JP2923748B2 - Coating method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a high quality film. 2. Description of the Related Art Conventionally, in a CVD apparatus such as a PCVD apparatus, since the pressure of a reaction system is as high as 0.05 to 10 torr, only VP is used for an exhaust system and the like.
It has been completely impossible to provide a TP or the like for generating a higher degree of vacuum. [0003] However, PCV in the above technique
In the D apparatus, the exhaust system is only a VP, and furthermore, since this VP makes a discontinuous rotational movement, the atmosphere (particularly oxygen) from the exhaust system at atmospheric pressure in contact with air flows backward, It was found that a part of the oil was mixed into the oil, from which it was re-evaporated, and then flowed back into the reaction vessel. Further, for this reason, oxygen is mixed into the film formed by the backflow, and for example, when a silicon film is formed, oxygen is mixed into the film at a concentration of 3 × 10 ¹⁹ to 2 × 10 ²⁰ cm ⁻³ . . For this reason, hydrogen or fluorine is added to such a film, so that what should be a silicon semiconductor can be called lower silicon oxide. An object of the present invention is to prevent the backflow of air from an exhaust system to a reaction furnace, which is a problem in forming a high quality film in the prior art. , Aim. According to the present invention, there is provided a method for producing a vapor-phase reaction film, comprising: forming a film on a substrate placed in a reaction system kept under reduced pressure; During the film formation, the reaction chamber has a structure that can be made independent from each reaction chamber by a gate valve. Use the one equipped with a vacuum pump and a turbo-molecular pump of a continuous exhaust system,
A buffer chamber for transferring a substrate is connected to the reaction chamber, and the buffer chamber is provided with a reaction gas introduction unit and a discontinuous rotation type vacuum pump and a continuous evacuation type turbo molecular pump for reducing the pressure or vacuum. Wherein each substrate of the non-single-crystal semiconductor layer is formed in an independent reaction chamber by moving the substrate exiting the reaction chamber to another reaction chamber via a buffer chamber. is there. Further, in forming a non-oxygen-based film by reacting a reactive gas by a gas phase reaction method in a reaction vessel, water and oxides in the reactive gas are reduced to 0.1 ppm or less and exhausted from the reaction vessel during the formation of the film. Is carried out by a turbo-molecular pump of a continuous evacuation method, and a non-oxygen-based film having a concentration of 5 × 10 ¹⁸ cm ⁻³ or less of oxygen or carbon can be formed on the substrate. Further, in a method of producing a non-oxygen-based coating composed of a first layer, a second layer, and a third layer by reacting a reactive gas by a gas phase reaction method in different reaction chambers, the second layer is formed into a silicon semiconductor coating. During the formation, a reactive gas in which water and oxides are reduced to 0.1 ppm or less is introduced into a reaction chamber kept under reduced pressure, and the reaction chamber during the formation of the second layer is connected to another reaction chamber by a gate valve. And a reaction gas or a reaction product from the reaction chamber during film formation can be discharged using a turbo-molecular pump of a continuous exhaust system. According to the present invention, a discontinuous rotary vacuum pump (hereinafter simply referred to as a vacuum pump) such as an oil rotary rotary pump or a mechanical booster pump is used to prevent the backflow of the atmosphere from the exhaust system in the production of a non-oxygen coating film. Or V
P), instead of using only a turbo-molecular pump of a continuous exhaust system (hereinafter simply referred to as a turbo-molecular pump or TP).
Between the reaction vessel and the vacuum pump,
This prevents backflow of the atmosphere from the exhaust system. As a result, a non-oxide film, for example, non-single-crystal silicon is converted to silane (Si _n H) as a reactive gas.
_{2n + 2} n ≧ 1) in forming with the amount of oxygen in the in the coating 5 × ¹⁰ 18 cm ^- 3 or less preferably 1 ×
It is intended to reduce the density to 10 ¹⁸ cm ⁻³ or less. According to the present invention, the TP is interposed between the reaction chamber and the VP through a valve for controlling the pressure during the reaction, so that the reaction chamber has a plasma gas phase reaction in a pressure range of 0.05 to 10 torr. (Photo-CVD (PCVD)
o CVD) or a combination thereof (hereinafter simply referred to as a CVD method) to form a film, and 1 × 10 ⁻² torr or less (generally 10 ⁻⁴ to 10 ⁻⁾ below the pressure regulating valve. ^The reaction system is maintained at a pressure of ⁶ torr and the TP is applied, so that the reaction system has a higher pressure (1 × 10 ^-2 torr or more, that is, 0.05) than the exhaust system.
