U.S. patent application number 10/387423 was filed with the patent office on 2003-12-04 for semiconductor manufacturing device, semiconductor manufacturing system and substrate treating method.
Invention is credited to Miyazaki, Kunihiro, Nakao, Takashi.
Application Number | 20030221960 10/387423 |
Document ID | / |
Family ID | 28035228 |
Filed Date | 2003-12-04 |
United States Patent
Application |
20030221960 |
Kind Code |
A1 |
Nakao, Takashi ; et
al. |
December 4, 2003 |
Semiconductor manufacturing device, semiconductor manufacturing
system and substrate treating method
Abstract
A semiconductor manufacturing device having a buffer unit which
receives a substrate treating substance from an external source,
stores it therein, and delivers it to an external unit.
Inventors: |
Nakao, Takashi; (Kanagawa,
JP) ; Miyazaki, Kunihiro; (Kanagawa, JP) |
Correspondence
Address: |
Finnegan, Henderson, Farabow,
Garrett & Dunner, L.L.P.
1300 I Street, N.W.
Washington
DC
20005-3315
US
|
Family ID: |
28035228 |
Appl. No.: |
10/387423 |
Filed: |
March 14, 2003 |
Current U.S.
Class: |
204/298.09 ;
204/298.33; 204/298.35 |
Current CPC
Class: |
Y02P 90/28 20151101;
Y02P 90/02 20151101; H01L 21/67017 20130101 |
Class at
Publication: |
204/298.09 ;
204/298.33; 204/298.35 |
International
Class: |
C25B 009/00; C25B
011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 15, 2002 |
JP |
P2002-73217 |
Claims
What is claimed is:
1. A semiconductor manufacturing device comprising a buffer unit
which receives a substrate treating substance from an external
source, stores it therein, and delivers it to an external unit.
2. A semiconductor manufacturing device comprising: a substrate
treating chamber; and a buffer unit provided in said substrate
treating chamber or in said semiconductor manufacturing device,
receiving a substrate treating substance from an external source,
storing it therein, and delivering it to said substrate treating
chamber or said semiconductor manufacturing device for the purpose
of treating substrates.
3. The semiconductor manufacturing device of claim 1 or 2 further
comprising a control unit controlling states of said substrate
treating substance in said buffer unit.
4. The semiconductor manufacturing device of claim 1 or 2 further
comprising a measuring unit measuring the states of said substrate
treating substance in said buffer unit.
5. The semiconductor manufacturing device of claim 1 or 2, wherein
said buffer unit stores a predetermined amount of said substrate
treating substance necessary for at least one substrate treating
process in said substrate treating chamber or said semiconductor
manufacturing device, and is capable of delivering said substrate
treating substance to either said substrate treating chamber or
said semiconductor manufacturing device.
6. The semiconductor manufacturing device of claim 1 or 2, wherein
said buffer unit stores simultaneously at least two kinds of
substrate treating substances used by said substrate treating
chamber, and is capable of delivering them to said substrate
treating chamber.
7. The semiconductor manufacturing device of claim 1 or 2, wherein
said buffer unit reacts said substrate treating substance, and
stores said reacted substrate treating substance therein.
8. The semiconductor manufacturing device of claim 3, wherein said
control unit controls at least a temperature, a pressure or a
concentration of said substrate treating substance stored in said
buffer unit.
9. The semiconductor manufacturing device of claim 4, wherein said
measuring unit measures at least a temperature, a pressure or a
concentration of said substrate treating substance stored in said
buffer unit.
10. The semiconductor manufacturing device of claim 1 or 2, wherein
said substrate treating substance in said substrate treating
chamber or said manufacturing device is a gas, a liquid or a solid
necessary for the substrate treatment.
11. The semiconductor manufacturing device of claim 1 or 2, wherein
said substrate treating substance is a cleaning gas for said
substrate treating chamber.
12. The semiconductor manufacturing device of claim 1 or 2 further
comprising a second buffer unit which recycles said substrate
treating substance discharged from said substrate treating chamber
or said semiconductor manufacturing device, and returns the
recycled substrate treating substance to said substrate treating
chamber or said semiconductor manufacturing device.
13. A semiconductor manufacturing system comprising: an external
source supplying a substrate treating substance; a semiconductor
manufacturing device including at least a substrate treating
chamber; a buffer unit receiving said a substrate treating
substance from said external source, storing it therein, and
delivering it to said substrate treating chamber or said
semiconductor manufacturing device; and a control unit controlling
the delivery of said substrate treating substance from said
external source to said buffer unit and the delivery of said
substrate treating substance from said buffer unit to said
substrate treating chamber or said semiconductor manufacturing
device.
14. The semiconductor manufacturing system of claim 13 further
comprising a computer-integrated manufacturing system which
thoroughly manages the delivery of said substrate treating
substance from said external unit, the receipt and storage of said
substrate treating substance in and from said buffer unit, and
controls the operations of said semiconductor manufacturing device
and said control unit.
15. The semiconductor manufacturing system of claim 14, wherein
said computer-integrated manufacturing system includes a
record-keeping database which records and manages an in-service
schedule of the substance treatment and a manufacture schedule, and
controls at least a delivery speed or a delivery order of said
substrate treating substance from said external source to said
semiconductor manufacturing device via said buffer unit.
16. A substrate treating method comprising: receiving a substrate
treating substance from an external source, storing in a buffer
unit said substrate treating substance necessary for at least one
substrate treating process, and delivering a predetermined amount
of said substrate treating substance to a substrate treating
chamber or a semiconductor manufacturing device provided with a
substrate treating chamber.
17. A substrate treating method comprising: delivering substrates
into a substrate treating chamber; receiving a substrate treating
substance from an external source, storing in a buffer unit said
substrate treating substance necessary for at least one substrate
treating process; and delivering a predetermined amount of said
substrate treating substance to a substrate treating chamber or a
semiconductor manufacturing device provided with a substrate
treating chamber.
18. The substrate treating method of claim 16 or 17, wherein at
least two kinds of substrate treating substances are simultaneously
stored in said buffer unit.
19. The substrate treating method of claim 16 or 17, wherein said
substrate treating substance is reacted and is stored in said
buffer unit.
20. The substrate treating method of claim 16 or 17, wherein at
least a temperature, a pressure or a concentration of said
substrate treating substance stored in said buffer unit is
controlled or measured.
21. The substrate treating method of claim 16 or 17, wherein said
substrate treating substances stored in said buffer unit are gases,
liquids or solids.
22. The substrate treating method of claim 16 or 17, wherein said
substrate treating substances stored in said buffer unit are
cleaning gases for said substrate treating chamber.
23. The substrate treating method of claim 16 or 17 further
comprising: recycling said substrate treating substance discharged
from said substrate treating chamber or said semiconductor
manufacturing device; storing said recycled substrate treating
substance in a second buffer unit; and returning said recycled
substrate treating substance to said substrate treating chamber or
said semiconductor manufacturing device from said second buffer
unit.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based on and claims the benefit of
priority from the prior Japanese Patent Application No.
2002-073,217 filed on or around Mar. 15, 2002, the entire contents
of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a semiconductor
manufacturing device, a semiconductor manufacturing system, and a
substrate treating method, and more particularly relates to a
semiconductor manufacturing device which comprises a source
supplying substrate treating substances to a substrate treating
chamber, a semiconductor manufacturing system which comprises at
least a source supplying substrate treating substances to a
substrate treating chamber and a semiconductor manufacturing
device, and a substrate treating method applicable to the
semiconductor manufacturing device and the semiconductor
manufacturing system.
[0004] 2. Description of the Related Art
[0005] A semiconductor manufacturing device uses a variety of
substances such as source gases, chemicals, and solvents in a
semiconductor manufacturing process. Generally, such substances are
supplied from a source which is located near a semiconductor
manufacturing plant, and includes cylinder cabinets, gas
generators, chemical and solvent tanks, a refiner like an ion
exchanger, and so on. The substances are delivered to a
semiconductor manufacturing device via gas delivery pipes, or
chemical or solvent delivery pipes. The source has a capacity which
is sufficient to deliver the substances without any problem.
[0006] Further, the foregoing pipes are large enough to reliably
deliver the substances at a required speed.
[0007] The foregoing semiconductor manufacturing device or a
semiconductor manufacturing system including such a semiconductor
manufacturing device seems to have the following problems.
[0008] The substances such as source gases, chemicals and solvents
are not always consumed at the same speed in the semiconductor
manufacturing device. For instance, an LPCVD (low pressure chemical
vapor deposition) device produces polycrystalline silicon films on
a plurality of semiconductor wafers using the LPCVD process of the
batch processing type, and requires a mono-silane gas as a source
gas only during the formation of polycrystalline silicon films. No
source gas is consumed for evacuating substrate treating chambers,
and loading or unloading semiconductor wafers to or from a shelf
shaped port in the substrate treating chamber even when the LPCVD
device is in operation. The capacities of the source or delivery
pipes are designed on the basis of feed rates of the source gases
which are being consumed. If ten LPCVD devices were provided in the
semiconductor manufacturing plant, the source and delivery pipes
would be required to have capacities for delivering the source
gases to them.
