JP3297288B2 - Apparatus and method for manufacturing semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus and a method for manufacturing a semiconductor device, and more particularly to a structure of a single wafer susceptor and a method for manufacturing a semiconductor device using the same.

[0002]

2. Description of the Related Art In order to deposit a polycrystalline silicon film on a semiconductor substrate when manufacturing a semiconductor device, conventionally, a heat
A VD (chemical vapor deposition) method and a single-wafer thermal CVD apparatus are widely used.

FIGS. 8 and 9 show conventional thermal CVs, respectively.
4 shows a D device. In the thermal CVD apparatus shown in FIG. 8, reference numeral 80 denotes a chamber, 81 denotes a single-wafer type wafer susceptor which is installed in the chamber and on which a semiconductor substrate (wafer) 30 is mounted, and which is coated with, for example, SiC. Carbon is used. A heater 82 is provided below the wafer susceptor. 1
Reference numeral 4 denotes a gas introduction port provided in the chamber for introducing a process gas. Reference numeral 15 denotes an exhaust port provided in the chamber, which is configured so that the inside of the chamber can be set to a predetermined pressure by an exhaust pump provided outside the chamber and connected to the exhaust port 15 via an exhaust pipe. Have been.

When depositing a polycrystalline silicon film on a wafer using a thermal CVD apparatus having the structure shown in FIG. 8, a process gas is introduced from a gas inlet 15 while the pressure in the chamber 80 is reduced to a predetermined pressure. (Material gas) is introduced. In this case, the wafer 30 is subjected to heat conduction from the wafer susceptor 81 heated by the heat radiation
It is heated to about 00 to 800 ° C. As a result, the material gas reacts on the wafer surface, and a polycrystalline silicon film is formed.

On the other hand, the thermal CVD apparatus shown in FIG. 9 is different from the thermal CVD apparatus shown in FIG.
Structure (1), (2) a point that the wafer susceptor 91 is supported by a vertical rotation shaft 92 and is rotatably provided in a horizontal plane, and (3) a susceptor for rotating and driving the wafer susceptor 91 as necessary. As the rotation mechanism 93, a mechanism for driving the rotation shaft 92 is provided. (4) The arrangement of the heater 94 is different, and the other is the same.

The structure of the wafer susceptor 11 is, for example, a disk-shaped susceptor base 911, a side wall 912 projecting upward from the peripheral edge of the susceptor base, and a wafer 30 projecting inward from the side wall. A wafer mounting portion 913 for mounting the outer peripheral edge of the lower surface.

When depositing a polycrystalline silicon film on a wafer using a thermal CVD apparatus having the configuration shown in FIG. 9, first, the temperature of the heater 94 is appropriately set.
The susceptor base 911 and the susceptor mounting portion 913 heated by the heat radiation of
At a desired wafer temperature (for example, about 600 to 800 ° C.).

In this case, the central portion of the wafer 30 is heated to about 600 to 800 ° C. by the heat radiation from the susceptor base 911 heated by the heat radiation from the heater 94, but the peripheral portion is heated from the heater 94. Is shielded by the wafer mounting portion 913, the temperature is lower than at the central portion of the wafer. Therefore, in order to keep the entire surface of the wafer at a desired temperature uniformly, it is necessary to set the temperature of the heater 94 so that the temperature of the wafer susceptor is higher than the desired wafer temperature.

Next, while the pressure in the chamber 90 is reduced to a predetermined pressure (for example, about 20,000 Pa), the wafer is moved by the susceptor rotating mechanism 93 in the direction of an arrow A in FIG.
At a speed of 50 rpm or more, a process gas (a material gas, in this example, silane gas SiH ₄ ) is introduced from the gas inlet 14.

In this state, when the material gas flows on the wafer surface and is exhausted out of the chamber, it reacts on the wafer surface, and a polycrystalline silicon film is formed on the oxide film (SiO ₂ ) on the wafer surface. Will be At this time, the growth of the polycrystalline silicon film within the above temperature range has a large temperature dependency, and the higher the temperature, the faster the growth.

