JPH0770487B2 - Deposited film forming equipment - Google Patents

Description

The present invention relates to a functional film, in particular, an electronic device such as a semiconductor device, a photosensitive device for electrophotography, an optical input sensor device for an optical image input device, and the like. The present invention relates to a deposited film forming apparatus useful for applications.

[Prior art and its problems]

2. Description of the Related Art Conventionally, as a semiconductor element, one having a semiconductor layer composed of an amorphous material having silicon atoms as a base material, so-called amorphous silicon (hereinafter, referred to as “a-Si”) on a substrate is known. There is.

Several methods have been proposed for forming an a-Si film that constitutes a semiconductor layer of such a semiconductor device, such as a vacuum deposition method, an ion plating method, a reactive sputtering method, a thermal CVD method, a plasma CVD method, and an optical CVD method. Among them, the plasma CVD method is put to practical use as an optimum method, and is generally widely known.

By the way, the conventional semiconductor layer composed of a-Si, for example, is obtained by the plasma CVD method, and although it is said that it has satisfactory characteristic expression and is satisfactorily satisfied, even if it is, it is possible to obtain a firm product. All the electrical, optical and photoconductive characteristics required for establishment, fatigue resistance characteristics after repeated use, points of use environment characteristics, points of stability and durability over time, and points of further homogeneity. There is still a problem to solve the problem of satisfying the above. The cause is not that the target semiconductor layer can be obtained by a simple layer deposition operation, not to mention the material used, but it requires a great deal of skill and ingenuity in the process operation during the process. .

Incidentally, for example, in the case of the so-called thermal CVD method, the so-called impurities are mixed after diluting the silicon-based gas material, and then 500
Since it decomposes at a high temperature of ~ 650 ° C, the desired a
-Since the formation of Si film requires precise process operation and control, the equipment becomes complicated and the cost becomes considerably high. It is extremely difficult to constantly obtain a semiconductor layer composed of a-Si, which is difficult to adopt on an industrial scale.

Further, as described above, even the plasma CVD method, which is generally widely used as the optimum method, has some problems in process operation and also problems in capital investment. Regarding the process operation, the conditions are more complicated than the above-mentioned thermal CVD method, and it is difficult to generalize. That is, for example, the parameters of the interrelation between the substrate temperature, the flow rate and flow rate of the introduced gas, the pressure at the time of layer formation, the high frequency power, the electrode structure, the structure of the reaction vessel, the exhaust speed, and the plasma generation method are already many. There are other parameters, and there are other parameters as well. Therefore, in order to obtain a desired product, a strict selection of parameters is required, and the parameters are strictly selected. One of the constituent factors, especially if it is a plasma and becomes unstable, the film formed is significantly adversely affected and cannot be realized as a product. As for the device, since the strict selection of parameters is required as described above, the structure naturally becomes complicated, and it is designed so that it can correspond to the individually selected parameters if the device scale and type change. Must. For these reasons, the plasma CVD method, although it has been considered to be the most suitable method at the present time, has the above-mentioned fact that the desired a-
Mass production of Si films requires a large amount of equipment investment for the equipment, and at that time, the process control items for mass production are many and complicated, the process control allowance is narrow, and the equipment adjustment is delicate. Therefore, in the end, there is a problem that the product is considerably expensive.

On the other hand, semiconductor elements have become diversified, satisfying the requirements such as the above-mentioned various characteristics as a whole, applicable contrast, suitable for the purpose, and in some cases, it has a large area, It is a social requirement that semiconductor elements having a semiconductor layer composed of a stable a-Si film be constantly supplied at a low cost, and there is a strong demand for development of a method and apparatus that meet this requirement. There is.

The same applies to other layers, for example, a layer made of an a-Si film containing at least one selected from oxygen atom, carbon atom and nitrogen atom.

[Object of the Invention]

The present invention forms a deposited film by removing the problems of the semiconductor layer and other deposited films formed by the conventional thermal CVD method or plasma CVD method, and a semiconductor device such as a photovoltaic device using the deposited film. The main object is to provide a deposited film forming apparatus that can be continuously manufactured.

That is, a main object of the present invention is to provide an apparatus capable of continuously forming a deposited film in a film forming space without passing through a plasma reaction.

Another object of the present invention is to simplify the management of film forming conditions and mass production of films while maintaining the characteristics of the formed film without increasing the plasma reaction in the film forming space and improving the deposition rate. It is an object of the present invention to provide an apparatus capable of continuously manufacturing semiconductor elements having a multi-layered structure, which can easily achieve the above.

