U.S. patent application number 10/339639 was filed with the patent office on 2003-09-04 for batch-type remote plasma processing apparatus.
This patent application is currently assigned to HITACHI KOKUSAI ELECTRIC INC.. Invention is credited to Inokuchi, Yasuhiro, Ishimaru, Nobuo, Kontani, Tadashi, Takebayashi, Motonari, Toyoda, Kazuyuki.
Application Number | 20030164143 10/339639 |
Document ID | / |
Family ID | 27806896 |
Filed Date | 2003-09-04 |
United States Patent
Application |
20030164143 |
Kind Code |
A1 |
Toyoda, Kazuyuki ; et
al. |
September 4, 2003 |
Batch-type remote plasma processing apparatus
Abstract
A plasma processing apparatus comprises a processing chamber in
which a plurality of substrates are stacked and accommodated; a
pair of electrodes extending in the stacking direction of the
plurality of substrates, which are disposed at one side of the
plurality of substrates in said processing chamber, and to which
high frequency electricity is applied; and a gas supply member
which supplies processing gas into a space between the pair of
electrodes.
Inventors: |
Toyoda, Kazuyuki; (Tokyo,
JP) ; Inokuchi, Yasuhiro; (Tokyo, JP) ;
Takebayashi, Motonari; (Tokyo, JP) ; Kontani,
Tadashi; (Tokyo, JP) ; Ishimaru, Nobuo;
(Tokyo, JP) |
Correspondence
Address: |
HOGAN & HARTSON L.L.P.
500 S. GRAND AVENUE
SUITE 1900
LOS ANGELES
CA
90071-2611
US
|
Assignee: |
HITACHI KOKUSAI ELECTRIC
INC.
|
Family ID: |
27806896 |
Appl. No.: |
10/339639 |
Filed: |
January 9, 2003 |
Current U.S.
Class: |
118/723E ;
156/345.47; 257/E21.274 |
Current CPC
Class: |
H01L 21/02183 20130101;
H01J 37/32357 20130101; C23C 16/4584 20130101; H01L 21/02274
20130101; H01J 37/32834 20130101; H01L 21/02205 20130101; H01J
37/3244 20130101; C23C 16/45542 20130101; H01J 2237/332 20130101;
C23C 16/45578 20130101; C23C 16/45546 20130101; H01L 21/02211
20130101; H01L 21/67109 20130101; H01J 37/32541 20130101; H01L
21/77 20130101; C23C 16/452 20130101; H01L 21/205 20130101; H01L
21/31604 20130101; C23C 16/54 20130101; C23C 16/45525 20130101;
H01J 37/32513 20130101; C23C 16/4583 20130101 |
Class at
Publication: |
118/723.00E ;
156/345.47 |
International
Class: |
C23F 001/00; C23C
016/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 10, 2002 |
JP |
2002-3615 |
Jul 12, 2002 |
JP |
2002-203397 |
Claims
What is claimed is:
1. A plasma processing apparatus, comprising: a processing chamber
in which a plurality of substrates are stacked and accommodated, a
pair of electrodes extending in the stacking direction of said
plurality of substrates, said electrodes being disposed at one side
of said plurality of substrates in said processing chamber, and
high frequency electricity being applied to said electrodes, and a
gas supply member which supplies processing gas into a space
between said pair of electrodes.
2. A plasma processing apparatus as recited in claim 1, wherein
said pair of electrodes are respectively covered with protecting
members.
3. A plasma processing apparatus as recited in claim 1, wherein an
electrical discharging chamber is formed at the one side of said
plurality of stacked substrates in said processing chamber such
that said electrical discharging chamber is partitioned from said
processing chamber such as to include said pair of electrodes, and
a gas blowout opening is provided in said electrical discharging
chamber for supplying the processing gas into said processing
chamber.
4. A plasma processing apparatus as recited in claim 3, wherein
said gas blowout opening is located between said pair of
electrodes.
5. A plasma processing apparatus as recited in claim 1, wherein
said pair of electrodes are rod-like electrodes extending in a
direction in which said plurality of stacked substrates are
stacked.
6. A plasma processing apparatus as recited in claim 5, further
comprising: a substrate holding tool which holds said plurality of
stacked substrates, and a substrate holding tool rotating driving
apparatus which rotates said substrate holding tool.
7. A plasma processing apparatus as recited in claim 1, wherein an
electrical discharging chamber which is independent from said
processing chamber is formed between said pair of electrodes, and a
gas blowout opening which supplies the processing gas into said
processing chamber is provided in said electrical discharging
chamber.
8. A plasma processing apparatus as recited in claim 1, wherein a
gas supplying pipe is disposed between said pair of electrodes, and
said gas supplying pipe is provided with a gas blowout opening
which supplies processing gas into said processing chamber.