When the susceptor rotating mechanism 93 rotates the wafer susceptor 91, a centrifugal force is generated in the direction indicated by the arrow B in FIG. In this case, when the wafer 30 is rotated at, for example, 2500 rpm or more, FIG.
As shown in FIG. 0 (b), the peripheral edge of the wafer comes into contact with the side wall of the wafer susceptor due to the centrifugal force, and heat conduction from the susceptor to the peripheral edge of the wafer occurs.

As a result, the temperature of the outer peripheral portion of the wafer becomes higher than that of the central portion of the wafer, and as shown in FIG. 10C, the thickness of the polycrystalline silicon film 31 formed on the wafer becomes larger than that of the central portion of the wafer. Also, the outer peripheral portion of the wafer becomes significantly thicker, and the variation in the thickness of the polycrystalline silicon film in the wafer surface increases. The growth of the polycrystalline silicon film by heat conduction from the susceptor to the outer peripheral end face of the wafer as described above is caused by the susceptor temperature T
This occurs because s and the wafer temperature Tw have a relationship of Ts> Tw.

The above-described variation in the thickness of the polycrystalline silicon in the wafer surface becomes remarkable when the wafer is rotated at a high speed. However, even when the wafer is not rotated, the outer peripheral edge of the lower surface of the wafer 30 is removed. The same problem occurs when the wafer 30 is placed on the mounting portion and the wafer 30 comes into contact with the wafer susceptor.

[0014]

As described above, the conventional thermal CVD apparatus and thermal CVD method have a problem that the thickness of a polycrystalline silicon film formed on a wafer has a large variation in the wafer surface. there were.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a semiconductor device capable of improving the uniformity of the thickness of a polycrystalline silicon film formed on a wafer by a thermal CVD method within the wafer plane. It is an object of the present invention to provide a manufacturing apparatus and a manufacturing method.

[0016]

According to the present invention, there is provided an apparatus for manufacturing a semiconductor device, comprising: a chamber which is provided with an inlet and an outlet for a process gas for processing a semiconductor wafer and which can be set to a predetermined pressure; With the installed heater,
A wafer mounting portion for mounting the lower surface of the outer peripheral edge of the semiconductor wafer, and a wafer outer peripheral end surface facing portion facing the outer peripheral end surface of the semiconductor wafer; When receiving predetermined heat radiation from a heater, a wafer susceptor of a single-wafer type in which the temperature of the wafer outer peripheral end surface facing portion is set lower than the temperature of the wafer mounting portion. .

Further, a method of manufacturing a semiconductor device according to the present invention
When a semiconductor film is formed on the semiconductor wafer by a thermal CVD method while a semiconductor wafer is held by a single wafer type wafer susceptor of a thermal CVD apparatus, the lower surface of an outer peripheral portion of the semiconductor wafer in the wafer susceptor is placed. The temperature of the wafer outer peripheral end surface facing portion facing the outer peripheral end surface of the semiconductor wafer is set lower than the temperature of the wafer mounting portion.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 schematically shows an example of the configuration of a chamber (reaction chamber) 10 of a thermal CVD apparatus according to a first embodiment of the semiconductor device manufacturing apparatus of the present invention.

FIG. 2 schematically shows a state in which the semiconductor wafer 30 and the single wafer type wafer susceptor 11 in FIG. 1 are taken out and viewed from above. That is, in FIG. 1 and FIG.
Is a single-wafer-type wafer susceptor for mounting a wafer.

Reference numeral 12 denotes a heater disposed below the wafer susceptor 11, a first heater 121 disposed below a central portion of the wafer susceptor, and a second heater 121 disposed below an outer peripheral portion of the wafer susceptor. The heat density of the outer second heater 122 is set to be slightly higher than the heat density of the inner first heater 121.

Reference numeral 14 denotes a gas inlet provided in the chamber for introducing a process gas. Reference numeral 15 denotes an exhaust port provided in the chamber, which is configured so that the inside of the chamber can be set to a predetermined pressure by an exhaust pump provided outside the chamber and connected to the exhaust port 15 via an exhaust pipe. Have been.

The wafer susceptor 11 is provided to be rotatable in a horizontal plane.
1 supported. As the susceptor rotating mechanism 22 for rotating and driving the wafer susceptor 11 as necessary, a mechanism for rotating and driving the rotating shaft 21 is provided.