[0009] Further, coolants are also supplied to the LPCVD device in
order to cool heaters and pumps, which are used to control
temperatures of the substrate treating chambers. A large amount of
coolants should be supplied during the operation of the heaters
while little coolants are necessary during the non-operation of the
heaters.
[0010] Still further, cleaning gases are supplied to the LPVCD
device in order to clean the substrate treating chambers, but are
required only when the treatment chambers are being cleaned.
[0011] Recently, semiconductor wafers are being enlarged in order
to lead better productivity of semiconductors. In response to this
trend, a semiconductor manufacturing device, e.g. a substrate
treating chamber of an LPCVD device, is also being enlarged, which
means increases in source gases, chemicals or solvents to be
consumed. Therefore, large sources or delivery pipes are required
in order to meet the foregoing requirements, which would lead to
large capital investments.
BRIEF SUMMARY OF THE INVENTION
[0012] According to a first feature of the embodiment of the
invention, there is provided a semiconductor manufacturing device
comprising a buffer unit which receives a substrate treating
substance from an external source, stores it therein, and delivers
it to an external unit.
[0013] In accordance with a second feature of the embodiment of the
invention, there is provided a semiconductor manufacturing device
comprising: a substrate treating chamber; and a buffer unit
provided in the substrate treating chamber or in the semiconductor
manufacturing device, receiving a substrate treating substance from
an external source, storing it therein, and delivering it to the
substrate treating chamber or the semiconductor manufacturing
device for the purpose of treating substrates.
[0014] As a third feature, the embodiment of the invention provides
a semiconductor manufacturing system comprising: an external source
supplying a substrate treating substance; a semiconductor
manufacturing device including a substrate treating chamber; a
buffer unit receiving the substrate treating substances from the
external source, storing it therein, and delivering it to the
substrate treating chamber or the semiconductor manufacturing
device; and a control unit controlling the delivery of the
substrate treating substances from the external source to the
buffer unit and the delivery of the substrate treating substances
from the buffer unit to the substrate treating chamber or the
semiconductor manufacturing device. The semiconductor manufacturing
system further comprises a computer-integrated manufacturing (CIM)
system which thoroughly manages the delivery of the substrate
treating substances from the external unit, the receipt and storage
of the substrate treating substance in the buffer unit, and
controls the operations of the semiconductor manufacturing device
and the control unit.
[0015] The CIM system includes a record-keeping database which
records and manages an in-service schedule of the substance
treatment and a manufacture schedule, and controls at least a
delivery speed or a delivery order of the substrate treating
substances from the external source to the semiconductor
manufacturing device via the buffer unit. According to a fourth
feature of the embodiment of the invention, there is provided a
substrate treating method comprising: receiving a substrate
treating substance from an external source, storing in a buffer
unit the substrate treating substance necessary for at least one
substrate treating process, and delivering a predetermined amount
of the substrate treating substance to a substrate treating chamber
or a semiconductor manufacturing device provided with a substrate
treating chamber.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0016] FIG. 1 is a block diagram of a semiconductor manufacturing
device and a semiconductor manufacturing system according to a
first embodiment of the invention.
[0017] FIG. 2 is a block diagram showing a first control method for
loading a substrate treating substance to a buffer unit in the
semiconductor manufacturing system of FIG. 1.
[0018] FIG. 3 is a block diagram showing a second control method
for loading the substrate treating substance to the buffer
unit.
[0019] FIG. 4 is a block diagram showing a third control method for
loading the substrate treating substance to the buffer unit.
[0020] FIG. 5 is a block diagram showing a first control method for
delivering the substrate treating substance to a substrate treating
chamber from the buffer unit in the semiconductor manufacturing
system of FIG. 1.
[0021] FIG. 6 is a block diagram showing a second control method
for delivering the substrate treating substance to the substrate
treating chamber from the buffer unit in the semiconductor
manufacturing system of FIG. 1.
[0022] FIG. 7 is a block diagram showing a third control method for
delivering the substrate treating substance to the substrate
treating chamber from the buffer unit in the semiconductor
manufacturing system of FIG. 1.
[0023] FIG. 8 is a flow chart showing an operation sequence of the
semiconductor manufacturing system of FIG. 7.
[0024] FIG. 9 is a graph showing time-dependent variations of a
concentration of a mono-silane gas.
[0025] FIG. 10 is a graph showing time-dependent variations of
deposition rate, thickness and speed of a polycrystalline silicon
film on a semiconductor wafer in the semiconductor manufacturing
system of FIG. 7.
[0026] FIG. 11 is a block diagram showing a control process for
loading a liquid substance to the buffer unit in the semiconductor
manufacturing device or semiconductor manufacturing system in the
first embodiment.
[0027] FIG. 12 is a block diagram showing a control process for
loading a solid substance to the buffer unit in the semiconductor
manufacturing device or semiconductor manufacturing system in the
first embodiment.
[0028] FIG. 13 is a block diagram of a semiconductor manufacturing
device or a semiconductor manufacturing system in a second
embodiment of the invention.
[0029] FIG. 14 is a block diagram of a semiconductor manufacturing
device or a semiconductor manufacturing system in a first modified
example of a third embodiment of the invention.
[0030] FIG. 15 is a block diagram of a semiconductor manufacturing
device or a semiconductor manufacturing system in a second modified
example of the third embodiment of the invention.
[0031] FIG. 16 is a block diagram of a semiconductor manufacturing
device or a semiconductor manufacturing system in a fourth
embodiment of the invention.
[0032] FIG. 17 is a block diagram of a semiconductor manufacturing
device or a semiconductor manufacturing system in a modified
example of the fourth embodiment of the invention.
[0033] FIG. 18 is a block diagram of a semiconductor manufacturing
device or a semiconductor manufacturing system in a fifth
embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] The invention will be described with reference to
embodiments of a semiconductor manufacturing device, a
semiconductor manufacturing system, and a substrate treating method
shown in the drawings, where like or corresponding parts are
denoted by like or corresponding reference numerals.
[0035] (First Embodiment of the Invention)
[0036] This first embodiment of the invention relates to a
semiconductor manufacturing device 1 as an LPCVD device, a
semiconductor manufacturing system including such a semiconductor
manufacturing device, and a substrate treating method applied to
them.
[0037] [Basic Structure of Semiconductor Manufacturing Device 1 and
Semiconductor Manufacturing System]
[0038] Referring to FIG. 1, the semiconductor manufacturing device
1 uses a mono-silane gas as a source gas in order to form
polycrystalline silicon films on semiconductor wafers, and includes
a substrate treating chamber 2, and a buffer unit 4 which receives
a substrate treating substance from an external source 20, stores
it therein, and delivers it to the substrate treating chamber 2 or
to the semiconductor manufacturing device 1.
[0039] The term "substrate treating" denotes not only forming thin
conductive or insulating films on semiconductor wafers (mainly made
of a III-V group elements), on glass substrates for a liquid
crystal display or the like, on insulating substrates used as
wiring substrates, but also etching films. The term "substrate
treating substances" refers not only to source gases, liquid
chemicals or solvents, granular or solid substances which are
directly used for treating substrates, but also to cleaning gases,
liquid coolants and so on which are indirectly used for treating
the substrates. The external source 20 is provided outside the
semiconductor manufacturing device 1 and supplies the substrate
treating substances.
[0040] The semiconductor manufacturing device 1 further includes a
control unit 6 which controls states of the substrate treating
substances in the buffer unit 4, and a measuring unit 5 which
measures the states of the foregoing substances.
[0041] The semiconductor manufacturing device 1 is generally
installed at an upper part (fab story) 101 of a clean room 100 in a
semiconductor manufacturing plant. The substrate treating chamber 2
includes a reaction tube 201 made of very pure quartz, and a port
(without a reference numeral) provided in the reaction tube 201 and
receiving substrates such as semiconductor wafers. A heater 202
surrounds the reaction tube 201 in order to control a temperature
thereof.
[0042] In this embodiment, the buffer unit 4 is housed in the
semiconductor manufacturing device 1, and is positioned between the
external source 20 and the substrate treating chamber 2, receives
the substrate treating substances from the external source 20,
stores them therein, and delivers a predetermined amount of them to
either the substrate treating chamber 2 or to the semiconductor
manufacturing device 1. The substrate treating substances are
intermittently delivered from the external source 20, and are
temporarily stored in the buffer unit 4. The buffer unit 4 is made
of quartz, metal or the like in order to be resistant to the
substrate treating substances and pressure and to improve
productivity, and is preferably in the shape of a tank having an
appropriate capacity.
[0043] The external source 20 includes a mono silane gas cylinder
21, a nitride gas generator 22, and a fluorine gas generator 23.