9. A plasma processing apparatus, comprising: a processing chamber
in which a plurality of substrates are stacked and accommodated, a
pair of electrodes which is disposed inside and outside of said
processing chamber such as to be opposed to each other at one side
of said plurality of substrates, and to which high frequency
electricity is applied, and a gas supplying pipe which supplies
processing gas into the processing chamber to a place which is away
from the space between said pair of electrodes.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a plasma processing
apparatus, and more particularly, to a batch-type remote plasma
processing apparatus, e.g., to an apparatus which is effectively
utilized for depositing an insulative film or a metal film on a
semiconductor wafer (wafer, hereinafter) on which a semiconductor
integrated circuit including semiconductor elements is formed in
producing a semiconductor device.
[0003] 2. Description of the Related Art
[0004] As a conventional batch-type remote plasma processing
apparatus, a single wafer-feeding type remote plasma CVD apparatus
has been used. However, in the single wafer-feeding type remote
plasma CVD apparatus, since wafers are processed one by one, there
has been a problem that throughput is small.
SUMMARY OF THE INVENTION
[0005] Therefore, it is a main object of the present invention to
provide a plasma processing apparatus capable of obtaining great
throughput.
[0006] According to a first aspect of the present invention, there
is provided a plasma processing apparatus, comprising:
[0007] a processing chamber in which a plurality of substrates are
stacked and accommodated,
[0008] a pair of electrodes extending in the stacking direction of
the plurality of substrates, the electrodes being disposed at one
side of the plurality of substrates in the processing chamber, and
high frequency electricity being applied to the electrodes, and
[0009] a gas supply member which supplies processing gas into a
space between the pair of electrodes.
[0010] According to a second aspect of the present invention, there
is provided a plasma processing apparatus, comprising:
[0011] a processing chamber in which a plurality of substrates are
stacked and accommodated,
[0012] a pair of electrodes which is disposed inside and outside of
the processing chamber such as to be opposed to each other at one
side of the plurality of substrates, and to which high frequency
electricity is applied, and
[0013] a gas supplying pipe which supplies processing gas into the
processing chamber to a place which is away from the space between
the pair of electrodes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The above and further objects, features and advantages of
the present invention will become more apparent from the following
detailed description taken in conjunction with the accompanying
drawings, wherein:
[0015] FIG. 1 is a transversal sectional view of a CVD apparatus
according to a first embodiment of the present invention;
[0016] FIG. 2 is a longitudinal sectional view taken along a line
II-II of FIG. 1;
[0017] FIG. 3 is a longitudinal sectional view taken along a line
III-III of FIG. 1;
[0018] FIG. 4 is a transversal sectional view of a CVD apparatus
according to a second embodiment of the present invention;
[0019] FIG. 5 is a longitudinal sectional view taken along a line
V-V of FIG. 4;
[0020] FIG. 6 is a transversal sectional view of a CVD apparatus
according to a third embodiment of the present invention;
[0021] FIG. 7 is a longitudinal sectional view taken along a line
VII-VII of FIG. 6;
[0022] FIG. 8 is a longitudinal sectional view taken along a line
VIII-VIII of FIG. 6;
[0023] FIG. 9 is a transversal sectional view of a CVD apparatus
according to a fourth embodiment of the present invention;
[0024] FIG. 10 is a transversal sectional view of a CVD apparatus
according to the fourth embodiment of the present invention;
[0025] FIG. 11 is a longitudinal sectional view taken along a line
X-X of FIG. 9;
[0026] FIG. 12 is a longitudinal sectional view taken along a line
XI-XI of FIG. 9;
[0027] FIG. 13 is a transversal sectional view of a CVD apparatus
according to a fifth embodiment of the present invention;
[0028] FIG. 14 is a longitudinal sectional view taken along a line
XIII-XIII of FIG. 12; and
[0029] FIG. 15 is a longitudinal sectional view taken along a line
XIV-XIV of FIG. 12.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] In order to form a capacitance portion (insulative film) of
a capacitor of a DRAM (Dynamic Random Access Memory) which is one
example of a semiconductor integrated circuit apparatus, studies
are carried out for using a tantalum pentoxide (Ta.sub.2O.sub.5).
Since Ta.sub.2O.sub.5 has high dielectric constant, it is suitable
for obtaining great capacitance with a fine area. In a producing
method of the DRAM, it is desired to form a Ta.sub.2O.sub.5 film by
an MOCVC apparatus in view of productivity, quality of film and the
like.
