas is preferably supplied for a short time.
However, when the duration of supplying the TEA gas is set to be
less than one second, valve control is difficult. Thus, the
duration of supplying the TEA gas is preferably set to fall within
a range of 1 to 60 seconds.
[0111] In the process B in which the supply of the Si.sub.2H.sub.6
gas and the TEA gas into the process chamber 201 is suspended and
the state in which the Si.sub.2H.sub.6 gas and the TEA gas are
confined in the process chamber 201 is maintained, materials
obtained when the Si.sub.2H.sub.6 gas and the TEA gas are thermally
decomposed in the process chamber 201 by supplying the
Si.sub.2H.sub.6 gas and the TEA gas into the heated process chamber
201 are reacted with each other. That is, a material such as
(SiH.sub.3+SiH.sub.3), (Si.sub.2H.sub.4+H.sub.2), or
(SiH.sub.4+SiH.sub.2) which is obtained by thermally decomposing
the Si.sub.2H.sub.6 gas and a material such as
(C.sub.2H.sub.5).sub.2N+C.sub.2H.sub.5),
(C.sub.2H.sub.5N+2C.sub.2H.sub.5), (N+3C.sub.2H.sub.5) which is
obtained by thermally decomposing the TEA gas are reacted with each
other. Most such reactions are gas-phase reactions but surface
reactions may slightly occur. Such a reaction occurs in the process
A and is maintained in the process B. Through the reaction, the SiC
film is formed on the wafer 200.
[0112] Since the Si.sub.2H.sub.6 gas and the TEA gas are difficult
to react with each other and have a very slow reaction rate (i.e.,
they need a time to react with each other), the SiC film may be
formed by maintaining the state in which the Si.sub.2H.sub.6 gas
and the TEA gas are confined in the process chamber 201 and
spending a time needed to perform the reaction so as to generate
the reaction.
[0113] In this case, the pressure in the process chamber 201 is
preferably maintained to fall within a range of 100 to 2,000 Pa.
Also, in this case, the temperature of the heater 207 is preferably
set such that the temperature of the wafer 200 falls within a range
of 350 to 450.degree. C. That is, the pressure in the process
chamber 201 and the temperature of the heater 207 are maintained to
fall within the ranges as in the process A.
[0114] The duration of suspending the supply of the Si.sub.2H.sub.6
gas is preferably set to fall within a range, for example, of 5 to
500 seconds. When the duration of suspending the supply of the
Si.sub.2H.sub.6 gas is set to be less than five minutes, materials
obtained by thermally decomposing the Si.sub.2H.sub.6 gas and the
TEA gas do not completely react with each other. When this reaction
proceeds to a certain degree, the amount of the materials obtained
by thermally decomposing the Si.sub.2H.sub.6 gas and the TEA gas
decreases and the efficiency of the reaction is lowered even if the
reaction occurs. Even if this state is maintained, a film is
continuously formed in a state in which the film forming rate is
lowered. That is, when the duration of suspending the supply of the
Si.sub.2H.sub.6 gas is excessively long, the throughput is lowered.
Accordingly, the duration of suspending the supply of the
Si.sub.2H.sub.6 gas is preferably set to fall within a range of 5
to 500 seconds.
[0115] It was revealed that a cycle rate of a SiC film formed
according to the present embodiment [film forming rate per one
cycle (cycle including the process A and the process B)] was 0.01
to 0.5 nm/cycle, and a film having an arbitrary thickness was
obtained by controlling the number of cycles. For example, the
thickness of the SiC film when an etch stopper is used may be in a
range of 100 to 500 .ANG. (10 to 50 nm), and may be achieved by
performing the cycle described above in, for example, 20 to 5000
cycles.
[0116] In the present embodiment, since the Si.sub.2H.sub.6 gas and
the TEA gas are supplied and confined in the process chamber 201,
the efficiency of a gas-phase reaction may be increased even when
the Si.sub.2H.sub.6 gas and the TEA gas that are difficult to react
in a low-temperature region are used, and the efficiency of film
forming (consumption of the Si.sub.2H.sub.6 gas and the TEA gas, a
film forming rate, etc.) may be improved.
[0117] According to this method, the concentration of carbon (C) in
the SiC film may be controlled to be in a range, for example, of 1
to 40% by adjusting the duration of maintaining the state in which
the Si.sub.2H.sub.6 gas and the TEA gas are confined in the process
chamber 201. That is, the concentration of carbon (C) in the SiC
film may be controlled by adjusting the duration of suspending the
supply of the Si.sub.2H.sub.6 gas and the TEA gas, and
particularly, the duration of suspending the supply of the
Si.sub.2H.sub.6 gas. In a film forming process using a thermal
process in a low-temperature region according to the present
embodiment, it was revealed that the concentration of carbon (C) in
the SiC film was limited to 40% and could not exceed 40%. A
relative dielectric constant k of the SiC film may be reduced and
an etching resistance of the SiC film may be increased by
controlling the concentration of carbon (C) in the SiC film and
increasing the concentration of carbon (C) in the SiC film.
[0118] In the present embodiment, an example of forming a SiC film
as a SiC-based film has been described above. However, the present
invention is not limited thereto, and nitrogen (N) contained in an
amine-based gas may be included in a film and a SiCN film may be
formed as a SiC-based film by increasing, for example, the
temperature of the wafer 200 and the pressure in the process
chamber 201.
[0119] Also, in the present embodiment, an example of forming a SiC
film as a SiC-based film has been described above. However, the
present invention is not limited thereto, and for example, at least
one film among a SiCN film, a SiOC film, and a SiOCN film which are
SiC-based films may be formed by performing the process B, and a
process of supplying a nitrogen-containing gas and/or a process of
supplying an oxygen-containing gas during the duration of
suspending the supply of the Si.sub.2H.sub.6 gas and the TEA
gas.