The mono-silane gas cylinder 21 and nitride gas generator 23 are
provided outside the clean room 100. The mono-silane gas cylinder
21 supplies a mono-silane gas to the buffer unit 4 via a pneumatic
valve 702. The nitride gas generator 22 supplies a nitride gas to
the buffer unit 4 via a pneumatic valve 703. The nitride gas is
used to clean the buffer unit 4 and the substrate treating chamber
2, and is also used as a dilution gas while the substrate treating
substance is reacted. Further, the nitride gas is used in order to
return a pressure in the substrate treating chamber 2 to
1.times.10.sup.5 Pa. The fluorine gas generator 23 is positioned in
a sub-fab story 102 under the clean room 100, and supplies a
cleaning gas to the buffer unit 4 via a pneumatic valve 701. The
cleaning gas is used to etch and clean an inner wall of the
substrate treating chamber 2 or silicon films on components made of
quartz, silicon-carbide and so on.
[0044] The buffer unit 4 and the substrate treating chamber 2 are
connected by a pneumatic valve 801, through which the mono-silane
gas, nitride gas or fluorine gas is delivered to the substrate
treating chamber 2 from the buffer unit 4.
[0045] The measuring unit 5 of the semiconductor manufacturing
device 1 is a pressure gauge, for instance, is connected to the
buffer unit 4, and measures a pressure (states) of the substrate
treating substance in the buffer unit 4.
[0046] For instance, the mono-silane gas in the substrate treating
chamber 2 is heated by a heater 202 in order to form a
polycrystalline silicon film on a semiconductor wafer using the
LPCVD reaction. The fluorine gas cleans the inner wall of the
substrate treating chamber 2 by the etching reaction. After the
LPCVD or etching reaction, reacted gases or non-used gases are
discharged by a vacuum exhaust pump 30 via a gate valve 802.
[0047] The gate valve 802 opens and closes in order to adjust a
fluid conductance in the substrate treating chamber 2, and also
interrupts the gas. The vacuum exhaust pump 30 is positioned in the
sub-fab story 102 in the cleaning room 100. An exhaust gas from the
vacuum exhaust pump 30 is purified in a purifier 31, and is
discharged to the outside via an exhaust duct 32 in the sub-fib
story 102.
[0048] The control unit 6 controls the operations of the heater
202, measuring unit 5, pneumatic valves 701 to 703 and 801, and
gate valve 802, which means that the control unit 6 controls the
whole operations of the semiconductor manufacturing device 1
[0049] Specifically, the control unit 6 is connected to a
manufacture managing database 10 which manages data of the LPCVD
process, to a device managing database 11 which manages the
operations of the semiconductor manufacturing device 1, and to a an
integrated in-plant buffer controller 12. The control unit 6 is in
connection with the manufacture managing database 10 and the device
managing database 11 via a local area network (called the "LAN") 13
of the computer-integrated manufacture control system (called the
"CIM system"). The control unit 6 receives outputs from a pressure
gauge (not shown) and heater 202 in the substrate treating chamber
2, i.e. measured values such as a furnace pressure and temperature
of the substrate treating chamber 2. The control unit 6 transfers
film depositing information to the manufacture managing database 10
via the LAN 13.
[0050] The semiconductor manufacturing system is constituted by:
the semiconductor manufacturing device 1 which includes at least
the external source 20 supplying the substrate treating substances
and the substrate treating chamber 2; the buffer unit 4 which
receives the substance treating substance from the external source
20, stores it therein, and delivers it to either the substrate
treating chamber 2 or the semiconductor manufacturing device 1; and
the control unit 6 which controls the delivery of the substrate
treating substances between the external source 20 and the buffer
unit 4, and between the buffer unit 4 and the substrate treating
chamber 2 or the semiconductor manufacturing device 1.
[0051] [Operation of Semiconductor Manufacturing Device 1 and
Semiconductor Manufacturing System, and Substrate Treating
Method]
[0052] A polycrystalline silicon film will be deposited on a
semiconductor wafer as described hereinafter by the semiconductor
manufacturing device 1 and the semiconductor manufacturing system.
In this case, the substrate is treated using the LPCVD process.
[0053] (1) First of all, the following LPCVD process data are input
into the control unit 6 from the manufacture managing database 10
via the LAN 13, which is performed before raw semiconductor wafers
are delivered to the semiconductor manufacturing device 1.
[0054] a. thickness of the polycrystalline silicon film: 100 nm
[0055] b. film depositing temperature: 620.degree. C.
[0056] c. feed rate of mono-silane gas: 100 sccm
[0057] d. film depositing pressure: 26.6 Pa
[0058] e. film depositing period: 10 minutes
[0059] A total amount of the mono-silane gas to be used is
expressed by the following formula.
100 sccm.times.10 minutes 1000 scc (i.e. a volume of 1000
cm.sup.3
[0060] under a standard state of a gas)
[0061] In this case, the buffer unit 4 has a 1000 scc capacity, for
instance.
[0062] (2) The control unit 6 opens the gate valve 802 once in
accordance with the received data, thereby evacuating the substrate
treating chamber 2 to a sufficiently low pressure using the vacuum
exhaust pump 30.
[0063] (3) Thereafter, the control unit 6 closes the gate valve
802, and opens the pneumatic valve 702, so that the mono-silane gas
will be delivered to the buffer unit 4 from the mono-silane gas
cylinder 21. When the buffer unit 4 is filled with the 1000 scc
mono-silane gas, the control unit 6 closes the pneumatic valve 702.
Therefore, the buffer unit 4 is sealed, thereby temporarily storing
the mono-silane gas.
[0064] The mono-silane gas is filled into the buffer unit 4 by any
of the following control methods shown in FIG. 2 to FIG. 4.
[0065] According to a first control method shown in FIG. 2, a
pressure regulator 710 is provided between the mono-silane gas
cylinder 21 and the buffer unit 4, and in front of (or behind) the
pneumatic valve 702, and automatically adjusts an amount of the
mono-silane gas to be supplied to the buffer unit 4 in response to
a command from the control unit 6. The pressure regulator 710 is
preferably a pressure control valve, and maintains a pressure of
the mono-silane gas at 26.6 Pa, which allows the buffer unit 4 to
store the mono-silane gas in the amount of 1000 scc.
[0066] With a second control method shown in FIG. 3, the amount of
the mono-silane gas to be supplied is controlled on the basis of a
feed rate and a feed period thereof. A mass flow controller 711 is
positioned between the mono-silane gas cylinder 21 and the buffer
unit 4 and in front of (or behind) the pneumatic valve 702, and
controls the amount of the mono-silane gas to the buffer unit 4.
When the mono-silane gas is supplied for 30 seconds at the feed
rate of 2 slm, the buffer unit 4 is filled with 1000 scc
mono-silane gas. Further, if an inexpensive mass flow meter is used
in place of the mass flow controller 711, the 1000 scc mono-silane
gas to the buffer unit 4 can be controlled on the basis of
integrated output values of the mass flow meter. According to a
third control method of FIG. 4, the amount of the mono-silane gas
is controlled on the basis of a pressure measured by the measuring
unit 5 attached to the buffer unit 4. When the measured pressure
becomes equal to a predetermined value, the control unit 6 closes
the pneumatic valve 702, thereby controlling the amount of the
mono-silane gas in the buffer unit 4. If the pressure of the
mono-silane gas quickly increases, a conductance regulator 712 is
preferably provided in front of the pneumatic valve 702 in order to
feed-back control the amount of the mono silane gas on the basis of
the measured pressure thereof. The conductance regulator 712 may be
an orifice, a piezzo valve or the like which opens or closes in
order to adjust a conductance.
[0067] The pressure regulator 710, mass flow controller 711 or
conductance regulator 712 which is rather expensive can be used in
common for a plurality of the semiconductor manufacturing devices 1
when it is positioned in front of them, i.e. just behind the
mono-silane gas cylinder 21.
[0068] No mass flow controller 711 (or no mass flow meter) is
employed in the first and third control methods (shown in FIG. 2
and FIG. 4, respectively). However, since the inner capacity of the
buffer unit 4 is constant in these control methods, the amount of
mono-silane gas to be loaded can be precisely controlled by
accurately measuring the temperature and pressure of the buffer
unit 4 in which the mono-silane gas is to be used in an optimum
state. In such a case, no flow rate of the mono-silane gas is
required to be measured. The semiconductor manufacturing device 1
or the semiconductor manufacturing system can adopt any of or any
combination of the first to third control methods in order to
obtain products (e.g. semiconductor devices) which satisfy required
specifications, have reasonable cost and so on.
[0069] In the semiconductor manufacturing device 1 or the
semiconductor manufacturing system including the buffer unit 4, the
mono-silane gas is quickly supplied to and stored in the buffer
unit 4 regardless of an actual period for forming the
polycrystalline silicon film. It is possible to shorten the time
period during which the semiconductor manufacturing device 1 is in
connection with the external source 20. Further, the buffer unit 4
stores the mono-silane gas before the film forming process is
started in the substrate treating chamber 2, so that it is possible
to remarkably reduce a chance in which the film forming process is
interrupted due to an accident or malfunction of the semiconductor
manufacturing system (in the semiconductor manufacturing plant),
interruption or reduction of the mono silane gas due to man-caused
errors, and so on. This means that the polycrystalline silicon
films can be more reliably and efficiently formed.