[0031] It is know that if the Ta.sub.2O.sub.1 film is formed by the
MOCVD apparatus, carbon (C) which may generate leak current adheres
to a surface of the Ta.sub.2O.sub.5 film or in the vicinity of the
surface. Therefore, after the Ta.sub.2O.sub.5 film is formed on a
wafer, it is necessary to eliminate carbon existing in the vicinity
of the surface of the Ta.sub.2O.sub.5 film. A single wafer-feeding
type remote plasma CVD apparatus can lower a heating temperature of
a wafer to 300 to 400.degree. C. while preventing plasma damage of
a wafer. Therefore, studies are carried out for eliminating the
carbon on a Ta.sub.2O.sub.5 film by the single wafer-feeding type
remote plasma CVD apparatus.
[0032] In the single wafer-feeding type remote plasma CVD
apparatus, however, since carbon of the Ta.sub.2O.sub.5 film is
eliminated one by one, there is a problem that throughput becomes
small. For example, if net processing time in a single
wafer-feeding type remote plasma CVD apparatus is ten minutes and
operation time of a transfer system is two minutes, the processing
number of wafers per one hour is as small as five.
[0033] A general single wafer-feeding type remote plasma CVD
apparatus is of a cold wall type in which only a susceptor is
heated to a processing temperature. Therefore, in such a single
wafer-feeding type remote plasma CVD apparatus, there are problems
that it is difficult to uniformly heat the entire surface of a
wafer, and it is difficult to heat the wafer to 400.degree. C. or
higher due to a problem of selection of material of a chamber.
Further, when a heater is embedded into a susceptor and a wafer is
heated, since heat is not uniformly transferred to the wafer due to
warpage of the wafer or roughness of a surface of the wafer, it is
difficult to heat the wafer to 500.degree. C..+-.1%. Therefore, it
is conceived to use a heater having an electrostatic fastener, but
the heater having an electrostatic fastener is extremely expensive,
and the reliability is low with respect to its price.
[0034] It is, therefore, a main object of preferred embodiment of
the present invention to provide a plasma processing apparatus
capable of obtaining great throughput, and capable of enhancing
uniformity of a temperature of a substrate to be processed.
[0035] A plasma processing apparatus according to one preferred
aspect of the present invention, comprises:
[0036] a processing chamber in which a plurality of substrates are
stacked and accommodated, and
[0037] a pair of electrodes extending in the stacking direction of
the plurality of substrates, the electrodes being disposed at one
side of said plurality of substrates in the processing chamber, and
high frequency electricity being applied to the electrodes,
wherein
[0038] the processing apparatus is constituted such that processing
gas is supplied into a space between the pair of electrodes.
[0039] A plasma processing apparatus according to another aspect of
the present invention, comprises:
[0040] a processing chamber in which a plurality of substrates are
stacked and accommodated, and
[0041] a pair of electrodes extending in the stacking direction of
the prurality of substrates, the electrodes being disposed inside
and outside of the processing chamber and at one side of the
plurality of substrates, and high frequency electricity being
applied to said electrodes, wherein
[0042] the processing apparatus is constituted such that processing
gas is supplied into a space between the pair of electrodes.
[0043] A plasma processing apparatus according to still another
aspect of the present invention, comprises:
[0044] a processing chamber in which a plurality of substrates are
stacked and accommodated,
[0045] a pair of electrodes extending in the stacking direction of
the plurality of substrates, said electrodes being disposed at one
side of the plurality of substrates, and high frequency electricity
being applied to the electrodes, and
[0046] an electrical discharging chamber which is separated from
the processing chamber and which includes a space between the pair
of electrodes, wherein
[0047] a gas blowout opening for supplying the processing gas into
the processing chamber is provided in the electrical discharging
chamber.
[0048] In the above-mentioned batch-type remote plasma processing
apparatuses according to each aspect of the present invention, when
high frequency electricity is applied between the pair of
electrodes, plasma is generated between the pair of electrodes.
When the processing gas is supplied into this plasma atmosphere,
active particles are formed, and if the active particles are
supplied to the plurality of substrates which were transferred into
a process tube, the plurality of substrates are collectively
subjected to plasma processing.
[0049] Since the plurality of substrates to be processed are
collectively batch-processed, it is possible to largely enhance the
throughput as compared with a case in which the substrates to be
processed are processed one by one (single substrate-processing).
Further, the entire surface of each substrate can be heated
uniformly by heating the plurality of substrates accommodated in
the processing chamber by a hot-wall type heater. Therefore,
processing of substrate by plasma can be carried out uniformly.
[0050] Next, preferred embodiments according to the present
invention will be explained in detail.
