JPH10209059A - Method for generating coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an I-type semiconductor coating containing silicon where oxygen and carbon are not more than specified density in measurement by means of SIMS, by guiding silicide vapor filled in a stainless cylinder into a reaction room and decompressing the reaction room through the use of a turbo molecule pump. SOLUTION: Reactive vapor is supplied from a doping system 50 of a system A. Namely, silane (Sin H2n+2 n>1, especially SiH4 or Si2 H6 ) and silicon fluoride (SiF2 or SiF4 ) which are purified and filled in the stainless cylinder are used as silicide vapor 24. The reaction system A is set to be 0.01-10Torr, 0.01-1Torr to be desirable, 0.08Torr, for example, and the degree of vacuum is realized by rotating the turbo molecule pump 87. Thus, the I-type semiconductor coating containing silicon where the density of oxygen and carbon is not more than 5×10<18> cm<-3> in measurement by SIMS(secondary ion measurement system) can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for producing a vapor phase reactive coating. In the present invention, when producing a coating using a reactive gas, a non-oxide coating is produced by performing a gas phase reaction (hereinafter referred to as CVD) using a turbo molecular pump in an exhaust system. The present invention relates to a gas phase reaction apparatus for controlling the concentration of oxygen in a coating film to a concentration of 1 × 10 ¹⁹ cm ⁻³ or less, and a method for manufacturing the same. The present invention relates to a discontinuous rotary vacuum pump (hereinafter referred to as an oil rotary rotary pump, a mechanical booster pump, etc.) for preventing the backflow of the atmosphere from the exhaust system in the production of a non-oxygen coating film. Instead of using only a vacuum pump or VP, a continuous exhaust type turbo molecular pump (hereinafter simply referred to as a turbo pump) is used.
(A molecular pump or TP) is interposed between the reaction vessel and the vacuum pump to prevent backflow of the atmosphere from the exhaust system.

When the non-oxide film of the present invention, for example, non-single-crystal silicon is formed using silane (Si _n H _{2n + 2} n ≧ 1) as a reactive gas, the amount of oxygen in the film is reduced to 5%. × 10 ¹⁸
The purpose of the present invention is to prevent backflow from the exhaust system in order to reduce the flow rate to cm ^-3 or less, preferably 1 × 10 ¹⁸ cm ^-3 or less.

According to the present invention, such an exhaust system is interposed between the reaction chamber and the VP through a valve for adjusting the pressure during the reaction between the reaction chamber and the VP, so that the reaction chamber has a plasma gas pressure range of 0.05 to 10 torr. The film is formed using a reaction (PCVD, photo-CVD (Photo-CVD)) or a method using both of them (hereinafter, collectively referred to as a CVD method), and under the pressure control valve, 1 × 10 ^-2 torr or less (generally, Is 10 ^-4 to 10 ^-6 torr)
Of holding the pressure, for applying a TP, the reaction system is high pressure (1 × 10 ^-2 torr or more words 0.05 than the exhaust system
It is intended to carry out film formation while holding at 10 torr).

Further, in the present invention, a plurality of reaction chambers are connected to such a plasma CVD apparatus, and a P-type non-single-crystal semiconductor, an I-type non-single-crystal semiconductor and an N-type non-single-crystal semiconductor are formed on a substrate in each reaction chamber. The present invention relates to a method for manufacturing a semiconductor device which is stacked to form a PIN junction.

[0005]

2. Description of the Related Art Conventionally, in a CVD apparatus such as a PCVD apparatus, since the pressure in a reaction system is as high as 0.05 to 10 torr, only VP is used in an exhaust system and the like, and TP or the like which generates a higher degree of vacuum is used. It was impossible at all.
However, the present inventor has found that in such a PCVD apparatus, the exhaust system is VP
In this case, the VP makes a discontinuous rotational movement, so that the atmosphere (especially oxygen) from the exhaust system at atmospheric pressure that is in contact with the air flows back, and a part of this atmosphere mixes with the oil. It was found that re-vaporization caused a backflow into the reaction vessel. Further, for this reason, oxygen is mixed into the film formed by the backflow. 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 . .

[0006] 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.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to prevent such disadvantages.