The wafer susceptor 11 includes, for example, a disk-shaped susceptor base 111 rotatably held, a susceptor side wall 112 integrally and projecting upward from a peripheral portion of the susceptor base, and a susceptor, for example. A wafer mounting portion 113, for example, integrally protruding from the inside of the side wall portion, for mounting the outer peripheral edge of the lower surface of the semiconductor wafer, and an integrated protruding upward from the upper surface of the wafer mounting portion. And an outer peripheral end surface facing portion 114 facing the outer peripheral end surface of the semiconductor wafer.

When the wafer susceptor 11 is heated by the heat radiation from the heater 12 provided below and heats the wafer 30, the wafer susceptor 11 is heated from the susceptor base 111 heated by the heat radiation from the first heater 121. The central part of the wafer is heated by thermal radiation. In this case, since there is a gap between the lower surface of the wafer 30 placed on the wafer mounting portion 113 and the upper surface of the susceptor substrate 111, heat is not directly conducted from the susceptor substrate 111 to the wafer 30.

The peripheral portion of the wafer is heated by heat conduction from the wafer mounting portion 113 heated by the heat radiation from the heat radiation from the second heater 122. Since the wafer is shielded by the wafer mounting portion 113, the temperature of the peripheral portion of the wafer may be lower than the temperature of the central portion of the wafer.

Therefore, in order to keep the entire surface of the wafer uniform at a desired wafer temperature, it is necessary to set the temperature of the wafer mounting portion 113 to be slightly higher than the desired wafer temperature. It is assumed that the heat density of the second heater 122 outside the first heater 121 is set slightly higher than that of the first heater 121.

Further, in this embodiment, the wafer susceptor 1
1 has a structure in which the temperature of the wafer outer peripheral end surface facing portion 114 is lower than the temperature of the wafer mounting portion 113 when receiving heat radiation from the heater 12 provided below.

FIG. 3A shows a partial cross-sectional structure of an example of the wafer susceptor 11. In this wafer susceptor, the susceptor base 111, the wafer side wall portion 112, the susceptor mounting portion 113, and the wafer outer peripheral end surface facing portion 114 are made of the same material (for example, carbon coated with SiC). On the inner side, a groove 115 having a predetermined depth and height is formed along the upper surface of the susceptor mounting portion.

According to the wafer susceptor having the above-described structure, the groove 115 is formed inside the opposed portion 114 on the outer peripheral end face of the wafer. The temperature Ts2 of the wafer outer peripheral end surface facing portion 114 is lower than the temperature Ts1 of the mounting portion 113.

Next, a thermal CVD method for depositing a polycrystalline silicon film on a wafer using a thermal CVD apparatus having the configuration shown in FIG.
An example of the method D will be described. First, heater 121,
By appropriately setting the temperature of 122 and the structure of the wafer susceptor 11, for example, as shown in FIG.
The wafer 30 is heated to a desired wafer temperature (for example, 600 to 800) by the susceptor base 111 and the susceptor mounting portion 113 heated by the heat radiation of the heaters 121 and 122.
(Degree C). At this time, the temperature Ts2 of the wafer outer peripheral end surface facing portion 114 of the susceptor becomes substantially equal to the desired wafer temperature Tw.

Next, while the pressure in the chamber 10 is reduced to a predetermined pressure (for example, about 20,000 Pa), the susceptor rotating mechanism 22 rotates the wafer susceptor 11 to, for example, 250 rpm or more in the arrow direction A in FIG.
4 to the process gas (material gas, silane gas S in this example)
iH ₄ ) is introduced.

In this state, when the material gas is introduced into the chamber, flows on the wafer surface and is exhausted out of the chamber, it reacts on the wafer surface, and FIGS. 4 (a) to 4 (c).
As shown in ( ₁ ), a polycrystalline silicon film 31 is formed on an oxide film (SiO ₂ ) on the wafer surface. At this time, the growth of the polycrystalline silicon film 31 within the above temperature range has a large temperature dependency, and the higher the temperature, the faster the growth.

As described above, the susceptor rotating mechanism 2
When the wafer is rotated by 2, a centrifugal force is generated in the arrow direction B shown in FIG. 3A, and when the susceptor rotation mechanism 22 rotates the wafer 30 at, for example, 2500 rpm or more, FIG. As shown in the drawing, a part of the outer peripheral end surface of the wafer comes into contact with a part of the side wall 114 of the wafer susceptor facing the outer peripheral end surface of the wafer due to the centrifugal force.