[0051] (First Embodiment)
[0052] In this embodiment, as shown in FIGS. 1 to 3, a batch-type
remote plasma processing apparatus of the invention is formed as a
batch-type vertical hot wall type remote plasma CVD apparatus (CVD
apparatus, hereinafter). That is, a CVD apparatus 10 is made of
material having high heat resistance such as quartz glass or the
like. The CVD apparatus 10 is provided with a cylindrical process
tube 11. One end of the process tube 11 is opened and the other end
thereof is closed. The process tube 11 is vertically fixedly
supported such that a center line of the tube 11 is vertically
directed. A cylindrical hollow portion of the process tube 11 forms
a processing chamber 12 in which a plurality of wafers 1 are
accommodated. A lower end opening of the process tube 11 is formed
into a furnace opening 13 through which the wafer 1 as a subject to
be processed is loaded and unloaded. An inner diameter of the
process tube 11 is set greater than a maximum outer diameter of the
wafer 1 to be handled.
[0053] Heaters 14 for uniformly heating the entire processing
chamber 12 are concentrically provided around the process tube 11
such as to surround the process tube 11. The heaters 14 are
supported by a machine frame (not shown) of the CVD apparatus 10
such that the heaters 14 are mounted vertically.
[0054] A manifold 15 abuts against a lower end surface of the
process tube 11. The manifold 15 is made of metal. The manifold 15
is formed into a cylindrical shape which is provided at its upper
and lower ends with flanges. The flanges project outward in a
diametrical direction of the manifold 15. The manifold 15 is
detachably mounted to the process tube 11 for maintenance operation
and cleaning operation for the process tube 11. The manifold 15 is
supported by a machine frame (not shown) of the CVD apparatus 10
and the process tube 11 is mounted vertically.
[0055] One end of an exhaust pipe 16 is connected to a portion of a
sidewall of the manifold 15. The other end of the exhaust pipe 16
is connected to an exhaust apparatus (not shown) so that the
processing chamber 12 can be evacuated. A seal cap 17 which closes
a lower end opening of the manifold 15 abuts against the lower end
opening of the manifold 15 from vertically lower side through a
seal ring 18. The seal cap 17 is formed into a disc-like shape
having substantially the same outer diameter as that of the
manifold 15. The seal cap 17 is moved up and down in the vertical
direction by an elevator (not shown) which is vertically provided
outside the process tube 11. A rotation shaft 19 passes through a
center line of the seal cap 17. The rotation shaft 19 is moved up
and down together with the seal cap 17, and is rotated by a
rotating driving apparatus (not shown). A boat 2 which holds the
wafers 1 as subjects to be processed is vertically supported on an
upper end of the rotation shaft 19 such as to stand thereon.
[0056] The boat 2 comprises a pair of upper and lower end plates 3
and 4, and a plurality of (three, in this embodiment) holding
members 5 vertically disposed between the end plates 3 and 4. Each
the holding member 5 is provided with a large number of holding
grooves 6 which are disposed in the longitudinal direction at equal
distances from one another. Outer peripheral edge sides of the
wafers 1 are respectively inserted into the large number of holding
grooves 6 of the holding member 5. With this design, the wafers 1
are arranged and held horizontally with respect to the boat 2 such
that centers of the wafers 1 are aligned to each other. A thermal
insulation cap 7 is formed on a lower surface of the lower end
plate 4 of the boat 2. A lower end surface of the thermal
insulation cap 7 is supported by the rotation shaft 19.
[0057] A gas supply pipe 21 for supplying processing gas vertically
stands on a position in the vicinity of an inner peripheral surface
of the process tube 11 different from a position of the exhaust
pipe 16 (at a position on the opposite side from the exhaust pipe
16 through 180.degree. in the illustrated example). The gas supply
pipe 21 is made of dielectric material, and is formed into a thin
and long circular pipe. A lower end of the gas supply pipe 21 is
bent into an elbow shape at right angles to form a gas introducing
portion 22. The gas introducing portion 22 passes through a
sidewall of the manifold 15 outward in the diametrical direction,
and projects outside. A plurality of blowout openings 23 are opened
in the gas supply pipe 21 and arranged in the vertical direction.
The number of blowout openings 23 corresponds to the number of
wafers 1 to be processed. In this embodiment, the number of blowout
openings 23 coincides with the number of wafers 1 to be processed,
and a height of each blowout opening 23 is set such that each
blowout opening 23 is opposed to a space between vertically
adjacent wafers 1 held by the boat.
[0058] A pair of support cylinders 24 and 24 project outward in the
diametrical direction on opposite sides of the gas introducing
portion 22 of the gas supply pipe 21 in the manifold 15 in the
circumferential direction. Holder portions 26 and 26 of a pair of
protect pipes 25 and 25 are supported such that the holder portions
26 and 26 pass through the support cylinders 24 and 24 in the
diametrical direction. Each the protect pipe 25 is made of
dielectric material, and is formed into a thin and long circular
pipe shape whose upper end is closed. Upper and lower ends of the
protect pipes 25 are vertically aligned to the gas supply pipe 21.