[0120] For example, as illustrated in FIG. 5, in the process B,
SiCN film may be formed as a SiC-based film by performing a process
of supplying, for example, NH.sub.3 gas as a nitriding gas, i.e., a
nitrogen-containing gas.
[0121] The nitrogen-containing gas is supplied into the process
chamber 201 from the gas supply pipe 232d via the MFC 241d, the
valve 243d, and the nozzle 249d,
[0122] Also, for example, as illustrated in FIG. 6, in the process
B, a SiOC film or a SiOCN film may be formed as a SiC-based film by
performing a process of supplying, for example, O.sub.2 gas as an
oxidizing gas, i.e., an oxygen-containing gas.
[0123] The oxygen-containing gas is supplied into the process
chamber 201 from the gas supply pipe 232c via the MFC 241c, the
valve 243c, and the nozzle 249c.
[0124] Also, for example, as illustrated in FIG. 7, in the process
B, a SiOCN film may be supplied as a SiC-based film by performing a
process of supplying NH.sub.3 gas as a nitrogen-containing gas and
a process of supplying O.sub.2 gas as an oxygen-containing gas.
[0125] Referring to FIG. 7, although the process of supplying the
NH.sub.3 gas and the process of supplying the O.sub.2 gas are
simultaneously performed, the process of supplying the NH.sub.3 gas
may be performed prior to the process of supplying the O.sub.2 gas
or the process of supplying the O.sub.2 gas may be performed prior
to the process of supplying the NH.sub.3 gas.
[0126] Referring to FIGS. 5 to 7, a case in which a process of
supplying a nitrogen-containing gas and/or a process of supplying
an oxygen-containing gas are performed while suspending the supply
of the Si.sub.2H.sub.6 gas and the TEA gas, e.g., in the process B,
has been described above. However, the present invention is not
limited to the above embodiment, and at least one film among a SiCN
film, a SiOC film, and a SiOCN film may be formed as a SiC-based
film by performing a process of supplying a nitrogen-containing gas
and/or a process of supplying an oxygen-containing gas, for
example, while maintaining the supply of the Si.sub.2H.sub.6 gas
and the TEA gas, e.g., in the process A.
[0127] Here, the silicon-based gas means a gas containing silicon
(silicon-containing gas). For example, a silane-based gas such as
disilane (Si.sub.2H.sub.6) gas or trisilane (Si3H8) gas may be
preferably used as the silicon-based gas. In the present
embodiment, a silane-based gas that contains silicon (Si) and
hydrogen (H) but does not contain chlorine (Cl) is used as the
silicon-based gas.
[0128] The amine-based gas means a gas containing an amine group,
and contains at least carbon (C), nitrogen (N), and hydrogen (H).
Examples of the amine-based gas include amines, e.g., ethylamine,
propylamine, isopropyl amine, butylamine, isobutyl amine, etc.
Here, "amine" is a generic term for a compound obtained by
replacing a hydrogen atom of ammonia (NH.sub.3) with a hydrocarbon
radical such as an alkyl group. That is, an amine contains a
hydrocarbon radical such as an alkyl group. The amine-based gas may
be referred to as a silicon-free gas since it does not contain
silicon (Si), and may be referred to as a silicon- and metal-free
gas since it does not contain a metal. For example, an
ethylamine-based gas such as triethylamine
[(C.sub.2H.sub.5).sub.3N, abbreviated to: TEA], diethylamine
[(C.sub.2H.sub.5).sub.2NH, abbreviated to: DEA], or monoethylamine
(C.sub.2H.sub.5NH.sub.2, abbreviated to: MEA); a propylamine-based
gas such as tripropylamine [(C.sub.3H.sub.7).sub.3N, abbreviated
to: TPA], dipropylamine [(C.sub.3H.sub.7).sub.2NH, abbreviated to:
DPA], or monopropylamine (C.sub.3H.sub.7NH.sub.2, abbreviated to:
MPA); an isopropyl amine-based gas such as triisopropyl amine
([(CH.sub.3).sub.2CH].sub.3N, abbreviated to: TIPA), diisoproyl
amine ([(CH.sub.3).sub.2CH].sub.2NH, abbreviated to: DIPA), or
monoisopropyl amine [(CH.sub.3).sub.2CHNH.sub.2, abbreviated to:
MIPA]; a butylamine-based gas such as tributyl amine
[(C.sub.4H.sub.9).sub.3N, abbreviated to: TBA], dibutylamine
[(C.sub.4H.sub.9).sub.2NH, abbreviated to: DBA], or monobutylamine
(C.sub.4H.sub.9NH.sub.2, abbreviated to: MBA); or an
isobutylamine-based gas such as triisobutylamine
([(CH.sub.3).sub.2CHCH.sub.2].sub.3N, abbreviated to: TIBA),
diisobutylamine ([(CH.sub.3).sub.2CHCH.sub.2].sub.2NH, abbreviated
to: DIBA), or monoisobutyl amine
[(CH.sub.3).sub.2CHCH.sub.2NH.sub.2, abbreviated to: MIBA] may be
preferably used as the amine-based gas. That is, for example, at
least one among ((C.sub.2H.sub.5).sub.xNH.sub.3-x),
((C.sub.3H.sub.7).sub.xNH.sub.3-x),
([(CH.sub.3).sub.2CH].sub.xNH.sub.3-x),
((C.sub.4H.sub.9).sub.xNH.sub.3-x), and
([(CH.sub.3).sub.2CHCH.sub.2].sub.xNH.sub.3-x) may be preferably
used as the amine-based gas. Here, `x` denotes an integer that is
equal to or greater than 1 and less than or equal to 3.