[0008]

FIG. 1 shows an 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). ) And an N-type semiconductor to form a bond 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 formed to form a semiconductor layer having a P, I, or N-type conductivity type having a low recombination center density, In addition to forming a PIN junction, it prevents each semiconductor layer from mixing impurities from other adjacent semiconductor layers and deteriorating 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 size of 10 cm x 10 cm or 10 to 50 cm in the electrode direction, e.g. 40 cm, and a width of 15 to 120 cm.
For example, a 60 cm substrate (20 batches of 40 cm × 60 cm or 20 cm × 60 cm are provided) was used.

FIGS. 1 and 2 show a reactive gas introducing means and an exhaust means, which are provided with a supply nozzle and an exhaust nozzle, respectively, and a pair of electrodes ( 61), (51) or (62), (52) and reactive gas supply nozzles (17), (18) and exhaust nozzles (17 '), (18')
Was arranged. That is, the structures (39) and (39 ') in which the outside of the electrode is wrapped with a hood insulator. In order to confine the reaction space between the hoods, the outer periphery was surrounded by insulators (38) and (38 ').

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 (eg, a halogen lamp) is provided on the inner surface of the door. 13) and (13 ') are provided. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0013]

【Example】

[Embodiment 1] An embodiment of a plasma gas phase reaction apparatus of the present invention will be described with reference to FIGS. 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, a part of a plurality of reaction systems constituting a PIN junction is shown. That is, two of the three reaction systems (A, A) formed by laminating P, I and N type semiconductor layers.
C) and an example of a multi-chamber plasma gas phase reaction apparatus having a first preliminary chamber and a transfer buffer chamber (B). The systems A, B and C in the drawing are 2
Reaction vessels (101), (103) and buffer chamber (102)
), And a separation section (44), (45),
(46) and (47). Independently, the reactive gas supply nozzles (17) and (18) and the exhaust nozzle (17 '),
(18 ′), 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 (10
0) was provided, and two substrates (1) each having two surfaces to be formed were inserted from the door (42) to two surfaces of the substrate holder (2). Further, the holder (3) was disposed at a predetermined equidistant distance from each other by an outer frame jig (only the outer periphery is shown as (38), (38 ')). That is, the substrate having the surface to be formed is brought into contact with the substrate holder (2) on the back surface on which no film is formed,
Two substrates and a substrate holder were used as one holder (3), and were erected in an outer frame jig of an insulator with a gap of 6 cm ± 0.5 cm. As a result, 20 40 cm × 60 cm substrates could be simultaneously formed. Thus 55 cm high and 80 deep
The reaction space (6), (8) with a width of 80 cm is surrounded by insulators (39), (39 ') on the upper and lower sides, and the outer periphery is surrounded by insulating outer frame jigs (38, 38'). Surrounded.

The first preparatory chamber (100) was fully evacuated with the pressure regulating valve (71) fully opened, and evacuated by the vacuum pump (35) through the TP (86). After this, the pressure adjustment valve (72)
Fully open, open the gate valve (44) for separation from the reaction vessel (101) which has been pre-evacuated to 3 × 10 ^-8 torr or less by TP, and attach it to the outer frame jig (38). The held substrate 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 stored in the buffer chamber (102) in advance or simultaneously.
), The jig and the substrate (2) held in the buffer chamber (102) are placed in the second reaction vessel (103), and the substrate held in the second reaction vessel (103) is placed in the second reaction vessel (103). Although illustration is omitted in the buffer chamber (104),
The substrate and jig in the third reaction chamber can be moved by opening the gate valves (45), (46), and (47) to the second preliminary chamber on the outlet side. Thereafter, the gate valves (44), (45), (46) and (47) were closed.

That is, the movement of the gate valve is such that when the door (42) is opened at atmospheric pressure, the gate valves (44), (45), (46), (4)
7) is closed, and a plasma gas phase reaction is performed in each chamber. Conversely, when the door (42) is closed and the spare chamber (100) is sufficiently evacuated, the gate valves (44), (45), (46), and (47) are opened, The substrate and jig in each chamber have a mechanism for moving to the next chamber so that outside air does not enter the reaction chambers (101) and (102).

