U.S. patent application number 09/769473 was filed with the patent office on 2001-08-09 for apparatus for manufacturing a semiconductor device in a cvd reactive chamber.
This patent application is currently assigned to KABUSHIKI KAISHA TOSHIBA. Invention is credited to Mikata, Yuichi.
Application Number | 20010012697 09/769473 |
Document ID | / |
Family ID | 13749059 |
Filed Date | 2001-08-09 |
United States Patent
Application |
20010012697 |
Kind Code |
A1 |
Mikata, Yuichi |
August 9, 2001 |
Apparatus for manufacturing a semiconductor device in a CVD
reactive chamber
Abstract
In a method of producing a semiconductor apparatus, when a thin
film is formed on a semiconductor substrate in the CVD reactive
chamber by the CVD method, a remaining region is provided where a
gas for film formation remains to a proximity of a surface of the
semiconductor substrate, and a CVD thin film is provided on the
substrate by decomposing only the gas for film formation existing
in the remaining region without supplying an additional gas from
the outside of the remaining region to the remaining region. With
the method, when the thin film is formed on the substrate by the
CVD method, the thin film is efficiently deposited on the substrate
in a reactive chamber by efficiently using a reactive gas for film
formation introduced into a CVD reactive chamber, to thereby reduce
cost of forming the thin film remarkably.
Inventors: |
Mikata, Yuichi;
(Yokohama-shi, JP) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT &
DUNNER LLP
1300 I STREET, NW
WASHINGTON
DC
20005
US
|
Assignee: |
KABUSHIKI KAISHA TOSHIBA
|
Family ID: |
13749059 |
Appl. No.: |
09/769473 |
Filed: |
January 26, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09769473 |
Jan 26, 2001 |
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08826146 |
Mar 27, 1997 |
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6211081 |
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Current U.S.
Class: |
438/758 ;
118/715; 216/58; 257/E21.101; 427/255.28 |
Current CPC
Class: |
C23C 16/4412 20130101;
H01L 21/02532 20130101; C23C 16/44 20130101; H01L 21/0262 20130101;
C23C 16/4405 20130101 |
Class at
Publication: |
438/758 ;
427/255.28; 118/715; 216/58 |
International
Class: |
H01L 021/31; C23F
001/00; C23C 016/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 3, 1996 |
JP |
8-081537 |
Claims
1. A method of producing a semiconductor apparatus, when a thin
film is formed by a CVD method on a semiconductor substrate in a
CVD reactive chamber, said method comprising the steps of:
providing a remaining region where a gas for film formation remains
to a proximity of a surface of said semiconductor substrate; and
forming a CVD thin film on said substrate by decomposing only the
gas for film formation existing in said remaining region without
supplying an additional gas from the outside of the remaining
region to said remaining region.
2. The method of producing a semiconductor apparatus according to
claim 1, wherein said step of providing said remaining region
includes the steps of: introducing said semiconductor substrate
into the CVD reactive chamber so as to reduce pressure in the CVD
reactive chamber to not more than a predetermined value; and
introducing a reactive gas into the CVD reactive chamber s as to
capture the reactive gas in the CVD reactive chamber by stopping
the introduction of the reactive gas when the pressure in the CVD
reactive chamber obtains the predetermined value.
3. The method of producing a semiconductor apparatus according to
claim 2, wherein; said step of providing said remaining region is
executed with a temperature of said semiconductor substrate being
set so that the CVD thin film is not formed, and said step of
forming the CVD thin film is executed with said semiconductor
substrate being heated to a temperature at which the CVD thin film
is formed and without supplying an additional reactive gas from the
outside of the CVD reactive chamber.
4. The method of producing a semiconductor apparatus according to
claim 1, wherein said step of providing said remaining region
includes: reducing pressure in the CVD reactive chamber to not more
than a predetermined value; introducing said semiconductor
substrate into the CVD reactive chamber; introducing a reactive gas
into the CVD reactive chamber so as to form a closed space to be
said remaining region in the proximity of the surface of said
semiconductor substrate when the pressure in the CVD reactive
chamber obtains a predetermined value; and reducing an introducing
flow rate of the reactive gas and at the same time introducing an
inert gas into the CVD reactive chamber so as to keep the pressure
in the reactive chamber at the predetermined value.
5. A method of producing a semiconductor apparatus according to
claim 4, wherein; said step of forming the closed space is executed
with a temperature of said semiconductor substrate being set so
that the CVD thin film is not formed, and said step of forming the
CVD thin film is executed with said semiconductor substrate being
heated to a temperature at which the CVD thin film is formed and
without supplying an additional reactive gas from the outside of
the closed space.
6. A method of producing a semiconductor apparatus according to
claim 5, wherein when said semiconductor substrate is heated, a
rear side of said semiconductor substrate is heated.
7. The method of producing a semiconductor apparatus according to
claim 5, wherein when said semiconductor substrate is heated, the
semiconductor substrate is moved from an area where the temperature
is lower to an area where the temperature is higher.
8. A semiconductor production equipment, comprising: a CVD reactive
chamber for inducing CVD reaction; a suscepter, for placing a
semiconductor substrate, which is provided to the outside of said
CVD reactive chamber; a first pipe arrangement, for introducing a
reactive gas, which is provided to the outside of said CVD reactive
chamber and is connected to said CVD reactive chamber; a first mass
flow controller and a first valve provided in a midway of said
first pipe arrangement; a second pipe arrangement, for introducing
an inert gas, which is provided to the outside of said CVD reactive
chamber and is connected to said CVD reactive chamber; a second
mass flow controller and a second valve provided to a midway of
said second pipe arrangement; a third pipe arrangement, for
discharging a gas, which is provided to the outside of said CVD
reactive chamber and is connected to said CVD reactive chamber; a
pressure gauge and a vacuum exhaust pump which are connected to
said third pipe arrangement; a main valve provided between a
pressure gauge connecting section and a pump connecting section of
said third pipe arrangement; heater means for heating said
suscepter and a semiconductor substrate via a wall of said CVD
reactive chamber; and a valve controller for when a thin film is
formed by a CVD method on said semiconductor substrate, controlling
said main valve so that said main valve is closed with pressure in
said CVD reactive chamber being reduced to not more than a
predetermined value and thereafter when the reactive gas is
introduced into said CVD reactive chamber, controlling said first
valve so that said first valve is closed with the pressure in said
CVD reactive chamber being set to a predetermined value.
9. A semiconductor production equipment, comprising: a CVD reactive
chamber for inducing CVD reaction; a suscepter, for placing a
semiconductor substrate, which is provided into said CVD reactive
chamber; remaining region forming means, for forming a remaining
region which is separated from an outside, for leaving a constant
volume of a gas for film formation, to a proximity of a surface of
said semiconductor substrate; heating means for heating said
semiconductor substrate; transporting means for transporting said
semiconductor substrate from a substrate stand-by chamber to said
CVD reactive chamber; gas supplying means for supplying a gas to
said remaining region; and gas exhausting means for exhausting the
gas from said remaining region.
10. The semiconductor production equipment according to claim 9,
wherein said gas supplying means is linked with a substrate
stand-by chamber, which is freely divided from said CVD reactive
chamber.
11. The semiconductor device according to claim 10, wherein said
heating means is positioned in the outside of said CVD reactive
chamber and heats said semiconductor substrate placed in said CVD
reactive chamber.
12. The semiconductor production equipment according to claim 9,
wherein said heating means heats a rear side of said semiconductor
substrate.