A lower end of each the protect pipe 25 is bent into an elbow shape
at right angles to form a the holder portion 26. The holder portion
26 passes through the support cylinder 24 of the manifold 15
outward in the diametrical direction and projects outside. A hollow
portion of each the protect pipe 25 is brought into communication
with outside (atmospheric pressure) of the processing chamber
12.
[0059] A pair of thin and long rod-like electrodes 27 and 27 made
of conductive material are concentrically disposed in the hollow
portions of the protect pipes 25 and 25. A portion-to-be-held 28
which is a lower end of each the electrode 27 is held by the holder
portion 26 through a insulative cylinder 29 and a shield cylinder
30 which prevent electric discharge. A high frequency power source
31 is electrically connected between both the electrodes 27 and 27
through a matching device 32. The high frequency power source 31
applies high frequency electricity.
[0060] Next, a method for eliminating carbon existing in the
vicinity of a surface of a Ta.sub.2O.sub.5 film for a capacitance
portion of a capacitor of the DRAM using the CVD apparatus 10
having the above structure will be explained. That is, in this
embodiment, it is assumed that the wafer 1 to be supplied to the
CVD apparatus 10 is coated with a Ta.sub.2O.sub.5 film (not shown)
for forming the capacitance portion of the capacitor by a previous
MOCVD step, carbon (not shown) exists in the vicinity of a surface
of the Ta.sub.2O.sub.5 film, and the carbon is to be eliminated by
the CVD apparatus 10.
[0061] A plurality of wafers 1 as substrates to be processed of the
CVD apparatus 10 are charged to the boat 2 by a wafer transfer
apparatus (not shown). As shown in FIGS. 2 and 3, the boat 2 into
which the plurality of wafers 1 are charged is moved upward by the
elevator together with the seal cap 17 and the rotation shaft 19,
and is loaded (boat-loaded) into the processing chamber 12 of the
process tube 11.
[0062] If the boat 2 holding the group of wafers 1 is loaded into
the processing chamber 12, the processing chamber 12 is evacuated
into a predetermined pressure or lower by an exhaust apparatus
connected to the exhaust pipe 16, and a temperature of the
processing chamber 12 is increased to a predetermined temperature
by increasing electricity supplied to the heaters 14. Since the
heater 14 is of the hot wall type structure, a temperature of the
processing chamber 12 is uniformly maintained entirely and as a
result, a temperature distribution of the group of wafers 1 held by
the boat 2 also becomes uniform over the entire length, and a
temperature distribution over the entire surface of each the wafer
1 also becomes uniform.
[0063] After a temperature of the processing chamber 12 reaches a
preset value and is stabilized, oxygen (O.sub.2) gas is introduced
as processing gas 41, and if a pressure thereof reaches a preset
value, the boat 2 is rotated by the rotation shaft 19 and in this
state, high frequency electricity is applied between the pair of
electrodes 27 and 27 by the high frequency power source 31 and the
matching device 32. The oxygen gas which is the processing gas 41
is supplied to the gas supply pipe 21, and if the high frequency
electricity is applied between both the electrodes 27 and 27,
plasma 40 is formed in the gas supply pipe 21 as shown in FIG. 2,
and reaction of the processing gas 41 becomes active.
[0064] As shown with broken arrows in FIGS. 1 and 2, activated
particles (oxygen radical) 42 of the processing gas 41 are emitted
from the blowout openings 23 of the gas supply pipe 21 into the
processing chamber 12.
[0065] The activated particles (active particles, hereinafter) 42
are emitted from the blowout openings 23, and flow between the
opposed wafers 1 and 1 and come into contact with the wafers 1.
Therefore, the contact distribution of the active particles 42 with
respect to the entire group of wafers 1 becomes uniform over the
entire length of the boat 2, and a contact distribution of the
entire surface of each the wafer 1 in its diametrical direction
which corresponds to a flowing direction of the active particles
also becomes uniform. At that time, since the wafer 1 is rotated by
rotation of the boat 2, a contact distribution of the entire
surface of the wafer of the active particles 42 which flow between
the wafers 1 and 1 also becomes uniform in the circumferential
direction.
[0066] The active particles (oxygen radical) 42 which came into
contact with the wafers 1 thermally reacts with carbon which exists
in the vicinity of a surface of the Ta.sub.2O.sub.5 film to
generate CO (carbon monoxide), thereby eliminating carbon from the
Ta.sub.2O.sub.5 film. At that time, as described above, the
temperature distribution of the wafers 1 is maintained uniform over
the entire length of the boat 2 and over the entire surface of the
wafer, and the contact distribution of the active particles 42 with
the wafers 1 is uniform over the all positions of the boat 2 and
the entire surface of the wafer. Therefore, the eliminating effect
of carbon on the wafers 1 by the thermal reaction of the active
particles 42 becomes uniform over the all positions of the boat 2
and the entire surface of the wafer.