In the first reaction vessel (101) in the system A, P
The case where the mold semiconductor layer is formed by the PCVD method will be described below.
The reaction system A (including the reaction vessel (101)) was set to 0.01 to 10 torr, preferably 0.01 to 1 torr, for example, 0.08 torr. That is, when the pressure regulating valve is closed, the pressure in the reaction vessel (101) is 0.05 to 1 torr, and 1 × 10 ^-2 to
rr or less, generally 1 × 10 ⁻⁴ to 1 × 10 ⁻⁷ torr, and this degree of vacuum is achieved by rotating the TP (87). In addition, since the continuous exhaust TP is operated, it is possible to prevent, for the first time, the reverse diffusion of the polymerized oil of VP (36) and the reverse flow of exhaust air impregnated in oil, especially oxygen. .

The reactive gas was supplied from the doping system (50) of system A. That is, silane (SinH _{2n + 2} ) purified as silicide gas (24) and further filled in a stainless steel cylinder
n> 1, especially SiH ₄ or Si ₂ H ₆ silicon fluoride (SiF ₂ or
SiF ₄ ) was used. Here, ultra-high-purity silane that is easy to handle (purity 99.99%, but water and oxygenates are less than 0.1 PPM)
Was used.

In order to form SixC _1-x (0 <x <1) in this embodiment, DMS (dimethylsilane (SiH ₂ (CH ₃ ) ₂ purity 99.99%)) was used as the carbide gas (25). Silicon (Si
For xC _1−x 0 <x <1), boron as a P-type impurity was simultaneously mixed into the above-mentioned monosilane to a concentration of 0.5% and supplied together with the silane from (24).

If necessary, hydrogen (purity of 7 N or more) or nitrogen (purity of 7 N or more) was supplied from (23) when the reaction chamber was brought to atmospheric pressure. 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. Reactive gas is a holder (38)
The coating was supplied to the substrate (1) which was supplied into the cylindrical space (6) surrounded by the substrate and constituted the space. Further, electric energy, for example, 13.56 MHz, between the negative electrode (61) and the positive electrode (51).
The high-frequency energy (14) is added to cause a plasma reaction,
The reaction product was coated on the substrate. Substrate is 100 ~
It was heated to 400 ° C., for example 200 ° C., by the same means as the infrared heaters arranged before and after the reaction vessel (103) shown in FIG.

The infrared heater uses a near-infrared halogen lamp (emission wavelength: 1 to 3 μm) or a ceramic infrared heater (emission wavelength: 8 to 25 μ) and is surrounded by a holder in the reaction vessel. 200 ±
The temperature was set at 10 ° C, preferably within ± 5 ° C. Thereafter, as described above, the above-described reactive gas is introduced into this container,
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
Under the conditions of H ₆ / SiH ₄ = 0.5% and DMS / (SiH ₄ + DMS) = 10%, the average film thickness of this reaction system A is 30 to 300 {for example, about 100}.
As a thin film having a thickness of Eg = 2.05eVσ =
It was 1 × 10 ^{−6 to} 3 × 10 ⁻⁵ (Ωcm) ⁻¹ . Substrates are conductive substrates (stainless steel, titanium, aluminum, and other metals), semiconductors (silicon, germanium), insulators (glass,
An organic thin film) or a composite substrate (glass or a light-transmitting organic resin to which a light-transmitting conductive film, fluorine-added tin oxide,
A single conductive film such as ITO or a two-layer film in which SnO ₂ is formed on ITO was 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 produce a silicon carbide film to which boron as a P-type impurity was added to a thickness of about 100 °. Further, the gate (45) is opened on the substrate on which the first semiconductor layer is formed, and the substrate is moved to the buffer chamber (102) according to the above-described operation sequence, and the gate (4) is opened.
5) Closed. This buffer chamber (102) has 10 ^-8 torr in advance.
Thereafter, e.g., 4 * 10 < ^-1 > torr is evacuated by a cryopump (88).

This substrate was similarly transferred to the system C by the TP (89) into a reaction vessel maintained at 1 × 10 ⁻⁷ torr or less through opening and closing of the gate (46). That is, in the reaction system C in FIG. 1, ultra-high purity monosilane or disilane as a semiconductor reactive gas (water or silicon oxide, the concentration of oxides gases below 0.1 PPM) (28) than y, also, 10 ¹⁷ cm ^- To add boron of ³ or less, 0.5 with hydrogen, silane, etc.
B ₂ H ₆ diluted to 3030 PPM 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
(88). 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 of FIG. In the drawing, a rod-shaped halogen lamp was used for the lamp heaters (13) and (13 '). The reaction space was set at 100 to 400 ° C, for example 250 ° C, depending on the 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 ').
SiH in a thickness of 5000 Å ₄ 60 cc / min, the film forming rate 2.5 Å /
Sec, the substrate (20 sheets of 20 cm × 60cm, total area 24000 cm ²⁾
At 0.1 torr. When Si ₂ H ₆ was used, the film formation rate was 28 ° / sec.

