U.S. patent application number 15/454235 was filed with the patent office on 2017-06-22 for plasma processing method.
The applicant listed for this patent is Panasonic Intellectual Property Management Co., Lt d.. Invention is credited to TOMOHIRO OKUMURA.
Application Number | 20170178925 15/454235 |
Document ID | / |
Family ID | 52995915 |
Filed Date | 2017-06-22 |
United States Patent
Application |
20170178925 |
Kind Code |
A1 |
OKUMURA; TOMOHIRO |
June 22, 2017 |
PLASMA PROCESSING METHOD
Abstract
To provide a plasma processing device, a plasma processing
method and a method of manufacturing electronic devices capable of
performing high-speed processing as well as using the plasma
stably. In an inductively-coupled plasma, torch unit, a coil, a
first ceramic block and a second ceramic block are arranged in
parallel, and a long chamber has an annular shape. Plasma generated
in the chamber is ejected from an opening in the chamber toward a
substrate. The substrate is processed by moving the long chamber
and the substrate mounting table relatively in a direction
perpendicular to a longitudinal direction of the opening. A
discharge suppression gas is introduced into a space between the
inductively-coupled plasma torch unit and the substrate inside the
chamber through a discharge suppression gas supply hole, thereby
generating long plasma stably.
Inventors: |
OKUMURA; TOMOHIRO; (Osaka,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Panasonic Intellectual Property Management Co., Lt d. |
Osaka |
|
JP |
|
|
Family ID: |
52995915 |
Appl. No.: |
15/454235 |
Filed: |
March 9, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14340568 |
Jul 25, 2014 |
9627183 |
|
|
15454235 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01J 37/32651 20130101;
H01J 37/321 20130101; H01J 37/32522 20130101; H01L 21/324 20130101;
H01L 21/02667 20130101; H01J 37/32733 20130101; H01J 37/3244
20130101; H01J 37/3211 20130101; H01J 37/32366 20130101 |
International
Class: |
H01L 21/324 20060101
H01L021/324; H01L 21/02 20060101 H01L021/02; H01J 37/32 20060101
H01J037/32 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 30, 2013 |
JP |
2013-224940 |
May 12, 2014 |
JP |
2014-098348 |
Claims
1. A plasma processing method ejecting a first gas toward a
substrate from an opening communicated to a chamber while supplying
the first gas into the long annular chamber surrounded by a first
dielectric member as well as generating a high-frequency
electromagnetic field in the chamber by supplying high-frequency
power to a coil to thereby generate plasma to process a surface of
the substrate, the method comprising the step of: processing the
substrate by arranging the chamber along a surface parallel to a
surface formed by a substrate mounting table while supplying a
second gas inside the chamber, wherein the opening has at least two
long straight line portions, and a movement mechanism is provided,
which is capable of moving the chamber and the substrate mounting
table relatively in a direction perpendicular to a longitudinal
direction of the opening, the second gas is provided to the
discharge suppression gas supply hole, and the opening and the
discharge suppression gas supply hole are formed on the same
plane.
2. The plasma processing method according to claim 1, wherein the
first gas is a noble gas, or a gas mainly containing the noble gas,
and the second gas is a gas mainly containing a gas other than the
noble gas.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a plasma processing device,
a plasma processing method and a method of manufacturing electronic
devices used for thermal plasma processing which processes a
substrate by irradiating the substrate with thermal plasma, a
low-temperature plasma processing which processes the substrate by
irradiating the substrate with plasma by a reactive gas or with
plasma and a reactive gas flow at the same time and other
processing.
[0003] 2. Description of Related Art
[0004] A semiconductor thin film such as polycrystalline silicon
(poly-Si) is widely used for a thin-film transistor (TFT) and a
solar cell in related art. As a method of forming the semiconductor
thin film inexpensively, there is a method of irradiating an
amorphous silicon film with laser light to crystallize the film.
The laser process can be also applied to activation of impurity
atoms implanted into a semiconductor substrate by ion implantation
or plasma doping. However, the crystallisation technique using
laser has problems such as occurrence of a seam, and further,
extremely expensive equipment is necessary.