[Means for solving problems]

In order to achieve the above object, the deposited film forming apparatus according to the present invention contacts a gaseous source material for forming a deposited film with a gaseous halogen-based oxidizer having a property of oxidizing the gaseous source material. By doing so, a plurality of types of precursors including excited state precursors are chemically generated, and at least one of these precursors is used as a source of the deposited film constituents to form the deposited film on the substrate. A deposition film forming apparatus for forming, comprising: a first introducing means for introducing the gaseous raw material and a second introducing means for introducing the gaseous halogen-based oxidant, which are connected in a circumferential shape. A plurality of film forming chambers, a substrate urging unit arranged on the center side of the plurality of circumferentially arranged film forming chambers, and a unit for moving the substrate into the plurality of film forming chambers And having.

Further, the plurality of film forming chambers are connected to the inside of the film forming chambers so that the substrates can sequentially pass therethrough.

[Explanation of action, etc.]

The present inventors, as a result of repeated studies to overcome the problems of the conventional semiconductor device and achieve the above-mentioned object,
A substance that contributes to the formation of a semiconductor layer of a semiconductor device,
Select a substance that does not form a deposited film in the energy state as it is and a substance that reacts with the substance and electronically oxidizes it (increases the oxidation number of atoms). When introduced into the simple reaction zone where the substrate is maintained at a temperature of ~ 300 ° C in the form of a gas through separate paths and brought into contact with each other in the upper space of the substrate surface, a chemical interaction occurs between the two. Then, the deposited film was formed extremely efficiently on the surface of the substrate without any formation of solid particles.

Moreover, it was confirmed that the deposited film was homogeneous and had excellent electrical and optical characteristics.
Furthermore, when the manufacture of a semiconductor element was attempted using the above method, a semiconductor element excellent in various characteristics such as electrical, optical characteristics, fatigue resistance, and operating environment characteristics was obtained, and this method has reproducibility. It was confirmed that the present invention was obtained, and further research was conducted based on these confirmed facts, and the present invention having the above-described structure was completed.

By the way, a typical example of a photovoltaic element, which is an example of a semiconductor element provided by the deposited film forming apparatus of the present invention, is shown in FIGS. 1 (A) to 1 (C).

That is, the example illustrated in FIG. 1 (A) is a photovoltaic element in which light irradiation is performed from the support side and can be applied to a solar cell.

In FIG. 1A, 101 is a support, 102 is a semiconductor layer (p type or n type), 103 is an i type semiconductor layer, 104 is a semiconductor layer (n type or p type), and 105 is a conductive layer. Show.

The example shown in FIG. 1 (B) has the same configuration as the example shown in FIG. 1 (A), but is a photovoltaic element of the type in which light irradiation is performed from the conductive layer side. It can also be applied to solar cells.

The example shown in FIG. 1 (C) has a photoconductive layer (i-type semiconductor layer), an insulating layer, and a metal layer on a support, and is a type of photovoltaic device in which light irradiation is performed from the metal layer side. It is a power device and can also be applied to a solar cell.

In FIG. 1C, 101 is a support, 103 is an i-type semiconductor layer, 106 is an insulating layer, and 107 is a metal layer.

In any of the formats shown in FIGS. 1 (A) to 1 (C), the shape of the support 101 is appropriately determined depending on the shape of the photovoltaic element to be formed. There are a cylindrical shape, a belt shape, a plate shape, and the like. The support 101 may be optically transparent or opaque, but in the case of the type in which the light irradiation shown in FIG. 1 (A) is performed from the support side, the support 101 is optically transparent. Made transparent.

The material of the support 101 may be conductive or electrically insulating. Examples of the conductive material include metals such as Al, Cr, Mo, Au, Ir, Nb, Ta, V, Ti, Pt, and Pd, or alloys of these Ni—Cr stainless steels.
Regarding electrically insulating materials, films or sheets of synthetic resin such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, etc., glass, ceramics, etc. are usually used. It It is preferable that at least one surface of these electrically insulating supports is subjected to a conductive treatment, and another layer is provided on the surface side subjected to the conductive treatment.