Thus, in the first reaction chamber, a P-type semiconductor layer was formed by the plasma vapor phase method, and then an I-type semiconductor layer was formed by the PCVD method to form a PI junction. After the substrate C is formed to a thickness of about 7,000 ° by the system C, the substrate is transferred to the next buffer chamber (102) according to the above-described operation, and further transferred to the next reaction chamber and subjected to the same PCVD process. A type semiconductor layer was formed. This N-type semiconductor layer is supplied by silane with a phosphine of PH ₃ / SiH ₄ = 1.0% by a PCVD method and hydrogen of a carrier gas at a SiH ₄ / H ₂ = 20% by the PCVD method. A polycrystalline semiconductor layer having an N-type microcrystalline or fibrous structure is formed to a thickness of Si, and silicon carbide is further formed on the upper surface thereof with DMS / (SiH ₄ + DMS) = 0.1.
The N-type semiconductor layer represented by xC _1-x (0 <x <1) is
It is formed by laminating to a thickness of, for example, 50 mm. Other reactors are the same as in system A.

After such a step, the PI is moved out of the second spare room.
An ITO having a thickness of 100 to 1500 mm is further formed on the substrate formed by forming the N junction and a reflective or sublimable metal electrode such as an aluminum electrode is formed thereon to a thickness of about 1 μm by a vacuum evaporation method. (ITO + SnO ₂ ) surface electrode ─ (PI
N semiconductor) ─ (backside electrode). The characteristics as a photoelectric conversion device are as follows: 7 to 9%, 8% on average, as an intrinsic efficiency characteristic under the condition of AM1 (100 mW / cm ² ) on a substrate of 10 cm × 10 cm, and 40 cm × 60
Even with a glass substrate of cm, 5.5% could be obtained with an effective efficiency. As a result, the open circuit voltage of one element is 0.85 ~
0.9V (0.87 ± 0.02V), but short circuit current is 18 ± 2 mA
/ Cm ^2, and the FF is as large as 0.60 to 0.70, and the variation is small in the panel and in the batch, and it has been found that the method of the present invention is extremely effective industrially.

FIG. 3 shows a concentration distribution of oxygen and carbon impurities in a semiconductor in a 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 exhaust method of the conventional method using only a rotary pump or a mechanical booster pump,
Since the continuous exhaust type TP was not used, carbon contained a high concentration of impurities as shown by the curve (95) and oxygen by the curve (96).

In particular, for oxygen, 5 × 10 ¹⁹ to 2 × 10 ²⁰ cm ^-3
Had in the type semiconductor (92). The drawing is 5 × 10 ¹⁹ cm
^-3 oxygen. In addition, oil rotation port 4 × 10 ²⁰
cm ^-3 . The drawing is for a case having 1 × 10 ²⁰ cm ⁻³ . On the other hand, in the exhaust system as shown in the present invention, the carbon concentration has 1 × 10 ^{17 to} 5 × 10 ¹⁸ cm ⁻³ , and generally 1 × 10 ¹⁷
Contains only ¹⁸ cm ^-3 or less. In addition, oxygen is 5 × 10 ¹⁸ cm ^-3
It is preferably 1 × 10 ¹⁸ cm ⁻³ or less, and in FIG.
The case of × 10 ¹⁸ cm ^-3 is shown.

In FIG. 3, the aluminum of the back electrode 94 has oxygen of ^{3 to} 6 × 10 ²⁰ cm ^-3 . For this reason, this oxygen is used for SIMS (secondary ion analysis) (Kameka
In the measurement of (3F type), it is considered that the oxygen became background oxygen, and the oxygen in the N-type semiconductor (93) became 10 ¹⁸ to 10 ²⁰ cm ⁻³ . Furthermore, there are impurities due to the presence of oxygen in the P-type semiconductor and water contained in the DMS, and it is necessary to further reduce the oxygen concentration by purifying the starting material to 0.1% or less oxygen or oxide by purifying silane. Can be estimated. Regarding the type of semiconductor to be formed, not only Si but also Ge, SixC _1-x (0
<X <1, SixG _1-x (0 <x <1) SixSn _1-x (0 <x
<1) Even if it is a single layer or a multilayer,
It goes without saying that non-oxygenated compounds such as compound semiconductors such as As, GaAlAs, BP and CdS may be used.