[0129] For example, ammonia (NH.sub.3) gas, diazene
(N.sub.2H.sub.2) gas, hydrazine (N.sub.2H.sub.4) gas,
N.sub.3H.sub.8 gas, etc. may be preferably used as a nitriding gas,
i.e., a nitrogen-containing gas. The nitrogen (N.sub.2) gas is an
inert gas, is not included in the SiC film, and is thus excluded
from the nitrogen-containing gas.
[0130] For example, oxygen (O.sub.2) gas, nitrous oxide (N.sub.2O)
gas, nitric oxide (NO) gas, nitrogen dioxide (NO.sub.2) gas, ozone
(O.sub.3) gas, hydrogen (H.sub.2) gas+O.sub.2 gas, H.sub.2
gas+O.sub.3 gas, vapor (H.sub.2O) gas, carbon monoxide (CO) gas,
carbon dioxide (CO.sub.2) gas, etc. may be preferably used as an
oxidizing gas, i.e., an oxygen-containing gas.
[0131] Although various embodiments of the present invention have
been described above, the present invention is not limited
thereto.
[0132] For example, in the above embodiments, it has been described
that the communication section 270 is formed above a region of the
inner tube 203b that horizontally encompasses the wafer region, and
particularly, on the upper end portion 203c of the inner tube 203b.
However, the present invention is not limited to the above
embodiments. That is, as described above, the communication section
270 may be formed above the wafer region at the sidewall portion of
the inner tube 203b and near the upper end portion 203c. Also, as
illustrated in FIG. 13, the communication section 270 may be formed
below a region of the sidewall portion of the inner tube 203b that
horizontally encompasses the wafer region and in a region that
horizontally encompasses the insulating plate arrangement
region.
[0133] When the communication section 270 is formed in the region
of the inner tube 203b that horizontally encompasses the wafer
region, the length of a path in which active species generated
between the outer tube 203a and the inner tube 203b arrives at the
wafer 200 is short and the active species easily contact the wafers
200. As a result, the uniformity of the thickness and quality of a
thin film formed on the wafers 200 is likely to be degraded within
and between planes of the wafers 200. That is, an average thickness
of a thin film formed on the wafer 200 adjacent to the
communication section 270 within the planes of the wafer 200 is
likely to be greater than that of a thin film formed on a wafer 200
distant from the communication section 270 within the planes of the
wafer 200. Also, the uniformity of the thickness of the thin film
formed on the wafer 200 adjacent to the communication section 270
within the planes of the wafer 200 is likely to be lower than that
of the thin film formed on the wafer 200 distant from the
communication section 270 within the planes of the wafer 200.
[0134] In this regard, as illustrated in FIG. 1 or 13, when the
communication section 270 is formed above or below the region of
the inner tube 203b horizontally encompassing the wafer region, the
length of a path in which active species generated between the
outer tube 203a and the inner tube 203b arrive at the wafer 200 may
be increased and the active species may be suppressed from
contacting the wafer 200. As a result, the uniformity of the
thickness and quality of the thin films formed on the wafers 200
within and between planes of the wafers 200 may be improved.
[0135] Also, in the above embodiments, it has been described above
that one communication section 270 is formed on the central portion
of the upper end portion 203c of the inner tube 203b. However, the
present invention is not limited to the above embodiments, and for
example, a plurality of communication sections 270 may be formed on
the upper end portion 203c of the inner tube 203b. That is, as
illustrated in FIG. 14, a plurality of communication sections 270
may be formed on the central portion of the upper end portion 203c
of the inner tube 203b and portions of the upper end portion 203c
of the inner tube 203b thereof (circumferential portions, etc.)
other than the central portion. Otherwise, a plurality of
communication sections 270 may be formed only on circumferential
portions of the upper end portion 203c of the inner tube 203b
rather than the central portion of the upper end portion 203c of
the inner tube 203b.
[0136] As described above, when the communication section 270 is
formed on the central portion of the upper end portion 203c of the
inner tube 203b, the length of a path in which active species
passing through the communication section 270 arrive at the wafer
200 may be increased. As a result, the active species passing
through the communication section 270 are likely to be consumed
before the active species arrives at the wafer 200. Thus, the
active species may be suppressed from contacting the wafer 200.
[0137] In this regard, when the communication section 270 is formed
on the circumferential portions or the like of the upper end
portion 203c of the inner tube 203b, the active species passing
through the communication section 270 may be suppressed from
contacting the wafer 200 by reducing the size (diameter, opening,
area, etc.) of the communication section 270. Specifically, the
active species may be suppressed from contacting the wafer 200 by
adjusting the sizes of the communication sections 270 formed on the
circumferential portions, etc. to set the amount of the active
species passing through the communication section 270 such that
most of the active species are consumed before the active species
arrive at the wafer 200. In this case, the sizes of the
communication sections 270 may be set to gradually reduce as the
distance between the central portion of the upper end portion 203c
of the inner tube 203b and each of the communication sections 270
increases.
[0138] However, even if the communication sections 270 are formed
on the circumferential portions, etc. of the upper end portion 203c
of the inner tube 203b, the communication sections 270 are
preferably formed to face the top surface (ceiling plate) 217a of
the boat 217 and to be closed by the top surface 217a of the boat
217. That is, when the communication sections 270 are formed on the
circumferential portions, etc. of the upper end portion 203c of the
inner tube 203b, the communication sections 270 are preferably
formed to face a portion more adjacent to the center of the top
surface 217a of the boat 217 than an end portion (edge) of the top
surface 217a of the boat 217. Thus, the length of a path in which
the active species passing through the communication section 270
arrive at the wafer 200 may be increased.
[0139] Also, in the above embodiments, cases in which both a
silicon-based gas and an amine-based gas are thermally decomposed
in the process A or B have been described. However, the present
invention is not limited to the above embodiments, and for example,
at least one of a silicon-based gas and an amine-based gas may be
thermally decomposed. For example, only the silicon-based gas or
the amine-based gas may be thermally decomposed. However, both the
silicon-based gas and the amine-based gas are more preferably
thermally decomposed when the efficiency of a reaction is
considered.