13. A semiconductor production equipment, comprising: a CVD
reactive chamber for inducing CVD reaction; a suscepter, for
placing a semiconductor substrate, which is provided to the outside
of said CVD reactive chamber; a first pipe arrangement, for
introducing a reactive gas, which is provided to the outside of
said CVD reactive chamber and is connected to said CVD reactive
chamber; a first mass flow controller and a first valve provided in
a midway of said first pipe arrangement; a second pipe arrangement,
for introducing an inert gas, which is provided to the outside of
said CVD reactive chamber and is connected to said CVD reactive
chamber; a second mass flow controller and a second valve provided
to a midway of said second pipe arrangement; a third pipe
arrangement, for exhausting a gas, which is provided to the outside
of said CVD reactive chamber and is connected to said CVD reactive
chamber; a pressure gauge and a vacuum exhaust pump which are
connected to said third pipe arrangement; a main valve and a
conductance valve for adjusting pressure, which are provided
between a pressure gauge connecting section and a pump connecting
section of said third pipe arrangement; a valve controller for
independently controlling said valves; a substrate introducing
chamber connected to said CVD reactive chamber via a gate valve; a
gate valve controller for controlling opening and closing of said
gate valve; a substrate transporter for introducing said
semiconductor substrate from said substrate introducing chamber
into said CVD reactive chamber; an exhausting device for setting
pressure in said substrate introducing chamber to a predetermined
value; a cover for surrounding a circumference of said
semiconductor substrate in front of said suscepter and forming a
constant volume of a closed space to be a remaining region for a
gas; a cover driving device which is provided so that said cover is
moved in front of said suscepter between a position which surrounds
the circumference of said semiconductor substrate and a forward
position of the position which surrounds the circumference of said
semiconductor substrate; and a heater, for heating said suscepter
and said semiconductor substrate, which is provided to a rear side
of said suscepter in said CVD reactive chamber.
14. The semiconductor production equipment according to claim 13,
wherein; when a thin film is formed by a CVD method on said
semiconductor substrate, said gate valve controller opens said gate
valve with pressure in said substrate introducing chamber and in
said CVD reactive chamber being reduced to not more than
predetermined values, and after said semiconductor substrate is
introduced from said substrate introducing chamber into said CVD
reactive chamber, closes said gate valve, and said cover driving
device is provided so as to move said cover in front of said
suscepter between the position which surrounds the circumference of
said semiconductor substrate and the forward position of the
position which surrounds the circumference of said semiconductor
substrate, and when a thin film is formed by a CVD method on said
semiconductor substrate, closes said cover with the reactive gas
being introduced into said CVD reactive chamber and the pressure in
said CVD reactive chamber being set to a predetermined value.
15. The semiconductor production equipment according to claim 13,
wherein after said semiconductor substrate is introduced from said
substrate introducing chamber into said CVD reactive chamber, said
valve controller controls said valves so that the reactive gas is
introduced into said CVD reactive chamber with said gate valve
being closed so that the pressure in said CVD reactive chamber is
set to a predetermined value, and after the cover is closed, the
inert gas is introduced into said CVD reactive chamber so that the
pressure in said CVD reactive chamber is set to a predetermined
value.
16. A method of producing a semiconductor apparatus when forming a
thin film by a CVD method on a semiconductor substrate in a CVD
reactive chamber by using the semiconductor production equipment
according to claim 13, said method comprising the steps of:
reducing pressure in said CVD reactive chamber to not more than a
predetermined value; introducing said semiconductor substrate into
said CVD reactive chamber; introducing a reactive gas into said CVD
reactive chamber so as to form a closed space to be a remaining
region in a proximity of a surface of said semiconductor substrate
when the pressure in said CVD reactive chamber obtains the
predetermined value; reducing an introducing flow rate of the
reactive gas and at the same time introducing an inert gas into
said CVD reactive chamber so as to keep the pressure in said
reactive chamber at the predetermined value; and forming a CVD thin
film on said substrate by decomposing only a gas for film formation
existing in said remaining region without supplying an additional
gas from the outside of said remaining region to said remaining
region.
17. The method of producing a semiconductor apparatus according to
claim 16, wherein; said step of forming the closed space is
executed with a temperature of said semiconductor substrate being
set so that a CVD thin film is not formed, and said step of forming
the CVD thin film is executed with said semiconductor substrate
being heated to a temperature at which the CVD thin film is formed
and without supplying an additional reactive gas from an outside of
the closed space.
18. A semiconductor production equipment, comprising: a CVD
reactive chamber for inducing CVD reaction; a substrate stand-by
chamber which is linked with said CVD reactive chamber; a shutter
which freely opens and closes a position which divides said CVD
reactive chamber and said substrate stand-by chamber; a shaft which
goes through a bottom plate of said substrate stand-by chamber and
freely moves up and down; a shaft driving device for driving said
shaft in an up-down direction; a cylindrical cover which is
provided to a top of a chamber of said shaft, has an opening in a
front towards said CVD reactive chamber, surrounds a circumference
of said semiconductor substrate with said opening being closed by
said semiconductor substrate, and forms a constant volume of a
closed space to be a gas remaining region; a first pipe
arrangement, for introducing a reactive gas, which is provided to
the outside of said substrate stand-by chamber and is connected to
said CVD reactive chamber; a first mass flow controller and a first
valve which are provided in a midway of said first pipe
arrangement; a second pipe arrangement, for introducing an inert
gas, which is provided to the outside of said CVD reactive chamber
and is connected to said CVD reactive chamber; a second mass flow
controller and a second valve which are provided to a midway of
said second pipe arrangement; a third pipe arrangement, for
exhausting a gas, which is provided to the outside of said CVD
reactive chamber and is connected to said CVD reactive chamber; a
pressure gauge and a vacuum exhaust pump which are connected to
said third pipe arrangement; a first main valve and a first
conductance valve for adjusting pressure which are provided between
a pressure gauge connecting section and a pump connecting section
of said third pipe arrangement; a fourth pipe arrangement, for
discharging a gas, which is provided to the outside of said
substrate stand-by chamber and is connected to said substrate
stand-by chamber; a pressure gauge and a vacuum exhaust pump which
are connected to said fourth pipe arrangement; a second main valve
and a second conductance valve for adjusting pressure which are
provided between a pressure gauge connecting section and a pump
connecting section of said fourth pipe arrangement; a valve
controller for independently controlling said valves; a substrate
introducing chamber which is connected to said substrate stand-by
chamber via a gate valve; an exhausting device for reducing
pressure in said substrate introducing chamber to a predetermined
value; a gate valve controller for opening and closing said gate
valve; a substrate transporting unit which has a function for
introducing said semiconductor substrate from said substrate
introducing chamber into said substrate stand-by chamber, a
function for retaining said semiconductor substrate in said
substrate stand-by chamber in a position separated from said cover,
and a function for placing a surface to be processed of said
semiconductor substrate towards the shaft side so as to close the
opening of said cylindrical cover; and a heater for heating said
semiconductor substrate through a top plate of said CVD reactive
chamber.
19. A method of producing a semiconductor apparatus, when a thin
film is formed by a CVD method on a semiconductor substrate in said
CVD reactive chamber by using the semiconductor production
equipment according to claim 18, said method comprising the steps
of: reducing pressure in said substrate introducing chamber to not
more than a predetermined value with said shutter; reducing
pressure in said substrate stand-by chamber to not more than a
predetermined value with said shutter being closed and said cover
being located in said substrate stand-by chamber; opening said gate
valve so as to introduce said semiconductor substrate from said
substrate introducing chamber into said substrate stand-by chamber
and to retain said semiconductor substrate in said substrate
stand-by chamber in a position separated from said cover, and
closing said gate valve; after introducing a reactive gas into aid
substrate stand-by chamber with said shutter being closed, and
placing the surface to be processed of said semiconductor substrate
towards the shaft side so that the opening of said cover is closed
when the pressure in said substrate stand-by chamber obtains the
predetermined value, and forming a closed space to be said
remaining region in a proximity of the surface of said
semiconductor substrate, reducing an introducing flow rate of the
reactive gas; introducing an inert gas into said CVD reactive
chamber so as to keep the pressure in said CVD reactive chamber at
the predetermined value; heating a top plate of said CVD reactive
chamber so as to set a temperature of said CVD reactive chamber to
a predetermined value; opening said shutter so as to introduce said
cover and said semiconductor substrate into said CVD reactive
chamber by moving them by said shaft, and heating a rear side of
said semiconductor substrate by heat radiation from the top plate
so as to set a temperature of said semiconductor substrate to a
predetermined value; and stopping the heating after a constant time
passes so as to introduce said cover and said semiconductor
substrate into said substrate stand-by chamber by moving them by
said shaft, and closing said shutter.
20. A method of producing a semiconductor apparatus, wherein when a
surface of a semiconductor substrate is etched in an etching
chamber, a remaining region where an etching gas remains in a
proximity of the surface of the substrate, is provided, and the
surface of the semiconductor substrate is etched only by the
etching gas existing in the remaining region without supplying an
additional etching gas from the outside of the remaining region to
the remaining region.
