JPH0811828B2 - Deposited film formation method - Google Patents

Description

The present invention relates to a functional film, particularly a semiconductor device, a photosensitive device for electrophotography, an optical input sensor for an optical image input device, an image pickup device, a device, and a photovoltaic device. The present invention relates to a method for forming a functional deposited film which is useful for applications of electronic devices such as power devices.

[Conventional technology]

Conventionally, amorphous or polycrystalline functional films such as a semiconductor film, an insulating film, a photoconductive film, a magnetic film, and a metal film have been individually formed from the viewpoints of desired physical properties and applications. The method has been adopted.

Vacuum deposition method, plasma CVD method, thermal C method
The VD method, the optical CVD method, the reactive sputtering method, the ion plating method, and the like have been tried, and in general, the plasma CVD method is widely used and commercialized.

However, since the deposited film obtained by these deposited film forming methods is required to be applied to electronic devices and optoelectronic devices that require higher functions, electrical and optical characteristics and repeated use are required. There is room for further comprehensive improvement in fatigue characteristics or operating environment characteristics, and in terms of productivity and mass productivity including uniformity and reproducibility.

FIG. 3 shows an example of a conventional apparatus for forming a deposited film by the plasma CVD method.
Is a film forming chamber as a film forming space, and the substrate support 30 inside
Place the desired substrate 303 on top of 2.

304 is a heater for heating the substrate, which is supplied with power through the conducting wire 305 to generate heat.

Reference numerals 306 to 309 denote gas supply sources, which are provided according to the types of gas of a silicon-containing compound, hydrogen, a halogen compound, an inert gas, and a compound containing an impurity element as a component. When using a liquid form of these raw material compounds in the standard state, an appropriate vaporizer is provided. In the figure, gas supply sources 306 to 309 are denoted by a, a branch pipe b is attached to a flow meter, c is attached to a pressure gauge for measuring the high pressure side of each flow meter, d or The symbol e is a valve for adjusting the flow rate of each substrate. The gas of the raw material compound is introduced into the film forming chamber 301 through the introduction pipe 310.

311 is a plasma generator, which is a plasma generator 3
The plasma from 11 acts on the source gas flowing in the direction of the arrow to excite and decompose the acted compound, and the decomposed compound chemically reacts to form an amorphous deposited film on the substrate 303. To do. Reference numeral 312 is an exhaust valve, and 313 is an exhaust pipe, which is connected to an exhaust device (not shown) for evacuating the film forming space.

When a deposited film of, for example, a-Si: H is formed using such an apparatus, an appropriate substrate 303 is placed on the support 302, and an exhaust device (not shown) is used to form the film through an exhaust pipe. Membrane room 301
The inside is evacuated and the pressure is reduced.

Then, if necessary, the substrate is heated, and a raw material gas such as SiH ₄ and Si ₂ H ₆ is introduced from the gas supply cylinder into the film formation chamber 301 through the gas introduction pipe 310, and the pressure inside the film formation chamber is set to a predetermined value. While maintaining the pressure, plasma is generated in the film forming chamber 301 by the plasma generator to form an a-Si: H film on the substrate 303.

By the way, conventional deposited films, for example, those obtained by the plasma CVD method are considered to be satisfactory because of their excellent property development, but even so, the electrical deposition required for a firm establishment of the product is required. , Optical and photoconductive characteristics, fatigue resistance after repeated use, points of use environment characteristics, points of stability and durability over time, and points of homogeneity as a whole. It is still in a state where there is still a solution.

The cause is not that the target deposited film can be obtained by a simple layer deposition operation, not to mention the materials used, but it requires a great deal of skill and ingenuity in the process operation during the process. .

By the way, for example, in the case of the so-called CVD method, so-called impurities are mixed after diluting the gas material, and then 500 to 650 ° C.
Since it undergoes thermal decomposition at high temperatures, precise process operation and control are required to form the desired deposited film, which makes the device complicated and costly. It is extremely difficult to constantly obtain a deposited film product which is homogenized and has the desired characteristics as described above, and thus is difficult to be adopted on an industrial scale.