-10 torr) to form a film. Further, the present invention connects such a plasma CVD apparatus to a plurality of reaction chambers, and stacks a P-type non-single-crystal semiconductor, an I-type non-single-crystal semiconductor, and an N-type non-single-crystal semiconductor on a substrate in each reaction chamber. And a method of manufacturing a semiconductor device forming a PIN junction. FIG. 1 shows the outline of the apparatus of the present invention.
That is, it has a doping system (50) for introducing a reactive gas, a reaction vessel (51), and an exhaust system (52). The reaction vessel has a semiconductor layer formed as a double reaction vessel type having a reaction space in which an inner surface is formed by an insulator, and additionally has a P-type semiconductor (system A in the drawing) and an I-type semiconductor (system C in the drawing). 1) and an N-type semiconductor to form a junction on the substrate, a multi-chamber PCVD method in which the respective reaction vessels are connected via a separation unit (system B in the drawing) as shown in FIG. There is to suggest. According to the present invention, a non-single-crystal semiconductor layer to which hydrogen or a halogen element is added is used to form a semiconductor layer having a P, I and N-type conductivity type having a low recombination center density, To form a PIN junction, to prevent each semiconductor layer from being mixed with impurities from another adjacent semiconductor layer to thereby degrade the junction characteristics. And to a plasma gas phase reaction for performing continuous production without forming an interlayer insulator by oxidizing a part of a semiconductor. Further, the present invention relates to a so-called mass production system in which a multi-chamber plasma reaction method in which a large number of such reaction vessels are independently connected in each reaction, the film growth rate of a large number of substrates at once is increased at the same time. . The present invention has a substrate (40 cm) having a size of 10 cm × 10 cm or 10 to 50 cm, for example, 40 cm in the electrode direction, and a width of 15 to 120 cm, for example, 60 cm.
cm × 60cm or 20cm × 60cm 1 batch 2
0). In FIGS. 1 and 2, a reactive gas introducing means and an exhausting means are provided, which are provided with a supply nozzle and an exhaust nozzle. , (61 ′) or (62), (6
2 ′) and reactive gas supply nozzles (17), (1)
8) and exhaust nozzles (17 ′) and (18 ′). That is, a structure in which the outside of the electrode is wrapped with a hood insulator (3)
9), (39 '). Further, in order to confine the reaction space between the hoods, the outer periphery is insulated (38), (3)
8 '). FIG. 2 is a drawing showing a cross section of FIG. 1. An opening / closing door is provided before (left side in the drawing) and after (right side in the drawing) the reaction vessel, and a heating means such as a halogen lamp is provided on the inner surface of the door. 13) and (13 ′). Hereinafter, embodiments of the present invention will be described with reference to the drawings. [Embodiment 1] An embodiment of a plasma vapor reactor according to the present invention will be described with reference to FIGS. 1 and 2. This drawing shows a semiconductor on a substrate such as a PIN junction, a PIP junction, a NIN junction or a PINPIN ... PIN junction, which is of a different conductivity type but has a different main component or a different stoichiometric ratio of the formed semiconductor. This is an apparatus for automatically and continuously forming layers into a multilayer for laminating each semiconductor layer without being affected (mixed) by a semiconductor layer formed in a previous step. In the drawings, some of a plurality of reaction systems constituting a PIN junction are shown. That is, a multi-chamber system having two (A, C) of three reaction systems formed by laminating P, I, and N type semiconductor layers, and further having a first spare chamber and a buffer chamber (B) for transfer. 1 shows an example of a plasma gas phase reaction apparatus. Systems A, B, C in the drawing
Has two reaction vessels (101) and (103) and a buffer chamber (102), and has gate valves (44), (45), (46) and (47) between the respective reaction vessels. ing. Also, independently, the reactive gas supply nozzles (17) and (18) and the exhaust nozzles (17 ') and (1)
8 ′), and the reactive gas is provided so as to form a laminar flow from the supply system to the exhaust system. This apparatus has a first spare room (1) at the entrance side.