[0067] Processing conditions for eliminating carbon from the
Ta.sub.2O.sub.5 film to form a capacitance portion of capacitor of
the DRAM are as follows: a supply flow rate of oxygen gas used as
the processing gas is 8.45.times.10.sup.-1 to 3.38
Pa.multidot.m.sup.3/s, a pressure in the processing chamber is 10
to 100 Pa, and a temperature thereof is 500 to 700.degree. C.
[0068] If a preset processing time is elapsed, after supply of
processing gas 41, rotation of rotation shaft 19, application of
high frequency electricity, heating of heaters 14, and evacuation
of the exhaust pipe 16 are stopped, if the seal cap 17 is lowered,
the furnace opening 13 is opened, and the group of wafers 1 is
transferred out from the processing chamber 12 from the furnace
opening 13 (the boat is unloaded).
[0069] The group of wafers 1 transferred outside of the processing
chamber 12 is discharged (unloaded) from the boat 2 by the wafer
transfer apparatus. Thereafter, the above operation is repeated,
thereby collectively batch processing the plurality of wafers
1.
[0070] According to the above embodiment, the following effects can
be obtained.
[0071] 1) The plurality of wafers are collectively batch processed.
Therefore, it is possible to largely enhance the throughput as
compared with a case in which the substrates to be processed are
processed one by one. For example, the number of substrates which
are processed per one hour when the substrates are processed one by
one is five if the processing time is 10 minutes and the operation
time of a transfer system is two minutes. Whereas, the number of
substrates which are batch processed per one hour is 66.7 if the
processing time is 30 minutes and the operation time of a transfer
system is 60 minutes.
[0072] 2) By heating the plurality of wafers which were held by the
boat and transferred into the processing chamber by means of the
hot wall type heaters, it is possible to uniformly distribute a
temperature of the wafers over the entire length of the boat and
over the entire surface of each wafer. Therefore, it is possible to
uniform the processing state of wafers by the active particles
which are formed by activating the processing gas by plasma, i.e.,
the eliminating distribution of carbon on the Ta.sub.2O.sub.5
film.
[0073] 3) By disposing the pair of thin and long electrodes in the
processing chamber such that the electrodes are opposed to each
other, it is possible to form plasma over the entire length of both
the electrodes. Therefore, it is possible to more uniformly supply
the active particles which are formed by activating the processing
gas by plasma, over the entire length of the group of wafers held
by the boat.
[0074] 4) By disposing the gas supplying pipe in the space between
the pair of thin and long electrodes to which the processing gas is
supplied, it is possible to activate the processing gas by plasma
in the gas supplying pipe. Therefore, it is possible to prevent the
wafer from being damaged by plasma, and it is possible to prevent
the yield of wafers from being deteriorated by the plasma
damage.
[0075] 5) The blowout opening is formed in the gas supplying pipe
such that the blowout opening is opposed to a space between the
upper and lower wafers held by the boat. With this structure, the
active particles are allowed to flow between the wafers. Therefore,
it is possible to uniform the contact distribution of the active
particles with respect to the group of wafers over the entire
length of the boat. As a result, it is possible to further uniform
the processing state by the active particles.
[0076] 6) By rotating the boat which holds the plurality of wafers,
the contact distribution of the active particles which flowed
between the wafers can be uniformed over the entire surface of the
wafer in the circumferential direction. Therefore, it is possible
to further uniform the processing state by the active
particles.
[0077] 7) By eliminating the carbon of the Ta.sub.2O.sub.5 film
used for the capacitance portion of the capacitor of the DRAM, it
is possible to reduce the leak current between the electrodes of
the capacitor. Therefore, it is possible to enhance the performance
of the DRAM.
[0078] (Second Embodiment)
[0079] A CVD apparatus of the second embodiment of the present
invention will be explained with reference to FIGS. 4 and 5.
[0080] The second embodiment is different from the first embodiment
in that a pair of electrodes 27A and 27B are disposed inside and
outside of the process tube 11, and a gas supply pipe 21A is
located at a position other than a space to which the electrodes
27A and 27B are opposed.
[0081] In this embodiment, the high frequency electricity is
applied between the inner electrode 27A and the outer electrode 27B
by the high frequency power source 31 and the matching device 32,
and if processing gas 41 is supplied to the processing chamber 12
by the gas supply pipe 21A, plasma 40 is formed between a sidewall
of the process tube 11 and the inner electrode 27A, and the
processing gas 41 is brought into a reaction active state. The
active particles 42 are dispersed over the entire processing
chamber 12 so that the active particles 42 come into contact with
each wafer 1. The active particles 42 which came into contact with
the wafer 1 eliminate carbon which exists on the Ta.sub.2O.sub.5
film of the wafer 1 by thermal reaction.