For example, in the case of glass, the surface is NiCr, Al, Cr, Mo, Au, I
Conductive treatment by providing a thin film of r, Nb, Ta, V, Ti, Pt, Pd, In ₂ O ₃ , SnO ₂ , ITO (In ₂ O ₃ + SnO ₂ ) or synthetic resin such as polyester film For film, NiCr, A
l, Ag, Pb, Zn, Ni, Au, Cr, Mo, Ir, Nb, Ta, V, Ti, Pt and other metals are processed by vacuum deposition, electron beam deposition, sputtering, etc., or laminated with the above metals. Then, the surface is subjected to conductive treatment. The thickness of the substrate is appropriately determined so as to obtain a desired photovoltaic element, but is usually 10 from the viewpoint of manufacturing the substrate, handling, mechanical strength and the like.
It is considered to be μ or more.

The semiconductor layer 102 in the photovoltaic device of the type shown in FIG. 1 (A) or FIG. 1 (B) is made of silicon atoms (Si).
And amorphous silicon containing either a hydrogen atom (H) or a halogen atom (X) [hereinafter, a-Si (H,
X). ] As a main material. And
When the semiconductor layer is a p-type that provides p-type conductivity, p-type impurities (hereinafter simply referred to as "semiconductor field")
It is called "p-type impurity". ) In particular. further,
As shown in FIG. 1 (A), in the case of a photovoltaic element of the type in which light irradiation is performed from the support side, the semiconductor layer 102
Is desirable to bring about a so-called window effect, and therefore, one or a band gap adjusting element such as carbon (C), oxygen (O), nitrogen (N) in a-Si (H, X) is used. Wide bandgap amorphous silicon including the above [hereinafter, a-Si (H, X) (C, O, N)
Say. ] As a main material and contains a p-type impurity.

On the other hand, when the photovoltaic element is of a type in which light irradiation is performed from the conductive layer side as shown in FIG. 1 (B), the semiconductor layer 102 is an n-type element that imparts n-type conductivity. Therefore, the semiconductor layer contains an n-type impurity (hereinafter simply referred to as “n-type impurity”) in the field of semiconductors.

In any of the above cases, the layer thickness of the semiconductor layer 102 is generally 30 to 5 × 10 ⁴ Å, preferably 50 to 5 × 10 ^4.
3 Å, and more preferably 50~1 × 10 ³ Å.

In addition, as described above, the p-type impurity contained when the semiconductor layer 102 is the p-type is a preferable example of an element of Group IIIA of the periodic table (hereinafter simply referred to as "Group III element"). B), Al, Ga, In, Tl, etc., among which B and Ga are most suitable.

The n-type impurities contained when the semiconductor layer 102 is of the n-type are, as a suitable example, N, P, As of an element of Group V group A (hereinafter simply referred to as “group V element”). , Sb, Bi, etc., among which As, P, Sb are most suitable.

These p-type impurities or n-type impurities are contained in the semiconductor layer 102 by being doped in the process of forming the layer, and the amount thereof is determined in consideration of factors such as desired electrical characteristics and optical characteristics. The p-type impurity is generally 3 × 10 ⁻² atomic% or less, and n
The type impurities are 5 × 10 ⁻³ atomic% or less.

The i-type semiconductor layer 103 in the photovoltaic device of the type shown in FIGS. 1A and 1B and the photoconductive layer 103 in the photovoltaic device of the type shown in FIG. It has a multi-bandgap multi-layered structure exhibiting photoconductivity that fully exerts the function of a power element, and contains silicon atoms and nitrogen (N) as a bandgap adjusting element.
And amorphous silicon nitrogen containing one of a hydrogen atom (H) and a halogen atom (X) [hereinafter a-SiN
(H, X). ] And a layer region of a-Si (H, X) and / or silicon atoms and germanium atoms (Ge)
And amorphous silicon germanium containing one of a hydrogen atom (H) and a halogen atom (X) [hereinafter,
It is called a-SiGe (H, X). ] It consists of a layer area.

The layer thickness of the i-type semiconductor layer 103 is set so that the functions of the i-type semiconductor layer and the functions of the p-type semiconductor layer and the n-type semiconductor layer are sufficiently and effectively exhibited, respectively. It is appropriately determined in consideration of the mutual layer thickness relationship, the relationship of the doping amount in the both layers, etc., but in a normal case, it is several times to several tens of times the layer thickness of the p-type semiconductor layer and the n-type semiconductor layer. Doubled.

As a specific value here, preferably 100Å ~ 1
The thickness is 0 μm, and more preferably 0.1 to 1 μm.