[0140] Also, in the above embodiments, cases in which the supply of
the silicon-based gas and the amine-based gas is suspended in the
process B have been described above. However, the present invention
is not limited to the above embodiments, and for example, an inert
gas such as N.sub.2 gas may be continuously supplied into the
nozzles 249a to 249d in the process B. In this case, the inert gas
is supplied into the process chamber 201 and the pressure in the
process chamber 201 increases. Also, the pressure in the process
chamber 201 is controlled not to exceed a process pressure, i.e., a
desired pressure that falls within a range of 100 to 2,000 Pa, by
controlling the flow rate of the inert gas supplied into the
nozzles 249a to 249d. In the process B, a film containing silicon
(Si) or carbon (C) may be prevented from being formed in the
nozzles 249a to 249d by continuously supplying the inert gas into
the nozzles 249a to 249d.
[0141] Also, in the above embodiments, cases in which a ladder boat
(in which locking grooves are formed in boat pillars) is used as a
support for supporting a substrate have been described. However,
the present invention is not limited to the above embodiments and
may be preferably applied to a case in which a ring boat is used.
In this case, the ring boat may be configured by, for example,
three or four boat pillars that stand at appropriate intervals in a
circumferential direction, and ring-shaped holders that are support
plates installed in a multistage manner and horizontally with
respect to the boat pillars to support an outer circumference of a
substrate at a back side thereof. In this case, the ring-shaped
holder may include a ring-shaped plate, the external diameter of
which is greater than the diameter of the substrate and the
internal diameter of which is less than the diameter of the
substrate, and a plurality of substrate supporting claws that are
installed at appropriate intervals and in the circumferential
direction of the ring-shaped plate and configured to support the
back surface of the outer circumference of the substrate.
Otherwise, the ring-shaped holder may include a ring-shaped plate,
the external and internal diameters of which are greater than the
diameter of the substrate, and substrate supporting claws that are
installed in the circumferential direction of an inner side of the
ring-shaped plate and at appropriate intervals and are configured
to support the back side of the circumference of the substrate.
When the ring-shaped plate is used, the distances between holes of
each of nozzles and regions partitioned between substrates (regions
partitioned by the ring-shaped plate in this case) are short and
gases emitted from the respective nozzles are can thus easily be
widely spread over the substrate arrangement region, compared to
when the ring-shaped plate is not present. Thus, a sufficient
supply rate of a gas supplied onto the substrate may be maintained,
and a film forming speed or uniformity may be prevented from being
degraded. When the ring boat is used, a SiC-based film having a
high flatness and a uniform thickness may be formed.
[0142] Also, in the above embodiments, cases in which a SiC-based
film is formed using a silicon-based gas and an amine-based gas
have been described above. However, the present invention is not
limited to the above embodiments, and for example, an organic
silicon-based gas (hereinafter referred to also as an organic
silicon source) may be used instead of the silicon-based gas and
the amine-based gas. For example, at least one source among
Si.sub.2C.sub.2H.sub.10, SiC.sub.2H.sub.8, Si.sub.2CH.sub.8,
SiC.sub.3H.sub.10, Si.sub.3CH.sub.10, SiC.sub.4H.sub.12,
Si.sub.2C.sub.3H.sub.12, Si.sub.3C.sub.2H.sub.12,
Si.sub.4CH.sub.12, SiC.sub.2H.sub.6, SiC.sub.3H.sub.8,
Si.sub.2C.sub.2H.sub.8, SiC.sub.4H.sub.10, Si.sub.2C.sub.3H.sub.10,
Si.sub.3C.sub.2H.sub.10, etc., which are organic silane sources,
may be preferably used as the organic silicon source. That is, a
source expressed as (Si.sub.xC.sub.yH.sub.2(x+y+1)) may be
preferably used as the organic silicon source when, for example,
carbon atoms are in a single bond, and a source expressed as
(Si.sub.xC.sub.(y+1)H.sub.2(x+y+1)) may be preferably used when,
for example, carbon atoms are in a double bond. In the above
formulae, `x` and `y` each denote an integer that is equal to or
greater than 1. Each of these organic silane sources consists of
only three components, i.e., silicon (Si), carbon (C), and hydrogen
(H) and does not contain chlorine (Cl), and may thus be referred to
as a chlorine-free silane-based source. The organic silicon source
may not only act as a silicon source when a SiC film is formed but
also act as a carbon source. In this case, a hydrogen-containing
gas may be supplied together with the organic silicon-based gas.
For example, hydrogen (H.sub.2) gas, ammonia (NH.sub.3) gas, a
hydrocarbon-based gas (e.g., methane (CH.sub.4) gas, diazene
(N.sub.2H.sub.2) gas, hydrazine (N.sub.2H.sub.4) gas,
N.sub.3H.sub.8 gas, etc.), a silane-based gas (e.g., SiH.sub.4,
Si.sub.2H.sub.6, etc.) may be preferably used as the
hydrogen-containing gas.
[0143] Also, in the above embodiments, cases in which a
silicon-based insulating film containing silicon (Si) which is a
semiconductor element, e.g., a SiC film, a SiCN film, a SiOCN film,
or a SiOC film, is formed have been described above. However, the
present invention is not limited to the above embodiments, and may
be applied to a case in which a metal-based thin film that contains
a metal element, e.g., titanium (Ti), zirconium (Zr), hafnium (Hf),
tantalum (Ta), aluminum (Al), or molybdenum (Mo), is formed.
[0144] For example, the present invention may be preferably applied
to a case in which a metal carbide film such as a titanium carbide
film (TiC film), a zirconium carbide film (ZrC film), a hafnium
carbide film (HfC film), a tantalum carbide film (TaC film), an
aluminum carbide film (AlC film), a molybdenum carbide film (MoC
film) is formed.