In this case, as described above, since the temperature Ts2 of the wafer outer peripheral end surface facing portion 114 of the wafer susceptor is substantially equal to the desired wafer temperature Tw, the heat conduction between the wafer outer peripheral end surface facing portion 114 and the wafer 30 is reduced. This makes it possible to prevent the wafer temperature from becoming locally non-uniform.

For example, when a polycrystalline silicon film is formed on a 6-inch diameter Si wafer, the thickness of the polycrystalline silicon film 31 formed on the wafer is, as shown in FIG. It was confirmed that the thickness was substantially equal between the portion and the outer peripheral portion of the wafer, and the variation in the polycrystalline silicon film thickness in the wafer plane was reduced.

That is, according to the thermal CVD apparatus of FIG. 1 and the thermal CVD method using the same as described above, the uniformity of the thickness of the polycrystalline silicon film formed on the wafer within the wafer surface is improved. can do.

FIGS. 5 to 7 show cross-sectional structures of a part of each of a plurality of modified examples of the wafer susceptor of FIG. The wafer susceptor shown in FIG. 5 includes the susceptor base 111 and the susceptor side wall 11 as described above.
2. a wafer mounting portion 113 and a susceptor mounting portion provided above the wafer mounting portion in a divided manner, and a wafer outer circumferential end surface facing portion 114 facing the outer circumferential end surface of the semiconductor wafer;
b, and a heat shield 116 interposed between the wafer outer peripheral end surface facing portion and the susceptor mounting portion.

Also in the wafer susceptor having the above structure, when heat radiation from a heater 12 provided below is received, the wafer susceptor 11
4b, the heat conduction to the wafer mounting portion 113 is suppressed.
The temperature Ts2 of the portion 114b facing the outer peripheral end face of the wafer is lower than the temperature Ts1.

The wafer susceptor shown in FIG. 6 is mounted and fixed on the susceptor base 111, the susceptor side wall portion 112, the wafer mounting portion 113, and the upper portion of the wafer mounting portion as described above. And an outer peripheral end surface facing portion 114c facing the outer peripheral end surface of the wafer.

Also in the wafer susceptor having the above structure, when heat radiation is received from the heater 12 provided below, the wafer susceptor is moved from the wafer mounting portion 113 to the wafer outer peripheral end facing portion 11.
Since the heat conduction to 4c is suppressed by the gap partially present between the two, the temperature Ts2 of the wafer outer peripheral end surface facing portion 114c is lower than the temperature Ts1 of the wafer mounting portion 113.

The wafer susceptor shown in FIG. 7 is made of a susceptor base 111, a susceptor side wall 112, a wafer mounting portion 113, and a material different from the wafer mounting portion (eg, SiC). And a wafer outer peripheral end surface facing portion 114d which is placed and fixed on the portion and is opposed to the outer peripheral end surface of the semiconductor wafer 30.

Also in the wafer susceptor having the above structure, by appropriately selecting the material of the portion 114d facing the outer peripheral end surface of the wafer, when the heat radiation from the heater 12 provided below is received, the wafer susceptor 113 It is possible to set the temperature Ts2 of the wafer outer peripheral end surface facing portion 114d to be lower than the temperature Ts1.

In each of the above examples, the wafer susceptor 11
Are rotatably provided in a horizontal plane, but when the wafer susceptor 11 is fixed so as not to be rotatable, a part of the wafer outer peripheral end face temporarily faces a part of the wafer outer peripheral end face opposing portion of the wafer susceptor 11. Even if it is in contact, as described above, the temperature Ts2
Is set so as to be substantially equal to the desired wafer temperature Tw, the heat conduction between the wafer outer peripheral end surface facing portion and the wafer is suppressed, and it is possible to prevent the wafer temperature from becoming locally non-uniform. Will be possible.

[0044]

As described above, according to the present invention, thermal CV
It is possible to provide a semiconductor device manufacturing apparatus and a manufacturing method capable of improving the uniformity of the thickness of a polycrystalline silicon film formed on a wafer by a method D in a wafer surface.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing an example of a thermal CVD apparatus according to a first embodiment of a semiconductor device manufacturing apparatus of the present invention.