Further, as described above, even in the plasma CVD method which is generally widely used as the optimum method, there are some problems in process operation and also problems in capital investment. Regarding the process operation, the conditions are more complicated than the above-mentioned CVD method, and it is difficult to generalize it. That is, for example, the basic 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 rate, and the parameters of the interrelationship of the plasma generation method are already many. There are other parameters, and there are other parameters as well, and in order to obtain a desired product, a strict selection of parameters is required, and the parameters are strictly selected. If one of the above-mentioned constituent factors, in particular, it is plasma and becomes unstable, the formed film is significantly adversely affected and cannot be realized as a product. As for the device, since strict selection of parameters is required as described above, the structure is naturally complicated, and it is designed to respond to individually selected parameters if the device scale and type change. Must.

For these reasons, the plasma CVD method is considered to be the most suitable method at the moment, but from the above, if the desired deposited film is mass-produced, a large amount of equipment investment is required for the device. By the way, since the process control items for mass production are many and complicated, the process control allowable range is narrow, and the device adjustment is also subtle,
In the end, there are problems such as making the product considerably expensive.

On the other hand, the above-mentioned various kinds of devices have been diversified, and the element members therefor, that is, the requirements such as the various characteristics described above are generally satisfied, and the application target and the application are suitable.
And in some cases, it is a large area, and it is a social requirement that a stable deposited film product is constantly supplied at a low cost, and a method of satisfying this requirement,
There are situations in which the development of devices is eagerly awaited.

[Object of the Invention]

The present invention solves the above-mentioned problems and solves the above-mentioned problems in a conventional device for forming a deposited film used in a photovoltaic device, a semiconductor device, an image input line sensor, an imaging device, an electrophotographic photosensitive device, and the like. The purpose is to satisfy.

That is, the main object of the present invention is that electrical, optical, and photoconductive properties are substantially always stable without depending on almost any use environment, have excellent light fatigue resistance, and can be used repeatedly. Provided is a deposited film forming method for forming a uniform and improved deposited film which does not cause deterioration phenomenon, has excellent durability and moisture resistance, and does not cause a problem of residual potential. Especially.

Another object of the present invention is to improve various characteristics of a film to be formed, film formation rate, reproducibility, and uniformize and homogenize the film quality, and is suitable for increasing the area of the film, thereby improving the productivity of the film. Another object of the present invention is to provide a method of forming a deposited film that can be easily mass-produced.

[Constitution and effect of the invention]

The present inventor has overcome the above-mentioned problems of the conventional device and has conducted extensive studies to achieve the above-mentioned object.
A gaseous raw material for forming a deposited film and a gaseous halogen-based oxidant that oxidizes the raw material are introduced into the reaction space and brought into contact with each other to chemically generate a precursor in an excited state, Forming a desired deposited film over a large area over a substrate existing in a film formation space with the precursor as a supply source of the deposited film component efficiently, while maintaining uniform film thickness and film quality. We have developed a method that can do it.

That is, the method of the present invention comprises a discharge port for discharging SiH ₄ , which is a gaseous raw material, which is alternately arranged in the film formation space, and a discharge for discharging F _2, which is a gaseous halogen-based oxidizer that oxidizes SiH _4. The SiH ₄ and the F ₂ are respectively introduced from the outlet and exhausted in the opposing direction from the outlet through the substrate for forming the deposited film from the outlet together with 0.001 Torr to 100 To.
The precursor is chemically generated by contacting the SiH ₄ and the F ₂ with each other at rr, and the precursor is then placed 5 mm to 15 cm from the outlet as a source of a deposition component. Another feature is a method for forming a deposited film that forms a silicon deposited film on the substrate.

When a gaseous raw material for forming a deposited film of the present invention and a gaseous halogen-based oxidizer that oxidizes the raw material are introduced into a reaction space, if they are circular, they are adjacent to each other. The distance from the other outlet, the flow rate of the raw material or the halogen-based oxidizer, the pressure in the reaction space and the like are appropriately determined in relation to the film forming factors, but the diameter is preferably 0.01 to 100 mm,
It is more preferably 0.05 to 50 mm, and most preferably 0.1 to 20 mm. Similarly, when the outlet is elliptical, its minor axis is preferably 0.01 to 50 mm, more preferably
0.05 to 20 mm, optimally 0.1 to 10 mm and short diameter (R)
And the length ratio (R / L) of the long diameter (L) is preferably 1/1 to 1/10
000, more preferably 1/2 to 1/1000. Similarly, when the outlet is slit-like, the slit width is preferably 0.01 to 50 mm, more preferably 0.05 to 50 mm.
20 mm, optimally 0.1 to 10 mm is desirable. The slit length is preferably 1 mm or more, more preferably 5 mm.
As described above, it is optimally set to 10 mm or more.