21. A method of cleaning a semiconductor production equipment,
wherein when a deposit which is deposited on an inner wall surface
of a semiconductor substrate processing chamber is removed by
etching, after an etching gas for removing a deposit is introduced
into the processing chamber, the etching gas remains in the
processing chamber, and the deposit is removed by etching without
supplying an additional etching gas from the outside.
22. The semiconductor production equipment according to claim 10,
wherein said heating means heats a rear side of said semiconductor
substrate.
23. The semiconductor production equipment according to claim 11,
wherein said heating means heats a rear side of said semiconductor
substrate.
24. The semiconductor production equipment according to claim 14,
wherein after said semiconductor substrate is introduced from said
substrate introducing chamber into said CVD reactive chamber, said
valve controller controls said valves so that the reactive gas is
introduced into said CVD reactive chamber with said gate valve
being closed so that the pressure in said CVD reactive chamber is
set to a predetermined value, and after the cover is closed, the
inert gas is introduced into said CVD reactive chamber so that the
pressure in said CVD reactive chamber is set to a predetermined
value.
25. The method of producing a semiconductor apparatus according to
claim 16, wherein; when a thin film is formed by a CVD method on
said semiconductor substrate, said gate valve controller opens said
gate valve with pressure in said substrate introducing chamber and
in said CVD reactive chamber being reduced to not more than
predetermined values, and after said semiconductor substrate is
introduced from said substrate introducing chamber into said CVD
reactive chamber, closes said gate valve, and said cover driving
device is provided so as to move said cover in front of said
suscepter between the position which surrounds the circumference of
said semiconductor substrate and the forward position of the
position which surrounds the circumference of said semiconductor
substrate, and when a thin film is formed by a CVD method on said
semiconductor substrate, closes said cover with the reactive gas
being introduced into said CVD reactive chamber and the pressure in
said CVD reactive chamber being set to a predetermined value.
26. The method of producing a semiconductor apparatus according to
claim 16, wherein after said semiconductor substrate is introduced
from said substrate introducing chamber into said CVD reactive
chamber, said valve controller controls said valves so that the
reactive gas is introduced into said CVD reactive chamber with said
gate valve being closed so that the pressure in said CVD reactive
chamber is set to a predetermined value, and after the cover is
closed, the inert gas is introduced into said CVD reactive chamber
so that the pressure in said CVD reactive chamber is set to a
predetermined value.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method of manufacturing a
semiconductor apparatus, a semiconductor production equipment and a
cleaning method thereof, more specifically relates to a method of
forming a CVD thin film on a surface of a semiconductor substrate,
a method of etching a semiconductor substrate, and a method of
cleaning a CVD unit and a CVD reactive chamber.
[0002] When a thin film is formed by a CVD method on a
semiconductor substrate, in a conventional method, a reactive gas
(for example, a silane SiH4) as a gas flow 5 for film formation is
supplied from outside to an upper portion of a substrate 2 placed
on a suscepter 8 provided into a reactive chamber 1 of a CVD unit,
shown in FIG. 5.
[0003] Gas in supplied via a value 5. A flow rate of the gas is
controlled by a mass flow controller 7 so that pressure in the
reactive chamber 1 is adjusted to be reduced to about 10 Torr while
monitoring a pressure gauge 13. Then, the substrate 2 and the
suscepter 8 are heated to 650.degree. C. by an external lamp 3
through a quartz-made wall of the reactive chamber 1, while flowing
the gas of 1 slm, so that a polycrystal silicon film is formed.
[0004] At this time, a boundary domain, which is called as a
remaining region 4 where a gas does not flow, appears on a surface
of the substrate 2, and a gas for film formation is supplied from
the gas flow 5 outside the remaining region 4. The gas for film
formation is diffused in the remaining region 4 and gets to the
surface of the substrate. Then, the gas is decomposed so that a
polycrystal silicon film is deposited.
[0005] A thickness of the remaining region 4 is influenced by the
gas flow 5. When the gas flow is not uniform, nonuniformity occurs
in thickness of the remaining region 4. As a result, the supply of
a gas to the surface of the substrate 2 becomes non-uniform, a
depositing speed is varied, and thus the film thickness is varied.
Moreover, the supply of the gas from the gas flow 5 is usually
determined by pressure division of the gas in the gas flow 5,
however under the above condition, only several percentage of the
gas in the gas flow 5 is supplied to the remaining region 4, and
thus only several percentage of the gas introduced into the
reactive chamber 1 is used for the deposition.
[0006] Therefore, most of the gas introduced into the reactive
chamber 1 is not decomposed, and passes through a main valve 9, a
pressure adjusting conductance valve 12 and a pipe arrangement 11
so as to be discharged out of a chamber by a pump 10. As a result,
cost of forming a thin film rises.
[0007] As mentioned above, in the conventional method of forming a
thin film on the semiconductor substrate by deposition, since
availability of a reactive gas for film formation introduced into
the CVD reactive chamber is low, there arises a problem that cost
of forming a thin film rises.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention has been achieved in order to solve
the above problem, and it is an object of the present invention to
provide a method of producing a semiconductor apparatus and a
semiconductor production equipment, which are capable of
efficiently depositing a thin film on a semiconductor substrate in
a reactive chamber by efficiently using a reactive gas for film
formation introduced into a CVD reactive chamber when the thin film
is formed by a CVD method on the semiconductor substrate, and is
thus capable of reducing the cost of forming a thin film
remarkably.
[0009] In addition, it is another object of the present invention
to provide a method of producing a semiconductor apparatus which is
capable of efficiently etching a semiconductor substrate by
efficiently using an etching gas introduced into an etching chamber
when a surface of the semiconductor substrate is etched in the
etching chamber, and is thus capable of reducing the etching cost
remarkably.
[0010] In addition, it is another object of the present invention
to provide a method of cleaning a semiconductor production
equipment which is capable of efficiently etching and removing a
deposit by efficiently using an etching gas introduced into a
semiconductor substrate processing chamber when the deposit on an
inner wall surface of the semiconductor substrate processing
chamber is etched and removed, and is thus capable of reducing the
cleaning cost remarkably.
[0011] According to the present invention, there is provided a
method of producing a semiconductor apparatus, when a thin film is
formed by a CVD method on a semiconductor substrate in a CVD
reactive chamber, the method comprising the steps of: providing a
remaining region where a gas for film formation remains to a
proximity of a surface of the semiconductor substrate; and forming
a CVD thin film on the substrate by decomposing only the gas for
film formation existing in the remaining region without supplying
an additional gas from the outside of the remaining region to the
remaining region. The step of providing the remaining region may
include the steps of: introducing the semiconductor substrate into
the CVD reactive chamber so as to reduce pressure in the CVD
reactive chamber to not more than a predetermined value; and
introducing a reactive gas into the CVD reactive chamber so as to
capture the reactive gas in the CVD reactive chamber by stopping
the introduction of the reactive gas when the pressure in the CVD
reactive chamber obtains the predetermined value. The step of
providing the remaining region may be executed with a temperature
of the semiconductor substrate being set so that the CVD thin film
may be not formed, and the step of forming the CVD thin film may be
executed with the semiconductor substrate being heated to a
temperature at which the CVD thin film is formed and without
supplying an additional reactive gas from the outside of the CVD
reactive chamber. The step of providing the remaining region may
include reducing pressure in the CVD reactive chamber to not more
than a predetermined value; introducing the semiconductor substrate
into the CVD reactive chamber; introducing a reactive gas into the
CVD reactive chamber so as to form a closed space to be the
remaining region in the proximity of the surface of the
semiconductor substrate when the pressure in the CVD reactive
chamber obtains a predetermined value; and reducing an introducing
flow rate of the reactive gas and at the same time introducing an
inert gas into the CVD reactive chamber so as to keep the pressure
in the reactive chamber at the predetermined value. The step of
forming the closed space may be executed with a temperature of the
semiconductor substrate being set so that the CVD thin film is not
formed, and the step of forming the CVD thin film may be executed
with the semiconductor substrate being heated to a temperature at
which the CVD thin film is formed and without supplying an
additional reactive gas from the outside of the closed space. When
the semiconductor substrate is heated, a rear side of the
semiconductor substrate may be heated. When the semiconductor
substrate is heated, the semiconductor substrate may be moved from
an area where the temperature is lower to an area where the
temperature is higher.