[0005] Accordingly, there has been studied a technique of
performing heat treatment without a seam inexpensively by
generating long thermal plasma and performing scanning only in one
direction (for example, refer to JP-A-2013-120633 (Patent Document
1), JP-A-2013-120684 (Patent Document 2) and JP-A-2013-120685
(Patent Document 3) as well as T. Okumura and H. Kawaura, Jpn. J.
Appl. Phys. 52 (2013) 05EE01 (Non-patent document 1)).
SUMMARY OF THE INVENTION
[0006] However, for the purposes of performing high-temperature
processing to the vicinity of a surface of a substrate for a very
short period of time such as in crystallization of semiconductor,
there is a problem that processing speed (the number of substrates
which can be processed per a unit time) is low in the technique of
generating thermal plasma to be long as disclosed in Patent
Documents 1 to 3 and Non-Patent Document 1 shown as related-art
examples. There is another problem that use efficiency of the gas
and high-frequency power is low as the long thermal plasma is far
from the substrate, or the substrate is irradiated directly by only
one of the two long straight line portions included in the
related-art device.
[0007] The present invention has been made in view of the above
problems, and an object thereof is to provide a plasma processing
device, a plasma processing method and a method of manufacturing
electronic devices capable of performing processing at high speed
as well as capable of stably using plasma when performing
high-temperature heat treatment uniformly to the vicinity of the
surface of the substrate for a very short period of time, or when
performing low-temperature plasma processing to the substrate by
irradiating the substrate with plasma by a reactive gas or with
plasma and a reactive gas flow at the same time.
[0008] According to an embodiment of the present invention, there
is provided a plasma processing device including a long annular
chamber surrounded by a first dielectric member, an opening
communicated to the chamber, a first gas supply pipe for
introducing a first gas into the chamber, a coil provided in the
vicinity of the chamber, a high-frequency power source connected to
the coil and a substrate mounting table, in which the chamber is
provided along a surface parallel to a surface formed by the
substrate mounting table, and a second gas supply pipe for
introducing a second gas is provided inside the chamber.
[0009] Due to the above structure, high speed processing can be
performed as well as plasma can be stably used.
[0010] Also according to the embodiment of the present invention,
there is provided a plasma processing method ejecting a first gas
toward a substrate from an opening communicated to a chamber while
supplying the first gas into the long annular chamber surrounded by
a first dielectric member as well as generating plasma in the
chamber by supplying high-frequency power to a coil, which includes
the step of processing the substrate by arranging the chamber along
a surface parallel to a surface formed by a substrate mounting
table while supplying a second gas inside the chamber.
[0011] Due to the above structure, high speed processing can be
performed as well as plasma can be stably used.
[0012] Also according to the embodiment of the present invention,
there is provided a method of manufacturing electronic devices
ejecting a first gas toward a substrate from an opening
communicated to a chamber while supplying the first gas into a long
annular chamber surrounded by a first dielectric member as well as
generating a high-frequency electromagnetic field in the chamber by
supplying high-frequency power to a coil to thereby generate plasma
to process a surface of the substrate. The method particularly
includes the step of processing the substrate by arranging the
chamber along a surface parallel to a surface formed by a substrate
mounting table while supplying a second gas inside the chamber.
[0013] Due to the above structure, high speed processing can be
performed as well as plasma can be stably used.
[0014] According to the embodiments of the present invention, high
speed processing can be performed as well as plasma can be stably
used when performing high-temperature heat treatment uniformly to
the vicinity of the surface of the substrate for a very short
period of time, or when performing plasma processing to the
substrate by irradiating the substrate with plasma by the reactive
gas or with plasma and the reactive gas flow at the same time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a cross-sectional view showing a structure of a
plasma processing device according to Embodiment 1 of the present
invention;
[0016] FIGS. 2A and 2B are perspective views showing the structure
of a plasma processing device according to Embodiment 1 of the
present invention;
[0017] FIG. 3 is a cross-sectional view showing a structure of a
plasma processing device according to Embodiment 2 of the present
invention;
[0018] FIG. 4 is a cross-sectional view showing a structure of a
plasma processing device according to Embodiment 3 of the present
invention;
[0019] FIGS. 5A and 5B are perspective views showing the structure
of the plasma processing device according to Embodiment 3 of the
present invention;
[0020] FIG. 6 is a cross-sectional view showing a structure of a
plasma processing device according to Embodiment 4 of the present
invention;
[0021] FIGS. 7A and 7B are perspective views snowing the structure
of the plasma processing device according to Embodiment 4 of the
present invention;
[0022] FIG. 8 is a cross-sectional view showing a structure of a
plasma processing device according to Embodiment 5 of the present
invention;
[0023] FIG. 9 is a cross-sectional view of a structure of a plasma
processing device according to Embodiment 6 of the present
invention; and
[0024] FIG. 10 is a cross-sectional view of a structure of a plasma
processing device according to Embodiment 7 of the present
invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] Hereinafter, a plasma processing device according to
embodiments of the present invention will be explained with
reference to the drawings.