[0070] Further, the mono-silane gas can be delivered to and stored
in the buffer unit 4 longer than the film depositing period. This
is effective in downsizing the facilities for supplying and
delivering the mono-silane gas, (e.g. delivery pipes may be made
thin), and in extensively reducing the cost of the foregoing
facilities. The necessary cost can be drastically decreased for
supply and delivery.
[0071] (4) While the mono-silane gas is being filled and stored in
the buffer unit 4, semiconductor wafers are conveyed into the
substrate treating chamber 2 which has been evacuated for the
purpose of film deposition. The substrate treating chamber 2 has
its temperature adjusted to 620.degree. C. by the heater 202, and
the pressure thereof adjusted to 26.6 Pa by the vacuum exhaust pump
30.
[0072] Referring to FIG. 5, the mass flow controller 811 is
provided between the pneumatic valve 801 and the substrate treating
chamber 2, i.e. behind the buffer unit 4, thereby regulating a feed
rate of the mono-silane gas to the substrate treating chamber 2
from the buffer unit 4.
[0073] When the conductance regulator 812 is positioned behind the
buffer unit 4 (as shown in FIG. 6) and is used together with the
pneumatic valve 801, the feed rate of the mono-silane gas can be
regulated without using the mass flow controller 811. The
conductance regulator 812 may be preferably an orifice, a piezzo
valve or the like. The conductance regulator 812 regulates the feed
rate of the mono-silane gas such that the mono-silane gas is
reduced at the rate of 1.times.10.sup.4 Pa/min where the output of
the measuring unit 5 (e.g. a pressure value) uniformly decreases.
This is because the mono-silane gas having the pressure of
1.times.10.sup.5 Pa is completely consumed for 10 minutes.
[0074] Therefore, it is not necessary to precisely measure the 1000
scc mono-silane gas used for the film deposition prior to the
manufacturing process.
[0075] (5) A polycrystalline silicon film is formed under the
conditions of 100 sccm and 10 minutes. After the film deposition,
the mono-silane gas remaining in the buffer unit 4 is directly
discharged to the vacuum exhaust pump 30 via a bi-path line 804
which is opened or closed by a valve 803 but without via the
substrate treating chamber 2. Otherwise, the mono-silane gas in the
buffer unit 4 is stored for the next following film deposition.
[0076] (6) The mono-silane gas and so on discharged by the vacuum
exhaust pump 30 are purified by the purifier 31, and are sent to an
exhaust duct 32.
[0077] After the foregoing LPCVD process, the polycrystalline
silicon film is completed on the semiconductor wafer.
[0078] [Application to Batch Processing]
[0079] The invention is applicable to a batch processing in which
100 to 200 semiconductor wafers, for instance, are placed in the
substrate treating chamber 2 and on which polycrystalline silicon
films are formed using the semiconductor manufacturing device 1
(LPCVD device).
[0080] In the batch processing, semiconductor wafers are vertically
placed, with 5 mm spaces kept therebetween, in a vertical substrate
treating chamber 2 (a vertical LPCVD furnace) of the semiconductor
manufacturing device 1. The substrate treating chamber 2 is heated
to a reaction temperature of 620.degree. C., for example, and
becomes stable. The mono-silane gas whose feed rate has been
controlled by the mass flow controller or the like is supplied to
the substrate treating chamber 2. However, the mono silane gas is
consumed at an upper part of the substrate treating chamber 2, and
a reaction gas is generated, so that the mono-silane gas may be
diluted at a lower part of the substrate treating chamber 2. This
means that film deposition will be slowed down. Specifically, the
mono-silane gas is consumed by the deposition or vapor reaction as
expressed by the following reaction formula, and silylene gas
(SiH.sub.2) or a hydrogen gas (H.sub.2) is generated. As a result,
a partial pressure of the mono-silane gas (SiH.sub.4) is reduced,
so that the deposition speed is reduced.
[0081] SiH.sub.4.fwdarw.SiH.sub.2+H.sub.2 (vapor reaction)
[0082] SiH.sub.4.fwdarw.Si+2H.sub.2 (deposition reaction)
[0083] SiH.sub.2.fwdarw.Si+H.sub.2 (deposition reaction)
[0084] When the mono-silane gas is continuously supplied to the
substrate treating chamber 2 at the predetermined feed rate, e.g.
100 sccm, film deposition on semiconductor wafers at the lower part
of the substrate treating chamber 2 will be slowed down for the
foregoing reasons. The vertical spaces between the semiconductor
wafers are small, i.e. 5 mm, compared with a diameter thereof. The
mono-silane gas is diffused toward the centers of the semiconductor
wafers via peripheral areas thereof. In each semiconductor wafer,
the peripheral area is an upstream while the center is a
downstream. Therefore, the polycrystalline silicon film is quickly
formed at the upstream compared with at the downstream, and is thin
at the downstream.
[0085] In the first embodiment, the feed rate of the mono-silane
gas to the buffer unit 4 is controlled by the mass flow controller
811 (shown in FIG. 5) or by the conductance regulator 812 (shown in
FIG. 6), which enables the polycrystalline silicon films to be
uniformly deposited. Further, the amount of the mono-silane gas
used for the film deposition can be controlled on the basis of a
total amount thereof supplied to the substrate treating chamber 2
from the buffer unit 4, so that the polycrystalline silicon films
will have the uniform thickness. In this case, the feed rate of the
mono-silane gas is not controlled at all as shown in FIG. 7.
[0086] FIG. 8 is the flow chart showing the sequence of the LPCVD
process for which the gas source of FIG. 7 is utilized.
[0087] (1) First of all, the mono-silane gas is delivered to the
buffer unit 4 from the mono-silane gas cylinder 21 of the external
source 20. The buffer unit 4 temporarily stores the mono-silane gas
(step S80). The amount of the mono-silane gas is measured in order
that the buffer unit 4 stores a predetermined amount thereof.
[0088] The presence of the buffer unit 4 is effective in reducing a
difference between the time when the mono-silane gas is required
and the time to supply the gas. This is effective in preventing the
gas source from having an excessively large capacity, and in
reducing costs of the gas source and delivering facilities.
Further, the mono-silane gas is controlled on the basis of the
total amount thereof in place of the feed rate thereof, which is
effective in promoting quick supply of the mono-silane gas, in
controlling the vaporization of solids or liquids, and in enabling
supply of intermediate precursors and so on in response the
chemical reaction.
[0089] (2) The gate valve 802 is opened in order to sufficiently
evacuate the substrate treating chamber 2 using the vacuum exhaust
pump 30 (step S81).
[0090] (3) When the pressure of the substrate treating chamber 2 is
lowered to 0.133 Pa, for example, the gate valve 802 is completely
closed, thereby sealing the substrate treating chamber 2 (step
S82).
[0091] (4) The pneumatic valve 801 between the substrate treating
chamber 2 and the buffer unit 4 is fully opened, thereby filling
the substrate treating chamber 2 with the target amount of the
mono-silane gas in several seconds (step S83). Therefore, the
mono-silane gas can be quickly filled in and diffused throughout
the narrow spaces between the semiconductor wafers in the substrate
treating chamber 2 compared with the reaction speed thereof. In
other words, it is possible to reduce chances in which deposited
films are non-uniform due to a diffusion-limit of the mono-silane
gas. As a result, the polycrystalline silicon films can have a
uniform thickness.
[0092] When the external source of FIG. 7 is used, the
concentration of the mono-silane gas reduces as polycrystalline
silicon films are being deposited as shown in FIG. 9. Further, a
film deposition rate varies with the time as shown in FIG. 10.
These differ from the case where the supply amount of the
mono-silane gas is controlled by the mass flow controller or the
like. However, the target film thickness is derived by integrating
the film deposition data, so that the film deposition period can be
determined on the target film thickness. Referring to FIG. 10, the
film deposition rate is large immediately after the start of the
film deposition, becomes smaller with the lapse of time, and
gradually is stabilized as the target thickness is attained.
Therefore, the polycrystalline silicon films can be formed as
reliably and quickly as possible, and have the uniform
thickness.
[0093] (5) The film deposition is carried out until the target
thickness is accomplished (step S84).
[0094] (6) The gate valve 802 is fully opened after the deposited
films have the target thickness, so that non-used mono-silane gas
and so on are discharged from the substrate treating chamber 2 by
the vacuum exhaust pump 30. In this state, the film deposition will
be completed (step S85).
[0095] [Application to Deposition of Doped Silicon Film]
[0096] The foregoing semiconductor manufacturing device 1 or
semiconductor manufacturing system is also applicable to the
deposition of polycrystalline (or single crystal) silicon films
which are doped with impurities such as arsenic (As), boron (B),
phosphor (P), impurities such as germanium (Ge) of the IV group
element similarly to silicon or the like. These impurities are used
as donors or acceptors, and are doped into films being
deposited.