In the present invention, a gaseous raw material for forming a deposited film and a gaseous halogen-based oxidant having an oxidizing action on the raw material are provided in a row in which discharge ports are introduced in the lateral direction, Alternatively, in the case of arranging a plurality of rows in the horizontal direction and the vertical direction, the distance between the adjacent outlets is appropriately determined in relation to the film forming factors such as the flow rate of the raw material and the halogen-based oxidant and the pressure in the reaction space. However, the distance between the ends of the discharge port is preferably 50 mm or less, more preferably 20 mm or less, optimally 10 mm.
The following is desirable. In the case of radial arrangement, it is desirable that at least two rows or more, preferably three rows or more, and three or more rows, preferably four or more rows, are arranged outwardly from the center and in the circumferential direction.

In the present invention, when the material of the outlet used is metal, stainless steel, Al, Cr, Mo, Au, Pt, Nb, Ta, V, Ti, Fe, P
In the case of resin such as d, Ni-Cr, polyester, polyethylene, polycarbonate, cellulose acetate,
In the case of ceramics such as polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, etc., Al ₂ O ₃ , SiO ₂ , BeO, MgO, ZrO ₂ , SiC, TiC, ZrC, BN, Al
N, Si ₃ N _{4 and the} like can be mentioned. Preferably, Al and stainless steel are used in terms of workability and corrosion resistance.

In the present invention, when a plurality of gas discharge ports are arranged,
For the purpose of improving the gas mixing ratio, the types of gas discharged from the respective discharge ports may be regularly discharged alternately, or may be discharged in groups of two, three, and a plurality, or with irregularity.

Since the method of the present invention as described above does not have the opportunity to generate an electric discharge in the film forming space, that is, the reaction chamber, the deposited film formed is adversely affected by ion damage or other abnormal discharge action. Never receive.

Further, according to the deposited film forming method of the present invention, energy saving as well as large area, film thickness uniformity, and film quality uniformity are sufficiently satisfied to simplify management and mass production, and to be applied to a mass production apparatus. It does not require a large capital investment, the management items for its mass production are clarified, the management allowance range is wide, and the adjustment of the device is easy.

In the present invention, the above-mentioned gaseous raw material and gaseous halogen-based oxidant may be those that are brought into a gaseous state when introduced and contacted, and in the usual case, they may be gas or liquid. It does not matter if it is solid.

When the raw material for forming the deposited film or the halogen-based oxidizer is liquid or solid, a carrier gas such as Ar, He, N ₂ or H ₂ is used, and bubbling is performed while adding heat as necessary. Then, the raw material for forming the deposited film and the halogen-based oxidizing agent are introduced into the reaction space in a gaseous state.

At this time, the partial pressure and mixing ratio of the gaseous raw material and the gaseous halogen-based oxidant are adjusted by adjusting the flow rate of the carrier gas or the vapor pressure of the raw material for forming the deposited film and the gaseous halogen-based oxidant. Is set.

As the raw material for forming the deposited film to be used, for example, if a tetrahedral deposited film such as a semiconductor or electrically insulating silicon deposited film or a germanium deposited film is obtained, a linear or branched Chain silane compounds,
Cyclic silane compounds and chain germanium compounds can be cited as effective compounds.

Specifically, as a linear silane compound, SinH ₂ n + 2
(N = 1,2,3,4,5,6,7,8), SiH ₃ SiH (SiH ₃ ) SiH ₂ SiH ₃ as a branched chain silane compound, and SinH ₂ n (as a cyclic silane compound. n = 3,4,5,6), and the chain germane compound includes GemH ₂ m + 2 (m = 1,2,3,4,5). In addition to this, for example, if you want to create a deposited film of tin
Tin hydride such as SnH ₄ can be cited as an effective raw material.

Of course, these raw materials can be used not only as one kind but also as a mixture of two or more kinds, but in the present invention, SiH ₄ is used.

The halogen-based oxidant used in the present invention is gasified when introduced into the reaction space, and is effective only by contacting with a gaseous source material for forming a deposited film which is simultaneously introduced into the reaction space. F ₂ , C
Halogen gas such as l ₂ , Br ₂ and I ₂ , nascent fluorine, chlorine and bromine can be mentioned as effective ones.
F ₂ is used in the present invention.