Embodiment 1
[0026] Embodiment 1 of the present invention will be explained
below with reference to FIG. 1, FIGS. 2A and 2B.
[0027] FIG. 1 shows a structure of a plasma processing device
according to Embodiment 1 of the present invention, which is a
cross-sectional view taken along a surface perpendicular to a
longitudinal direction of a long inductively-coupled plasma torch
unit. FIGS. 2A and 2B are assembly structure views of the
inductively-coupled plasma torch unit shown in FIG. 1, in which
perspective views of respective parts (portions) are aligned. FIG.
2A is a view seen from an upper oblique direction of FIG. 1, and
FIG. 2B is a view seen from a lower oblique direction of FIG.
1.
[0028] In FIG. 1, a substrate 2 is mounted on a substrate mounting
table 1. In an inductively-coupled plasma torch unit T, a coil 3
made of a conductor is disposed in the vicinity of a first ceramic
block 4 and a second ceramic block 5. The coil 3 is bonded to the
second ceramic block 5 by a not-shown adhesive. A long chamber 7 is
defined by a space surrounded by the first ceramic block 4 and the
substrate 2.
[0029] The coil 3 and the chamber 7 are disposed along a surface
parallel to a surface formed by the substrate mounting table 1. An
inner wall surface of the chamber 7 in a side closer to the coil 3
is a surface parallel to the coil 3. In such structure, distances
between the coil 3 and the chamber 7 are equivalent in arbitrary
portions of the coil 3, therefore, inductively-coupled plasma can
be generated with small high-frequency power, and efficient plasma
generation can be realised.
[0030] The inductively-coupled plasma torch unit T is surrounded by
a sealing member (not shown) made of a conductor which is entirely
grounded, capable of effectively preventing leakage of high
frequency (noise) as well as effectively preventing undesirable
abnormal discharge.
[0031] The chamber 7 is surrounded by an annular groove
continuously formed in the first ceramic block 4. That is, the
entire chamber 7 is surrounded by a dielectric. The chamber 7 has
an annular shape. The annular shape means, in this case, a closed
continuous string shape, and is not limited to a rectangular shape
as shown in FIG. 2B. In the present embodiment, the chamber 7
having a race-track shape (closed continuous string shape in which
straight line portions forming two long sides and straight lines
forming two short sides are connected to both ends) is shown as an
example. Plasma P generated in the chamber 7 is ejected from a
plasma ejection port as an opening 8 in the chamber 7 toward the
substrate 2. The longitudinal direction of the chamber 7 is
disposed in parallel to the longitudinal direction of the opening 8
as the plasma ejection port.
[0032] A rectangular groove provided in the second ceramic block 5
is a plasma gas manifold 9. A porous ceramic material is fitted
thereinto. The gas supplied from a plasma gas supply pipe 10 to the
plasma gas manifold 9 is introduced to the chamber 7 through plasma
gas supply holes 11 (through holes) as a gas introducing portion
provided in the first ceramic block 4. According to the structure,
the gas flow which is uniform in the longitudinal direction can be
easily realised. A flow amount of gas to be introduced to the
plasma gas supply pipe 10 is controlled by providing a flow
controller such as a mass-flow controller in the upstream. As the
porous ceramic material is used in the plasma manifold 9, the
uniform gas flow can be realised as well as abnormal discharge in
the vicinity of the plasma gas manifold 9 can be prevented.
[0033] The plasma gas supply holes 11 are constructed by forming
plural round holes in the longitudinal direction, or may be
constructed by forming a long slit-shaped hole in the longitudinal
direction.