[0145] Also, the present invention may be preferably applied to a
case in which a metal carbonitride film, such as a titanium
carbonitride film (TiCN film), a zirconium carbonitride film (ZrCN
film), a hafnium carbonitride film (HfCN film), a tantalum
carbonitride film (TaCN film), an aluminum carbonitride film (AlCN
film), or a molybdenum carbonitride film (MoCN film), is
formed.
[0146] Also, the present invention may be preferably applied to a
case in which a metal oxycarbonitride film, such as a titanium
oxycarbonitride film (TiOCN film), a zirconium oxycarbonitride film
(ZrOCN film), a hafnium oxycarbonitride film (HfOCN film), a
tantalum oxycarbonitride film (TaOCN film), an aluminum
oxycarbonitride film (AlOCN film), or a molybdenum oxycarbonitride
film (MoOCN film), is formed.
[0147] Also, the present invention may be preferably applied to a
case in which a metal oxycarbide film, such as a titanium
oxycarbide film (TiOC film), a zirconium oxycarbide film (ZrOC
film), a hafnium oxycarbide film (HfOC film), a tantalum oxycarbide
film (TaOC film), an aluminum oxycarbide film (AlOC film), or a
molybdenum oxycarbide film (MoOC film), is formed.
[0148] In this case, a film may be formed according to a sequence
similar to in the above embodiments using a metal-based source gas
that contains metal elements instead of the silicon-based gas used
in the above embodiments.
[0149] For example, a titanium (Ti) based source gas, such as
titanium tetrachloride (TiCl.sub.4) or titanium tetrafluoride
(TiF.sub.4), may be used as a source gas when a metal-based thin
film containing titanium (Ti) (e.g., a TiC film, a TiCN film, a
TiOCN film, or a TiOC film) is formed. Here, the types of an
amine-based gas, a nitrogen-containing gas, and an
oxygen-containing gas may be the same as in the above embodiments.
In this case, process conditions may be the same as, for example,
in the above embodiments.
[0150] Also, for example, a zirconium (Zr) based source gas, such
as zirconium tetrachloride (ZrCl.sub.4) or zirconium tetrafluoride
(ZrF.sub.4), may be used as a source gas when a metal-based thin
film containing zirconium (Zr) (e.g., a ZrC film, a ZrCN film, a
ZrOCN film, or a ZrOC film) is formed. Here, the types of an
amine-based gas, a nitrogen-containing gas, and an
oxygen-containing gas may be the same as in the above embodiments.
In this case, process conditions may be the same as, for example,
in the above embodiments.
[0151] Also, for example, a hafnium (Hf) based source gas, such as
hafnium tetrachloride (HfCl.sub.4) or hafnium tetrafluoride
(HfF.sub.4), may be used as a source gas when a metal-based thin
film containing hafnium (Hf) (e.g., a HfC film, a HfCN film, a
HfOCN film, or a HfOC film) is formed. Here, the types of an
amine-based gas, a nitrogen-containing gas, and an
oxygen-containing gas may be the same as in the above embodiments.
In this case, process conditions may be the same as, for example,
in the above embodiments.
[0152] Also, for example, a tantalum (Ta) based source gas, such as
tantalum pentachloride (TaCl.sub.5) or tantalum pentafluoride
(TaF.sub.5), may be used as a source gas when a metal-based thin
film containing tantalum (Ta) (e.g., a TaC film, a TaCN film, a
TaOCN film, or a TaOC film) is formed. Here, the types of an
amine-based gas, a nitrogen-containing gas, and an
oxygen-containing gas may be the same as in the above embodiments.
In this case, process conditions may be the same as, for example,
in the above embodiments.
[0153] Also, for example, an aluminum (Al) based source gas, such
as aluminum trichloride (AlCl.sub.3) or aluminum trifluoride
(AlF.sub.3), may be used as a source gas when a metal-based thin
film containing aluminum (Al) (e.g., an AlC film, an AlCN film, an
AlOCN film, or an AlOC film) is formed. Here, the types of an
amine-based gas, a nitrogen-containing gas, and an
oxygen-containing gas may be the same as in the above embodiments.
In this case, process conditions may be the same as, for example,
in the above embodiments.
[0154] Also, for example, a molybdenum (Mo) based source gas, such
as molybdenum pentachloride (MoCl.sub.5) or molybdenum
pentafluoride (MoF.sub.5), may be used as a source gas when a
metal-based thin film containing molybdenum (Mo) (e.g., a MoC film,
a MoCN film, a MoOCN film, or a MoOC film) is formed. Here, the
types of an amine-based gas, a nitrogen-containing gas, and an
oxygen-containing gas may be the same as in the above embodiments.
In this case, process conditions may be the same as, for example,
in the above embodiments.
[0155] That is, the present invention may be preferably applied to
a case in which a thin film containing a predetermined element such
as a semiconductor element or a metal element is formed.
[0156] The present invention may be also applied to a case in which
a film other than a film containing a predetermined element and
carbon (C), a film containing a predetermined element, carbon (C),
and nitrogen (N), a film containing a predetermined element, oxygen
(O), carbon (C), and nitrogen (N), and a film containing a
predetermined element, oxygen (O), and carbon (C) is formed. For
example, the present invention may be applied to a case in which a
film, such as a SiN film, a SiO film, a SiON film, a TiN film, a
TiO film, a TiON film, a ZrN film, a ZrO film, a ZrON film, a HfN
film, a HfO film, a HfON film, a TaN film, a TaO film, a TaON film,
an AlN film, an AlO film, an AlON film, a MoN film, a MoO film, a
MoON film, a WN film, a WO film, or a WON film, is formed.