[0097] The semiconductor manufacturing device 1 or semiconductor
manufacturing system also includes another buffer unit (which is
similar to the buffer unit 4 for the mono-silane gas, but is not
shown) in order to store impurities and to obtain doped
polycrystalline silicon films. This buffer unit stores source gases
such as an arsine gas (AsH.sub.3), a diborane gas (B.sub.2H.sub.6),
a phosphine gas (PH.sub.3), a germane gas (GeH.sub.4) or the like
which are used as dopants. The source gases are supplied to the
substrate treating chamber 2 similarly to the mono-silane gas,
thereby easily obtaining doped polycrystalline silicon films.
[0098] Alternatively, both the mono-silane gas and the foregoing
source gases (e.g. arsine gas and so on) may be mixed and stored
together in the buffer unit 4. The dopants can be controlled in
order to have a uniform concentration before they are delivered to
the buffer unit 4.
[0099] In the foregoing case, the measuring unit 5 is further
provided with a mass spectrograph, an infrared absorption
spectrograph and so on, analyzes the gases stored in the buffer
unit 4, and outputs analyzed results to the CIM system. Therefore,
it is possible to precisely detect concentrations of the mixed
gases prior to the film deposition. Further, the concentration and
amount of the mono-silane gas and source gases to the buffer unit 4
can be easily controlled by operating the pneumatic valve 702 and
so on which control the feed rates of the gases.
[0100] Still further, even when the measuring unit 5 includes only
a pressure gauge, mixing ratios of the mono-silane gas and source
gases can be easily calculated by measuring pressure increases
thereof using the pressure gauge when these gases are stored in the
buffer unit 4.
[0101] Both non-doped and doped polycrystalline silicon films are
made in the identical manner regardless of the methods for storing
the mixed gases in the buffer unit 4.
[0102] [Application to Making Insulating Film: Liquid Source]
[0103] The semiconductor manufacturing device 1 or the
semiconductor manufacturing system is still further applicable to
making insulating films. The following describe how a tantalum
oxide film is made using the LPCVD process.
[0104] Referring to FIG. 11, the external source 20 is provided
with a liquid tank 25 where penta ethoxyl tantalum (called the
"PET") is stored. The PET is a liquid at normal pressures and
normal temperatures. An amount of the PET necessary for the
substrate treatment is measured and controlled at least by a weight
meter 251, a liquid level gauge 252, a liquid scale 253, or the
mass flow controller (MFC) 254. The PET is delivered to the buffer
unit 4.
[0105] The buffer unit 4 further includes a heater and a thermostat
40. The PET delivered to the buffer unit 4 is heated by the heater
under the control of the thermostat 40, is vaporized in a state
where it does not thermally react, is changed to a gas, and is
stored in the buffer unit 4.
[0106] The PET is delivered to the substrate treating chamber 2
from the buffer unit 4, and is used to obtain the tantalum oxide
film using the LPCVD process. Since the semiconductor manufacturing
device 1 or the semiconductor manufacturing system includes the
buffer unit 4, the substrate treating substance can be reliably
supplied without any problem caused by a reduced capacity of a
vaporizer or the like in response to the vapor phase LPCVD reaction
of the PET which is liquid at the normal pressures and
temperatures. Further, the necessary amount of source gases can be
reliably supplied for forming tantalum oxide films.
[0107] [Application to Making Metal Film: Solid and Liquid
Sources]
[0108] The semiconductor manufacturing device 1 or the
semiconductor manufacturing system is also applicable to forming
metal films (e.g. platinum films). The following describe how
ruthenium films are made by the LPCVD process.
[0109] Referring to FIG. 12, the external source 20 includes a
solid tank 26 storing ruthenium cyclopentane (Ru(Cp)2) powders,
grains or pellets at the normal pressures and temperatures. A
necessary amount of the ruthenium cyclopentane is supplied to the
buffer unit 4. For this purpose, at least a weight and weighing
capacity of ruthenium cyclopentane are measured by a weightometer
261 and a weighing scale 263, respectively , or the number of
powders, grains or pellets thereof is counted by a counter 264.
[0110] The buffer unit 4 includes a heater and a thermostat 40
which are similar to those shown in FIG. 11. The ruthenium
cyclopentane is vaporized by the heater and thermostat 40 in the
buffer unit 4, and is stored therein.
[0111] The stored ruthenium cyclopentane is delivered to the
substrate treating chamber 2, so that a ruthenium film can be
formed by the LPCVD process similarly to the polycrystalline
silicon film using the mono-silane gas.
[0112] The semiconductor manufacturing device 1 or the
semiconductor manufacturing system includes the buffer unit 4, so
that the solid substrate treating substance (Ru(Cp)2) can be
reliably supplied without any problem caused by a reduced capacity
of a vaporizer or the like in response to the vapor phase LPCVD
reaction. Further, the necessary amount of source gases can be
reliably supplied in order to from ruthenium cyclopentane
films.
[0113] Further, ruthenium ethyl cyclopentane (Ru(EtCP)2) which is
liquid at the normal pressures and temperatures can be used for
forming ruthenium films. In this case, the semiconductor
manufacturing device 1 or the semiconductor manufacturing system of
FIG. 11 is also usable.
[0114] (Second Embodiment of the Invention)
[0115] In this embodiment, the buffer unit 4 of the first
embodiment is provided as an external semiconductor manufacturing
device.
[0116] Referring to FIG. 13, the external semiconductor
manufacturing device 1A is provided as an external device in
addition to the semiconductor manufacturing device 1 with the
substrate treating chamber 2, and includes the buffer unit 4 in
order to receive and store the substrate treating substance from
the external source 20, and delivers the stored substrate treating
substance to the substrate treating chamber 2 of the semiconductor
manufacturing device 1.
[0117] The external semiconductor manufacturing device 1A includes:
a control unit 6A controlling the substrate treating substance in
the buffer unit 4; the measuring unit 5 measuring the substrate
treating substance; the pneumatic valve 702 controlling the
delivery of the mono-silane gas from the mono-silane gas cylinder
21 of the external source 20; the pneumatic valve 703 controlling
the delivery of the nitride gas from the nitride gas generator 22;
the pneumatic valve 701 controlling the delivery of the fluorine
gas from the fluorine gas generator 23; and the pneumatic valve 801
controlling the delivery of the substrate treating substance to the
substrate treating chamber 2 of the semiconductor manufacturing
device 1 from the buffer unit 4. The control unit 6A is dedicated
to the buffer unit 4, controls the pneumatic valves 701 to 703 and
801, and is controlled by the CIM system via the LAN 13.
[0118] In this embodiment, the semiconductor manufacturing device 1
is essentially identical to the semiconductor manufacturing device
1 of the first embodiment except for the buffer unit 4, measuring
unit 5, pneumatic valves 701 to 703 and 801, all of which
constitute the external semiconductor manufacturing device 1A. The
external semiconductor manufacturing device 1A includes the control
unit 6A dedicated to the buffer unit 4 in order to control the
temperatures of the heater 202 and the operation of the gate valve
802.
[0119] The external semiconductor manufacturing device 1A including
the buffer unit 4 functions as an external unit for the
semiconductor manufacturing device 1 which actually deposits films.
The combination of the semiconductor manufacturing devices 1 and 1A
is as effective as the semiconductor manufacturing device 1 or the
semiconductor manufacturing system of the first embodiment.
Further, the external semiconductor manufacturing device 1A is very
versatile, and can be attached to a different semiconductor
manufacturing device, e.g. a sputtering device, an etching device,
a cleaning device or the like.
[0120] (Third Embodiment of the Invention)
[0121] In this embodiment, the semiconductor manufacturing device 1
or the semiconductor manufacturing system of the first embodiment
is applied to cleaning an inner wall of a reaction tube 201 of the
substrate treating chamber 2.
[0122] [Basic Cleaning Method]
[0123] The following describe, with reference to FIG. 1, how to
clean the inner wall of the reaction tube 201 covered with
polycrystalline silicon films deposited by the LPCVD process. The
foregoing process directly relates to the making of the
polycrystalline silicon films. However, the cleaning process is
indirect but indispensable to make the polycrystalline silicon
films.
[0124] (1) First of all, cleaning data are transmitted to the
control unit 6 of the semiconductor manufacturing device 1 from the
manufacture managing database 11 via the LAN 13 as shown in FIG. 1.
The cleaning data denote at least etching data and so on which are
necessary to remove the polycrystalline silicon films from the
inner wall of the substrate treating chamber 2. For instance, in
order to remove a 100 nm-thick polycrystalline silicon film from
the inner wall of the reaction tube 201, etching should be
performed by introducing for 5 minutes a fluorine gas at the feed
rate of 1000 sccm, at the temperature of 300.degree. C. and at the
pressure of 1.333.times.10.sup.3 Pa. A total of 5000 scc fluorine
gas will be introduced in 5 minutes.