[0034] A line-shaped groove provided in the second ceramic block 5
is a discharge suppression gas manifold 12. A porous ceramic
material is fitted thereinto. The gas supplied from a discharge
suppression gas supply pipe 14 is introduced into a space between
the inductively-coupled plasma torch unit T and the substrate 2
inside the chamber 7 through a discharge suppression gas supply
hole 13 (through hole) as a gas introducing portion provided in the
first ceramic block 4.
[0035] The discharge suppression gas supply hole 13 is constructed
by forming plural round holes in the longitudinal direction, or may
be constructed by forming a long slit-shaped hole in the
longitudinal direction.
[0036] It is also preferable to arrange a shielding gas nozzle as a
shielding gas supply port in a position close to the substrate
mounting table 1, though not shown. The shielding gas is supplied
In addition to the plasma gas suitable for generating plasma,
thereby reducing the mixture of gas which is not necessary for
processing or adversely affects the processing such as oxygen and
carbon dioxide in the air to a plasma irradiation surface. The
shielding gas supply port may be a slit having a shape elongated in
a direction parallel to the longitudinal direction of the opening
8, or may be many holes aligned in the direction parallel to the
longitudinal direction of the opening 8.
[0037] The coil 3 is formed by bonding a copper pipe having a
circular shape in cross section to a copper block having a
rectangular parallelepiped shape in cross section. The coil 3 is a
hollow tube, and the inside of the tube is a flow path for
refrigerant. That is, cooling can be performed by allowing the
refrigerant such as water to flow. It is also preferable to provide
refrigerant flow paths so as to be in parallel to the longitudinal
direction of the opening 8 in the first ceramic block 4 the second
ceramic block 5. Also, the first, ceramic block 4 and the second
ceramic block 5 as well as the second ceramic block 5 and the coil
3 are respectively bonded by using an adhesive, thereby cooling the
first ceramic block 4 and the second ceramic block 5 through the
adhesive. In this case, a cooling portion for cooling the chamber 7
is the coil 3, and the second ceramic block 5 having a higher heat
conductivity than the first ceramic block 4 is provided between the
first ceramic block 4 and the coil 3. That is, the first ceramic
block 4 is made of silicon nitride end the second ceramic block 5
is made of aluminum nitride. Due to the structure, the first
ceramic block 4 can be cooled more effectively than in a case where
the second ceramic block 5 is also made of silicon nitride,
therefore, larger high-frequency power can be inputted and higher
speed processing can be realized. As excellent heat resistance is
required for the first ceramic block 4, ceramic materials mainly
containing silicon nitride, or ceramic materials mainly containing
silicon, aluminum, oxygen and nitrogen are suitable. On the other
hand, as the second ceramic block 5 does not directly contact
thermal plasma reaching several thousand degrees to 10,000 degrees,
excellent heat conductivity is required more than the heat
resistance, therefore, ceramic materials mainly containing aluminum
nitride or ceramic materials mainly containing boron nitride are
suitable.
[0038] As shown in FIGS. 2A and 2B, the coil 3 has a flat spiral
shape forming a rectangular shape as a whole, in which a
refrigerant supply and discharge port 15 is provided at an end
portion.
[0039] The rectangular opening 8 is provided, and the substrate
mounting table 1 (or the substrate 2 on the substrate mounting
table 1) is arranged opposite to the opening 8. The high frequency
power is supplied to the coil 3 from a not-shown high-frequency
power source while supplying the plasma gas into the chamber 7 and
ejecting the gas from the opening 8 toward the substrate 2 in the
above state, thereby generating the plasma P in the chamber 7 and
irradiating the substrate 2 with the plasma from the opening 8, as
a result, the plasma processing can be performed to the thin film
22 on the substrate 2. The substrate 2 is processed by moving the
chamber 7 and the substrate mounting table 1 relatively in a
direction perpendicular to the longitudinal direction of the
opening 8. That is, the inductively-coupled plasma torch unit T or
the substrate mounting table 1 is moved in a right and left
direction of FIG. 1.
[0040] Various kinds of gases can be used as the plasma gas to be
supplied to the chamber 7, but it is desirable to use inert gases,
particularly desirable to mainly use noble gases when considering
stability and ignition performance of plasma, lifetime of members
exposed to plasma and so on. Among them, Ar gas is typically used.
When plasma is generated only by the Ar gas, plasma will be a
considerably high temperature (10,000K or more).