[0157] In this case, combinations of various gases described above
may be used when a film containing silicon (Si), i.e., a silicon
(Si) based film, is formed. Also, combinations of various gases
described above may be used when a film containing a metal, i.e., a
metal-based film, is formed. When a silicon (Si) based film is
formed, not only combinations of the various gases described above
but also those of an organic source, e.g.,
tris(dimethylamino)silane (Si[N(CH.sub.3).sub.2].sub.3H,
abbreviated to: 3DMAS), tetrakis(dimethylamino)silane
(Si[N(CH.sub.3).sub.2].sub.4, abbreviated to: 4DMAS),
bis(diethylamino)silane (Si[N(C.sub.2H.sub.5).sub.2].sub.2H.sub.2,
abbreviated to: 2DEAS), bis(tertiarybutylamino)silane
(SiH.sub.2[NH(C.sub.4H.sub.9)].sub.2, abbreviated to: BTBAS),
hexamethyl disilazane [(CH.sub.3).sub.3Si--NH--Si(CH.sub.3).sub.3,
abbreviated to: HMDS], or tetraethoxysilane
[Si(OC.sub.2H.sub.5).sub.4, abbreviated to: TEOS], may be used.
[0158] Also, in the above embodiments, the process tube 203
including the outer tube 203a, the inner surface of the upper end
portion of which has a flat shape, and the inner tube 203b, the
upper end portion 203c (top surface) of which covers at least a
portion of the top surface 217a of the boat 217 supporting the
wafers 200 and in which the communication section 270 that
communicates between the inside of the inner tube 203b and the
inside of the outer tube 203a is formed on the central portion of
the upper end portion 203c (top surface) thereof has been described
above. However, the present invention is not limited to the above
embodiments.
[0159] For example, the inner tube 203b may have the structure
according to one of the above embodiments as illustrated in FIG. 8A
or may have a structure as illustrated in one of FIGS. 8B to 8L. As
illustrated in FIGS. 8A to 8L, the communication section 270 may
have not only a ring shape (circular shape) but also a triangular
shape, a quadrilateral shape, a polygonal shape, or a combination
thereof. Also, the number of the communication sections 270 may be
more than one as described above. For example, two, three, or more
(many) communication sections 270 may be formed. When a plurality
of communication sections 270 are formed, the arrangement of the
plurality of communication sections 270 is not limited. Also, the
communication section 270 may have a slit shape. In the case of a
type of a substrate processing apparatus in which a process gas
contained in the inner tube 203b is exhausted via a lower portion
thereof, the inner tube 203b may have a structure as illustrated in
one of FIGS. 9A to 9H. Otherwise, the inner tube 203b may have a
structure that is a combination of an upper structure of the inner
tube 203b illustrated in one of FIGS. 8A to 8L and a lower
structure of the inner tube 203b illustrated in one of FIGS. 9A to
9H. Also, the shape of the inner tube 203b may be the same as or
roughly similar to a pure cylindrical shape. Also, the inner tube
203b may have an inner wall surface structure as illustrated in
FIG. 10A or 10B. Also, the inner tube 203b may have a structure
obtained from an appropriate combination of the structures
illustrated in FIGS. 8A to 8L, 9A to 9H, 10A, and 10B.
[0160] The outer tube 203a may have a structure as illustrated in
one of FIGS. 11A to 11J. Also, the shape of the outer tube 203a may
be the same as or roughly similar to a pure cylindrical shape.
Also, the outer tube 203a may have an inner wall surface structure
as illustrated in FIG. 12A or 12B. Also, the outer tube 203a may
have a structure obtained from an appropriate combination of the
structures illustrated in FIGS. 11A to 11J, 12A, and 12B.
[0161] Also, in the above embodiments, a case in which a film is
formed using a batch type substrate processing apparatus capable of
processing a plurality of substrates at once has been described.
However, the present invention is not limited to the above
embodiments and may be preferably applied to a case in which a film
is formed using, for example, a single-wafer substrate processing
apparatus capable of processing one or several substrates at
once.
[0162] Also, an appropriate combination of the methods of forming a
film according to the above embodiments or application examples
thereof may be used.
[0163] A plurality of process recipes (programs each storing a
process sequence or conditions) may be preferably individually
prepared according to the details of substrate processing (e.g.,
the type, composition ratio, quality, and thickness of a film to be
formed) to form the thin film as described above. When substrate
processing is started, an appropriate process recipe may be
preferably selected among the plurality of process recipes based on
the details of the substrate processing. Specifically, the
plurality of process recipes that are individually prepared
according to the details of the substrate processing are preferably
stored (installed) beforehand in the memory device 121c of the
substrate processing apparatus via an electrical communication line
or a recoding medium that stores the process recipes (the external
memory device 123). Then, it is preferable when substrate
processing is started for the CPU 121a of the substrate processing
apparatus to appropriately select a program recipe among the
plurality of process recipes stored in the memory device 121c
according to the details of the substrate processing. Accordingly,
one substrate processing apparatus is capable of commonly and
reproducibly forming thin films of various types and having various
composition ratios, qualities, and thicknesses. Also, substrate
processing may be rapidly started while reducing a workload on an
operator (e.g., when a process sequence or conditions are input,
etc.) and without causing errors during the manipulation.
[0164] The present invention is not limited to cases in which
process recipes are newly prepared and may be applied to, for
example, a case in which process recipes installed in a substrate
processing apparatus are modified. When a process recipe is
modified, the modified process recipe may be installed in the
substrate processing apparatus via an electrical communication line
or a recording medium recording the process recipe. A process
recipe installed in the substrate processing apparatus may be
directly changed by manipulating the I/O device 122 of the
substrate processing apparatus.