2 is a plan view schematically showing a state in which a semiconductor wafer and a single wafer type wafer susceptor in FIG. 1 are taken out and viewed from above.

FIG. 3 is a cross-sectional view showing a part of the wafer susceptor in FIG. 1 and a wafer cross-sectional view showing a process of forming a polycrystalline silicon film on a wafer using the wafer susceptor.

FIG. 4 is a wafer cross-sectional view showing a process when a polycrystalline silicon film is formed on the wafer by a thermal CVD method using the thermal CVD apparatus of FIG.

FIG. 5 is a sectional view showing a part of a modification of the wafer susceptor of FIG. 3;

FIG. 6 is a sectional view showing a part of another modification of the wafer susceptor of FIG. 3;

FIG. 7 is a sectional view showing a part of another modification of the wafer susceptor of FIG. 3;

FIG. 8 is a sectional view schematically showing an example of a conventional thermal CVD apparatus.

FIG. 9 shows a conventional thermal CVD having a rotary wafer susceptor.
Sectional drawing which shows an apparatus schematically.

FIG. 10 is a wafer cross-sectional view showing a process when a polycrystalline silicon film is formed on a wafer using the thermal CVD apparatus of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Chamber, 11 ... Wafer susceptor, 111 ... Susceptor base, 112 ... Susceptor side wall part, 113 ... Wafer mounting part, 114, 114b, 114c, 114d ... Wafer outer peripheral end surface opposing part, 115 ... Groove, 116 ... Heat shielding material Reference numeral 12: heater, 121: first heater, 122: second heater, 14: gas inlet port, 15: exhaust port, 21: rotating shaft, 22: susceptor rotating mechanism, 30: semiconductor wafer, 31: polycrystalline Silicon film.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-65119 (JP, A) JP-A-4-211117 (JP, A) JP-A-5-90165 (JP, A) JP-A-5-90165 152207 (JP, A) JP-A-9-125251 (JP, A) JP-A-6-53174 (JP, A) JP-A-5-29270 (JP, A) JP-A-3-23923 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/205 C23C 16/458 C23C 16/46 H01L 21/68

Claims (15)