The semiconductor layer 104 is an n-type semiconductor layer in the photovoltaic element shown in FIG. 1 (A) and a p-type semiconductor layer in the photovoltaic element shown in FIG. 1 (B). Is. In either case, the main layer structure is a-Si (H, X), but in the format shown in FIG. 1 (B), it causes a so-called window effect, so that it is a wide band. It is composed of gapped a-Si (H, X) (C, O, N). As in the above case, the n-type impurity in the former case and the p-type impurity in the latter case
A type impurity is contained in each layer by being doped in the manufacturing process.

Regarding the wide bandgap of the layer structure of the semiconductor layer, normally, the p-type semiconductor layer is made to have a wide bandgap, but the p-type semiconductor layer is made to have such an n-type semiconductor layer. Of course, it is also possible. The degree of the wide band gap is preferably larger than that of the i-type semiconductor layer described above.

In the photovoltaic element shown in FIGS. 1A and 1B, the conductive layer 105 is made of a transparent or opaque conductive material. In particular, when the support 101 is opaque, light is generally irradiated from the conductive layer 105 side as shown in FIG. 1 (B), so that it is sufficient that the conductive layer is optically transparent or close to it. Required for efficiency.

In ₂ O ₃ , SnO ₂ , ITO (In
₂ O ₃ + SnO ₂ ) or a thin metal film of Pd, Pt, Cu, Ag, Au, Al or the like. As an opaque conductive material, most metal films such as NiCr, Al, Cr, Mo, Au, Ir, Nb, Ta, V, Ti, Pt, Pd, Z
n, Ag, etc. may be mentioned.

In the photovoltaic element shown in FIG. 1 (C), the support 10
Where 1 and photoconductive layer 103 are as described above,
For the metal layer 107, a metal having a large work function such as Au, Pt, or Pd is used to form a Schottky junction with the photoconductive layer 103. Such a metal layer 107 is formed on the photoconductive layer 103 by vacuum resistance heating evaporation or electron beam heating evaporation. Since the photoconductive layer 103 is irradiated with light through the metal layer 107, the thickness of the metal layer 107 is preferably 500 Å or less.

An insulating layer 106 is formed extremely thin (usually 2000 Å or less) to reinforce the barrier between the photoconductive layer 103 and the metal layer 107. The insulating layer 106 is not always necessary. The insulating layer 106 is
N _2, NH _3, NO, gas containing N such as NO _2, or O _2, gas containing O of CO ₂ or the like, and _{CF 4, C 2 F 6,} CH 4 gas containing C, such as It is formed as a wide bandgap layer formed by adding a precursor gas or a gaseous halogen-based oxidizing agent.

The photovoltaic element described up to the above example has excellent electrical and optical characteristics and excellent fatigue characteristics and use environment characteristics, and the photoelectric conversion efficiency is considerably higher than the conventional one. It is particularly suitable for use in solar cells.

Next, in the deposited film forming apparatus according to the present invention, the method for producing a photovoltaic element characterized by having the above-mentioned specific photoelectric conversion layer is a substance that contributes to the formation of the photoelectric conversion layer, and In the energy state, there is almost no or no formation of a deposited film, but when excited, a substance that produces the precursor that causes the formation of a deposited film (hereinafter referred to as "raw material (A)"). , A substance that interacts with the raw material substance (A) and electronically oxidizes it (increases the oxidation number of atoms) (hereinafter referred to as “oxidizing agent”), Introduced into the installed reaction field in the state of no electric field in a gas state through different paths respectively, and contact them in the upper space of the surface of the substrate to cause a chemical interaction between them, whereby the substrate Desired on the surface It is characterized in that the allowed to sequentially formed photoelectric conversion layer serving deposited films continuously separate deposition space.

That is, in the method of manufacturing a photovoltaic element using the deposited film forming apparatus of the present invention, since the discharge energy of plasma or the like does not act and the plasma reaction does not occur, the deposited film to be formed, that is, the photoelectric conversion layer is a film forming operation. It is not adversely affected by etching or other effects (for example, abnormal discharge) inside, and because photoelectric conversion layers etc. are continuously laminated in the separated deposition space, there is no mixing of impurities and it is dense. High quality deposited film structures can be obtained. In addition, the photoelectric conversion layer has excellent characteristics and high photoelectric conversion efficiency, and thus the photovoltaic device manufactured thereby has high quality.

Further, in the above-described method for manufacturing a photovoltaic element, a desired deposited film having a uniform film thickness and a uniform film thickness can be obtained only by introducing the raw material substance (A) and the oxidant into the reaction zone and bringing them into contact with each other. Since it enables the formation of a photoelectric conversion layer), it is easy to manage the operation process and uses a small amount of energy, and the equipment investment is much smaller than the conventional one. It will enable the mass production.