[0125] (2) In this embodiment, the buffer unit 4 has a capacity of
5000 scc in order to clean the substrate treating chamber 2. In
response to the cleaning data, the control unit 6 opens the
pneumatic valve 801, thereby evacuating the buffer unit 4 to a
sufficiently low pressure by the vacuum exhaust pump 30.
[0126] (3) Thereafter, the control unit 6 closes the pneumatic
valve 801, and opens the pneumatic valve 701, so that the fluorine
gas will be introduced into the buffer unit 4 from the fluorine gas
generator 23 of the external source 20.
[0127] (4) The 5000 scc fluorine gas (corresponding to 5000
cm.sup.3 of the fluorine gas in the normal state) is filled in the
buffer unit 4, and is stored therein as soon as the control unit 6
closes the pneumatic valve 701. The fluorine gas generator 23
generates the fluorine gas by the electrolysis of KF and 2HF, or
pyrolysis of KF and 6HF. When the fluorine gas is generated at the
rate of 100 sscm/min, the fluorine gas generator 23 should have a
capacity which is ten times as large as its normal capacity in
order to generate the fluorine gas at the feed rate of 1000 sccm.
However, such a feed rate is necessary for only approximately 5
minutes for the cleaning process.
[0128] In this embodiment, the buffer unit 4 starts to store the
fluorine gas 50 minutes prior to the cleaning process, so that the
necessary 1000 sccm fluorine gas can be obtained even when the
fluorine gas generator 23 has only the 100 sccm capacity.
[0129] In other words, the buffer unit 4 starts storing the
fluorine gas immediately after the polycrystalline silicon film is
formed and the mono silane gas is emitted therefrom. Further, the
fluorine gas is stored during the cleaning of the reaction tube
201, during the return of the pressure in the buffer unit 4 to the
normal state, during the unloading of the semiconductor wafer from
the substrate treating chamber 2, and during the evacuation and
thermal stabilization of the buffer unit 4 for the cleaning
process. Therefore, the cleaning period is not lengthened.
[0130] Alternatively, the buffer unit 4 is dedicated to the storage
of the mono-silane gas, and a cleaning buffer unit 4 may be
provided in order to store the fluorine gas. The cleaning buffer
unit 4 may be incorporated in the semiconductor manufacturing
device 1 as in the first embodiment, or may be provided as an
external unit similarly to the external semiconductor manufacturing
device 1A of the second embodiment.
[0131] (5) The fluorine gas is delivered to the substrate treating
chamber 2 from the buffer unit 4 in order to clear the substrate
treating chamber 2.
[0132] Generally speaking, the substrate treating chamber 2 is
cleaned less frequently than the number of times of polycrystalline
silicon film deposition, which is effective in reducing the supply
capacity of the fluorine gas generator 23. In other words,
capacities of the external source 20 and gas delivery facilities
can be reduced, and capital investment for such an external source
and gas delivery facilities can be also reduced.
[0133] In the third embodiment, the cleaning process (etching
process) for the substrate treating chamber 2 is essentially
identical to the polycrystalline silicon film deposition in the
first embodiment. Especially, in the cleaning process, a final
point of temperature rise, analysis of exhaust gases and so on in
the reaction tube 20 can be monitored on the real time basis.
Therefore, the semiconductor manufacturing system shown in FIG. 7
is very effective since it controls the cleaning process on the
basis of a total amount of supplied fluorine gas without
controlling the feed rate of the fluorine gas using the mass flow
controller 811, conductance regulator 812 and so on. In the
semiconductor manufacturing system of FIG. 7, it is not necessary
to measure time-dependent variations of the etching rate
beforehand.
FIRST MODIFIED EXAMPLE
[0134] In a first modified example of the third embodiment, the
semiconductor manufacturing device 1 or the semiconductor
manufacturing system includes a retrieving buffer unit 35 (a second
buffer unit) between the substrate treating chamber 2 and the
vacuum exhaust pump 30 in parallel. Referring to FIG. 14, the
retrieving buffer unit 35 connects to the external source 20 via a
three-way valve 805, to the vacuum exhaust pump 30 via a valve 806,
and to the buffer unit 4 via a return valve 807.
[0135] The retrieving buffer unit 35 retrieves and stores the
cleaning gas (fluorine gas) exhausted from the substrate treating
chamber 2, and delivers it to the buffer unit 4. The fluorine gas
returned to the buffer unit 4 is reused for a next following
cleaning of the substrate treating chamber 2, which is effective in
promoting to effective use of the cleaning gas, reducing cleaning
cost, and promoting energy saving. The retrieving buffer unit 35
may be positioned in either in or out of the semiconductor
manufacturing device 1.
SECOND MODIFIED EXAMPLE
[0136] Referring to FIG. 15, the semiconductor manufacturing system
includes a temporary storage buffer unit 36 between the vacuum
exhaust pump 30 and the purifier 31. The temporary storage buffer
unit 36 temporarily stores an exhaust gas, and is connected to the
vacuum exhaust pump 30 via a three-way valve 808 and an exhaust gas
compressor 37, to the nitride gas generator 22 via a valve 810 in
order to supply a nitride gas, and to the purifier 31 via a return
valve 809.
[0137] In this modified example, the semiconductor manufacturing
device 1 handles not only the substrate treating substances such as
source gases used for the film deposition and cleaning gases used
for the cleaning of the substrate treating chamber 2, and it also
handles the exhaust gas. Specifically, the temporary storage buffer
unit 36 is provided in a path for discharging exhaust gases, and
functions similarly to the buffer unit 4. If exhaust gases are
discharged beyond the capacity of the purifier 31, the temporary
storage buffer unit 36 controls a feed rate of the exhaust gases.
Generally, the purifier 31 operates only while the exhaust gases
are being discharged. The temporary storage buffer unit 36 enables
the purifier 31 to process exhaust gases from a plurality of
semiconductor manufacturing devices 1 (not shown).
[0138] In the foregoing case, the temporary storage buffer unit 36
temporarily stores exhaust gases, and gradually supplies them to
the purifier 31, so that the purifier 31 can reliably process them.
Even if one semiconductor manufacturing device 1 happens to
discharge exhaust gases beyond the capacity of the purifier 31, the
temporary storage buffer unit 35 operates as described above.
[0139] Therefore, the purifier 31 can have a reduced capacity.
Further, a setting number of purifiers 31 can be reduced in the
semiconductor manufacturing system. The gas source and delivery
facilities of the semiconductor manufacturing system can be
downsized, and capital investment for such facilities can be
reduced.
[0140] (Fourth Embodiment of the Invention)
[0141] In this embodiment, the present invention is applied to the
cleaning of inner walls of reaction tubes in the substrate treating
chambers of a plurality of semiconductor manufacturing devices in
the semiconductor manufacturing system of the third embodiment.
[0142] [Basic Structure of Semiconductor Manufacturing Device and
Semiconductor Manufacturing System]
[0143] Referring to FIG. 16, the semiconductor manufacturing system
comprises at least: a plurality of semiconductor manufacturing
devices 1(1), 1(2) and 1(3); an external source 20 supplying
substrate treating substances to the semiconductor manufacturing
devices 1(1) to 1(3); a external semiconductor manufacturing device
1B distributing the substrate treating substances to the
semiconductor manufacturing devices 1(1) to 1(3); and a CIM server
14.
[0144] The semiconductor manufacturing device 1(1) is essentially
identical to the semiconductor manufacturing device 1 of the first
embodiment (refer to FIG. 1), and includes at least: a substrate
treating chamber 2; a buffer unit 4 receiving and storing the
substrate treating substances from the external source 20 and
delivering the substrate treating substances to the substrate
treating chamber 2 or the semiconductor manufacturing device 1(1);
a control unit 6(1) controlling the states of the substrate
treating substances in the buffer unit 4(1); and a measuring unit 5
(not shown) measuring the state of the substrate treating
substances. The control unit 6(1) is connected to the CIM server 14
via the LAN 13.
[0145] The semiconductor manufacturing device 1(2) is identical to
the semiconductor manufacturing device 1(1), and includes at least:
a substrate treating chamber 2 (not shown), a measuring unit 5, a
buffer unit 4(2), and a control unit 6(2). The semiconductor
manufacturing device 1(3) includes at least: a substrate treating
chamber 2 (not shown), a measuring unit 5, a buffer unit 4(3), and
a control unit 6(3). The semiconductor manufacturing system is
assumed to include three semiconductor manufacturing devices 1(1)
to 1(3) in order to simplify the description thereof.
Alternatively, the semiconductor manufacturing system may have two
semiconductor manufacturing devices 1 or four or more semiconductor
manufacturing devices 1.
[0146] The external semiconductor manufacturing device 1B is
essentially identical to the external semiconductor manufacturing
device 1A of the second embodiment (shown in FIG. 13), but does not
include a substrate treating chamber 2, and functions only as a
buffer. Specifically, the external semiconductor manufacturing
device 1B receives and stores the substrate treating substances
from the external source 20, and includes a buffer unit 4B
delivering the substrate treating substances to an external unit,
distribution valves 721, 722 and 723, and a control unit 6B
controlling the operations of the valves 721 to 723.