[0012] According to the present invention, there is also provided a
semiconductor production equipment, comprising: a CVD reactive
chamber for inducing CVD reaction; a suscepter, for placing a
semiconductor substrate, which is provided to the outside of the
CVD reactive chamber; a first pipe arrangement, for introducing a
reactive gas, which is provided to the outside of the CVD reactive
chamber and is connected to the CVD reactive chamber; a first mass
flow controller and a first valve provided in a midway of the first
pipe arrangement; a second pipe arrangement, for introducing an
inert gas, which is provided to the outside of the CVD reactive
chamber and is connected to the CVD reactive chamber; a second mass
flow controller and a second valve provided to a midway of the
second pipe arrangement; a third pipe arrangement, for discharging
a gas, which is provided to the outside of the CVD reactive chamber
and is connected to the CVD reactive chamber; a pressure gauge and
a vacuum exhaust pump which are connected to the third pipe
arrangement; a main valve provided between a pressure gauge
connecting section and a pump connecting section of the third pipe
arrangement; heater means for heating the suscepter and a
semiconductor substrate via a wall of the CVD reactive chamber; and
a valve controller for when a thin film is formed by a CVD method
on the semiconductor substrate, controlling the main valve so that
the main valve is closed with pressure in the CVD reactive chamber
being reduced to not more than a predetermined value and thereafter
when the reactive gas is introduced into the CVD reactive chamber,
controlling the first valve so that the first valve is closed with
the pressure in the CVD reactive chamber being set to a
predetermined value.
[0013] According to the present invention, there is yet further
provided a semiconductor production equipment, comprising: a CVD
reactive chamber for inducing CVD reaction; a suscepter, for
placing a semiconductor substrate, which is provided into the CVD
reactive chamber; remaining region forming means, for forming a
remaining region which is separated from an outside, for leaving a
constant volume of a gas for film formation, to a proximity of a
surface of the semiconductor substrate; heating means for heating
the semiconductor substrate; transporting means for transporting
the semiconductor substrate from a substrate stand-by chamber to
the CVD reactive chamber; gas supplying means for supplying a gas
to the remaining region; and gas exhausting means for exhausting
the gas from the remaining region. The gas supplying means may be
linked with a substrate stand-by chamber, which is freely divided
from the CVD reactive chamber. The heating means may be positioned
in the outside of the CVD reactive chamber and may heat the
semiconductor substrate placed in the CVD reactive chamber. The
heating means may heat a rear side of the semiconductor
substrate.
[0014] According to the present invention, there is still further
provided a semiconductor production equipment, comprising: a CVD
reactive chamber for inducing CVD reaction; a suscepter, for
placing a semiconductor substrate, which is provided to the outside
of the CVD reactive chamber; a first pipe arrangement, for
introducing a reactive gas, which is provided to the outside of the
CVD reactive chamber and is connected to the CVD reactive chamber;
a first mass flow controller and a first valve provided in a midway
of the first pipe arrangement; a second pipe arrangement, for
introducing an inert gas, which is provided to the outside of the
CVD reactive chamber and is connected to the CVD reactive chamber;
a second mass flow controller and a second valve provided to a
midway of the second pipe arrangement; a third pipe arrangement,
for exhausting a gas, which is provided to the outside of the CVD
reactive chamber and is connected to the CVD reactive chamber; a
pressure gauge and a vacuum exhaust pump which are connected to the
third pipe arrangement; a main valve and a conductance valve for
adjusting pressure, which are provided between a pressure gauge
connecting section and a pump connecting section of the third pipe
arrangement; a valve controller for independently controlling the
valves; a substrate introducing chamber connected to the CVD
reactive chamber via a gate valve; a gate valve controller for
controlling opening and closing of the gate valve; a substrate
transporter for introducing the semiconductor substrate from the
substrate introducing chamber into the CVD reactive chamber; an
exhausting device for setting pressure in the substrate introducing
chamber to a predetermined value; a cover for surrounding a
circumference of the semiconductor substrate in front of the
suscepter and forming a constant volume of a closed space to be a
remaining region for a gas; a cover driving device which is
provided so that the cover is moved in front of the suscepter
between a position which surrounds the circumference of the
semiconductor substrate and a forward position of the position
which surrounds the circumference of the semiconductor substrate;
and a heater, for heating the suscepter and the semiconductor
substrate, which is provided to a rear side of the suscepter in the
CVD reactive chamber. When a thin film is formed by a CVD method on
the semiconductor substrate, the gate valve controller may open the
gate valve with pressure in the substrate introducing chamber and
in the CVD reactive chamber being reduced to not more than
predetermined values, and after the semiconductor substrate is
introduced from the substrate introducing chamber into the CVD
reactive chamber, may close the gate valve, and the cover driving
device may be provided so as to move the cover in front of the
suscepter between the position which surrounds the circumference of
the semiconductor substrate and the forward position of the
position which surrounds the circumference of the semiconductor
substrate, and when a thin film is formed by a CVD method on the
semiconductor substrate, may close the cover with the reactive gas
being introduced into the CVD reactive chamber and the pressure in
the CVD reactive chamber being set to a predetermined value. After
the semiconductor substrate is introduced from the substrate
introducing chamber into the CVD reactive chamber, the valve
controller may control the valves so that the reactive gas is
introduced into the CVD reactive chamber with the gate valve being
closed so that the pressure in the CVD reactive chamber is set to a
predetermined value, and after the cover is closed, the inert gas
may be introduced into the CVD reactive chamber so that the
pressure in the CVD reactive chamber is set to a predetermined
value.
[0015] According to the present invention, there is also provided a
method of producing a semiconductor apparatus when forming a thin
film by a CVD method on a semiconductor substrate in a CVD reactive
chamber by using a semiconductor production equipment comprising: a
CVD reactive chamber for inducing CVD reaction; a suscepter, for
placing a semiconductor substrate, which is provided to the outside
of the CVD reactive chamber; a first pipe arrangement, for
introducing a reactive gas, which is provided to the outside of the
CVD reactive chamber and is connected to the CVD reactive chamber;
a first mass flow controller and a first valve provided in a midway
of the first pipe arrangement; a second pipe arrangement, for
introducing an inert gas, which is provided to the outside of the
CVD reactive chamber and is connected to the CVD reactive chamber;
a second mass flow controller and a second valve provided to a
midway of the second pipe arrangement; a third pipe arrangement,
for exhausting a gas, which is provided to the outside of the CVD
reactive chamber and is connected to the CVD reactive chamber; a
pressure gauge and a vacuum exhaust pump which are connected to the
third pipe arrangement; a main valve and a conductance valve for
adjusting pressure, which are provided between a pressure gauge
connecting section and a pump connecting section of the third pipe
arrangement; a valve controller for independently controlling the
valves; a substrate introducing chamber connected to the CVD
reactive chamber via a gate valve; a gate valve controller for
controlling opening and closing of the gate valve; a substrate
transporter for introducing the semiconductor substrate from the
substrate introducing chamber into the CVD reactive chamber; an
exhausting device for setting pressure in the substrate introducing
chamber to a predetermined value; a cover for surrounding a
circumference of the semiconductor substrate in front of the
suscepter and forming a constant volume of a closed space to be a
remaining region for a gas; a cover driving device which is
provided so that the cover is moved in front of the suscepter
between a position which surrounds the circumference of the
semiconductor substrate and a forward position of the position
which surrounds the circumference of the semiconductor substrate;
and a heater, for heating the suscepter and the semiconductor
substrate, which is provided to a rear side of the suscepter in the
CVD reactive chamber, the method comprising the steps of: reducing
pressure in the CVD reactive chamber to not more than a
predetermined value; introducing the semiconductor substrate into
the CVD reactive chamber; introducing a reactive gas into the CVD
reactive chamber so as to form a closed space to be a remaining
region in a proximity of a surface of the semiconductor substrate
when the pressure in the CVD reactive chamber obtains the
predetermined value; reducing an introducing flow rate of the
reactive gas and at the same time introducing an inert gas into the
CVD reactive chamber so as to keep the pressure in the reactive
chamber at the predetermined value; and forming a CVD thin film on
the substrate by decomposing only a gas for film formation existing
in the remaining region without supplying an additional gas from
the outside of the remaining region to the remaining region. When a
thin film is formed by a CVD method on the semiconductor substrate,
the gate valve controller may open the gate valve with pressure in
the substrate introducing chamber and in the CVD reactive chamber
being reduced to not more than predetermined values, and after the
semiconductor substrate is introduced from the substrate
introducing chamber into the CVD reactive chamber, may close the
gate valve, and the cover driving device may be provided so as to
move the cover in front of the suscepter between the position which
surrounds the circumference of the semiconductor substrate and the
forward position of the position which surrounds the circumference
of the semiconductor substrate, and when a thin film is formed by a
CVD method on the semiconductor substrate, may close the cover with
the reactive gas being introduced into the CVD reactive chamber and
the pressure in the CVD reactive chamber being set to a
predetermined value. After the semiconductor substrate is
introduced from the substrate introducing chamber into the CVD
reactive chamber, the valve controller may control the valves so
that the reactive gas is introduced into the CVD reactive chamber
with the gate valve being closed so that the pressure in the CVD
reactive chamber is set to a predetermined value, and after the
cover is closed, the inert gas may be introduced into the CVD
reactive chamber so that the pressure in the CVD reactive chamber
is set to a predetermined value. The step of forming the closed
space may be executed with a temperature of the semiconductor
substrate being set so that a CVD thin film is not formed, and the
step of forming the CVD thin film may be executed with the
semiconductor substrate being heated to a temperature at which the
CVD thin film is formed and without supplying an additional
reactive gas from an outside of the closed space.