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, where silicon nitride was converted to silane (Si
It is effective to form the film by a PCVD reaction between H ₄ or Si ₂ H ₆ ) and ammonia (NH ₃ ). The non-single-crystal semiconductor film formed by 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 type field effect semiconductor device. Furthermore, it is a PIN diode and the energy bandwidth is W
N─W (WIDE-NALLOW-WIDE) or SixC _1-x ─Si─SixC
_1-x (0 <x <1) structure PIN junction type visible light laser,
A light-emitting element or a photoelectric conversion device may be manufactured. In particular, a so-called W (P or N type) ─N (I type) (WIDE) having a heterojunction structure in which the energy band width on the light incident light side is increased.
It is possible to produce and stack different products not only of conductivity type but also of different types in each reaction chamber, and it is believed that this is extremely important industrially.

[0032]

According to the present invention, the separating portion is not limited to a gate valve, but is provided with two gate valves and one buffer chamber as a system 2 so that impurities of a P-type semiconductor can be introduced into an I-type semiconductor layer. It was effective to further prevent the contamination and 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, a part or all of the composite film may be formed by photo-CVD without plasma, LT CVD (also called HOMO CVD), or low-pressure CVD.

[Brief description of the drawings]

FIG. 1 shows an outline of an apparatus for producing a film for a plasma gas 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.

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 18, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Coating preparation method

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for producing a vapor phase reactive coating. According to the present invention, when producing a coating using a reactive gas, a non-oxide coating is produced by performing a gas phase reaction (hereinafter referred to as CVD) using a turbo molecular pump in an exhaust system. The present invention relates to a gas-phase reaction apparatus in which the amount of mixed oxygen is set to a concentration of 1 × 10 ¹⁹ cm ⁻³ or less and a method for manufacturing the same. The present invention, in the production of a non-oxygen coating, in order to prevent the backflow of the atmosphere from the exhaust system, an oil rotary rotary pump,
Instead of using only a discontinuous rotation type vacuum pump (hereinafter simply referred to as a vacuum pump or VP) such as a mechanical booster pump, a continuous evacuation type turbo-molecular pump (hereinafter simply referred to as a turbo-molecular pump or TP) is connected to a reaction vessel and a vacuum. The present invention relates to preventing the backflow of the atmosphere from the exhaust system by interposing between the pump and the pump.

[0002] The non-oxide film of the present invention, for example, non-single-crystal silicon is converted to a reactive gas of silane (Si _n H _{2n + 2} n ≧
When forming using 1), the amount of oxygen in the film is 5 × 10 ¹⁸ cm ⁻³ or less, preferably 1 × 10 ¹⁸ cm ^−3.
The purpose is to prevent backflow from the exhaust system in order to make it ⁻³ or less.

According to the present invention, such an exhaust system is provided by using TP as a reaction chamber and V
By interposing a pressure control valve during the reaction between P and P, the inside of the reaction chamber has a plasma gas phase reaction (PCVD, called light
A film is formed using VD (Photo CVD) or a method using both of them (hereinafter simply referred to as a CVD method), and 1 × 10 ⁻² below the pressure adjusting valve.
torr or less (generally 10 ⁻⁴ to 10 ⁻⁶ torr)
The reaction system is intended to form a film while maintaining the pressure at a pressure higher than that of the exhaust system (1 × 10 ⁻² torr or more, that is, 0.05 to 10 torr). .

Further, in this embodiment, a plurality of reaction chambers are connected to such a plasma CVD apparatus, and a P-type non-single-crystal semiconductor, an I-type non-single-crystal semiconductor and an N-type non-single-crystal semiconductor are formed on a substrate in each reaction chamber. The present invention relates to a method for manufacturing a semiconductor device that forms a PIN junction by laminating a semiconductor device.