(57) [Claims] A chamber provided with an inlet and an outlet for a process gas for processing a semiconductor wafer and capable of being set at a predetermined pressure; a heater installed inside the chamber; and a heater installed inside the chamber. A wafer mounting portion for mounting the lower surface of the outer peripheral edge of the semiconductor wafer, and a wafer outer peripheral end surface facing portion facing the outer peripheral end surface of the semiconductor wafer, receiving predetermined heat radiation from the heater; And a wafer susceptor of a single-wafer type wherein the temperature of the portion facing the outer peripheral end face of the wafer is set lower than the temperature of the wafer mounting portion. 2. The semiconductor device manufacturing apparatus according to claim 1, wherein the wafer susceptor includes a susceptor base, and a susceptor side wall protruding upward from a peripheral portion of the susceptor base.
A wafer mounting portion for projecting from the inside of the susceptor side wall portion, for mounting an outer peripheral edge of a lower surface of the semiconductor wafer, and projecting upward integrally from an upper surface of the wafer mounting portion; A wafer outer peripheral end surface facing portion facing the outer peripheral end surface of the semiconductor wafer, and a groove having a predetermined depth and height is formed along the upper surface of the wafer mounting portion in the wafer outer peripheral end surface facing portion. Characteristic semiconductor device manufacturing equipment. 3. The semiconductor device manufacturing apparatus according to claim 1, wherein the wafer susceptor includes a susceptor base, a susceptor side wall protruding upward from a peripheral portion of the susceptor base, and
A wafer mounting portion protruding from the inside of the susceptor side wall portion for mounting an outer peripheral edge of a lower surface of the semiconductor wafer, and a susceptor mounting portion provided separately above the wafer mounting portion; A semiconductor wafer facing the outer peripheral end face of the semiconductor wafer, and a heat shield interposed between the wafer outer peripheral end face opposing section and the susceptor mounting section. manufacturing device. 4. The apparatus for manufacturing a semiconductor device according to claim 1, wherein said wafer susceptor includes a susceptor base, and a susceptor side wall protruding upward from a peripheral portion of said susceptor base.
A wafer mounting portion protruding from the inside of the susceptor side wall portion for mounting an outer peripheral edge of a lower surface of the semiconductor wafer, and a semiconductor wafer mounted and fixed on an upper portion of the wafer mounting portion; And a wafer outer peripheral end surface facing portion facing the outer peripheral end surface of the semiconductor device. 5. The semiconductor device manufacturing apparatus according to claim 1, wherein the wafer susceptor includes a susceptor base, and a susceptor side wall protruding upward from a peripheral portion of the susceptor base.
The wafer mounting portion, which is protruded from the inside of the susceptor side wall portion and is for mounting the outer peripheral edge of the lower surface of the semiconductor wafer, is made of a different material from the wafer mounting portion, A semiconductor device manufacturing apparatus, comprising: a wafer outer peripheral end surface facing portion which is mounted and fixed on an upper portion and faces an outer peripheral end surface of the semiconductor wafer. 6. The semiconductor device manufacturing apparatus according to claim 1, wherein said wafer susceptor is rotatably provided in a horizontal plane. . 7. The semiconductor device manufacturing apparatus according to claim 1, wherein the heater includes a first heater installed below a central portion of the wafer susceptor, and an outer periphery of the wafer susceptor. And a second heater installed below the lower portion, wherein the heat density of the outer second heater is set higher than that of the inner first heater. For manufacturing semiconductor devices. 8. The semiconductor device manufacturing apparatus according to claim 1, wherein the temperature of the heater is such that the temperature of the wafer mounting portion is higher than a desired wafer temperature. An apparatus for manufacturing a semiconductor device, wherein the temperature of the wafer outer peripheral end surface facing portion is set to be substantially equal to a desired wafer temperature. 9. The semiconductor device manufacturing apparatus according to claim 1, wherein the semiconductor wafer has a silicon oxide film formed on an upper surface of a silicon wafer, the process gas is a silane gas, and the wafer susceptor has SiC
An apparatus for manufacturing a semiconductor device, wherein carbon coated with a carbon is used. 10. When a semiconductor film is formed on a semiconductor wafer by a thermal CVD method in a state where a semiconductor wafer is held by a single wafer susceptor of a thermal CVD apparatus, a lower surface of an outer peripheral portion of the semiconductor wafer in the wafer susceptor is formed. A method of setting the temperature of a wafer outer peripheral end surface facing portion facing an outer peripheral end surface of a semiconductor wafer lower than the temperature of a wafer mounting portion for mounting a semiconductor device. 11. A step of accommodating a single wafer type wafer susceptor in a chamber and mounting a semiconductor wafer on the wafer susceptor, and heating the wafer susceptor by heat radiation from a heater to form an outer peripheral edge of the semiconductor wafer. Heating the semiconductor substrate to a predetermined temperature in a state where the temperature of the wafer outer peripheral end facing portion facing the outer peripheral end surface of the semiconductor wafer is set lower than the temperature of the wafer mounting portion for mounting the lower surface of the semiconductor wafer. Manufacturing a semiconductor device, comprising: setting a predetermined reduced pressure in the chamber; and introducing a process gas into the chamber to form a semiconductor film on the semiconductor wafer. Method. 12. The method of manufacturing a semiconductor device according to claim 11, wherein the temperature of the heater is set higher than a desired wafer temperature when the temperature of the wafer mounting portion is higher than a desired wafer temperature. Is set to be substantially equal to a desired wafer temperature. 13. The method of manufacturing a semiconductor device according to claim 11, wherein the semiconductor film is formed on the semiconductor wafer while rotating the wafer susceptor at a predetermined rotation speed or more. Production method. 14. The method of manufacturing a semiconductor device according to claim 11, wherein a rotation speed of said wafer susceptor is 200 rpm or more. 15. The method for manufacturing a semiconductor device according to claim 11, wherein the semiconductor wafer has a silicon oxide film formed on an upper surface of a silicon wafer, and the process gas is a silane gas. And a method for manufacturing a semiconductor device, wherein the semiconductor film is a polycrystalline silicon film.