[0016] According to the present invention, there is further
provided a semiconductor production equipment, comprising: a CVD
reactive chamber for inducing CVD reaction; a substrate stand-by
chamber which is linked with the CVD reactive chamber; a shutter
which freely opens and closes a position which divides the CVD
reactive chamber and the substrate stand-by chamber; a shaft which
goes through a bottom plate of the substrate stand-by chamber and
freely moves up and down; a shaft driving device for driving the
shaft in an up-down direction; a cylindrical cover which is
provided to a top of a chamber of the shaft, has an opening in a
front towards the CVD reactive chamber, surrounds a circumference
of the semiconductor substrate with the opening being closed by the
semiconductor substrate, and forms a constant volume of a closed
space to be a gas remaining region; a first pipe arrangement, for
introducing a reactive gas, which is provided to the outside of the
substrate stand-by chamber and is connected to the CVD reactive
chamber; a first mass flow controller and a first valve which are
provided in a midway of the first pipe arrangement; a second pipe
arrangement, for introducing an inert gas, which is provided to the
outside of the CVD reactive chamber and is connected to the CVD
reactive chamber; a second mass flow controller and a second valve
which are provided to a midway of the second pipe arrangement; a
third pipe arrangement, for exhausting a gas, which is provided to
the outside of the CVD reactive chamber and is connected to the CVD
reactive chamber; a pressure gauge and a vacuum exhaust pump which
are connected to the third pipe arrangement; a first main valve and
a first conductance valve for adjusting pressure which are provided
between a pressure gauge connecting section and a pump connecting
section of the third pipe arrangement; a fourth pipe arrangement,
for discharging a gas, which is provided to the outside of the
substrate stand-by chamber and is connected to the substrate
stand-by chamber; a pressure gauge and a vacuum exhaust pump which
are connected to the fourth pipe arrangement; a second main valve
and a second conductance valve for adjusting pressure which are
provided between a pressure gauge connecting section and a pump
connecting section of the fourth pipe arrangement; a valve
controller for independently controlling the valves; a substrate
introducing chamber which is connected to the substrate stand-by
chamber via a gate valve; an exhausting device for reducing
pressure in the substrate introducing chamber to a predetermined
value; a gate valve controller for opening and closing the gate
valve; a substrate transporting unit which has a function for
introducing the semiconductor substrate from the substrate
introducing chamber into the substrate stand-by chamber, a function
for retaining the semiconductor substrate in the substrate stand-by
chamber in a position separated from the cover, and a function for
placing a surface to be processed of the semiconductor substrate
towards the shaft side so as to close the opening of the
cylindrical cover; and a heater for heating the semiconductor
substrate through a top plate of the CVD reactive chamber.
[0017] According to the present invention, there is still further
provided a method of producing a semiconductor apparatus, when a
thin film is formed by a CVD method on a semiconductor substrate in
the CVD reactive chamber by using the semiconductor production
equipment, comprising: a CVD reactive chamber for inducing CVD
reaction; a substrate stand-by chamber which is linked with the CVD
reactive chamber; a shutter which freely opens and closes a
position which divides the CVD reactive chamber and the substrate
stand-by chamber; a shaft which goes through a bottom plate of the
substrate stand-by chamber and freely moves up and down; a shaft
driving device for driving the shaft in an up-down direction; a
cylindrical cover which is provided to a top of a chamber of the
shaft, has an opening in a front towards the CVD reactive chamber,
surrounds a circumference of the semiconductor substrate with the
opening being closed by the semiconductor substrate, and forms a
constant volume of a closed space to be a gas remaining region; a
first pipe arrangement, for introducing a reactive gas, which is
provided to the outside of the substrate stand-by chamber and is
connected to the CVD reactive chamber; a first mass flow controller
and a first valve which are provided in a midway of the first pipe
arrangement; a second pipe arrangement, for introducing an inert
gas, which is provided to the outside of the CVD reactive chamber
and is connected to the CVD reactive chamber; a second mass flow
controller and a second valve which are provided to a midway of the
second pipe arrangement; a third pipe arrangement, for exhausting a
gas, which is provided to the outside of the CVD reactive chamber
and is connected to the CVD reactive chamber; a pressure gauge and
a vacuum exhaust pump which are connected to the third pipe
arrangement; a first main valve and a first conductance valve for
adjusting pressure which are provided between a pressure gauge
connecting section and a pump connecting section of the third pipe
arrangement; a fourth pipe arrangement, for discharging a gas,
which is provided to the outside of the substrate stand-by chamber
and is connected to the substrate stand-by chamber; a pressure
gauge and a vacuum exhaust pump which are connected to the fourth
pipe arrangement; a second main valve and a second conductance
valve for adjusting pressure which are provided between a pressure
gauge connecting section and a pump connecting section of the
fourth pipe arrangement; a valve controller for independently
controlling the valves; a substrate introducing chamber which is
connected to the substrate stand-by chamber via a gate valve; an
exhausting device for reducing pressure in the substrate
introducing chamber to a predetermined value; a gate valve
controller for opening and closing the gate valve; a substrate
transporting unit which has a function for introducing the
semiconductor substrate from the substrate introducing chamber into
the substrate stand-by chamber, a function for retaining the
semiconductor substrate in the substrate stand-by chamber in a
position separated from the cover, and a function for placing a
surface to be processed of the semiconductor substrate towards the
shaft side so as to close the opening of the cylindrical cover; and
a heater for heating the semiconductor substrate through a top
plate of the CVD reactive chamber, the method comprising the steps
of: reducing pressure in the substrate introducing chamber to not
more than a predetermined value with the shutter; reducing pressure
in the substrate stand-by chamber to not more than a predetermined
value with the shutter being closed and the cover being located in
the substrate stand-by chamber; opening the gate valve so as to
introduce the semiconductor substrate from the substrate
introducing chamber into the substrate stand-by chamber and to
retain the semiconductor substrate in the substrate stand-by
chamber in a position separated from the cover, and closing the
gate valve; after introducing a reactive gas into aid substrate
stand-by chamber with the shutter being closed, and placing the
surface to be processed of the semiconductor substrate towards the
shaft side so that the opening of the cover is closed when the
pressure in the substrate stand-by chamber obtains the
predetermined value, and forming a closed space to be the remaining
region in a proximity of the surface of the semiconductor
substrate, reducing an introducing flow rate of the reactive gas;
introducing an inert gas into the CVD reactive chamber so as to
keep the pressure in the CVD reactive chamber at the predetermined
value; heating a top plate of the CVD reactive chamber so as to set
a temperature of the CVD reactive chamber to a predetermined value;
opening the shutter so as to introduce the cover and the
semiconductor substrate into the CVD reactive chamber by moving
them by the shaft, and heating a rear side of the semiconductor
substrate by heat radiation from the top plate so as to set a
temperature of the semiconductor substrate to a predetermined
value; and stopping the heating after a constant time passes so as
to introduce the cover and the semiconductor substrate into the
substrate stand-by chamber by moving them by the shaft, and closing
the shutter.