[0005]

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 in an exhaust system and the like, and a higher degree of vacuum is generated. It was completely impossible to provide a TP or the like. However, the present inventor has proposed such PCVD
In the device, if the exhaust system is a VP alone, the VP makes a discontinuous rotational movement, so that the atmosphere (particularly oxygen) from the atmospheric exhaust system in contact with the air flows backward, and a part of this atmosphere is It has been found that they are mixed into oil and re-evaporated from there to cause a backflow 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 contained in the film.
It was mixed at a concentration of × 10 ^{19 to} 2 × 10 ²⁰ cm ⁻³ .

[0006] 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.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to prevent such disadvantages.

[0008]

According to the present invention, there is provided a method for manufacturing a semiconductor device by a CVD method.
When preparing a semiconductor coating, fill a stainless steel cylinder.
The charged silicide gas is introduced into the reaction chamber, and the reaction chamber is
Oxygen and carbon are reduced by SIM using a molecular pump.
5 × 10 ¹⁸ cm as measured by S (secondary ion analysis)
^Forming an I-type semiconductor film containing silicon at a concentration of ^-3 or less
This is a method for producing a film characterized by forming a film.

An embodiment of the present invention will be described below with reference to the drawings.
I do.

[00 10 ]

[Embodiment 1] In this embodiment , an outline of the apparatus is shown in FIG. That is, a doping system (50) for introducing a reactive gas.
The reaction vessel (51) has 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). )
A multi-chamber PCVD method in which respective reaction vessels are connected via a separation part (system B in the drawing) when a bond is formed on a substrate by laminating with a N-type semiconductor is proposed as shown in FIG. To be.

[00 11] This embodiment by forming the non-single-crystal semiconductor layer a hydrogen or halogen element is added, the recombination center density of small P, and the semiconductor layer having a conductivity type I and the N-type is formed, the laminate A PIN junction is formed at the boundary, and impurities from other adjacent semiconductor layers are prevented from being mixed into each semiconductor layer to prevent the junction characteristics from being degraded. In particular, the present invention relates to a plasma gas phase reaction for performing continuous production in which part of a semiconductor is not oxidized to form an interlayer insulator by exposure to oxygen.

[00 12] The present embodiment, in the plasma reaction method of a multi-chamber system in which multiple, interconnected as independently in each reaction such reaction vessel, simultaneously so mass production was increased the coating growth rate many substrates at a time About the method. In this embodiment, a substrate 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 (20 batches of 40 cm × 60 cm or 20 cm × 60 cm are provided) is used.

[00 13] In FIG. 1, FIG. 2, means for introducing reactive gases, an exhaust means, these supply nozzles, the exhaust nozzle is provided, the insulation inside by relatively than hood pair of electrodes (61 ), (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 ').

[00 14] In addition, shows a drawing showing a cross-section of FIG. 1 in FIG. 2, a door provided in front of the reaction vessel (the left side in the drawing) after (right side in the figure), the heating means by a halogen lamp or the like on the inner surface of the door (13) and (13 ') are provided .

[00 15] FIG. 1, an embodiment of a plasma gas phase reactor of the present embodiment will be described with reference to FIG. This drawing shows a PIN junction, PIP junction, NIN junction or PINPIN ...
A semiconductor on a substrate such as a PIN junction is formed of a semiconductor layer having a different main component or a different stoichiometric ratio from a semiconductor layer of a different conductivity type even though the semiconductor layer is of a different conductivity type. This is an apparatus for automatically and continuously forming a multilayer to be laminated without being affected (mixed) by the above.

Shows a part of a plurality of reaction systems that make up the PIN junction in [00 16] drawings. 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 separation parts (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.

[00 17] The apparatus first preliminary chamber to the inlet side (1
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').

[00 18] The first preliminary chamber (100) and fully opening the pressure regulating valve (71) was evacuated by a vacuum pump (35) via a 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.

[00 19] In other words the movement of the gate valve, doors (42) when opened by the atmospheric pressure gate valve of the separation part (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).

[00 20] system showing a first 1 P-type semiconductor layer in the reaction vessel (101) in the following cases formed by a PCVD method in A. Reaction system A (including reaction vessel (101)) is 0.0
1 to 10 torr, preferably 0.01 to 1 torr, for example, 0.08 torr. That is, the pressure in the reaction vessel (101) is set to 0.05 to 1 t by closing the pressure regulating valve.
orr, and below this valve is 1 × 10 ⁻² torr.
In general, it is 1 × 10 ⁻⁴ to 1 × 10 ⁻⁷ torr, and this degree of vacuum is achieved by rotating the TP (87). In addition, since the continuous exhaust type TP is operated, it is possible to prevent, for the first time, the reverse diffusion of the polymerized oil of VP (36) and the reverse flow of the exhaust air impregnated in the oil, particularly oxygen. .