The gaseous raw material (A) in the method of the present invention is activated by being chemically contacted with a gaseous oxidant and receiving an oxidizing action by the oxidant to be activated, which is a supply source of the deposited film (photoelectric conversion layer) constituent element. It is a substance that produces a substance, that is, a precursor, and may be kept in a gaseous state when it comes into contact with a gaseous oxidizing agent. Therefore, it does not necessarily have to be gaseous before use and may be liquid or solid.
If the raw material (A) is liquid or fixed before use, A
A carrier gas such as r, He, N ₂ and H ₂ is used, and bubbling is performed while applying heat as necessary to introduce gas into the system by bubbling.

On the other hand, the oxidizing agent has a property of activating the raw material substance (A) to be an excited state substance, that is, a film formation precursor by the oxidizing action caused by the contact with the gaseous raw material substance (A). And specific examples thereof are air, oxygen,
Oxygen such as ozone Compounds of oxygen or nitrogen such as N ₂ O ₄ , N ₂ O ₃ and N ₂ O, peroxides such as N ₂ O ₂ and halogens such as F ₂ , Cl ₂ , Br ₂ and I ₂ Examples include gas, nascent fluorine, chlorine, bromine, and the like.

This oxidant also needs to be kept in a gaseous state when it comes into contact with the gaseous precursor raw material. Therefore, they do not necessarily have to be gaseous before use,
It may be liquid or solid. If the oxidizing agent is a liquid or solid prior to use, similar to the precursor raw materials Ar, the He, N _2, using a carrier gas of H ₂ and the like, if necessary by performing bubbling with the addition of heat in the system Introduce into the form of gas.

The above-mentioned raw material (A) (in gaseous form) and the above-mentioned oxidant (in gaseous form) pass through separate flow paths, respectively, and both are in the reaction zone in which the substrate is installed, and in the upper part of the substrate surface. The raw material (A) is activated by being oxidized by the oxidant and activated by generating an excited state precursor by flowing into the film formation space and contacting by mixing and collision. It is introduced into the system by adjusting the supply pressure and the flow rate so that a deposited film is formed.

Further, the combination of the above-mentioned raw material substance (A) and the above-mentioned kind of the oxidizing agent is appropriately selected and used according to the kind of layer constituting the photoelectric conversion layer formed on the substrate for the photovoltaic element. .

That is, for example, for forming a p-type a-Si (O, C, N) (H, X) layer, SiH ₄ , Si is used as the above-mentioned raw material (A).
_In addition to compounds containing silicon such as silanes such as ₂ H ₆ , Si ₃ H ₈ and Si ₄ H ₁₀ and halogenated silanes such as SiH ₃ Cl, SiH ₃ F and SiH ₃ Br, N ₂ and NH Nitrogen compounds such as ₃ , H ₂ NNH ₂ , HN ₃ , NH ₄ N ₃ or hydrocarbon compounds such as CH ₄ , C ₂ H ₆ , C ₃ H ₈ , C ₂ H ₄ , C ₃ H ₆ C ₂ H ₂ B, which is a raw material for introducing p-type impurities
₂ H ₆ , B ₄ H ₁₀ , B ₅ H ₉ , B ₅ H ₁₁ , B ₆ H ₁₀ , B ₆ H ₁₂ , Al (CH ₃ ) ₃ ; Al (C ₂
A compound containing a Group III atom such as H ₅ ) ₃ , Ga (CH ₃ ) ₃ and In (CH ₃ ) ₃ as a constituent element may be used. In addition, as the above-mentioned oxidant, halogen gas, halogen such as generation period (the above is referred to as “halogen-based oxidant”), O ₂ , O ₃ ,
At least one selected from N ₂ O ₄ , N ₂ O ₃ , and N ₂ O (the above are referred to as “oxygen-based and nitrogen-based oxidizers”) may be used.

For forming the i-type semiconductor layer composed of a-Si (O, C, N) (H, X), silicon such as silane or halogenated silane is used as the starting material (A). At least one selected from the compound, the above-mentioned nitrogen compound, and the above-mentioned carbon compound is used, and as the above-mentioned oxidizing agent, a halogen-based oxidizing agent and / or an oxygen-based, nitrogen-based oxidizing agent may be used. For forming the n-type a-Si (H, X) layer,
A silicon compound such as silane or halogenated silane is used as the above-mentioned raw material (A), and a raw material for introducing n-type impurities such as PH ₃ , P ₂ H ₄ , AsH ₃ , SbH ₃ , BiH ₃ A compound containing a group V atom as a constituent element may be contained. or,
As the above-mentioned oxidant, a halogen-based oxidant such as halogen gas or halogen in the nascent stage may be used.