[0041] As a discharge suppression gas to be introduced into the
space between the inductively-coupled plasma torch unit T and the
substrate 2 inside the chamber 7, a gas mainly containing a gas
other than noble gases is preferable. For example, nitrogen,
oxygen, carbon dioxide and so on can be used as gases which are
relatively safe and low in price. As these gases do not easily
become thermal plasma as compared with noble gases, it is possible
to suppress a phenomenon in which the annular thermal plasma is
connected between two openings 3 positioned at right and left in
FIG. 1 in the space between the inductively-coupled plasma torch
unit T and the substrate 2 inside the chamber 7 and a small
circular plasma is generated instead of the long thermal
plasma.
[0042] As the Ar gas is particularly suitable for generating
thermal plasma in noble gases, it is preferable that the Ar gas is
used as a plasma gas and another noble gas is used as a discharge
suppression gas. If another gas is mixed several % or more even
when using the gas which mainly contains Ar, thermal plasma is not
easily generated, therefore, the mixed gas mainly containing Ar or
another noble gas but containing a gas other than Ar several % or
more may be used as the discharge suppression gas.
[0043] In the present structure, the length of the opening 8 in the
longitudinal direction is larger than the width of the substrate 2.
Therefore, the entire thin film 22 in the vicinity of the surface
of the substrate 2 can be processed by one scanning (to relatively
move the inductively-coupled plasma torch unit T and the substrate
mounting table 1). Due to the structure, the plasma in the short
sides of the opening 8 having a rectangular shape as a whole is not
irradiated to the substrate, therefore, uniform, processing can be
performed.
[0044] A high frequency power of 13.56 MHz is supplied to the coil
3 from the not-shown high-frequency power source while supplying
the Ar gas or an Ar+H.sub.2 gas as the plasma gas into the chamber
7 and ejecting the gas from the opening 8 toward the substrate 2 in
the above plasma processing device, thereby generating an
electromagnetic field in the chamber 7 to generate the plasma P.
The substrate 2 is irradiated with the plasma from the opening 8
and scanned, thereby performing heat treatment such as
crystallization of a semiconductor film and so on.
[0045] As conditions for generating plasma, appropriate values are
approximately: the distance between the opening 8 and the substrate
2=0.1 to 5 mm, the scanning speed=20 to 3000 mm/s, the total flow
of plasma gas=1 to 100 SLM, the H.sub.2 density in Ar+H.sub.2 gas=0
to 10%, the flow of discharge suppression gas (N.sub.2)=1 to 100
SLM, and the high frequency power=0.5 to 10 kW. The gas flow and
the power in these values show values per a length 100 mm of the
opening 8. It is because, it is suitable that an amount
proportional to the length of the opening 8 is inputted concerning
parameters such as the gas flow and the power.
[0046] As described above, the long chamber 7 and the substrate
mounting table 1 are relatively moved in the direction
perpendicular to the longitudinal direction of the opening 8 while
arranging the longitudinal direction of the opening 8 and the
substrate mounting table 1 in parallel to each other, therefore, it
is possible to construct the device so that the length of plasma to
be generated is substantially equivalent to the length of the
substrate 2 to be processed.
[0047] As described above, in the structure according to the
embodiment, the substrate 2 is positioned close to the long thermal
plasma as well as the substrate 2 is directly irradiated with the
plasma by using both sides of two long straight line portions
forming the long chamber 7, therefore, use efficiency of the gas
and the high-frequency power is excellent. That is, high-speed
processing can be realized as well as the plasma can be stably used
at the time of performing high-temperature heat-treatment uniformly
to the vicinity of the surface of the substrate for a very short
period of time, or at the time of performing low-temperature plasma
processing to the substrate by irradiating the substrate with
plasma by a reactive gas or with plasma and a reactive gas flow at
the same time.
Embodiment 2
[0048] Hereinafter, Embodiment 2 of the present embodiment will be
explained with reference to FIG. 3.
[0049] FIG. 3 shows a structure of a plasma processing device
according to Embodiment 2 of the present invention, which is a
cross-sectional view taken along a surface perpendicular to the
longitudinal direction of the inductively-coupled plasma torch unit
and corresponds to FIG. 1.