[00 21] reactive gas doping system of the 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.
nH _{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).

[00 22] in this embodiment _{SixC 1-x (0 <x} <1)
To form DMS (dimethylsilane (SiH ₂ (CH ₃ ) ₂ ) purity 99.99 as a carbide gas (25).
%). Silicon carbide (SixC _1-x 0 <x <
Regarding 1), boron as a P-type impurity is simultaneously mixed into the above-mentioned monosilane to a concentration of 0.5% (2).
4) Supplied with silane.

[00 23] If necessary, when the atmospheric pressure and the reaction chamber with hydrogen (or purity 7N) or nitrogen (or purity 7N) (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 (61 ' ).
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.

[00 24] The infrared heater, using near infrared halogen lamp (emission wavelength 1～3Myu) heater or far-topical ceramic heater (emission wavelength 8～25Myu), cylindrical surrounded by the holder in the reaction vessel 20 spaces
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 = 2.05 eV
σ = 1 × 10 ^{−6 to} 3 × 10 ⁻⁵ (Ωcm) ⁻¹ . Substrate is a conductive substrate (stainless steel, titanium, aluminum, other metal), semiconductor (silicon, germanium), insulator (glass, organic thin film) or composite substrate (glass or translucent organic resin, translucent conductive film) (A single-layer conductive film made of tin oxide or ITO to which fluorine is added, or a two-layer film in which SnO ₂ is formed on ITO). 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.

[00 25] Thus by 1 to 5 minutes plasma vapor reaction, it was prepared to a thickness of about 100Å silicon carbide film which boron is added as a P-type impurity. 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, for example, 4 × 10 ⁻¹ torr by a cryopump (88).

[00 26] Similarly TP on the substrate system C (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.
(28) y in the reaction system C, ultra-high-purity monosilane or disilane is used as a semiconductor reactive gas (the concentration of water, silicon oxide, or oxide gas is 0.1 PPM or less).
Further, in order to add boron of 10 ¹⁷ cm ⁻³ or less, B ₂ H ₆ diluted to 0.5 to 30 PPM with hydrogen, silane, or the like is used according to (27), and a carrier gas is added as necessary (26). ). 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.

[00 27] outlining the Figure 2. 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 '). _SiH 4 to a thickness of 5000Å 6
0 cc / min, film formation rate 2.5Å / sec, substrate (20 c
The pressure was set to 0.1 torr with 20 m × 60 cm sheets having a total area of 24000 cm ² ). When Si ₂ H ₆ is used,
It had a film formation rate of 28 ° / sec.

[00 28] Thus I by a PCVD method on the formation of the P-type semiconductor layer by plasma vapor phase method in the first reaction chamber
A PI junction was formed by forming a mold semiconductor layer. Also after a thickness of about 50 Å in system C, in accordance with the operation substrates described above, is transferred next to the buffer chamber (10 4), further similar PCVD process was transferred to the reaction chamber of the adjacent Thus, an N-type semiconductor layer was formed. This N-type semiconductor layer has a phosphine of PH ₃ / SiH ₄ =
1.0% silane and hydrogen of the carrier gas were converted to SiH ₄
/ H ₂ = 20% and supplied in a manner similar to
A polycrystalline semiconductor layer having an N-type microcrystalline or fibrous structure is formed to a thickness of 00 °, and furthermore, on its upper surface, silicon carbide is DMS / (SiH ₄ + DMS) = 0.1 and SixC _1-x It is formed by laminating N-type semiconductor layers represented by (0 <x <1) to a thickness of 10 to 200 °, for example, a thickness of 50 °. For other reactors, use system A
Is the same as

[00 29] Following this step, P out from the second preliminary chamber
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 with a substrate of 10 cm × 10 cm, AM1 (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.

[00 30] Figure 3 shows the oxygen and the concentration distribution of the impurity in the carbon in the semiconductor in the PIN type photoelectric conversion device made 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.