These halogen-based oxidants are gaseous, and are introduced into the reaction space at a desired flow rate and supply pressure together with the gas of the raw material for forming the deposited film, and are mixed and collided with the raw material. By efficiently oxidizing the raw material, a plurality of kinds of precursors including a precursor in an excited state are efficiently generated. The excited state precursors and other precursors that are produced serve as a source for at least one of the constituents of the deposited film, one of which is formed.

The produced precursor decomposes or reacts to become a precursor in another excited state or a precursor in another excited state, or releases energy as necessary, but forms a film as it is. By touching the surface of the substrate arranged in the space, a deposited film having a three-dimensional network structure is formed when the substrate surface temperature is relatively low, and a crystalline deposited film is formed when the substrate surface temperature is high.

In the present invention, the deposited film forming process proceeds smoothly, and a film having high quality and desired physical properties can be formed. The combination, the mixing ratio of these, the pressure at the time of mixing, the flow rate, the internal pressure of the film forming space, the gas flow type, and the film forming temperature (base temperature and atmospheric temperature) are appropriately selected as desired. These film forming factors are organically related, and are not determined individually but are determined according to each other under mutual relation. In the present invention, the ratio of the amounts of the gaseous raw material substance for forming a deposited film and the gaseous halogen-based oxidant introduced into the reaction space is related to the film forming factors related to the above film forming factors. It is appropriately determined as desired, but the introduction flow rate ratio is preferably 1/20 to 100/1, more preferably 1/5 to 50.
It is preferable to be set to / 1.

The pressure at the time of mixing when introduced into the reaction space is preferably higher in order to stochastically enhance the contact between the gaseous raw material and the gaseous halogen-based oxidant, but the reactivity is taken into consideration. Then, it is preferable to appropriately determine the optimum value as desired. The pressure at the time of mixing is determined as described above, but the pressure at each introduction is preferably 1 ×
It is desirable that the pressure is 10 ⁻⁷ atm to 5 atm, more preferably 1 × 10 ⁻⁶ atm to 2 atm.

The pressure in the film-forming space, that is, the pressure in the space in which the substrate on which the film is to be formed is arranged, depends on the precursor (E) in the excited state generated in the reaction space and in some cases. The precursor (D) derived from the precursor (E) is appropriately set as desired so that it effectively contributes to film formation.

The internal pressure of the film formation space is the pressure introduced into the reaction space between the base material for forming a deposited film and the gaseous halogen-based oxidant when the film formation space is open and continuous with the reaction space. In relation to the flow rate and the flow rate, it is possible to make adjustments by adding, for example, differential exhaust or using a large exhaust device.

Alternatively, when the conductance at the connection between the reaction space and the film formation space is small, an appropriate exhaust device may be provided in the film formation space, and the pressure in the film formation space may be adjusted by controlling the exhaust amount of the device. I can do it.

Further, when the reaction space and the film formation space are integrally formed and the reaction position and the film formation position are spatially different from each other, differential evacuation is performed as described above, or a large size with sufficient evacuation capacity is provided. It suffices if an exhaust device is provided.

As described above, the pressure in the film formation space is determined by the relationship between the gaseous raw material introduced into the reaction space and the introduction pressure of the gaseous halogen oxidizing agent, and is preferably 0.001 T
Orr to 100 Torr, more preferably 0.01 Torr to 30 Torr, most preferably 0.05 to 10 Torr.

Regarding the gas flow type, when the raw material for forming the deposited film and the halogen-based oxidant are introduced into the reaction space, these are uniformly and efficiently mixed, and the precursor (E) is efficiently mixed. It is necessary to design in consideration of the geometrical arrangement of the gas introduction port and the substrate gas exhaust port so that the film can be properly formed and the film can be properly formed. Specifically, it is preferable to dispose the base material at a position opposed to the direction in which the raw material capable of forming the base material and the gaseous halogen-based oxidizing agent are introduced into the reaction space.

The substrate temperature (Ts) at the time of film formation is individually set as desired according to the type of gas used, the number of kinds of deposited film to be formed, and the required characteristics. When the film of (1) is obtained, the temperature is preferably from room temperature to 450 ° C, more preferably 50 to 400 ° C. In particular, when forming a crystalline deposited film having better semiconductor properties and photoconductivity, the substrate temperature (Ts) is preferably 300 to 700 ° C.