00), first, two substrates (1) each having two surfaces to be formed were attached to two surfaces of the substrate holder (2) from the door (42). Further, the holder (3) was disposed at a predetermined equal distance from each other by an outer frame jig (only the outer periphery is shown as (38) and (38 ')). That is, the substrate having the surface on which the film is to be formed is in contact with the substrate holder (2) on the back surface on which no film is formed, and has a gap of 6 cm ± 0.5 cm using the two substrates and the substrate holder as one holder (3). Standing in the outer frame jig of the insulator. As a result, 40cm
A film could be simultaneously formed on 20 × 60 cm substrates. Thus, height 55cm, depth 80cm, width 80
The reaction spaces (6) and (8) of cm were surrounded on upper and lower sides by insulators (39) and (39 '), and the periphery was surrounded by insulating outer frame jigs (38) and (38'). The first preparatory chamber (100) was fully opened with the pressure regulating valve (71) and evacuated by the vacuum pump (35) through the TP (86). Thereafter, the pressure regulating valve (72) is fully opened, and 3 × 10 ⁻⁸ torr by TP.
r reaction vessel (10
The gate valve (44) for separation from 1) was opened, and the substrate held by the outer frame jig (38) was transferred. For example, the substrate is moved from the preliminary chamber (100) to the first reaction vessel (101), and the substrate is moved to the first reaction vessel (101) by closing the gate valve (44). At this time, the substrate (1) and the like held in the first reaction vessel (101) are previously or simultaneously placed in the buffer chamber (102), and the jig and the substrate (2) held in the buffer chamber (102). Is stored in the second reaction vessel (103), and the substrate held in the second reaction vessel (103) is stored in the second buffer chamber (104).
The substrate and the jig in the reaction chamber can be moved to the second preparatory chamber on the outlet side by opening the gate valves (45), (46), and (47). Thereafter, the gate valves (44), (4
5), (46) and (47) were closed. That is, when the door (42) is opened at atmospheric pressure, the gate valves (44), (4)
5), (46), and (47) are closed, and a plasma gas phase reaction is performed in each chamber. Conversely, when the door (42) is closed and the preliminary chamber (100) is sufficiently evacuated, the gate valves (44), (45), (4)
6) and (47) are opened, and the substrate and the jig in each chamber have a mechanism for moving to the next chamber.
01) and (102). The first reaction vessel (10
The case where the P-type semiconductor layer is formed by the PCVD method in 1) will be described below. The reaction system A (including the reaction vessel (101)) is 0.01 to 10 torr, preferably 0.01 to 1 torr.
r, for example, 0.08 torr. That is, the pressure regulating valve (72) is closed, the pressure in the reaction vessel (101) is 0.05 to 1 torr, and the pressure below the valve is 1 ×.
10 ⁻² torr or less, generally 1 × 10 ⁻⁴ to 1 × 10
^-7 torr, and this degree of vacuum is achieved by rotating the TP (87). Further, since the continuous exhaust TP is operated, the powdery product generated by the PCVD reaction can be discharged from the reaction vessel (101), and
For the first time, it was possible to prevent the reverse diffusion of the polymerized oil of VP (36) and the backflow of the exhaust air impregnated in the oil, particularly oxygen. The reactive gas is a doping system of system A (50).
Supplied more. That is, silane (Si) purified as a silicide gas (24) and further filled in a stainless steel cylinder is used.
_{n H 2n + 2 n> 1} ) in particular SiH ₄ or _Si 2 _H 6,
Silicon fluoride (SiF ₂ or SiF ₄ ) was used. Here, ultra-high-purity silane (purity 99.99) which is easy to handle
%, But water and oxygenates are 0.1 PPM or less).
To form the present embodiment _{Si x C 1-x (0} <X <1), it was used as a carbide gas (25) DMS (dimethyl silane _(SiH 2 _{(CH 3) 2} 99.99% purity). for silicon carbide _{(Si x C 1-x 0} <x <1), was fed together with silanes than is mixed simultaneously a concentration of 0.5% in monosilane said boron as impurities in the P-type (24) If necessary, hydrogen (purity of 7 N or more) or nitrogen (purity of 7 N or more) is added to the reaction chamber at atmospheric pressure (2
3). These reactive gases pass through respective flow meters (33) and valves (32), and from the reactive gas supply nozzle (17) to the reaction space (6) via the negative electrode (61) of the high frequency power supply (14). Supplied. The reactive gas was supplied into the cylindrical space (6) surrounded by the holder (38), and a film was formed on the substrate (1) constituting this space. Further, electric energy, for example, 13.56 MHz high-frequency energy (1) is applied between the negative electrode (61) and the positive electrode (51).
