JPH0645884B2 - Deposited film formation method - 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 method for forming a semiconductor deposited film which is useful for applications.

[Conventional technology]

Hitherto, a functional film, particularly an amorphous or polycrystalline semiconductor film, has been formed by a film forming method which is individually suitable from the viewpoint of desired physical characteristics and intended use.

For example, amorphous or polycrystalline non-single-crystal silicon (hereinafter referred to as "NON-Si (H)" in which unpaired electrons are compensated with a compensating agent such as a hydrogen atom (H) or a halogen atom (X), if necessary. ，
X) ”, and in particular,“ A—Si (H, X) ”indicates amorphous silicon, and“ poly-Si (H, X) ”indicates polycrystalline silicon. A silicon-based deposited film such as a film (it is needless to say that microcrystalline silicon, which is commonly called, is in the category of A-Si (H, X)), is formed by a vacuum deposition method, Plasma CVD method,
A thermal CVD method, a reactive sputtering method, an ion plating method, an optical CVD method and the like have been tried, and in general, a plasma CVD method is widely used and commercialized.

[Problems to be Solved by the Invention] However, a reaction process in forming a silicon-based deposited film by a plasma CVD method which has been conventionally generalized is as follows.
It is considerably complicated as compared with the conventional CVD method, and its reaction mechanism is often unknown. In addition, there are many parameters for forming the deposited film (for example, substrate temperature, flow rate and ratio of introduced gas, forming pressure, high frequency power, electrode structure, reaction vessel structure, exhaust speed, plasma generation method, etc.). Due to the combination of many parameters, the plasma was sometimes in an unstable state and had a considerable adverse effect on the formed deposited film. In addition, the parameters peculiar to the device must be selected for each device, which makes it difficult to generalize the manufacturing conditions.

On the other hand, in order to develop a silicon-based deposited film that can sufficiently satisfy the electrical and optical characteristics for each application, it is currently best formed by the plasma CVD method.

However, depending on the application of the silicon-based deposited film, it may be necessary to achieve a large area, film thickness uniformity, and film quality uniformity for mass production with reproducibility.
In forming a silicon-based deposited film by the VD method, a large amount of capital investment is required for mass production equipment, the management items for mass production are complicated, the control allowance is narrow, and the adjustment of equipment is delicate. From these, these are pointed out as problems to be improved in the future.

Further, in the case of the plasma CVD method, since plasma is directly generated by a high frequency wave or a microwave in the film formation space in which the substrate to be formed is arranged, electrons and a large number of ion species are generated. Causes damage to the film during the film formation process and causes deterioration of film quality and nonuniformity of film quality.

A method proposed as an improvement on this point is an indirect plasma CVD method.

In the indirect plasma CVD method, plasma is generated by microwaves or the like at an upstream position away from the film formation space, and the plasma is transported to the film formation space to selectively use chemical species effective for film formation. It is measured so that it can be done.

However, even in such a plasma CVD method, since transport of plasma is essential, the lifetime of the chemical species effective for film formation must be long, and naturally, the gas species used is limited,
Various deposited films cannot be obtained, a large amount of energy is required to generate plasma, and the generation and amount of chemical species effective for film formation are essentially not placed under simple control. The problem remains.

In contrast to the plasma CVD method, the photo CVD method is advantageous in that it does not generate ion species or electrons that damage the film quality and film quality, but there are not so many types of light sources, and the wavelength of the light source is large. Is also deviated to the ultraviolet region, a large light source and its power source are required for industrialization, and a window for introducing the light from the light source into the film formation space is covered during the film formation and the film is formed during film formation. There is a problem that the amount of light decreases, and in other words, the light from the light source does not enter the film formation space.

As described above, in the formation of the silicon-based deposited film, the points to be solved still remain, and energy saving can be achieved with a low-cost device while maintaining its practicable characteristics and uniformity. It is earnestly desired to develop a mass-production forming method. In particular, when forming a p-type, n-type, or i-type conduction type semiconductor film while increasing the doping rate, the degree of the above requirement is high. These are other functional membranes,
For example, semiconducting silicon nitride film, silicon carbide film,
A silicon-based film such as a silicon oxide film and a germanium-based film can be mentioned as similar problems to be solved.

〔Purpose〕

An object of the present invention is to eliminate the above-mentioned drawbacks of the deposited film forming method, and at the same time provide a novel deposited film forming method which does not depend on the conventional forming method.

Another object of the present invention is to provide a deposited film forming method capable of obtaining a semiconductor deposited film doped with a valence electron control agent having a uniform property over a large area in order to save energy and to easily control film quality. It is provided.

Still another object of the present invention is to provide a deposited film forming method which is excellent in productivity and mass productivity, and which can easily obtain a film having high quality and excellent physical properties such as electrical, optical and semiconductor properties. is there.