Furthermore, a p-type, i-type, or n-type semiconductor layer is formed of a-Si.
In the case of using a film composed of Ge, the raw material (A) for introducing germanium atoms may be used in addition to the raw material (A) used for forming each semiconductor layer. Examples of raw materials (A) include GeH ₄ , GeH ₆ , and Ge
_A linear germanium compound such as ₃ H ₈ , Ge ₄ H ₁₀ or Ge ₅ H ₁₂ can be used.

By the way, in the method for manufacturing a photovoltaic device of the present invention, a film-forming process proceeds smoothly, high quality, desired electrical and optical characteristics, and high photoelectric conversion efficiency are obtained. Therefore, the gaseous raw material (A) is combined with the type of the gaseous oxidant, and the mixing ratio of these, the pressure at the time of mixing, the flow rate, the pressure in the film forming space, the flow rate of the carrier gas, the film forming temperature, the gas It is necessary to appropriately select the flow pattern and the like as desired. Further, various factors in these film formations are organically related and are not determined individually, but need to be determined in consideration of mutual relations. The ratio of substance (A) and gaseous oxidant is
The introduction flow rate ratio is preferably 1/20 to 100/1, more preferably 1/5 to 50/1. The ratio of the amounts of the gaseous raw material for introducing p-type impurities or n-type impurities and the gaseous raw material (A) is preferably 1/10 ^{6 in} terms of the introduction flow rate ratio.
~ 1/10, more preferably 1/10 ⁵ ~ 1/20, optimally 1/10 ⁵ ~
1/50 is preferable. Further, the pressure at the time of mixing the gaseous raw material (A) and the gaseous oxidant is preferably higher in order to increase the probability of chemical contact, but is preferably determined in consideration of reactivity, Preferably 1 × 10 ⁻⁷ to 10
Atmospheric pressure, more preferably 1 × 10 ^{−6 to} 3 atmospheric pressure is desirable.

The pressure in the film formation space, that is, the pressure in the space in which the substrate on which the film is formed is disposed, is derived from the excited state precursor generated in the reaction space and, in some cases, the precursor. It is appropriately set as desired so that the precursors that are generated in an effective manner can effectively contribute to the film forming process.

When the film formation space is openly continuous with the reaction space, the internal pressure of the film formation space is such that the gaseous source material (A) and the gaseous substance for introducing p-type impurities or n-type impurities, and the gaseous oxidation. The relationship with the introduction pressure and the flow rate in the reaction space with the agent can be adjusted by, for example, adding differential exhaust or using a large exhaust device.

Alternatively, when the conductance of the connecting portion between the reaction space and the film formation space is small, an appropriate exhaust device is provided in the film formation space,
The pressure in the film formation space can be adjusted by controlling the exhaust amount of the apparatus.

In addition, when the reaction space and the film formation space are integrated and the film formation positions at the reaction positions are spatially different, differential evacuation as described above or a large size with sufficient evacuation capacity is performed. The exhaust device may be provided.

As described above, the pressure in the film formation space is the relationship between the gaseous source material (A) introduced into the reaction space, the gaseous substance for introducing p-type impurities or n-type impurities, and the introduction pressure of the gaseous oxidant. However, preferably 0.001 Torr to 100 To
rr, more preferably 0.01 Torr to 30 Torr, optimally 0.
05Torr to 10Torr is desirable.

Regarding the gas flow type, these are uniformly and efficiently introduced when the gaseous raw material (A), the p-type impurity or n-type impurity introduction gaseous substance and the gaseous oxidant are introduced into the reaction space. It must be designed in consideration of the geometrical arrangement of the gas inlet, the substrate, and the gas outlet so that the precursors can be efficiently mixed and the film formation can be performed properly without any trouble. .

The substrate temperature at the time of film formation is individually set as desired according to the type of gas used and the type of the deposited film to be formed and the required characteristics, but when obtaining an amorphous film Preferably from room temperature to 450 ° C, more preferably 50 to 400
It is desirable to set the temperature to 70 ° C, optimally 70 to 350 ° C.

As the ambient temperature of the film forming space, the precursor to be generated and the precursor derived from the precursor do not change to those unsuitable for film formation, and the precursor is efficiently generated, It is appropriately determined as desired in relation to the substrate temperature.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing an embodiment of a deposited film forming apparatus according to the present invention. However, here, as an example, pi
The case where the functional layers of the photoelectric conversion layer of the n-type photovoltaic element are continuously formed is shown.