EXAMPLES
[0165] As an example of the present invention, a SiC film was
formed on a plurality of substrates using the substrate processing
apparatus according to the embodiment illustrated in FIG. 1,
according to the film forming sequence illustrated in FIG. 4. Here,
the types of process gases and a process sequence and conditions
were set to be the same as those in the above embodiments. Also, as
Comparative Example of the present invention, a SiC film was formed
on a plurality of substrates using a substrate processing apparatus
in which an inner surface of an upper end portion (ceiling portion)
of an outer tube was formed in a dome shape rather than a flat
shape and a top surface of a boat was not completely covered with
an upper end portion of an inner tube (i.e., the top surface of the
boat is fully open). Here, the types of process gases and a process
sequence and conditions were set to be the same as those in the
above embodiments. Then, the thicknesses of the respective SiC
films formed according to Example of the present invention and
Comparative Example were measured.
[0166] FIG. 15A is an enlarged view of portions of vertical process
furnaces of substrate processing apparatuses according to Example
and Comparative Example of the present invention. FIG. 15B is a
graph illustrating a result of measuring the thicknesses of SiC
films according to Example and Comparative Example of the present
invention. In the graph of FIG. 15B, the horizontal axis denotes
locations on a wafer region in which wafers are accommodated, and
the vertical axis denotes average thicknesses (.ANG.) of the
respective SiC films within planes of wafers. In FIG. 15B,
`Bottom,``Center,` and `Top` denote a lower portion, central
portion, and upper portion of the wafer region, respectively. Also,
`.diamond.` denotes Example of the present invention, and
`.tangle-solidup.` denotes Comparative Example.
[0167] As illustrated in FIG. 15B, the average thicknesses of the
SiC film within the planes of the wafers according to Example of
the present invention were substantially the same from the upper
portion Top to the lower portion Bottom, and the uniformity (WtW)
of the thicknesses within the planes of the wafers was .+-.3.66%.
In contrast, the average thicknesses of the SiC film within the
planes of the wafers according to Comparative Example increased in
the direction from the lower portion Bottom to the upper portion
Top, and the uniformity (WtW) of the thicknesses within the planes
of the wafers was .+-.24.12%. That is, it was concluded that the
uniformity of the thicknesses of the SiC film according to Example
of the present invention was far greater than that of the SiC film
according to Comparative Example, within the planes of the
wafers.
ADDITIONAL EXEMPLARY EMBODIMENTS OF THE PRESENT INVENTION WILL NOW
BE DESCRIBED
Supplementary Note 1
[0168] According to an aspect of the present invention, there is
provided a method of manufacturing a semiconductor device including
forming thin films on a plurality of substrates by performing a
cycle a predetermined number of times, the cycle including: (a)
supplying a process gas into a process container and confining the
process gas in the process container in a state where the plurality
of substrates arranged and supported by a support are accommodated
in the process container, the process container including an outer
reaction tube and an inner reaction tube disposed in the outer
reaction tube, the inner reaction tube having a flat top inner
surface at an upper end portion thereof covering at least a portion
of a top surface of the support arranging and supporting the
plurality of substrates in the inner reaction tube and including a
communication section connecting an inside of the inner reaction
tube to an inside of the outer reaction tube, wherein the
communication section is disposed at a region other than a region
horizontally encompassing a substrate arrangement region where the
plurality of substrates are arranged; (b) maintaining a state where
the process gas is confined in the process container; and (c)
exhausting the process gas from the process container via the
communication section and a space between the inner reaction tube
and the outer reaction tube.
Supplementary Note 2
[0169] In the method according to supplementary note 1, it is
preferable that the communication section is disposed above or
below the region horizontally encompassing the substrate
arrangement region.
Supplementary Note 3
[0170] In the method according to supplementary note 1 or 2, it is
preferable that the communication section is disposed at one of the
upper end portion of the inner reaction tube and a sidewall portion
of the inner reaction tube.
Supplementary Note 4
[0171] In the method according to one of supplementary notes 1 to
3, it is preferable that the communication section is disposed at a
central portion of the upper end portion of the inner reaction
tube.
Supplementary Note 5
[0172] In the method according to one of supplementary notes 1 to
4, it is preferable that the communication section includes a
plurality of communication portions disposed at the upper end
portion of the inner reaction tube.
Supplementary Note 6
[0173] In the method according to one of supplementary notes 1 to
3, it is preferable that the support includes a plate-shaped member
disposed at the top surface thereof, and the plate-shaped member
faces the communication section (or closes the communication
section).
Supplementary Note 7
[0174] In the method according to one of supplementary notes 1 to
6, it is preferable that the support includes a plate-shaped member
disposed at the top surface thereof, and the plate-shaped member
covers a surface of an uppermost one of the plurality of substrates
supported by the support.
Supplementary Note 8
[0175] In the method according to one of supplementary notes 1 to
7, it is preferable that the support includes a plate-shaped member
disposed at the top surface thereof, and the plate-shaped member
faces the communication section and a surface of an uppermost one
of the plurality of substrates supported by the support.
Supplementary Note 9
[0176] In the method according to one of supplementary notes 1 to
8, it is preferable that at least a top inner surface at an upper
end portion of the outer reaction tube is flat.
Supplementary Note 10
[0177] In the method according to one of supplementary notes 1 to
9, it is preferable that the upper end portion of the inner
reaction tube is parallel to an upper end portion of the outer
reaction tube.
Supplementary Note 11
[0178] In the method according to one of supplementary notes 1 to
10, it is preferable that an upper end portion of the outer
reaction tube, the upper end portion of the inner reaction tube and
the top surface of the support are parallel to one another.
Supplementary Note 12
[0179] In the method according to one of supplementary notes 1 to
11, it is preferable that an upper end portion of the outer
reaction tube, the upper end portion of the inner reaction tube,
the top surface of the support and surfaces of the plurality of
substrates are parallel to one another.
Supplementary Note 13
[0180] In the method according to one of supplementary notes 1 to
3, it is preferable that the support arranges and supports a
plurality of insulating plates, and the communication section is
disposed in a region horizontally encompassing an insulating plate
arrangement region where the plurality of insulating plates are
arranged.