[Means for solving problems]

The deposited film forming method of the present invention which achieves the above-mentioned object is a gaseous raw material for forming a deposited film, a gaseous halogen-based oxidizing agent having a property of oxidizing the raw material, and a valence electron control agent. A gaseous substance (D) containing a component as a constituent element is introduced into the reaction space and chemically contacted with each other to generate a plurality of precursors including a precursor in an excited state, and at least one of these precursors is generated. The present invention is characterized in that a deposited film is formed on a substrate in a film formation space by using one precursor as a supply source of a deposited film constituent.

[Action]

According to the above-described 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 used in 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 deposited film forming method of the present invention, the gaseous substance (D) containing a gaseous raw material substance for forming a deposited film and a component serving as a valence electron control agent used as a constituent is a gaseous halogen-based oxidant. It is subjected to an oxidative effect by chemical contact with, and is appropriately selected according to the desired type, characteristics, intended use, etc. of the deposited film. In the present invention, the above-mentioned gaseous raw material, gaseous substance (D) and gaseous halogen-based oxidant may be those which are brought into a gaseous state during chemical contact, and in the usual case Can be gas, liquid or solid.

When the source material for forming the deposited film, the material (D) or the halogen-based oxidant is a liquid or a solid in the normal state, a carrier gas such as Ar, He, N ₂ or H ₂ is used, which is required. According to the above, bubbling is performed while also applying heat to introduce the raw material substance for forming the deposited film, the substance (D) and the halogen-based oxidant into the reaction space in a gaseous state.

At this time, the partial pressure and mixing ratio of the gaseous raw material, the gaseous substance (D) and the gaseous halogen-based oxidant are such that the flow rate of the carrier gas or the raw material for forming the deposited film and the gaseous halogen-based oxidant are different. It is set by adjusting the vapor pressure.

As the raw material for forming the deposited film used in the present invention, for example, in order to obtain a tetrahedral deposited film such as a semiconducting silicon-based deposited film or a germanium-based deposited film, a straight-chain type, and A branched chain silane compound, a cyclic silane compound, a chain germanium compound and the like can be mentioned as effective ones.

Specific examples of the linear silane compound Si _n H
_{2n + 2} (n = 1,2,3,4,5,6,7,8), as the branched chain silane compound, SiH ₃ SiH (Si
Examples of H ₃ ) SiH ₂ SiH ₃ and chain germane compounds include Ge _m H _{2m + 2} (m = 1,2,3,4,5). In addition to these compounds, for example SnH ₄
It is also possible to use tin hydride such as, etc. together as a raw material for forming a deposited film.

Of course, these silicon-based compounds and germanium-based compounds may be used alone or in combination of two or more.

The halogen-based oxidant used in the present invention is gasified when introduced into the reaction space, and at the same time, only by chemical contact with a gaseous raw material for forming a deposited film which is introduced into the reaction space. It has the property of effectively oxidizing, and F
Halogen gas such as ₂ , Cl ₂ , Br ₂ and I ₂ , nascent fluorine, chlorine, bromine and the like can be cited as effective ones.

These halogen-based oxidizers are gaseous, and are introduced into the reaction space at a desired flow rate and supply pressure together with the above-mentioned raw material gas for forming a deposited film and the above-mentioned substance (D) gas. A plurality of precursors including excited state precursors are chemically contacted by being mixed and collided with the raw material and the substance (D) to oxidize the raw material and the substance (D), thereby including a precursor in an excited state. Generate efficiently. The excited state precursors and other precursors that are produced serve as a source of constituents of the deposited film, at least one of which is formed.

The generated 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. A deposited film having a three-dimensional network structure is created by touching the surface of the substrate arranged in the space.

The excited energy level is preferably an energy level accompanied by light emission during the process of energy transition of the precursor in the excited state to a lower energy level or change to another chemical species. By forming activated precursors including excited state precursors accompanied by light emission in such energy transition, the deposited film formation process of the present invention proceeds more efficiently and more energy saving, A deposited film that is uniform over the entire surface and has better physical properties is formed.

In the method of the present invention, the substance (D) containing a component serving as a valence electron control agent as a constituent is in a gas state at room temperature and normal pressure, or is a gas at least under the conditions for forming a deposited film, It is preferable to select a compound that can be easily vaporized by the vaporizer of.

As the substance (D) used in the present invention, in the case of a silicon-based semiconductor film and a germanium-based semiconductor film,
A p-type valence electron control agent, an element of Group III A of the periodic table that acts as a so-called p-type impurity, such as B, Al, Ga, In, T
a compound containing 1 or the like, and an n-type valence electron control agent, which is an element of Group V group A, such as N,
Examples thereof include compounds containing P, As, Sb, Bi and the like.

Specifically, NH ₃ , HN ₃ , N ₂ H ₅ N ₃ , N
₂ H ₄ , NH ₄ N ₃ , PH ₃ , P ₂ H ₄ , AsH ₃ , S
_{bH 3, BiH 3, B 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 H ₅ ) ₃ , G
A (CH ₃ ) ₃ , In (CH ₃ ) _{3 and the} like can be cited as effective ones.

In order to introduce the gas of the substance (D) into the reaction space, it is introduced by being mixed with the raw material substance for forming the deposited film in advance.
Alternatively, it can be introduced from a plurality of independent gas supply sources.