[00 31] particularly ^{oxygen, 5 × 10 19 ~2 × 10} 20
cm ^-3 in the type I semiconductor (92). The drawing shows a case where oxygen of 5 × 10 ¹⁹ cm ⁻³ is included.
In addition , the drawing is for a case having 1 × 10 ²⁰ cm ⁻³ of 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 curve
Preferably 5 × ¹⁰ 18 ^{cm -3} or less, as shown by (97) is 1 × ¹⁰ 18 ^{cm -3} or less, 2 in FIG. 3
A case of × 10 ¹⁸ cm ⁻³ is shown.

[00 32] In FIG. 3, has a oxygen 3~6 × ¹⁰ 20 ^{cm -3} in the aluminum back electrode (94). For this reason, this oxygen becomes background oxygen in the measurement of SIMS (secondary ion analysis method) (using a 3F type of Kameka), and the oxygen in the N-type semiconductor (93) is 10 ¹⁸ to 10 ²⁰ cm ^−3. It is thought that it has become. Furthermore, there are impurities due to the presence of oxygen in the P-type semiconductor and water contained in the DMS, and the oxygen concentration is further reduced by purifying the silane starting material to 0.1% or less oxygen or oxide. The possibility of this can be estimated. Regarding the type of semiconductor to be formed,
In addition to Si, the others are Ge, SixC _1-x (0 <
x <1, SixG _1-x (0 <x <1) SixSn
_1-x (0 <x <1) It may be a single layer or a multilayer, or a non-oxygenated compound such as a compound semiconductor such as GaAs, GaAlAs, BP, and CdS. .

[00 33] This example shows the PCVD method in a multi-chamber system using three reaction vessels. But this is 1
Where two silicon nitrides were converted to silane (SiH ₄ or Si ₂ H ₆ ) and ammonia (N
It is effective to form it by a PCVD reaction with H ₃ ). The non-single-crystal semiconductor film formed in the present embodiment is used for N (source) I in an insulated gate type field effect semiconductor device.
(Channel forming region) N (drain) junction or PIP
It is also effective for joining. Furthermore, it is a PIN diode having an energy bandwidth of WNW (WIDE-N
ALL0W-WIDE) or SixC1 _-x- Si-
A PIN junction type visible light laser, light emitting element, or photoelectric conversion device having a SixC _1-x (0 <x <1) structure may be manufactured. In particular, a so-called W (P or N type) -N having a heterojunction structure in which the energy band width on the light incident light side is increased.
(I type) (WIDE TO NALLOW) and not only the conductivity type in each reaction chamber but also different products can be produced and laminated independently, which is extremely important industrially. I believe there is.

[00 34] In this embodiment, the separation unit is not merely gate valves, the mixing of the I-type semiconductor layer of the P-type semiconductor impurity provided with two gate valves and one buffer chamber as a system 2 It was effective to further prevent and improve the characteristics.

[00 35] It is needless to say that application of Burazuma CVD apparatus of this embodiment in a single chamber or multi-chamber system having another structure.

Example of [00 36] The present invention is a multi-chamber system shown in FIG. 1, PCVD at all of the reaction vessel
Act supplied. However, if necessary, a part or all of the composite film may be formed by photo-CVD without plasma, LT CVD (also referred to as HOMO CVD), or low-pressure CVD.

[0037]

According to the present invention, oxygen and carbon are converted to SIMS
5 × 10 ¹⁸ cm as measured by (secondary ion analysis)
^Forming an I-type semiconductor film containing silicon at a concentration of ^-3 or less
Could be achieved.

[Brief description of the drawings]

FIG. 1 shows an outline of an apparatus for producing a film for a plasma gas 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 sources (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) First reaction chamber reaction space (8) Second reaction chamber reaction space (7) (9) Buffer chamber space (71) (72) ( 73) (74) pressure control valve (86) (87) (88) (89 Turbomolecular pump (34) (35) (36) (37) Vacuum pump

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 3

Claims (1)

[Claims] When a semiconductor film is formed by a CVD method, a silicide gas filled in a stainless steel cylinder is introduced into a reaction chamber, and the reaction chamber is depressurized using a turbo-molecular pump so that oxygen and carbon are reduced by SIMS. A method for producing a film, comprising forming an I-type semiconductor film containing silicon having a concentration of 5 × 10 ¹⁸ cm ⁻³ or less as measured by (secondary ion analysis).