The device shown in FIG. 2 comprises a top wall, a cylindrical side wall and a bottom wall,
Three film forming chambers formed by a partition wall for separating a space surrounded by the upper and cylindrical side walls and the bottom wall into three chambers, and a source gas is introduced into the film forming chambers. And a gas exhaust pipe for exhausting gas in the film forming chamber.

In the figure, 201 to 203 are film forming chambers for forming photoelectric conversion layers, and 201a to 201c are raw materials for introducing raw material gases for forming photoelectric conversion layers into the film forming chambers 201, respectively. Gas introduction pipes, 202a to 202c, respectively, a raw material gas introduction pipe for introducing a raw material gas for forming a photoelectric conversion layer into the film forming chamber 202,
203a ~ 203c is a raw material gas introduction pipe for introducing a raw material gas for forming the photoelectric conversion layer into the film forming chamber 203, respectively, the raw material gas introduction pipes 201a ~ 201c, 202a ~ 202c, 203a ~ 20c
3c is connected to a source gas supply system including a source gas cylinder (not shown), a gas flow rate adjusting device (not shown), a valve (not shown), and the like. 201d is an exhaust pipe for exhausting the gas in the film forming chamber 201, and 202d and 202d 'are the film forming chamber 202.
An exhaust pipe for exhausting the gas inside, 203d is the film forming chamber 203
It is an exhaust pipe for exhausting the gas inside, and is connected to an exhaust system including a rotary pump (not shown), a turbo molecular pump (not shown), and the like. The substrate 211 conveyed from the feed roller 210 is supported by the substrate supporting rollers 220a to 220i and sequentially passes through the film forming chambers 201, 202 and 203,
It is wound by the winding roller 212. The base 211
Is heated to a desired temperature by the heater 230 for heating the substrate.

First, a belt-shaped stainless steel plate having a thickness of 0.7 mm is used as a base body 211, and the base body 211 is used as a feed roller 210 and a base body supporting roller.
220a to 220i and winding roller 212 are used to form film forming chambers 201, 2
It was continuously conveyed to 02,203. Further, the inside of the film forming chambers 201, 202 and 203 was sufficiently exhausted by using a rotary pump (not shown) or a turbo molecular pump (not shown).

Next, the base material 211 was heated to 250 ° C. and held by the heater 230.

Then, first, in the film forming chamber 201, SiH ₄ gas is used as a gaseous source material, PH ₃ gas is used as an n-type impurity introducing source material, and F ₂ gas is used as a gaseous halogen-based oxidant.
A type a-Si: H: F: P semiconductor layer was formed.

That is, SiH ₄ gas was introduced into the film forming chamber 201 at a flow rate of 2 SCCM through the gas introduction pipe 201a, and PH ₃ / He gas (PH ₃ concentration of 5000 ppm) at 10 SCCM through the gas introduction pipe 201c.

When the flow rate of each gas became stable, the pressure in the film forming chamber 201 was adjusted and set to 0.8 Torr. In this state, ₂ sccm of F ₂ gas filled in the cylinder was introduced into the film forming chamber 201 through the gas introduction pipe 201b. As described above, approximately
An n-type a-Si: H: F: P semiconductor layer having a film thickness of 500Å was formed.

Next, the substrate 211 is moved, and in the film forming chamber 202, only SiH ₄ gas is used as a gaseous raw material and F ₂ gas is used as a gaseous oxidant to form the i-type a-Si on the n-type semiconductor layer. : H: F
Layers were formed.

That is, SiH ₄ gas with a flow rate of 20 SCCM is introduced into the gas introduction pipes 202a, 202a
It is introduced into the film forming chamber 202 via c, and the flow rate of F ₂ gas is 2SCC.
M was introduced into the film forming chamber 202 through the gas introduction pipe 202b, and the internal pressure was set to 0.8 Torr. In this way, the thickness is about 5000Å
The i-type a-Si: H: F layer semiconductor was formed.

Finally, in the film forming chamber 203, SiH is used as a gaseous raw material.
₄ and CH ₄ gas, B ₂ H ₆ / He gas (B ₂ H ₆ concentration of 3000 ppm) as a p-type impurity introduction source substance, and F ₂ gas as a gaseous halogen-based oxidant, A p-type a-SiC: H: F: B semiconductor layer was formed on the type semiconductor layer.