[0018] According to the present invention, there is yet further
provided a method of producing a semiconductor apparatus, wherein
when a surface of a semiconductor substrate is etched in an etching
chamber, a remaining region where an etching gas remains in a
proximity of the surface of the substrate, is provided, and the
surface of the semiconductor substrate is etched only by the
etching gas existing in the remaining region without supplying an
additional etching gas from the outside of the remaining region to
the remaining region.
[0019] According to the present invention, there is also provided a
method of cleaning a semiconductor production equipment, wherein
when a deposit which is deposited on an inner wall surface of a
semiconductor substrate processing chamber is removed by etching,
after an etching gas for removing a deposit is introduced into the
processing chamber, the etching gas remains in the processing
chamber, and the deposit is removed by etching without supplying an
additional etching gas from the outside.
[0020] Additional object and advantages of the invention will be
set forth in the description which follows, and in part will be
obvious from the description, or may be learned by practice of the
invention. The object and advantages of the invention may be
realized and obtained by means of the instrumentalities and
combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0021] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate presently
preferred embodiments of the invention, and together with the
general description given above and the detailed description of the
preferred embodiments given below, serve to explain the principles
of the invention.
[0022] FIG. 1 is a cross sectional view which shows a schematic
arrangement of an example of a CVD unit used in a method of forming
a CVD thin film according to a first embodiment of a method of
producing a semiconductor apparatus of the present invention;
[0023] FIG. 2 is a cross sectional view which shows a schematic
arrangement of an example of the CVD unit used in the method of
forming a CVD thin film according to a second embodiment of the
present invention;
[0024] FIGS. 3 and 4 are cross sectional views which show different
operating states of a schematic arrangement of an example of the
CVD unit used in the method of forming a CVD unit according to a
third embodiment of the present invention; and
[0025] FIG. 5 is a cross sectional view which shows a schematic
arrangement of a conventional CVD unit.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The following describes embodiments of the present invention
in detail on reference to drawings.
[0027] FIG. 1 shows an example of a CVD unit which is used for a
method of forming a CVD thin film according to a first embodiment
in a method of producing a semiconductor apparatus of the present
invention.
[0028] The CVD unit shown in FIG. 1 is different from the
conventional CVD unit shown in FIG. 5 in that a pressure adjusting
conductance valve is not provided, however the other parts are
substantially the same.
[0029] Specifically, in FIG. 1, 21 is a quartz-made reactive
chamber, 27 is a suscepter made of, for example, SiC, provided in
the reactive chamber, and 22 is a semiconductor substrate placed on
the suscepter 27.
[0030] The outside of the reactive chamber 21 is provided with a
first pipe arrangement 11 for introducing a reactive gas (material
gas, such as a SiH.sub.4 gas), a first mass flow controller 26 and
a first valve 25, for controlling a flow rate of the reactive gas,
which are provided in a midway of the first pipe arrangement, a
second pipe arrangement 12 for introducing an inert gas (for
example N.sub.2), a second mass flow controller 13 and a second
valve 14, for controlling a flow rate of the inert gas, which are
provided to a midway of the second pipe arrangement, a third pipe
arrangement 15 for discharging a gas, a pressure gauge 16 and a
vacuum exhausting pump 29 which are connected to the third pipe
arrangement, a main valve 28 provided to a midway of the third pipe
arrangement (between the pressure gauge connecting section and the
pump connecting section), a lamp 23 for heating the suscepter 27
and the substrate 22 through the wall of the reactive chamber,
etc.
[0031] The following describes a method of forming a CVD thin film
using the CVD unit shown in FIG. 1.
[0032] First, after the substrate 22 is introduced into the
reactive chamber 21 at a temperature of not more than 300.degree.
C., pressure is reduced to not more than 10.sup.-2 Torr (1
Torr=133.322 Pa) by the pump 29. Thereafter, the main valve 28 is
closed, and a SiH.sub.4 gas 24 is introduced from a reactive gas
source into the reactive chamber 21 through the first mass flow
controller 26 and the first valve 25. Then, the pressure in the
reactive chamber is checked by the pressure gauge 16 to becomes 10
Torr, and the introduction of the reactive gas is stopped by
closing the first valve 25.
[0033] In such a manner, with the SiH.sub.4 gas being sealed in the
reactive chamber at the pressure of 10 Torr, the substrate 22 and
the suscepter 27 are heated by the lamp 23 with heat up rate of
20.degree. C./sec, and after a temperature of the substrate 22 is
set to 800.degree. C. and kept for one minutes, the heating is
stopped. As a result, the SiH.sub.4 is decomposed on the substrate
22, and thus a polycrystal silicon with a thickness of 400 nm is
deposited on the substrate 22 and the suscepter 27. Thereafter,
when the temperature is lowered to not more than 600.degree. C.,
the main valve 28 is opened so that the gas is discharged out of
the reactive chamber.
[0034] In the aforementioned method of forming the CVD thin film,
since the reactive gas 24 hardly flows in the reactive chamber 21,
a remaining region is produced on the substrate 22. Therefore,
nonuniformity of the reactive gas flow does not occur, and
scattering of the supplying of the reactive gas to the substrate
does not occur. By the way, such a satisfactory result, that the
uniformity of a thickness of the formed CVD thin film in the
substrate was less than .+-.2%, was obtained.
[0035] In addition, since the gas is not exhausted from the chamber
during the film formation, the availability of the using gas can be
improved. Such a satisfactory result, that the availability of the
reactive gas was not less than 50%, was obtained.
[0036] Here, during the film formation, a temperature of the inner
wall of the reactive chamber 21 becomes not more than 400.degree.
C. due to air cooling, and depositing of polycrystal silicon hardly
occurs on the inner surface of the reactive chamber 21. However,
since the polycrystal silicon is deposited on the suscepter 27,
etc. due to long-time use, it is necessary to execute cleaning.
[0037] Therefore, after the polycrystal silicon of 30 .mu.m, for
example, is deposited on the suscepter 27, the deposit is removed
by an etching gas such as HCI and CIF.sub.3 (execute gas
cleaning).
[0038] In this case, the etching may be execute while letting HCI
flow in the reactive chamber 21, but according to the
aforementioned formation of the CVD thin film, the etching is
executed under high pressure of about 100 Torr with the etching gas
remaining in the reactive chamber 21 so that the availability of
the etching gas can be improved to not less than 50%. Here, the
polycrystal silicon which adhered to the quartz-made inner wall of
the reactive chamber 21 can be removed by acid-cleaning.
[0039] In addition, in the above embodiment, the CVD thin film is
deposited under the conditions of 10 Torr and 800.degree. C., but
the pressure may be in the range of 1 mTorr-200 Torr, and the
temperature may be in the range of 500.degree. C.-900.degree.
C.
[0040] In addition, the method of forming a CVD thin film of the
present invention is not limited to the polycrystal silicon, so it
is applicable to the case where a silicon oxide film, a silicon
nitride, thin films made of W, WSi, TiN, etc. are deposited.
[0041] FIG. 2 shows an example of the CVD unit which is used for a
method of forming a CVD thin film according to a second embodiment
of the present invention.
[0042] The CVD unit shown in FIG. 2 is different from the CVD unit
shown in FIG. 1 in that (1) a pressure adjusting conductance valve
32 is placed between the main valve 28 and the pump connecting
section in the midway of the third pipe arrangement, (2) a
substrate introducing chamber 39 for introducing the substrate 22
into a reactive chamber 31 is connected to the reactive chamber 31
via a gate valve 38, and the substrate introducing chamber 39 can
be set so as to have reduced pressure by an exhausting pump (not
shown) before the introduction of the substrate 22, (3) a cover,
which has a such a shape that surrounds a circumference of the
substrate on the suscepter 27, is provided, and the cover 33 can be
moved up and down between the position which surrounds the
circumference of the substrate on the suscepter 27 and its upward
position by a driving unit (not shown), and (4) a
resistance-heating-type heater 37 is provided below the suscepter
27 in the reactive chamber 31 so as to heat the suscepter 27 and
the rear side of the substrate, and the aforementioned lamp outside
the reactive chamber is not provided. The other parts are
substantially the same.