[0082] (Third Embodiment)
[0083] A CVD apparatus of the third embodiment of the present
invention will be explained with reference to FIGS. 6 to 8.
[0084] In the third embodiment, a pair of protect pipes 25 and 25
provided vertically along an inner wall surface of the process tube
11 are bent at lower portions thereof and pass through a side
surface of the process tube 11. A pair of electrodes 27 and 27 are
inserted through both the protect pipes 25 and 25 from a lower
portion of the side surface of the process tube 11. A
guttering-like partition 34 forming a plasma chamber 33 is disposed
around an inner peripheral of the process tube 11 such as to
air-tightly surround both the protect pipes 25 and 25. A plurality
of blowout openings 35 are arranged in the partition 34 such as to
be opposed to a space between the upper and lower wafers 1 and 1. A
gas supply pipe 21 is provided at a position of a lower portion of
a side surface of the process tube 11 where gas can be supplied to
the plasma chamber 33.
[0085] After the processing gas 41 is supplied to the plasma
chamber 33 and a pressure of the gas is maintained at a
predetermined value, if the high frequency electricity is applied
between both the electrodes 27 and 27 by the high frequency power
source 31 and the matching device 32, plasma 40 is formed in the
plasma chamber 33 and the processing gas 41 is activated. Activated
electrically neutral particles 42 are emitted from the blowout
openings 35 which are opened at the partition 34 and are supplied
to the processing chamber 12, and the particles come into contact
with each wafer 1 held by the boat 2. The active particles 42 which
came into contact with wafer 1 processes a surface of the wafer
1.
[0086] (Fourth Embodiment)
[0087] A CVD apparatus of the fourth embodiment of the present
invention will be explained with reference to FIG. 9.
[0088] This embodiment is different from the third embodiment in
that the pair of electrodes 27 and 27 and their protect pipes 25
are located closer to the partition 34 provided with blowout
openings 35 than the process tube 11.
[0089] If the protect pipes 25 are located closer to the partition
34 than the process tube 11 in this manner, it is possible to limit
the gas flow between the protect pipe 25 and the partition 34. As a
result, most of processing gas pass between the two protect pipes
25, i.e., pass through a space having great plasma density.
[0090] (Fifth Embodiment)
[0091] A CVD apparatus of the fifth embodiment of the present
invention will be explained with reference to FIGS. 10 to 12.
[0092] A CVD apparatus of this embodiment includes a pair of thin
and long flat plate-like electrodes 27C and 27C which are shorter
than the process tube 11. Both the electrodes 27C and 27C are
inserted, from outside of the process tube 11, into a pair of
electrode insertion openings 36 and 36 which extend in the vertical
direction in a state in which the electrodes 27C and 27C are in
parallel to a portion of the sidewall of the process tube 11 and
upper and lower ends of the electrodes 27C and 27C are aligned to
each other. A protect pipes 25C and 25C project from an inner
peripheral surface of the process tube 11 such as to be opposed to
the pair of electrode insertion openings 36 and 36, respectively.
Inserting ends of the electrodes 27C and 27C are inserted into the
pair of protect pipes 25C and 25C and surrounded. A distance
between the electrode insertion opening and protect pipe 25C is set
slightly greater than a thickness of the electrode 27C so that the
electrode 27C is exposed to atmospheric pressure. Connecting
portions 28C and 28C respectively project from lower ends of the
electrodes 27C and 27C. The high frequency power source 31 for
applying high frequency electricity is electrically connected to
the connecting portions 28C and 28C through the matching device 32.
A flat plate-like partition 34C which forms a plasma chamber 33C in
cooperation with both the protect pipes 25C and 25C is provided
between both the protect pipes 25C and 25C. A plurality of blowout
openings 35C are arranged in the partition 34C such as to be
opposed to the upper and lower wafers 1 and 1. Processing gas 41 is
supplied from the gas supply pipe 21 into the plasma chamber
33C.
[0093] After the processing gas 41 is supplied to the plasma
chamber 33C by the gas supply pipe 21 and a pressure of the gas is
maintained at a predetermined value, if the high frequency
electricity is applied between both the electrodes 27C and 27C by
the high frequency power source 31 and the matching device 32,
plasma 40 is formed in the plasma chamber 33C and the processing
gas 41 is activated. The activated particles 42 are emitted from
the blowout openings 35C which are opened at the partition 34C and
are supplied to the processing chamber 12, and the particles come
into contact with each wafer 1 held by the boat 2. The active
particles 42 which came into contact with wafer 1 processes a
surface of the wafer 1.