As the ambient temperature (Tat) of the film forming space, the generated precursor (E) and the precursor (D) do not change into chemical species unsuitable for film formation, and the precursor (E) is efficiently generated. ) Is produced as desired in relation to the substrate temperature (Ts).

The substrate used in the present invention may be conductive or electrically insulating as long as it is appropriately selected according to the intended use of the deposited film to be formed. As the conductive substrate, for example, NiCr, stainless steel, Al, Cr, Mo, Au, I
Examples thereof include metals such as r, Nb, Ta, V, Ti, Pt and Pd or alloys thereof.

As the electrically insulating substrate, a film or sheet of synthetic resin such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene and polyamide, glass, ceramics and the like are usually used. Preferably, at least one surface of these electrically insulating substrates is subjected to a conductive treatment, and another layer is provided on the conductive-treated surface side.

For example, in the case of glass, the surface is NiCr, Al, Cr, Mo, A
u, Ir, Nb, Ta, VTi, Pt, Pd, In ₂ O ₃ ,, SnO ₂ ,, ITO (In ₂ O ₃ + SnO ₂ )
Conductive treatment by providing a thin film such as NiC, if it is a synthetic resin film such as polyester film
r, Al, Ag, Pb, Zn, Ni, Au, Cr, Mo, Ir, Nb, Ta, V, Ti, Pt, etc. are processed by vacuum evaporation, electron beam evaporation, sputtering, etc. The surface of the laminate is subjected to a conductive treatment by laminating. The shape of the support may be any shape such as a cylindrical shape, a belt shape, a plate shape, and the shape is determined as desired.

The substrate is preferably selected from the above in consideration of adhesion and reactivity between the substrate and the film. Further, if the difference between the two thermal expansions is large, a large amount of strain is generated in the film, and a film of good quality may not be obtained. Is preferred.

Further, since the surface condition of the substrate is directly related to the structure (orientation) of the film and the generation of a cone-shaped structure, it is necessary to treat the surface of the substrate so as to have a film structure and a film structure with desired characteristics. Is desirable. In order to increase the uniformity of film quality and film thickness, the substrate may be subjected to movement such as rotation and vibration in the film forming space in addition to the use of the gas discharge port according to the present invention.

The deposited film forming apparatus used in the method of the present invention will be described below with reference to the drawings.

FIGS. 1 (1) to (12) show a raw material substance used in the above-mentioned deposited film forming apparatus, which can be made into a gaseous state for forming a deposited film, and a gaseous halogen system having a property of oxidizing the raw material substance. FIG. 2 is a schematic view seen from the outlet side when the outlets for the oxidizing agent are alternately arranged, and FIG. 2 shows an example of an apparatus suitable for embodying the deposited film forming method of the present invention. is there.

In FIGS. 1 (1) to (12), 101 is a discharge port of a raw material substance that can be made into a gaseous state for forming a deposited film, and 102 is a discharge port of a gaseous halogen-based oxidant. And are alternately arranged as indicated by the diagonal lines. However, 10
Even if 1 is used as the emission port of the gaseous halogen-based oxidant and 102 is used as the emission port of the raw material for forming the deposited film, the quality of the deposited film that is essentially obtained does not change. Reference numeral 103 denotes the distance between the ends of the outlet 101 and the outlet 102.

FIG. 1 (1) is a case where circular ones are arranged in a horizontal row without a gap, and FIG. 1 (2) is a case where circular ones are arranged in a horizontal row with a distance 103, and FIG. 1 (3) is Fig. 1 (4) shows the case where the elliptical shapes are arranged in a horizontal row without a gap, and the oval shapes are arranged in a horizontal row with a distance 103.
Figure (5) shows the slit-shaped ones arranged vertically with no gaps, and Fig. 1 (6) shows the slit-shaped ones arranged vertically with a distance 103 between them. Circular ones arranged radially with a distance 103, Fig. 1 (8) ones arranged circularly, Fig. 1 (9) shows a circular one radially arranged with a distance 103, Moreover, when the products discharged in the circumferential direction are arranged differently, Fig. 1 (10) shows the slit-like ones arranged radially, and Fig. 1 (11) shows the circular ones vertically and horizontally. FIG. 1 (12) shows the case where the slit-shaped ones are arranged in the lateral direction without a gap, when they are arranged without a gap in the direction. The example shown here is only one example, and the arrangement of the outlets can be changed according to the desired size of the substrate.