[0147] In this embodiment, the substrate treating chambers 2 of the
semiconductor manufacturing devices 1(1) to 1(3) are cleaned using
fluorine gases temporarily stored in the buffer unit 4B, which is
connected to a fluorine gas generator 23 of the external source
20.
[0148] The distribution valve 721 is positioned between the buffer
unit 4B and the semiconductor manufacturing device 1(1), and is
controlled by the control unit 6B. The distribution valve 722 is
provided between the buffer unit 4B and the semiconductor
manufacturing device 1(2), and is controlled by the control unit
6B. The distribution valve 723 is provided between the buffer unit
4B and the semiconductor manufacturing device 1(3), and is
controlled by the control unit 6B. The control unit 6B is connected
to the CIM server 14 via the LAN 13.
[0149] The CIM server 14 stores information concerning order of
processing raw semiconductor wafer lots, information concerning
kinds of lots, and classified information concerning priorities of
processing sequences in manufacturing lines, and so on. The CIM
server 14 manages manufacturing schedules on the basis of these
pieces of information, i.e. which lot should be processed and when
it should be processed by the semiconductor manufacturing device
1(1), 1(2) or 1(3).
[0150] The CIM server 14 can calculate currently accumulated
thicknesses of the polycrystalline silicon films obtained in each
substrate treating chamber 2 of each of the semiconductor
manufacturing devices 1(1) to 1(3). Further, the CIM server 14 can
artificially or automatically calculate and estimate a recommended
film thickness for cleaning the substrate treating chambers 2 on
the basis of chronological information, in present or past, on film
thicknesses or film dust. Still further, the CIM server 14 can
prepare schedules concerning a time to clean the substrate treating
chambers 2 on the basis of the calculated and estimated data,
information concerning current or waiting lots, manufacture
schedules and so on.
[0151] [Operation of Semiconductor Manufacturing Device and
Semiconductor Manufacturing System, and Substrate Treating
Method]
[0152] The cleaning is performed as briefly described
hereinafter.
[0153] (1) First of all, the CIM server 14 prepares a cleaning
schedule for the semiconductor manufacturing device 1(1), 1(2) or
1(3) which should be cleaned. It is assumed here that the substrate
treating chamber 2 of the semiconductor manufacturing device 1(1)
should be cleaned first.
[0154] (2) In accordance with the cleaning schedule, the CIM server
14 not only provides control information to the control unit 6(1)
of the semiconductor manufacturing device 1(1) via the LAN 13 and
opens the pneumatic valve 701, but also provides the control
information to the control units 6(2) and 6(3) of the semiconductor
manufacturing devices 1(2) and 1(3), and closes the pneumatic
valves 701 of the semiconductor manufacturing devices 1(2) and
1(3).
[0155] (3) The fluorine gas generator 23 supplies the fluorine gas
to the buffer unit 4B of the external semiconductor manufacturing
device 1B. The buffer unit 4B stores the fluorine gas therein.
[0156] (4) The CIM server 14 opens the distribution valve 721 via
the control unit 6B of the external semiconductor manufacturing
device 1B, and closes the distribution valves 722 and 723. The
fluorine gas from the buffer unit 4B is delivered to and stored in
the buffer unit 4(1) of the semiconductor manufacturing device
1(1). An amount of the fluorine gas in the buffer unit 4(1) is
equal to the amount necessary for the cleaning process which has
been calculated by the CIM server 14 on the basis of the
accumulated film thickness information. For instance, the amount of
the stored fluorine gas can be easily measured and controlled using
the pressure regulator 710 (shown in FIG. 2), the mass flow
controller 711 (shown in FIG. 3) or the conductance regulator 712
(shown in FIG. 4). When the preset amount of the fluorine gas is
stored in the buffer unit 4(1), this information is transmitted to
the CIM server 14 via the LAN 13.
[0157] (5) The CIM server 14 starts to supply the fluorine gas to
the buffer units 4(2) and 4(3) of the semiconductor manufacturing
device 1(2) and 1(3), respectively, in accordance with the priority
of the next following cleaning process. These buffer units 4(2) and
4(3) can store the fluorine gas necessary for the cleaning
process.
[0158] (6) In the foregoing state, if the fluorine gas stored in
the buffer units 4(1) to 4(3) is not in use, the fluorine gas
supplied from the fluorine gas generator 23 is stored in the buffer
unit 4B of the external semiconductor manufacturing device 1B to a
pressure limit. Further, when the fluorine gas in the buffer units
4(1) to 4(3) is not still in use, the fluorine gas generator 23 is
stopped in response to a control command from the CIM server
14.
[0159] (7) The substrate treating chamber 2 of the semiconductor
manufacturing device 1(1) is cleaned using the fluorine gas in the
buffer unit 4(1). Further, the substrate treating chambers 2 of the
semiconductor manufacturing devices 1(2) and 1(3) are also cleaned
using the fluorine gases in the buffer units 4(2) and 4(3),
respectively.
[0160] In the fourth embodiment, the external semiconductor
manufacturing device 1B including the buffer unit 4B serves for the
devices 4(1) to 4(3), which enables effective use of the fluorine
gas generator 23. Therefore, it is possible to downsize the
fluorine gas generator 23 and facilities for supplying the fluorine
gas, and reduce installation cost, maintenance cost and so on.
[0161] Further, the external semiconductor manufacturing device 1B
with the buffer unit 4B serves for semiconductor manufacturing
devices without any buffer units in addition to the semiconductor
manufacturing devices 4(1) to 4(3). For instance, those
semiconductor manufacturing devices can be designed in a manner
such that any of their valves can operate together with the valve
721, 722 or 723 of the external semiconductor manufacturing device
1B in response to the control command from the CIM server 14. In
this case, those semiconductor manufacturing devices can function
as if they include buffer units 4.
[0162] The external semiconductor manufacturing device 1B with the
buffer unit 4B is attached as an external unit to the external
source 20 in the fourth embodiment. Alternatively, the external
semiconductor manufacturing device 1B may be incorporated in the
external source 20.
MODIFIED EXAMPLE
[0163] In a modified example of the fourth embodiment, a
semiconductor manufacturing system comprises at least the
semiconductor manufacturing devices 1(1), 1(2) and 1(3), the
external source 20 supplying the substrate treating substances to
the semiconductor manufacturing devices 1(1) to 1(3), a external
semiconductor manufacturing device IC distributing the substrate
treating substances from the external source 20 to the
semiconductor manufacturing devices 1(1) to 1(3), and the CIM
server 14 managing the semiconductor manufacturing devices 1(1) to
1(3). Refer to FIG. 17.
[0164] The semiconductor manufacturing device 1(1) is essentially
identical to the semiconductor manufacturing device 1 of the second
embodiment (shown in FIG. 13), and includes at least a substrate
treating chamber 2, and a control unit 6(1) controlling the
substrate treating chamber 2. The control unit 6(1) is connected to
the CIM server 14 via the LAN 13. However, the semiconductor
manufacturing device 1(1) does not include any buffer unit 4(1),
and differs from the semiconductor manufacturing device 1(1) of the
fourth embodiment in this respect.
[0165] The semiconductor manufacturing devices 1(2) and 1(3)
include at least treating chambers 2 and control units 6(2) and
6(3), respectively. The following describe the semiconductor
manufacturing system having three semiconductor manufacturing
devices 1(1) to 1(3). Alternatively, the semiconductor
manufacturing system may have two or more than four semiconductor
manufacturing devices.
[0166] The external semiconductor manufacturing device IC is
essentially identical to the external semiconductor manufacturing
device 1B of the fourth embodiment (shown in FIG. 16), but does not
have any substrate treating chamber 2, and functions as a dedicated
buffer unit. The external semiconductor manufacturing device IC
includes at least a main buffer unit 4C and sub-buffer units 4C1 to
4C3. The main buffer unit 4C receives the substrate treating
substance from the external source 20, stores them and delivers
them to the sub-buffer units 4C1 to 4C3, which transfer them to the
semiconductor manufacturing devices 1(1) to 1(3).
[0167] The external semiconductor manufacturing device IC includes:
valves 721 to 723 via which the substrate treating substance is
distributed to the sub-buffer units 4C1 to 4C3 from the main buffer
unit 4C; pneumatic valves 725 to 727 via which the substrate
treating substance is distributed to the semiconductor
manufacturing devices 1(1) to 1(3); and a control unit 6C
controlling the operations of the valves 721 to 723 and 725 to 727,
and is connected to the CIM server 14 via the LAN 13.
[0168] The substrate treating substance, i.e. the fluorine gas, in
the main buffer unit 4C is used for cleaning the substrate treating
chambers 2 of the semiconductor manufacturing devices 1(1) to 1(3).
Specifically, the fluorine gas from the fluorine gas generator 23
is temporarily stored in the main buffer unit 4C, is distributed to
the sub-buffer units 4C1 to 4C3, and is temporarily stored therein.