4) was added to cause a plasma reaction to form a film of the reaction product on the substrate. The substrate is at 100 to 400 ° C, for example, 2
It was heated to 00 ° C. by the same means as the infrared heaters arranged before and after the reaction vessel (103) shown in FIG. This infrared heater uses a near-infrared halogen lamp (emission wavelength: 1 to 3 μm) heater or a far-infrared ceramic heater (emission wavelength: 8 to 25 μ), and a cylindrical space surrounded by a holder in the reaction vessel. 20
The temperature was set at 0 ± 10 ° C., preferably within ± 5 ° C. After this,
As described above, the reactive gas described above is introduced into this container,
Further, high-frequency energy (14) was supplied to 10 to 500 W, for example, 100 W to cause a plasma reaction. Thus, the P-type semiconductor layer is B ₂ H ₆ / SiH ₄ = 0.5%, DM
Under the condition of S / (SiH ₄ + DMS) = 10%, this reaction system A was formed as a thin film having an average film thickness of 30 to 300 {for example, about 100}. Eg = 2.05e
V), σ = 1 × 10 ^{−6 to} 3 × 10 ⁻⁵ (Ωcm) ⁻¹
Met. The substrate may be a conductor substrate (stainless steel, titanium, aluminum, other metals), a semiconductor (silicon, germanium), an insulator (glass, organic thin film), or a composite substrate (glass or translucent organic resin). A single conductive film of tin oxide to which fluorine is added, ITO, or the like, which is a conductive conductive film, or a two-layer film in which SnO ₂ is formed on ITO is used. These are collectively referred to as a substrate in the present invention as well as in all of the present invention. Of course, this substrate may be flexible or a hard plate. Thus, a plasma gas phase reaction was performed for 1 to 5 minutes to form a silicon carbide film to which boron as a P-type impurity was added to a thickness of about 100 °. Further, the substrate on which the first semiconductor layer was formed was opened to the gate (45), moved to the buffer chamber (102) according to the operation sequence described above, and the gate (45) was closed. The buffer chamber (102) is previously evacuated to ^10-8 torr or less by a cryopump (88). Buffer chamber (102) is CVD
Since no reaction is performed, a cryopump can be used instead of a turbo molecular pump. This substrate is the same as the system C in the TP (89)
As a result, the gate was moved to a reaction vessel maintained at 1 × 10 ⁻⁷ torr or less through opening and closing of a gate (46). That is, FIG.
In the reaction system C, ultra-high-purity monosilane or disilane is used as the semiconductor reactive gas (water or silicon oxide, the concentration of the oxide gas is 0.1 PPM or less) (28), and 10 ¹⁷ cm ⁻³ or less. In order to add boron, B ₂ H ₆ diluted to 0.5 to 30 PPM with hydrogen, silane, or the like was supplied from (27), and a carrier gas was supplied from (26) as needed. The reactive gas flows downward from above along the surface on which the substrate (1) is formed, and TP
(89). FIG. 2 shows a longitudinal sectional view of the system C as viewed from the outlet side. FIG. 2 is outlined. FIG. 2 is a longitudinal sectional view of the reaction system C of FIG. In the drawing, a rod-shaped halogen lamp was used for the lamp heaters (13) and (13 '). The reaction space was heated to 100 to 400 ° C, for example, 250 ° C by a heater. The substrate (1) is held by the substrate holder (2), and the confined space (8) is constituted by the outer frame jigs (38) and (38 '). Following conditions I layer to a thickness of 5000Å in the reaction chamber shown in FIG. 2 (103), SiH ₄
60 cc / min, film formation rate 2.5Å / sec, substrate (2
20 pieces of 0cm x 60cm, total area 24000c
m ² ) at a pressure of 0.1 torr. When Si ₂ H ₆ was used as the reaction gas, the film formation rate was 28 ° / sec. Thus, a P-type semiconductor layer is formed in the first reaction chamber by the plasma vapor phase method, and then the P-type semiconductor layer is formed by the PCVD method.
A circular junction was formed by forming a mold semiconductor layer. Next, after being formed to a thickness of about 5000 ° by the system C, the substrate is transferred to an adjacent buffer chamber (104) according to the above-described operation, and further transferred to an adjacent reaction chamber, and subjected to a similar PCVD process to obtain an N-type substrate. A semiconductor layer was formed. This N-type semiconductor layer is composed of P
Phosphine was converted to PH ₃ / SiH ₄ = 1.0 by the CVD method.