Supplementary Note 14
[0181] In the method according to one of supplementary notes 1 to
13, it is preferable that the forming of the thin films includes
heating an inside of the process container to a thermal
decomposition temperature of the process gas.
Supplementary Note 15
[0182] In the method according to one of supplementary notes 1 to
14, it is preferable that the forming of the thin films is
performed in a non-plasma atmosphere.
Supplementary Note 16
[0183] In the method according to one of supplementary notes 1 to
15, it is preferable that, the forming of the thin films includes
alternately performing a predetermined number of times the act of
alternately performing a predetermined number of times (a)
confining the process gas in the process container and (b)
maintaining the state where the process gas is confined in the
process container; and the act of (c) exhausting the process gas
from the process container.
[0184] If a cycle includes (a) confining the process gas in the
process container and (b) maintaining the state where the process
gas is confined in the process container, "alternately performing a
predetermined number of times (a) confining the process gas in the
process container and (b) maintaining the state where the process
gas is confined in the process container" includes a case of
performing the cycle once and a case of performing the cycle a
plurality of times (repeating the cycle a plurality of times),
which means that the cycle is performed at least once (once or a
plurality of times). Similarly, if a cycle includes the act of
alternately performing a predetermined number of times (a)
confining the process gas in the process container and (b)
maintaining the state where the process gas is confined in the
process container, and the act of (c) exhausting the process gas
from the process container, "alternately performing a predetermined
number of times the act of alternately performing a predetermined
number of times (a) confining the process gas in the process
container and (b) maintaining the state where the process gas is
confined in the process container; and the act of (c) exhausting
the process gas from the process container" includes a case of
performing the cycle once and a case of performing the cycle a
plurality of times (repeating the cycle a plurality of times),
which means that the cycle is performed at least once (once or a
plurality of times).
Supplementary Note 17
[0185] In the method according to one of supplementary notes 1 to
16, it is preferable that the forming of the thin films includes
repeating a cycle a plurality of times, the cycle including: (a)
confining the process gas in the process container; (b) maintaining
the state where the process gas is confined in the process
container; and (c) exhausting the process gas from the process
container
Supplementary Note 18
[0186] In the method according to one of supplementary notes 1 to
16, it is preferable that the forming of the thin films includes
repeating a cycle a plurality of times, the cycle including: the
act of alternately repeating a predetermined number of times (a)
confining the process gas in the process container and (b)
maintaining the state where the process gas is confined in the
process container; and the act of (c) exhausting the process gas
from the process container.
Supplementary Note 19
[0187] In the method according to one of supplementary notes 1 to
18, it is preferable that the forming of the thin films includes:
thermally decomposing the process gas supplied into the process
chamber; and causing chemical reactions among materials generated
by thermally decomposing the process gas in the state where the
process gas is confined in the process chamber to react with one
another, and forming the thin films by the chemical reactions.
Supplementary Note 20
[0188] In the method according to one of supplementary notes 1 to
19, it is preferable that the exhausting of the process container
is suspended in confining the process gas in the process chamber
and maintaining the state where the process gas is confined in the
process chamber.
Supplementary Note 21
[0189] In the method according to one of supplementary notes 1 to
19, it is preferable that, in confining the process gas in the
process chamber and maintaining the state where the process gas is
confined in the process chamber, the process gas is exhausted from
the process container while the process gas is supplied into the
process container, wherein an exhaust rate of the process gas
exhausted from the process container is maintained to be less than
a supply rate of the process gas supplied into the process
container.
Supplementary Note 22
[0190] According to another aspect of the present invention, there
is provided a substrate processing apparatus including: a process
container including: an outer reaction tube; and an inner reaction
tube disposed in the outer reaction tube, the inner reaction tube
having a flat top inner surface at an upper end portion thereof
covering at least a portion of a top surface of the support
arranging and supporting the plurality of substrates in the inner
reaction tube and including a communication section connecting an
inside of the inner reaction tube to an inside of the outer
reaction tube, wherein the communication section is disposed at a
region other than a region horizontally encompassing a substrate
arrangement region where the plurality of substrates are arranged;
a process gas supply system configured to supply a process gas into
the process container; an exhaust system configured to exhaust the
process gas from the process container via the communication
section and a space between the inner reaction tube and the outer
reaction tube; and a control unit configured to control the process
gas supply system and the exhaust system to form thin films on the
plurality of substrates by performing a cycle a predetermined
number of times, the cycle including: (a) supplying the process gas
into the process container and confining the process gas in the
process container in a state where the plurality of substrates
arranged and supported by the support are accommodated in the
process container; (b) maintaining a state where the process gas is
confined in the process container; and (c) exhausting the process
gas from the process container via the communication section and
the space between the inner reaction tube and the outer reaction
tube.
Supplementary Note 23
[0191] According to still another aspect of the present invention,
there is provided a non-transitory computer readable recording
medium storing a program that causes a computer to perform a
process of forming thin films on a plurality of substrates by
performing a cycle a predetermined number of times, the cycle
including: (a) supplying a process gas into a process container and
confining the process gas in the process container in a state where
the plurality of substrates arranged and supported by a support are
accommodated in the process container, the process container
including an outer reaction tube and an inner reaction tube
disposed in the outer reaction tube, the inner reaction tube having
a flat top inner surface at an upper end portion thereof covering
at least a portion of a top surface of the support supporting the
plurality of substrates in the inner reaction tube and including a
communication section connecting an inside of the inner reaction
tube to an inside of the outer reaction tube, wherein the
communication section is disposed at a region other than a region
horizontally encompassing a substrate arrangement region where the
plurality of substrates are arranged; (b) maintaining a state where
the process gas is confined in the process container; and (c)
exhausting the process gas from the process container via the
communication section and a space between the inner reaction tube
and the outer reaction tube.
* * * * *