[0043] Namely, in FIG. 2, 31 is a metal-made reactive chamber, 27
is a suscepter, 22 is a substrate, 11 is a first pipe arrangement
for introducing a reactive gas, 26 is a mass flow controller for
controlling a flow rate of a reactive gas, 25 is a valve of the
first pipe arrangement, 12 is a second pipe arrangement for
introducing an inert gas, 13 is a mass flow controller for
controlling a flow rate of an inert gas, 14 is a valve of the
second pipe arrangement, 15 is a third pipe arrangement for
discharging a gas, 16 is a pressure gauge, 28 is a main valve, 29
is a pump for vacuum exhaust, and 32 is a pressure adjusting
conductance valve.
[0044] The following explains a method of forming a CVD thin film
using the CVD unit shown in FIG. 2.
[0045] First, the pressure of the substrate introducing chamber 39
is reduced to not more than 10.sup.-2 Torr, and in the same manner
as the substrate introducing chamber 39, the pressure of the
reactive chamber 31 is reduced to not more than 10.sup.-2 Torr and
its temperature is set to not more than 300.degree. C.
[0046] Next, the gate valve 38 is opened, and the substrate 22 is
introduced from the substrate introducing chamber 39 into the
reactive chamber 31 with the same pressure as the substrate
introducing chamber 39. Then, the substrate 22 is placed on the
suscepter 27 with the cover 33 being opened, and the gate valve 38
is closed.
[0047] Next, a SiH.sub.4 gas is passed from a reactive gas source
through the mass flow controller 26 and the valve 25 so as to be
introduced into the reactive chamber 31. Then, the pressure in the
reactive chamber 31 is adjusted so as to be 10 Torr by the
conductance valve 32 while checking the pressure through the
pressure gauge 16.
[0048] When the cover 33 is closed, a closed space (a reactive gas
remaining region), which surrounds the circumference of the
substrate, is formed by the suscepter 27 and the cover 33.
Thereafter, the flow rate of the reactive gas in the mass flow
controller 26 is reduced, and at the same time N.sub.2 gas is
introduced from an inert gas source through the mass flow
controller 13 and the valve 14 into the reactive chamber 31 so that
the pressure in the reactive chamber 31 is kept at 10 Torr.
[0049] In such a manner, with the SiH.sub.4 gas being captured at
10 Torr in the closed space which surrounds the circumference of
the substrate, the suscepter 27 is heated by the heater 37, the
temperature of the substrate 22 in the closed space is raised to
800.degree. C. with heat up rate of 10.degree. C./sec. As a result,
the SiH.sub.4 in the closed space is decomposed on the substrate
22, and polycrystal silicon is deposited on the substrate. Then,
when the heating by the heater 37 is stopped after one minutes, the
temperature of the substrate is lowered, and after the cover 33 is
opened and a residual gas in the reactive chamber 31 is exhausted,
the substrate 22 is taken out from the reactive chamber 31.
[0050] In such a method, similarly to the first embodiment, the
polycrystal silicon could be deposited on the substrate. At his
time, the temperature in the substrate 22 could be set constant by
heating the suscepter by the heater 37. Moreover, since the
SiH.sub.4 gas does not remain except in the closed space by an
purge effect of the N.sub.2 gas, the polycrystal silicon is not
deposited on the inner wall of the reactive chamber 31.
[0051] As to the polycrystal silicon deposited in the cover 33 by
the long-period film formation, the etching gas is captured in the
closed space in the same manner as the deposition so that the
polycrystal silicon is removed by etching at a temperature of
900.degree. C. As a result, the availability of the HCI gas can be
improved to not less than 50%. At this time, while letting the HCI
gas of about 5 slm flow in the reactive chamber 31, the polycrystal
silicon may be removed by etching. Moreover, the condition of the
deposition may be changed in the same manner as the first
embodiment. Moreover, as to the arrangement of the CVD unit, while
the relative position of the cover 33, the suscepter 27, the
substrate 22 and the heater 37 is being retained, their up-down
relation may be inverted or their direction may be changed
arbitrarily.
[0052] FIGS. 3 and 4 show different operating states for an example
of the CVD unit used in the method of forming a CVD thin film
according to a third embodiment of the present invention.
[0053] The CVD unit shown in FIGS. 3 and 4 is different from the
CVD unit shown in FIG. 2 in that (1) a SiC-made reactive chamber 41
and a substrate stand-by chamber 414 are separated by the
water-cooled shutter 410 and are connected to each other, (2) the
first pipe arrangement 11 for introducing a reactive gas is
connected to a substrate stand-by chamber 414, and the second pipe
arrangement 12 for introducing an inert gas is connected to the
reactive chamber 41, (3) similarly to the reactive chamber 41, a
fourth pipe arrangement 419 for discharging a gas is connected to
the substrate stand-by chamber 414, a pressure gauge 415 and a
vacuum exhausting pump 418 are connected to the fourth pipe
arrangement, and a main valve 416 and a pressure adjusting
conductance valve 417 are provided to a midway of the fourth pipe
arrangement 419 (between a pressure gauge connecting section and a
pump connecting section), (4) a shaft 412 is provided so as to go
through a bottom plate of the substrate stand-by chamber 414 and to
freely move up and down, a cylindrical cover 411 with an opened top
where a substrate 413 is placed downward is provided to the top of
the shaft 412, and a shaft driving unit (not shown) for driving the
shaft 412 up and down is provided outside the substrate stand-by
chamber, (5) a substrate transporting/retaining unit (not shown),
which has a function for introducing the substrate 413 from the
substrate introducing chamber 46 into the substrate stand-by
chamber 414, a function for retaining the substrate 413 in a
position separated from the cover 411 in the substrate stand-by
chamber 414 and a function for placing the surface to be processed
of the substrate 413 towards the shaft 412 so that the opening of
the cover 411 is closed, is provided, and (6) a heater 43 for
heating the rear side of the substrate 413 through a SiC-made top
plate 42 of the reactive chamber 41 is provided outside the
reactive chamber, and the aforementioned heater 37 in the reactive
chamber is not provided.
[0054] Namely, the CVD unit shown in FIGS. 3 and 4 includes the CVD
reactive chamber 41 for inducing CVD reaction, the substrate
stand-by chamber 414 linked with the CVD reactive chamber, the
shutter 410 which freely opens and closes the position separating
the CVD reactive chamber from the substrate stand-by chamber, the
shaft 412 which goes through the bottom plate of the substrate
stand-by chamber and freely moves up and down, the shaft driving
unit (not shown) for driving the shaft in the up-down direction,
the cylindrical cover 411 which is provided to the top of the
chamber of the shaft, has the opening at the front towards the CVD
reactive chamber, surrounds the circumference of the substrate with
the opening being closed by the substrate 413, and forms a constant
volume of closed space to be a gas remaining region, the first pipe
arrangement 11, for introducing a reactive gas, which is provided
outside the substrate stand-by chamber and is connected to the CVD
reactive chamber, the first mass flow controller 49 and the first
valve 48 which are provided to the midway of the first pipe
arrangement, the second pipe arrangement 12, for introducing an
inert gas, which is provided outside the CVD reactive chamber and
is connected to the CVD reactive chamber, the second mass flow
controller 45 and the second valve 44 which are provided to the
midway of the second pipe arrangement, the third pipe arrangement
421, for exhausting a gas, which is provided outside the CVD
reactive chamber and is connected to the CVD reactive chamber, a
pressure gauge 424 and a vacuum exhausting pump 420 which are
connected to the third pipe arrangement, a first main valve 423 and
a first conductance valve 422 for adjusting pressure which are
provided between a pressure gauge connecting section and a pump
connecting section of the third pipe arrangement 421, the fourth
pipe arrangement 419, for discharging gas, which is provided
outside the substrate stand-by chamber 414 and is connected to the
substrate stand-by chamber, the pressure gauge 415 and the vacuum
exhausting pump 418 which are connected to the fourth pipe
arrangement, the second main valve 416 and the second conductance
valve 417 for adjusting pressure which are provided between a
pressure connecting section and a pump connecting section of the
fourth pipe arrangement, a valve controller (not shown) for
independently controlling the valves, the substrate introducing
chamber 46 which is connected to the substrate stand-by chamber via
the gate valve 47, an exhausting unit (not shown) for setting the
substrate introducing chamber so as to have a reduced pressure, a
gate valve controller (not shown) for controlling opening and
closing of the gate valve 47, a substrate transporting unit (not
shown) which has a function for introducing the substrate from the
substrate introducing chamber into the substrate stand-by chamber,
a function for retaining the substrate in a position separated from
the cover in the substrate stand-by chamber, and a function for
placing the surface to be processed of the substrate towards the
shaft so that the opening of the cover is closed, and a heater 43,
for heating the substrate through the top plate 42 of the CVD
reactive chamber, which is provided outside the CVD reactive
chamber.