% Of silane and hydrogen of carrier gas as SiH ₄ / H ₂
= 20% and supplied as about 200
A polycrystalline semiconductor layer having an N-type microcrystalline or fibrous structure is formed at a thickness of, and silicon carbide is set to DMS / (SiH ₄ + DMS) = 0.1 and Si _x
The N-type semiconductor layer represented by C _1-x (0 <x <1)
It is formed by laminating to a thickness of about 200 mm, for example, a thickness of 50 mm. Other reactors are the same as in system A. After such a step, P
100-1500 on the substrate which is formed by forming the IN junction
An ITO having a thickness of Å is further formed thereon with a reflective or sublimable metal electrode such as an aluminum electrode to a thickness of about 1 μm by a vacuum evaporation method, and (ITO + SnO) is formed on a glass substrate.
₂ ) A front electrode- (PIN semiconductor)-(back electrode) was formed. The characteristics of the photoelectric conversion device are as follows: 7 to 9%, 8% on average, AMI (100 mW
/ Cm ² ), and 5.5% could be obtained with an effective efficiency even on a 40 cm × 60 cm glass substrate integrated and hybridized. As a result, the open circuit voltage of one element is 0.85 to
Although 0.9 V (0.87 ± 0.02 V), the short circuit current was as large as 18 ± ² mA / cm ² and the FF was 0.6
0 to 0.70, and the variation is within the panel,
Small in batches, the process of the invention has been found to be very effective industrially. FIG. 3 shows the concentration distribution of oxygen and carbon impurities in the semiconductor in the PIN photoelectric conversion device manufactured by the present invention and the conventional method. The drawing shows an aluminum back electrode (94), an N-type semiconductor (93), an I-type semiconductor (92), a P-type semiconductor (91), and a tin oxide translucent conductive film (90) on a substrate, respectively. In the conventional exhaust method using only a rotary pump or a mechanical booster pump, the continuous exhaust system TP is not used, so that carbon has a high concentration of impurities shown by a curve (95) and oxygen has a high concentration shown by a curve (96). Contained. Especially oxygen is 5
× 10 ^{19 to} 2 × 10 ²⁰ cm ⁻³ is an I-type semiconductor (9
It had in 2). The drawing is 5 × 10 ¹⁹ cm ⁻³
Of oxygen. In addition , the drawing is 1 × 10
^This is the case with ²⁰ cm ^-3 carbon . On the other hand, in the exhaust system as shown in the present invention, the carbon concentration is 1 × 10 ¹⁷ as shown by the curve (98).
Has ~5 × ¹⁰ 18 ^{cm -3,} is generally 1 × ^{10 18}
cm ^-3 or less. In addition, the oxygen concentration is 5 × 10 ¹⁸ cm ⁻³ or less, preferably 1 × 10 ¹⁸ cm ⁻³ or less, as shown by the curve (97).
The case of × 10 ¹⁸ cm ⁻³ is shown. In FIG. 3, the aluminum of the back electrode (94) has 3 to 6 × 1
It has 0 ²⁰ cm ⁻³ of oxygen. For this reason, this oxygen becomes background oxygen in the measurement by SIMS (secondary ion analysis method) (using 3F type of Kameka), and oxygen in the N-type semiconductor (93) is 10 ¹⁸ to 10 ^20.
It is considered that the value became cm ⁻³ . Further, there are impurities due to the presence of oxygen contained in the P-type semiconductor and water contained in the DMS, and this starting material is further purified by purifying silane into oxygen or oxide of 0.1 PPM or less to further increase oxygen. The possibility of lowering the concentration can be estimated. Regarding the type of semiconductor to be formed,
Not only Si other Group 4 of _{Ge, Si x C 1-x} (0 <
_{x <1, Si x Ge 1} -x (0 <x <1) Si x
Sn _1-x (0 <x <1) Even if it is a single layer or a multilayer,
Besides these, GaAs, GaAlAs, BP, Cd
Needless to say, it may be a non-oxygenated compound such as a compound semiconductor such as S. The present invention has shown the PCVD method in a multi-chamber system using three reaction vessels. However, this was used as one reaction vessel, and silicon nitride was converted to silane (SiH ₄ or Si ₂ H ₆ ) and ammonia (NH ₂ ) by the PCVD method.