The deposited film forming apparatus shown in FIG. 2 is roughly divided into three parts: an apparatus main body, an exhaust system and a gas supply system.

The apparatus main body is provided with a reaction space and a film formation space.

201 to 105 are cylinders filled with gas used for film formation, 201a to 205a are gas supply pipes,
201b-205b are mass flow controllers for adjusting the flow rate of gas from each cylinder, 201c-205c are gas pressure gauges, 201d-205d and 201e-201e are valves, and 201f-
201f is a pressure gauge showing the pressure in the corresponding gas cylinder.

Reference numeral 222 denotes a vacuum chamber having a structure in which a gas introducing pipe is provided in an upper part thereof and a reaction space is formed in the downstream of the pipe, and the substrate 22 faces the gas outlet of the pipe.
It has a structure in which a film formation space in which a substrate holder 214 is provided so that 0 is set is formed. The pipe for gas introduction is
One of the arrangement structures shown in FIGS. 1 (1) to (12) is adopted, and the gas from the gas cylinders 101 and 102 is introduced into the first gas introduction pipe 213 and the gas from the gas cylinders 203 to 205. It has the 2nd gas introduction pipe introduced, and the 1st gas introduction pipe and the 2nd gas introduction pipe are arranged by turns.

Gas supply from the cylinder to each inlet pipe is made by gas supply pipelines 223 and 224, and further gas distributor 21
It is distributed by 0,211 and is led to each gas introduction pipe.

The gas introduction pipes, the gas supply pipelines, and the vacuum chamber 222 are vacuum-exhausted by a vacuum exhaust device (not shown) via the main vacuum valve 221.

The substrate 220 is installed at a desired distance from the position of each gas introduction pipe by moving the substrate holder 214 up and down.

In the case of the present invention, the distance between the substrate and the gas outlet of the gas inlet pipe is in an appropriate state in consideration of the type of deposited film to be formed and its desired characteristics, gas flow rate, internal pressure of the vacuum chamber, etc. However, it is preferably several mm to 20.
cm, more preferably about 5 mm to 15 cm.

215 is for heating the substrate 220 to an appropriate temperature during film formation,
Alternatively, the substrate 220 may be preheated before film formation, or further,
It is a heater for heating the substrate, which is heated to anneal the film after the film is formed.

Electric power is supplied to the substrate heater 215 from a power supply 217 via a lead wire 216.

218 is a thermocouple for measuring the temperature of the substrate temperature (Ts) and is electrically connected to the temperature display device 219.

 Hereinafter, the present invention will be specifically described with reference to Examples.

Example 1 Using the film forming apparatus shown in FIG. 2, a deposited film was prepared by the method of the present invention as follows.

The gas outlets are of a type arranged in a horizontal row as shown in FIG. 1 (1). The gas introduction pipes 212, 213 are circular and have a diameter of 5 mm, and 65 pieces are arranged in a horizontal row.

SiH ₄ gas filled in the cylinder 201 at a flow rate of 20 sccm, through the gas introduction pipe 213, F ₂ gas filled in the cylinder 203 at a flow rate of 5 sc cm, He gas filled in the cylinder 204 at a flow rate of 20 sc cm. It was introduced into the vacuum chamber 222 through the gas introduction pipe 212.

At this time, the pressure in the vacuum chamber 222 is adjusted to the vacuum valve 2
I adjusted the opening and closing degree of 21 to 0.9 Torr. Quartz glass (30 cm x 1 cm) was used as the substrate, and the distance between the gas inlets 212 and 213 and the substrate was set to 3 cm. Pale white emission was strongly observed in the mixed region of SiH ₄ gas and F ₂ gas. The substrate temperature (Ts) was set to 250 ° C.

When gas was flowed for 3 hours in this state, a Si: H: F film having a film thickness as shown in Table 1 was deposited on the substrate.

In addition, the unevenness of the film thickness distribution was within 3% in both the vertical and horizontal directions. The characteristics were also uniform. It was confirmed by electron beam diffraction that the formed Si: H: F film was amorphous.