That is, B ₂ H ₆ / He gas at 10 SCCM through the gas introduction pipe 203a, SiH ₄ and CH ₄ gas at 20 SCCM through the gas introduction pipe 203c, each introduced into the film forming chamber 203, at a stable position. The pressure inside the film forming chamber 203 was set to 0.8 Torr. F _{2 in} this state
Gas was introduced into the film forming chamber 203 through the gas introducing pipe 203b with 2 SCCM to form a p-type a-SiC: H: F: B semiconductor layer having a thickness of about 300Å.

As described above, the n-type, i-type and p-type semiconductor layers were continuously formed on the base 211 and wound on the winding roller 212. A 1 cm × 1 cm partial body was cut out from the substrate on which the photoelectric conversion layer was wound by the winding roller, and p
A 1000Å SnO ₂ film was formed on the type semiconductor layer by a thermal CVD method to obtain a pin solar cell having a layer structure shown in FIG. 1 (B).

When the solar cell thus obtained was examined, each of the layers formed on the substrate had uniform film quality and film thickness, and had excellent quality.

Next, in this solar cell, AM-1100mW / cm ² from the glass substrate side.
When exposed to the light of, the open circuit voltage is 0.9V, the short circuit current is 18mA / c.
The solar cell characteristics of m ² and conversion efficiency of 9% were obtained.

〔The invention's effect〕

As described in detail above, the deposited film forming apparatus according to the present invention has a plurality of film forming chambers, the plurality of film forming chambers are connected to each other, and are arranged in a circumferential shape. At
The gaseous raw material (A) and the gaseous oxidant having a property of oxidizing the gaseous raw material (A) are introduced into the film forming chamber through different paths to bring them into chemical contact with each other. Thus, the deposited film is continuously formed without the plasma reaction.

Therefore, for example, the deposition space for controlling impurities and the deposition space for forming a film into which impurities are not introduced can be separated, and continuous film formation can be performed in a vacuum state. It is possible to easily obtain a laminated structure of uniform quality and excellent quality.

For example, when manufacturing a pin type photovoltaic element, p
Layers, i layers, and n layers are each provided with three separate deposition spaces, and the substrate successively passes through these deposition spaces to form a photoelectric conversion layer having a pin structure. And a photovoltaic device having excellent characteristics.

Further, since the plurality of film forming chambers are circumferentially arranged around the substrate urging means, it is possible to concentrate the substrate heating means in one place for the plurality of film forming chambers, which is effective for energy saving. It is something. The device according to the invention also has the advantage that it requires a very small installation space.

Further, the deposited film forming apparatus according to the present invention can achieve the simplification of the management of the film forming conditions and the mass production while maintaining the characteristics of the deposited film and improving the film forming speed.

[Brief description of drawings]

1 (A) to 1 (C) are schematic configuration diagrams each showing a typical example of a photovoltaic element, and FIG. 2 is a schematic configuration diagram showing one embodiment of a deposited film forming apparatus according to the present invention. is there. 101 is a support, 102 to 104 are semiconductor layers forming a photoelectric conversion layer, 105 is a conductive layer, 106 is an insulating layer, 107 is a metal layer, 201, 20
2, 203 is a film forming chamber, 201a to 201c, 202a to 202c, 203a to 203c are gas introduction pipes, 201d, 202d, 202d ', 203d are exhaust pipes, 210 is a feed roller, 211 is a substrate, 212 is a take-up roll, 220a. ~twenty two
Reference numeral 0i is a substrate supporting roller, and 230 is a substrate heating heater.

Claims (2)

[Claims] 1. A plurality of precursors in an excited state are produced by bringing a gaseous raw material for forming a deposited film into contact with a gaseous halogen-based oxidant having a property of oxidizing the gaseous raw material. A deposited film forming apparatus for chemically forming a precursor of a seed, and forming a deposited film on a substrate by using at least one precursor of these precursors as a supply source of a deposited film constituent, A plurality of film forming chambers, which are arranged in a circumferential connection, and which are provided with a first introducing means for introducing a gaseous raw material and a second introducing means for introducing the gaseous halogen-based oxidant, Forming a deposited film, comprising: a substrate urging unit arranged on the center side of a plurality of film forming chambers arranged in a circumferential shape; and a unit for moving the substrate into the plurality of film forming chambers. apparatus. 2. The deposited film forming apparatus according to claim 1, wherein the plurality of film forming chambers are connected to each other so that the substrate can pass therethrough sequentially.