[0050] In Embodiment 2, the first ceramic block 4 and the second
ceramic block 5 are formed by the same material (silicon nitride).
The plasma gas manifold 9 and the discharge suppression gas
manifold 12 are formed by the groove provided in the first ceramic
block 4, and the second ceramic block 5 is a simple flat plate.
[0051] The above structure has an advantage in which it is
sufficient that complicated processing is performed only to the
first ceramic block 4 though the cooling ability of the first
ceramic block 4 is inferior.
Embodiment 3
[0052] Hereinafter, Embodiment 3 of the present embodiment will be
explained with reference to FIG. 4, FIGS. 5A and 5B.
[0053] FIG. 4 shows a structure of a plasma processing device
according to Embodiment 3 of the present invention, which is a
cross-sectional view taken along a surface perpendicular to the
longitudinal direction of the inductively-coupled plasma torch unit
and corresponds to FIG. 1. FIGS. 5A and 5B are assembly structure
views of the inductively-coupled plasma torch unit shown in FIG. 4,
in which perspective views of respective parts (portions) are
aligned. FIG. 5A is a view seen from an upper oblique direction of
FIG. 4 and FIG. 5B is a view seen from a lower oblique direction of
FIG. 4.
[0054] In FIG. 4, a refrigerant flow path 16 is provided between
the coil 3 and the chamber 7 along the chamber 7. The refrigerant
flow path 16 is formed by a groove provided in the first ceramic
block 4 and the second ceramic block 5 bonded thereto. A
refrigerant flowing in the refrigerant flow path 16 is configured
to directly contact the first ceramic block 4, which can
effectively keep the chamber 7 to be in a low temperature. As the
refrigerant flow path 16 is arranged so as to be extend along the
chamber 7 for giving priority to maximization of cooling
efficiency, the plasma gas manifold 9 for storing the plasma gas is
arranged in the outside of the refrigerant flow path 16, and the
plasma gas supply holes 11 are provided in an inclined manner. That
is, the direction in which the gas flows in the plasma gas supply
holes 11 are inclined with respect to the flat surface formed by
the chamber 7.
[0055] As shown in FIGS. 5A and 5B, supply and discharge of, for
example, cooling water flowing in the refrigerant flow path 16 are
performed by a supply and discharge pipe 17. In the present
embodiment, two grooves are formed in the second ceramic block 5 so
that the refrigerant flow path 16 does not interfere with the
plasma gas manifold 9.
Embodiment 4
[0056] Hereinafter, Embodiment 4 of the present embodiment will be
explained with reference to FIG. 6, FIGS. 7A and 7B.
[0057] FIG. 6 shows a structure of a plasma processing device
according to Embodiment 4 of the present invention, which is a
cross-sectional view taken along a surface perpendicular to the
longitudinal direction of the inductively-coupled plasma torch unit
and corresponds to FIG. 1. FIGS. 7A and 7B are assembly structure
views of the inductively-coupled plasma torch unit shown in FIG. 6,
in which perspective views of respective parts (portions) are
aligned. FIG. 7A is a view seen from an upper oblique direction of
FIG. 6 and FIG. 7B is a view seen from a lower oblique direction of
FIG. 6.
[0058] The present embodiment differs from Embodiment 3 in a point
that the refrigerant flow path 16 is provided on a lower surface
(surface facing the substrate mounting table 1) of the second
ceramic block 5, and the plasma gas manifold 9 and the discharge
suppression, gas manifold 12 are provided on the opposite surface,
namely, an upper surface of the second ceramic block 5 (surface not
facing the substrate mounting table 1) in FIG. 6, FIG. 7A and FIG.
7B. The refrigerant flow path 16 is formed by a groove provided in
the second ceramic block 5 and the first ceramic block 4 bonded
thereto. The plasma gas manifolds 9 and the discharge suppression
gas manifold 12 are formed by a groove provided in the second
ceramic block 5 and a ceramic plate 25 bonded thereto.
[0059] The plasma gas manifold 9 and the plasma gas supply holes 11
are connected by pipes 18 formed by through holes communicated to
the plasma gas manifold 9 made of the porous ceramic material
fitted to the groove provided in the second ceramic block S.
Similarly, the discharge suppression gas manifold 12 and the
discharge suppression gas supply hole 13 are connected by a pipe 19
formed by a through hole communicated to the discharge suppression
gas manifold 12 made of the porous ceramic material fitted to the
groove provided in the second ceramic block 5.