It is effective to form by PCVD reaction with ₃ ). The non-single-crystal semiconductor film formed in the present invention is also effective for an N (source) I (channel forming region) N (drain) junction or a PIP junction in an insulated gate field effect semiconductor device. Furthermore, it is a PIN diode having an energy bandwidth of WNW (WIDE-NAL).
LOW-WIDE) or _{Si x C 1-x -Si-} Si
A visible light laser, a light emitting element, or a photoelectric conversion device of a PIN junction type having a structure of _x C _1-x (0 <x <1) may be manufactured.
In particular, a so-called W (P or N type) -N (I) having a heterojunction structure having an increased energy band width on the light incident light side.
(WIDE TO NALLOW) and in each reaction chamber, not only the conductivity type but also the products can be made different from each other and made independently and laminated, which is extremely important industrially. believe. In the present invention, the separation portion is not limited to a gate valve, but is provided with two gate valves and one buffer chamber as a system B to further prevent impurities of the P-type semiconductor from being mixed into the I-type semiconductor layer. It was effective to improve the characteristics. It goes without saying that the plasma CVD apparatus of the present invention can be applied to a single-chamber or multi-chamber system having another structure. In the embodiment of the present invention, the multi-chamber system shown in FIG. 1 was used, and the PCVD method was supplied to all the reaction vessels. However, if necessary, part or all of this can be performed by a photo CVD method using no plasma, LT
CVD method (also called HOMO CVD method), low pressure CVD
The composite coating may be formed by employing a method. According to the present invention, a reactive gas is reacted by a plasma gas phase reaction method in different reaction chambers to form a first layer, a second layer and a third layer, at least one of which is made of silicon. In the method for producing a semiconductor film containing, at the time of forming the at least one layer, water,
Introduce a reactive gas containing less than 0.1 ppm of oxide,
The reaction chamber during the formation of the second layer is separated from the other reaction chambers by a gate valve, and the reactive gas and reaction products from the reaction chamber during the formation of the film are discharged using a turbo-molecular pump of a continuous exhaust system. In order to achieve good film formation in the prior art, the pressure in the reaction vessel is adjusted to 0.01 to 10 torr by adjusting a valve provided between the turbo molecular pump and the reaction vessel. It is possible to prevent the backflow of the atmosphere from the exhaust system to the reaction furnace, which is an important problem, and to produce a high-quality coating.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an outline of an apparatus for producing a coating for a plasma vapor phase reaction for carrying out the present invention. FIG. 2 shows an outline of an apparatus for producing a film for a plasma gas phase reaction for carrying out the present invention. FIG. 3 shows the distribution of impurities in a semiconductor device manufactured according to the present invention and a conventional method. [Description of Signs] (50) Doping System (51) for Introducing Reactive Gas (51) Reaction Vessel (52) Exhaust System (61) (61 ′) (62) (62 ″) Electrode (17) (18) Reactive Gas Supply nozzles (17 ') (18') Reactive gas exhaust nozzles (14) (15) High frequency energy source (38) (38 ') (39) (39') Insulator (13) (13 ') Halogen Heating means such as lamps (101) (103) Reaction vessels (102) (104) Buffer chamber vessels (44) (45) (46) (47) Gate valve (100) Spare chamber (42) Spare chamber door (5) Preliminary chamber space (2) Substrate holder (1) Substrate (6) Reaction space of first reaction chamber (8) Reaction space of second reaction chamber (7) (9) Buffer chamber space (71) (72) ( 73) (74) Pressure adjusting valve (86) (87) (88) (89) ) Turbo molecular pump (34) (35) (36) (37) Vacuum pump

Claims (1)

(57) [Claims] In a method for forming a film for forming an I-type layer of a semiconductor device by using a high-frequency plasma CVD method, there is provided an exhaust pump having a continuous exhaust turbo molecular pump between a reaction chamber and a discontinuous rotary vacuum pump. Depressurizing using a system, introducing a reactive gas into the reaction chamber, and adjusting the pressure of the reaction chamber to 0.01 to 10 t by a pressure control valve provided between the reaction chamber and the turbo molecular pump.
a pressure of orr, oxygen and carbon, respectively SIMS
5 × 10 ¹⁸ cm as measured by (secondary ion analysis)
Forming an I-type semiconductor film containing silicon having a concentration of ^-3 or less on the surface on which the film is to be formed.