On this amorphous Si: H: F film, a comb-shaped electrode of Al (gap length)
200 μm) was vapor-deposited to prepare a sample for conductivity measurement.
Each sample was placed in a vacuum cryostat, a voltage of 100 V was applied, the current was measured with a micro ammeter (YHP4140B), and the dark conductivity (σd) was obtained. Also, irradiate with light of 600 nm, 0.3 mw / cm ² ,
The photoconductivity (σp) was determined. Furthermore, the optical bandgap (Eg opt) was obtained from the absorption of light. These results are shown in Table 1.
It was shown to.

Examples 2 to 12 The same film forming apparatus as in Example 1 was used, the gas flow rate, pressure, etc. were kept constant, and the gas discharge ports had the shapes shown in FIGS. 1 (2) to (12), respectively. The substrate was made of quartz glass and had the dimensions shown in Table 1, and the deposited films were formed using the dimensions shown in Tables 1 to 3. The results are shown in Tables 1 to 3.

A deposited film having very uniform film thickness unevenness and characteristics over the entire surface of the substrate was obtained.

[Effect] From the above detailed description and each example, according to the deposited film forming method of the present invention, it is possible to achieve energy saving and at the same time easily control the film quality and to obtain a deposited film having uniform physical characteristics over a large area. can get. Further, it is possible to easily obtain a film which is excellent in productivity and mass productivity, and which is high in quality and excellent in physical properties such as electrical, optical and semiconductor properties.

[Brief description of drawings]

FIG. 1 is a schematic diagram of the discharge ports for the raw material and the halogen-based oxidizing agent used in the examples of the present invention. FIG. 2 is a schematic diagram of a film forming apparatus used in the examples of the present invention. FIG. 3 is a schematic diagram of a conventional film forming apparatus by the plasma CVD method. 101,102 ...... Gaseous source material discharge port and gaseous halogen-based oxidizer discharge port 103 …… Distance between discharge ports 201 to 205 …… Gas cylinder 201a to 205a …… Gas inlet pipe 201b to 205b …… Mass flow Meters 201c to 205c …… Gas pressure gauges 201d to 205d, 201e to 205e …… Valves 201f to 205f …… Pressure gauges 210,211 …… Gas distributors 212,213 …… Gas introduction pipes 214 …… Base body holders 215 …… Base body heaters 216 ... Lead wire 217 ... Power supply 218 ... Thermocouple for substrate temperature motor 219 ... Temperature display device 220 ... Substrate 221 ... Vacuum exhaust valve 222 ... Vacuum chamber 301 ... Deposition chamber 302 ... Substrate support 303 ... Base 304 ... Base heating heater 305 ... Conductor 306 to 309 ... Gas supply source a ... Branch pipe, b ... Flow type, c ... Pressure gauge d, e ... Valve 310 ... Raw material Gas inlet pipe 311 ... Plasma generator 312 ... Exhaust valve 313 ... Exhaust pipe respectively And wrinkle.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isamu Shimizu 2-41-21 Fujigaoka, Midori-ku, Yokohama-shi, Kanagawa Prefecture (56) References Shokai 56-15818 (JP, U)

Claims (6)

[Claims] 1. A discharge port for discharging SiH ₄ , which is a gaseous source material, which is alternately arranged in a film forming space, and a discharge port for discharging F _2, which is a gaseous halogen-based oxidizing agent that oxidizes SiH _4. From the SiH ₄ and the F ₂ , respectively, while holding the film forming space at 0.001 Torr ~ 100 Torr by exhausting in the opposite direction from the discharge port through the substrate for deposition film formation together with the introduction, A precursor is chemically generated by contacting SiH ₄ and F _2, and the precursor is then placed on the substrate placed 5 mm to 15 cm from the outlet as a source of the deposited film constituent. A method for forming a deposited film, which comprises forming a silicon deposited film. 2. The deposited film forming method according to claim 1, wherein the SiH ₄ emission port and the F ₂ emission port are circular, elliptical, or slit-shaped. 3. The deposited film forming method according to claim 1, wherein the SiH ₄ emission ports and the F ₂ emission ports are alternately arranged in a row in a lateral direction. 4. The deposited film forming method according to claim 1, wherein the SiH ₄ emission ports and the F ₂ emission ports are alternately arranged in a horizontal direction and a vertical direction. 5. The deposited film forming method according to claim 1, wherein the SiH ₄ emission ports and the F ₂ emission ports are alternately arranged in a radial pattern. 6. The deposited film forming method according to claim 1, wherein the materials of the SiH ₄ emission port and the F ₂ emission port are made of metal, resin, or ceramics.