[0060] In the above Embodiment 3, the first ceramic block 4 and the
second ceramic block 5 are connected by the adhesive to prevent the
leakage of the refrigerant from the refrigerant flow path 16. In
the present embodiment, the refrigerant flow path 16 is sealed by
an O-ring 21. The refrigerant flow path 16, the plasma gas manifold
9 and the discharge suppression, gas manifold 12 are formed by the
groove provided on another surface of the second ceramic block 5,
thereby forming the refrigerant flow path 16 in a simple annular
shape as shown in FIG. 7B, as a result, a structure in which the
sealing by the O-ring 21 is easily performed can be obtained.
[0061] Though the first ceramic block 4 and the second ceramic
block 5 may be bonded to each other, it is also preferable that
they are not bonded but fastened to each other by a not-shown
bolt/nut and so on. Accordingly, there is an advantage that
maintenance such as disassembly and cleaning can be performed.
Embodiment 5
[0062] Hereinafter, Embodiment 5 of the present embodiment will be
explained with reference to FIG. 8.
[0063] FIG. 8 shows a structure of a plasma processing device
according to Embodiment 5 of the present invention, which is a
cross-sectional view taken along a surface perpendicular to the
longitudinal direction of the inductively-coupled plasma torch unit
and corresponds to FIG. 1.
[0064] The present embodiment differs from Embodiment 3 in a point
that the refrigerant flow path 16 and the plasma gas manifold 9 are
provided on an upper surface of the first ceramic block 4 (surface
not facing the substrate mounting table 1) in FIG. 8. Such
structure can be also applied.
Embodiment 6
[0065] Hereinafter, Embodiment 6 of the present embodiment will be
explained with reference to FIG. 9.
[0066] FIG. 9 shows a structure of a plasma processing device
according to Embodiment 6 of the present invention, which is a
cross-sectional view taken along a surface perpendicular to the
longitudinal direction of the inductively-coupled plasma torch unit
and corresponds to FIG. 1.
[0067] The present embodiment differs from Embodiment 3 in a point
that a shielding plate 23 made of silicon is provided on a lower
surface of the first ceramic block 4 (surface facing the substrate
mounting table 1) in FIG. 9. Due to the structure, as the
high-frequency electromagnetic field generated by the coil 3 is
effectively shielded by the shielding plate 23, the high-frequency
electromagnetic field in the vicinity of the substrate 2 is
considerably reduced, therefore, there is an advantage that
breakdown/deterioration of electronic devices such as a transistor
formed on the substrate 2 caused by electrostatic damage hardly
occur.
Embodiment 7
[0068] Hereinafter, Embodiment 7 of the present embodiment will be
explained with reference to FIG. 10.
[0069] FIG. 10 shows a structure of a plasma processing device
according to Embodiment 7 of the present invention, which is a
cross-sectional view taken along a surface perpendicular to the
longitudinal direction of the inductively-coupled plasma torch unit
and corresponds to FIG. 1.
[0070] In FIG. 10, the shielding plate 23 made of metal is arranged
on a concave portion provided in a lower surface (surface facing
the substrate mounting table 1) of the first ceramic block 4, and a
shielding plate cover 24 covering the shielding plate 23 is further
provided. Due to the structure, there are advantages that
electrostatic damage can be suppressed in the same manner as
Embodiment 6 and that abnormal discharge such as arc which may
occur on the surface of the shielding plate 23 in Embodiment 6
hardly occurs.
[0071] The plasma processing devices and the plasma processing
methods described above are just typical examples in the
application range of the present invention.
[0072] For example, the inductively-coupled plasma torch unit T may
be scanned with respect to the fixed substrate mounting table 1 as
well as the substrate mounting table 1 may be scanned with respect
to the fixed inductively-coupled plasma torch unit T.