Thereafter, the fluorine gas is delivered to the semiconductor
manufacturing devices 1(1) to 1(3) via the pneumatic valves 725 to
727. In short, the external semiconductor manufacturing device IC
includes the sub-buffer units 4C1 to 4C3 which serve for the
semiconductor manufacturing devices 1(1) to 1(3).
[0169] The semiconductor manufacturing system of the modified
example is as effective and advantageous as the semiconductor
manufacturing system of the fourth embodiment.
[0170] In the modified example, the external semiconductor
manufacturing device IC is provided as an external unit for the
external source 20. Alternatively the external semiconductor
manufacturing device 1C may be incorporated in the external source
20.
[0171] (Fifth Embodiment of the Invention)
[0172] In this embodiment, the present invention is applied to a
semiconductor wafer cleaning device (semiconductor manufacturing
device) and a semiconductor wafer cleaning system (semiconductor
manufacturing system) in which a cleaning agent can be
recycled.
[0173] [Basic Structure of Semiconductor Manufacturing Device and
Semiconductor Manufacturing System]
[0174] Referring to FIG. 18, the semiconductor manufacturing system
(semiconductor wafer cleaning system) comprises at least:
semiconductor manufacturing devices 1(4), 1(5) and 1(6) cleaning
substrates; a primary tube 90 introducing a cleaning agent; an
evaporating/refining unit 95 which evaporates and refines the
cleaning agent discharged from the semiconductor manufacturing
devices 1(4), 1(5) and 1(6); and external semiconductor
manufacturing devices ID, 1E and 1F which are provided with buffer
units 4D, 4E and 4F receiving and storing the cleaning agent from
the primary tube 90 or the evaporating/refining unit 95,
respectively.
[0175] Although not shown in detail, the semiconductor
manufacturing device 1(4) is structured to function as a single
wafer cleaning device. In other words, the semiconductor
manufacturing device 1(4) is sheet-fed processing type cleaning
device. The semiconductor manufacturing devices 1(5) and 1(6) whose
structure is not shown in detail function as semiconductor wafer
cleaning devices of the batch processing type.
[0176] A primary tube 90 is arranged in the clean room 100, and
simultaneously supplies the cleaning agent, i.e. a hydrogen
fluoride solution (HF), to the semiconductor manufacturing devices
1(4) to 1(6) via control valves 731, which are opened or closed by
the database 11 of the CIM system via the LAN 13.
[0177] The hydrogen fluoride solution used for cleaning
semiconductor wafers is discharged from the semiconductor
manufacturing devices 1(4) to 1(6) to the evaporating/refining unit
95 via a conduit pipe 91. Specifically, a part of the hydrogen
fluoride solution is used for cleaning semiconductor wafers (i.e.
for etching silicon oxide films) while a part of the remaining
hydrogen fluoride solution is diluted by pure water or like, and is
discharged via the conduit pipe 91. Only the hydrogen fluoride
components of the discharged hydrogen fluoride solution are
extracted and refined by the evaporating/refining unit 95. The
refined hydrogen fluoride solution is delivered to the external
semiconductor manufacturing devices 1D to 1F via a return pipe 94,
and is reused. Non-reused hydrogen fluoride solution is discharged
via an industry effluent pipe 93.
[0178] The buffer unit 4D of the external semiconductor
manufacturing device 1D stores the hydrogen fluoride solution
(supplied via the primary valve 90 and the control valve 731) and
the recycled hydrogen fluoride solution (delivered from the
evaporating/refining unit 95 via the return valve 94 and the
control valve 732), and delivers the stored hydrogen fluoride
solutions to the semiconductor manufacturing device 1(4). The
operation of the control valve 732 is controlled by the control
unit 6D connected to the CIM system via the LAN 13.
[0179] Similarly to the external semiconductor manufacturing device
ID, the buffer unit 4E of the external semiconductor manufacturing
device 1E stores the hydrogen fluoride solution (supplied via the
primary valve 90 and the control valve 731) and the recycled
hydrogen fluoride solution (delivered from the evaporating/refining
unit 95 via the return valve 94 and the control valve 732), and
delivers the stored hydrogen fluoride solutions to the
semiconductor manufacturing device 1(5). The operation of the
control valve 732 is controlled by the control unit 6E connected to
the CIM system via the LAN 13.
[0180] The buffer unit 4F of the external semiconductor
manufacturing device IF stores the hydrogen fluoride solution
(supplied via the primary valve 90 and the control valve 731) and
the reused hydrogen fluoride solution (delivered from the
evaporating/refining unit 95 via the return valve 94 and the
control valve 732), and delivers the stored hydrogen fluoride
solutions to the semiconductor manufacturing device 1(6). The
operation of the control valve 732 is controlled by the control
unit 6F.
[0181] [Operation of Semiconductor Manufacturing Device and
Semiconductor Manufacturing System, and Substrate Treating
Method]
[0182] The following describe the operations of the semiconductor
manufacturing devices 1(4) to 1(6) (semiconductor wafer cleaning
devices), external semiconductor manufacturing devices 1D to 1F
having the buffer units 4D, 4E and 4F, and semiconductor
manufacturing system.
[0183] (1) In the semiconductor manufacturing devices 1(4) to 1(6),
the hydrogen fluoride solution is delivered to and stored in the
buffer units 4D, 4E and 4F via the primary supply pipe 90 and the
control valve 731. The hydrogen fluoride solution stored in the
buffer units 4D, 4E and 4F is used for cleaning semiconductor
wafers in the semiconductor manufacturing devices 1(4), 1(5) and
1(6), respectively.
[0184] (2) As in the fourth embodiment, the CIM server 14 (not
shown) calculates amounts of the hydrogen fluoride solution to be
distributed to the semiconductor manufacturing devices 1(4) to 1(6)
(not shown) on the basis of distribution priority order. The
operation of the control valves 731 and 732 is controlled via the
LAN 13 on the basis of the calculated results. For instance, the
hydrogen fluoride solution is preferentially delivered to the
semiconductor manufacturing device 1(4).
[0185] (3) If necessary, an extensively pure hydrogen fluoride
solution for cleaning semiconductor wafers is preferentially
delivered to the semiconductor manufacturing device 1 via the
primary supply pipe 90 and the buffer unit 4. Otherwise, the
recycled hydrogen fluoride solution is preferentially supplied from
the evaporating/refining unit 95.
[0186] (4) Usually, the recycled hydrogen fluoride solution is
preferentially applied to cleaning semiconductor wafers. When the
recycled hydrogen fluoride solution becomes short, the hydrogen
fluoride solution is re supplied to the semiconductor manufacturing
device 1 via the primary supply pipe 90 and the buffer unit 4.
[0187] The semiconductor wafer cleaning system of this embodiment
includes the buffer units 4D to 4F in order to store the hydrogen
fluoride solution from the primary supply pipe 90 and the recycled
hydrogen fluoride solution from the evaporating/refining unit 95.
The hydrogen fluoride solutions are stored in the buffer units 4D
to 4F under control of the CIM system during the cleaning or
delivery of semiconductor wafers. It is possible to carry out the
cleaning process at the predetermined speed, and downsize the
semiconductor manufacturing system or the cleaning agent delivering
facilities. Generally, a semiconductor manufacturing system tends
to become bulky when it includes the recycling unit as well as the
evaporating/refining unit 95. As a result, the cleaning agent
delivery facilities also become bulky. The semiconductor
manufacturing system of the fifth embodiment can be downsized
because it is provided with the buffer units 4D to 4F.
[0188] Alternatively, the semiconductor manufacturing device and
the semiconductor manufacturing system is also applicable to
cleaning glass substrates, insulating substrates and so on.
Further, the external semiconductor manufacturing devices 1D to 1F
attached to the semiconductor manufacturing devices 1(4) to 1(6) as
external units may be incorporated therein.
[0189] (Other Embodiments of the Invention)
[0190] The semiconductor manufacturing devices in the first and
second embodiments are LPCVD devices. Alternatively, the present
invention is applicable to CVD devices other than the LPCVD devices
(e.g. an atmospheric CVD device or a plasma CVD device), or an
epitaxial growth system. Further, the present invention is
applicable not only to a system which includes different types of
semiconductor manufacturing devices, film deposition devices,
etching units, cleaning units and so on but also other substrate
treating methods.
[0191] As described above, the present invention provides the
semiconductor manufacturing device in which only necessary amounts
of substances such as gases, liquids and solids directly or
indirectly used for treating substrates are supplied only when they
are necessary, and which can downsize the source and delivery
pipes.
[0192] Further, the invention provides the semiconductor
manufacturing system which can downsize substance sources and
delivering facilities.
[0193] Finally, the invention provides the substrate treating
method which promotes efficient use of the source and delivering
facilities.
[0194] Although the present invention has been described and
illustrated in detail, it is to be clearly understood that the same
is by way of illustration and example only, and is not to be taken
by way of limitation. The spirit and scope of the present invention
are to be limited only by the terms of the appended claims.
* * * * *