[0055] When the CVD thin film is formed by the CVD method on the
substrate in the CVD reactive chamber by using the CVD unit shown
in FIGS. 3 and 4, the following steps are followed.
[0056] Namely, the following steps are followed: the step of
reducing pressure in the substrate introducing chamber 414 to a
predetermined value with the shutter 410 being closed; the step of
reducing pressure in the substrate stand-by chamber with the
shutter 410 is being closed and the cover 411 being positioned in
the substrate stand-by chamber; the step of opening the gate valve
47 so that the substrate 413 is introduced from the substrate
introducing chamber 46 into the substrate stand-by chamber and that
the substrate is retained in a position separated from the cover
411 in the substrate stand-by chamber, and closing the gate valve
47; the step of introducing a reactive gas into the substrate
stand-by chamber with the shutter 410 being closed, placing the
surface to be processed of the substrate towards the shaft 412 so
that the opening of the cover is closed when the pressure in the
chamber comes to the set pressure, and after the closed space to be
a gas remaining region is formed in the proximity of the surface of
the substrate, reducing a flow rate of the reactive gas; the step
of introducing an inert gas into the CVD reactive chamber 41 so as
to retain the pressure in the CVD reactive chamber at a
predetermined value; the step of heating the top plate 42 of the
CVD reactive chamber so as to set the temperature of the CVD
reactive chamber to a predetermined value; the step of opening the
shutter 410 so as to introduce the cover 411 and the substrate 413
into the CVD reactive chamber by moving them by the shaft 412, and
heating the rear side of the substrate by heat radiation from the
top plate 42 so as to set the temperature of the substrate to a
predetermined value; and step of stopping the heating after a
constant time passed, introducing the cover 411 and the substrate
410 into the substrate stand-by chamber 414 by moving them by the
shaft 412, and closing the shutter 413.
[0057] The following concretely describes the above steps.
[0058] First, with the substrate being set in the substrate
introducing chamber 414, and as shown in FIG. 3, the gate valve 47
being closed, the pressure in the substrate introducing chamber 46
is reduced to not more than 10.sup.-2 Torr. Moreover, with the
cover 411 being positioned in the substrate stand-by chamber 414,
the pressure of the substrate stand-by chamber 414 is reduced to
not more than 10.sup.-2 Torr in the same manner as the substrate
introducing chamber 46.
[0059] Next, the gate valve 47 is opened, and the substrate 413 is
introduced from the substrate introducing chamber 46 into the
substrate stand-by chamber 414 with the same pressure as the
chamber 46. Then, the substrate is retained above the cover 411
with the substrate facing downward, and the gate valve 47 is
closed.
[0060] Next, in the same manner as the second embodiment, a
SiH.sub.4 gas is allowed to pass from the reactive gas source
through the mass flow controller 49 and the valve 48 so as to
introduced into the substrate stand-by chamber 414. Then, the
pressure in the reactive chamber is adjusted to 10 Torr by the
conductance valve 417 while checking the pressure through the
pressure gauge 415. The substrate is placed on the cover 411 with
it facing downward so that the closed space which surrounds the
circumference of the substrate is formed.
[0061] Next, in order to reduce the flow rate of the reactive gas
into the mass flow controller 49 and to purge the reactive chamber
41 other than the closed space by a N.sub.2 gas, the N.sub.2 gas of
1 slm is allowed to pass from the inert gas source through the mass
flow controller 45 and the valve 44 so as to be introduced into the
reactive chamber 41, and the pressure in the reactive chamber 41 is
maintained at 10 Torr in the same manner as the substrate stand-by
chamber. Moreover, the top plate 42 of the reactive chamber 41 is
heated by the heater 43 so that the temperature of the top side of
the reactive chamber 41 to 1150.degree. C.
[0062] Next, as shown in FIG. 4, the shutter 410 is opened, and
with the SiH.sub.4 gas being captured in the closed space which
surrounds the circumference of the substrate at 10 Torr, as
mentioned above, the cover 411 and the substrate 413 are raised. At
this time, the substrate 413 is brought close to the top plate 42
of the reactive chamber, and when the rear side of the substrate
413 receives the heat radiation from the top plate 42, the
temperature of the substrate 413 rises. Distance between the top
plate 42 and the substrate 413 is adjusted so that the temperature
of the substrate 413 becomes 800.degree. C. with heat up rate of
20.degree. C./sec, and the temperature is maintained at 800.degree.
C. for one minutes.
[0063] As a result, the SiH.sub.4 gas in the closed space is
decomposed on the substrate 413, and polycrystal silicon is
decomposed on the substrate. Then, in order to stop the heating by
the heater 43 after one minutes, the cover 411 and the substrate
413 are lowered so as to be moved to the substrate stand-by chamber
414. Then, the shutter 410 is closed.
[0064] Next, the substrate 413 is raised by a mechanism, not shown,
and a gas remaining in the substrate stand-by chamber 414 is
exhausted by the pump 418. Thereafter, the substrate 413 is taken
out of the CVD unit.
[0065] Similarly to the first and second embodiments, the
polycrystal silicon could be deposited on the substrate uniformly
by the above method. Moreover, since the SiH.sub.4 gas does not
remain in the reactive chamber 41 other than the closed space by
the purge effect of the N.sub.2 gas, polycrystal silicon is not
decomposed on the inner wall of the reactive chamber 41. Moreover,
the availability of gas was improved more than the first and second
embodiments.
[0066] Here, the polycrystal silicon deposited on the cover 411 by
the long-period film formation was removed by etching with a dummy
substrate being used, an etching being captured in the closed space
in the same manner as the deposition, and the temperature of the
reactive chamber 41 being raised to 900.degree. C. in the same
manner as the deposition.
[0067] At this time, only the cover 411 is introduced into the
reactive chamber 41, and while letting HCI of 5 slm flow in the
reactive chamber 41, the polycrystal silicon may be removed by
etching at 900.degree. C. and at 10 Torr. Moreover, The SiH.sub.4
may be supplied to the closed space through an inner section of the
shaft.
[0068] As mentioned above, in accordance with the present
invention, it is possible to provide the method of producing a
semiconductor apparatus and the semiconductor production equipment,
which is capable of, when a thin film is formed on the substrate by
the CVD method, depositing the thin film on the substrate in the
reactive chamber efficiently and uniformly by efficiently using a
reactive gas for film formation introduced into the CVD reactive
chamber, and reducing the cost of forming the thin film
remarkably.
[0069] In addition, in accordance with the method of forming a
semiconductor apparatus according to the present invention, when
etching the surface of the substrate in the etching chamber, the
substrate can be etched efficiently by efficiently using an etching
gas introduced into the chamber, and the cost of etching can be
reduced remarkably.
[0070] In addition, in accordance with the method of cleaning a
semiconductor production equipment according to the present
invention, when removing a deposition which is deposited on the
inner wall of the substrate processing chamber by etching, the
deposition can be removed by etching efficiently by efficiently
using an etching gas introduced into the processing chamber, and
the cost of cleaning can be reduced remarkably.
[0071] Additional advantages and modifications will readily occur
to those skilled in the art. Therefore, the invention in its
broader aspects is not limited to the specific details and
representative embodiments shown and described herein. Accordingly,
various modifications may be made without departing from the spirit
or scope of the general inventive concept as defined by the
appended claims and their equivalent.
* * * * *