[0073] Various structures of the present invention enable
high-temperature processing to the vicinity of the surface of the
substrate 2. Accordingly, the present invention can be applied to
not only crystallization of a semiconductor film for TFT and
quality improvement of a semiconductor film for a solar cell
described in related-art examples but also various surface
processing such as oxidation and activation of a silicon
semiconductor integrated circuit, annealing for forming silicide,
clean-up and reduction of degassing of a protective layer of a
plasma display panel, surface planarization and reduction of
degassing of a dielectric layer made of an aggregation of silica
particles, the reflow of various electronic devices, and plasma
doping using a solid impurity source. The present invention can be
also applied to a method of manufacturing solar cells, in which
powder obtained by crushing a silicon ingot is applied on the
substrate to be irradiated with plasma and melted to thereby obtain
a polycrystalline silicon film.
[0074] It is also possible to use an ignition source for
facilitating the ignition of plasma. As the ignition source, a
sparking apparatus for ignition used for a gas water heater and so
on can be applied.
[0075] The word "thermal plasma" is used in the explanation for
simplification, however, it is strictly difficult to distinguish
between thermal plasma and low-temperature plasma. It is also
difficult to distinguish types of plasma only based on the thermal
equilibria, for example, as commented in "Non-equilibria of thermal
plasma" by TANAKA Yasunori in a journal of plasma and fusion
research Vol. 82, NO. 8 (2006) pp. 479-483. An object of the
present invention is to perform heat treatment to the substrate,
and the present invention can be applied to the technique of
irradiating high-temperature plasma regardless of words such as
thermal plasma, thermal equilibria plasma and high-temperature
plasma.
[0076] Though the case where high-temperature heat treatment is
performed uniformly to the vicinity of the surface of the substrate
for a very short period of time has been explained in detail as an
example, the present invention can be also applied to the case
where low-temperature plasma processing is performed to the
substrate by irradiating the substrate with plasma by the reactive
gas or with plasma and the reactive gas flow at the same time. The
reactive gas is mixed into the plasma gas, thereby realizing
etching and CVD by irradiating the substrate with plasma by the
reactive gas.
[0077] Alternatively, when a gas including a reactive gas as a
shielding gas is supplied while using a noble gas or a gas obtained
by adding a small amount of H.sub.2 gas to the noble gas as a
plasma gas, thereby irradiating the substrate with plasma and the
reactive gas flow at the same time and realising plasma processing
such as etching, CVD and doping. When using the gas mainly
containing argon as the plasma gas, thermal plasma is generated as
explained in the embodiments in detail.
[0078] On the other hand, when using a gas mainly containing helium
as a plasma gas, relatively low-temperature plasma can be
generated. It is possible to perform processing such as etching and
film deposition without heating the substrate to a high degree by
using the above method. As reactive gases used for etching, there
are halogen-containing gases such as CxFy (x and y are natural
numbers) and SF.sub.6, whereby performing etching of silicon,
silicon compounds and the like. When O.sub.2 is used as a reactive
gas, removal of organic matters, resist ashing and so on can be
performed. As reactive gases used for CVD, there are monosilane,
disilane and so on, whereby performing depositing of silicon and
silicon compounds.
[0079] Alternatively, when using a mixed gas of an organic gas
containing silicon represented by TEOS (Tetraethoxysilane) and
O.sub.2, a silicon oxide film can be deposited. Other various
low-temperature plasma processing such as surface processing for
improving water repellency and hydrophilia can be performed. As the
present technique relates to the inductively-coupled type device,
the arc discharge does not easily occur even when higher power
density per a unit volume is inputted as well as higher density
plasma can be generated as compared with the related art technique
using capacitive-coupled atmospheric plasma, as a result, higher
reaction speed can be obtained and a desired region to be processed
in the substrate can be entirely processed efficiently for a short
period of time.
[0080] As described above, the present invention can be applied to
crystallization of the semiconductor film for TFT and quality
improvement of the semiconductor film for a solar cell. The present
invention is useful, which is capable of performing high-speed
processing as well as using plasma stably at the time of performing
high-speed heat treatment uniformly to the vicinity of the surface
of the substrate for a very short period of time in various surface
processing such as clean-up and reduction of degassing of a
protective layer of a plasma display panel, surface planarization
and reduction of degassing of a dielectric layer made of an
aggregation of silica particles, the reflow of various electronic
devices, and plasma doping using a solid impurity source.
[0081] The present invention is also useful, which is capable of
processing an entire desired region to be processed in the
substrate for a short period of time efficiently in low-temperature
plasma processing such as etching, deposition, doping, surface
quality improvement and so on in the manufacture of various
electronic devices.
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