[0094] (Sixth Embodiment)
[0095] A CVD apparatus of the sixth embodiment of the present
invention will be explained with reference to FIGS. 13 to 15.
[0096] A CVD apparatus of this embodiment includes a discharge tube
38 forming a plasma chamber 37. The discharge tube 38 is made of
dielectric material, and is formed into a substantially triangular
prism shape which is shorter than the process tube 11. The
discharge tube 38 extends in the vertical direction along a portion
of an outer periphery of a sidewall of the process tube 11. A
plurality of blowout openings 39 are arranged in the sidewall of
the process tube 11 surrounded by the discharge tube 38 such as to
be opposed to the space between the upper and lower wafers 1 and 1.
The processing gas 41 is supplied from the gas supply pipe 21 to
the plasma chamber 37 of the discharge tube 38. A pair of thin and
long flat plate-like electrodes 27D and 27D which are shorter than
the discharge tube 38 are provided on opposite sides of the
discharge tube 38 in its circumferential direction in a state in
which the electrodes 27D and 27D are exposed to the atmospheric
pressure. The high frequency power source 31 which applies high
frequency electricity is electrically connected to connecting
portions 28D and 28D respectively formed on the electrodes 27D and
27D through the matching device 32.
[0097] After the processing gas 41 is supplied to the plasma
chamber 37 by the gas supply pipe 21 and a pressure of the gas is
maintained at a predetermined value, if the high frequency
electricity is applied between both the electrodes 27D and 27D by
the high frequency power source 31 and the matching device 32,
plasma 40 is formed in the plasma chamber 37 and the processing gas
41 is activated. The activated particles 42 are emitted from the
blowout openings 35C which are in communication with the discharge
tube 38 and are supplied to the processing chamber 12, and the
particles come into contact with each wafer 1 held by the boat 2.
The active particles 42 which came into contact with wafer 1
processes a surface of the wafer 1.
[0098] The above-described batch-type remote plasma processing
apparatuses according to the preferred embodiments of the present
invention are preferably used for a substrate processing method for
processing a substrate, a film forming method and a semiconductor
device manufacturing method.
[0099] The present invention is not limited to the above
embodiments and can be variously modified of course.
[0100] For example, the number of blowout openings of the gas
supplying pipe is not necessarily the same as the number of wafers
to be processed, and may be increased or decreased in
correspondence with the number of wafers to be processed. For
example, the blowout opening is not necessarily opposed to the
space of the upper and lower adjacent wafers, and two or three
blowout openings may be disposed between the adjacent wafers.
[0101] Although carbon existing on the Ta.sub.2O.sub.5 film of the
capacitance portion of the capacitor was eliminated in the above
embodiment, the batch-type remote plasma processing apparatus of
the present invention can also be applied to a case in which a
foreign matter existing on another film (molecule, atom or the like
on other films) is to be eliminated, a case in which a CVD film is
formed on a wafer, a case in which thermal processing is carried
out, and the like.
[0102] For example, in a processing for nitriding an oxide film for
a gate electrode of a DRAM, a surface of the oxide film could be
nitrided by supplying nitrogen (N.sub.2) gas, ammonia (NH.sub.3)
gas or nitrogen monoxide (N.sub.2O) to a gas supplying pipe, and by
heating a processing chamber to a temperature in a range from a
room temperature to 750.degree. C. A surface of a silicon wafer
before a silicon germanium (SiGe) film was formed was processed by
plasma using active particles of hydrogen (H.sub.2) gas, a natural
oxide film could be eliminated, and a desired SiGe film could be
formed. When a nitrogen film was formed at a low temperature, if
ALD (atomic layer deposition atomic layer film forming) in which
DCS (dichlorosilane) and NH.sub.3 (ammonia) were alternately
supplied to form Si (silicon) and N (nitrogen) were formed one
each, a high quality nitrogen film could be obtained by activating
NH.sub.3 with plasma and supplying the same when NH.sub.3 was
supplied.
[0103] Although a wafer was processed in the above embodiment, a
subject to be processed may be a photomask, a printed wiring
substrate, a liquid crystal panel, a compact disk, a magnetic disk
or the like.
[0104] The entire disclosures of Japanese Patent Application No.
2001-3703 filed on Jan. 11, 2001, Japanese Patent Application No.
2002-3615 filed on Jan. 10, 2002 and Japanese Patent Application
No. 2002-203397 filed on Jul. 12, 2002 including specifications,
claims, drawings and abstracts are incorporated herein by reference
in their entireties.
[0105] Although various exemplary embodiments have been shown and
described, the invention is not limited to the embodiments shown.
Therefore, the scope of the invention is intended to be limited
solely by the scope of the claims that follow.
* * * * *