In the present invention, the deposited film forming process proceeds smoothly, and a film having high quality and desired physical properties can be formed. D) and the type of halogen-based oxidant, the mixing ratio of these, the pressure at the time of mixing, the flow rate, the film formation space internal pressure, the gas flow pattern, and the film formation temperature (base temperature and atmospheric temperature) are as desired. It is selected appropriately. 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. In this case, it can be determined as desired according to need, but the introduction flow rate ratio is preferably 1/100 to 100 /
1 is suitable, and more preferably 1/50 to 50/1.

The ratio of the introduced amount of the gaseous substance (D) is appropriately set according to the kind of the gaseous raw material and the desired semiconductor characteristics of the deposited film to be produced. On the other hand, it is preferably 1 / 1,000,000 to 1
/ 10, more preferably 1/100000 to 1/20,
Optimally, it is desirable that the value is 1/100000 to 1/50.

The pressure at the time of mixing when introduced into the reaction space is higher in order to stochastically enhance the chemical contact between the gaseous raw material and gaseous substance (D) and the gaseous halogen-based oxidant. It is better, but it is better to determine the optimum value as appropriate in consideration of reactivity. The pressure at the time of mixing is determined as described above, but the pressure at each introduction is preferably 1 × 10 ⁻⁷ atm to 10 atm, more preferably 1 × 10 ⁻⁶ atm to 3 atm. It is desirable to be done.

The pressure in the film-forming space, that is, the pressure in the space where the substrate on which the film is to be formed is disposed, is the precursor (E) in the excited state generated in the reaction space and the precursor in some cases. The precursor (F) derived from the body (E) is appropriately set as desired so as to effectively contribute to the film forming process.

The internal pressure of the film formation space is such that when the film formation space is open and continuous with the reaction space, the gaseous source material for forming the deposited film, the substance (D) and the gaseous halogen-based oxidant are used. The relationship between the introduction pressure and the flow rate in the reaction space 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 forming space can be adjusted by controlling the exhaust amount of the apparatus.

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

As described above, the pressure in the film formation space is determined in relation to the introduction pressures of the gaseous source material, the gaseous substance (D), and the gaseous halogen-based oxidant introduced into the reaction space. The pressure is preferably 0.001 Torr to 100 Torr, more preferably 0.01 Torr to 30 Torr, and most preferably 0.05 Torr to 10 Torr.

Regarding the gas flow type, when the raw material for forming the deposited film, the substance (D) and the halogen-based oxidant are introduced into the reaction space, these are uniformly and efficiently mixed, and the precursor ( In order for E) to be efficiently generated and the film to be formed appropriately without any trouble, it is necessary to design in consideration of the geometrical arrangement of the gas inlet, the substrate and the gas outlet. One suitable example of this geometric arrangement is shown in FIG.

The substrate temperature (Ts) at the time of film formation is individually set as desired according to the type of gas used, the type of deposited film to be formed and the required characteristics. When obtained, the temperature is preferably from room temperature to 450 ° C, more preferably 50 to 400 ° C. Especially when forming a silicon-based deposited film having better semiconductor properties and photoconductivity, the substrate temperature (Ts) is 70 to 350.
It is desirable to set the temperature to ℃. Further, when a polycrystalline film is obtained, it is preferably 200 to 650 ° C., more preferably 3 to 650 ° C.
It is desirable that the temperature is from 00 to 600 ° C.

Regarding the ambient temperature (Tat) of the film formation space, the chemical species unsuitable for film formation of the precursor (E) and the precursor (F) generated do not change, and the precursor (E) is efficiently generated. ) Is appropriately determined 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, C
r, Mo, Au, Ir, Nb, Ta, V, Ti, Pt,
Examples include metals such as Pd and 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, paper and the like are usually used. It is preferable that at least one surface of these electrically insulating substrates is subjected to a conductive treatment, and another layer is provided on the surface subjected to the conductive treatment.

For example, in the case of glass, the surface is NiCr, Al, C
r, Mo, Au, Ir, Nb, Ta, V, Ti, Pt,
Pd, In ₂ O ₃ , SnO ₂ , ITO (In ₂ O ₃ + S
nO ₂ ), a conductive film is provided by a thin film, or a synthetic resin film such as a polyester film is NiCr, Al, Ag, Pb, Zn, Ni, Au,
The surface is subjected to a conductive treatment by treatment with a metal such as Cr, Mo, Ir, Nb, Ta, V, Ti, Pt by vacuum vapor deposition, electron beam vapor deposition, sputtering, or the like, or by laminating with the metal. The shape of the support may be any shape such as a cylindrical shape, a belt shape and a plate shape, and the shape is determined as desired.

The substrate is preferably selected from the above in consideration of the adhesion and reactivity between the substrate and the film. Furthermore, if the difference in thermal expansion between the two is large, a large amount of strain may occur in the film, and a good quality film may not be obtained. Therefore, select and use a substrate with a close difference in thermal expansion between the two. Is preferred.

Further, since the surface condition of the substrate is directly related to the structure (orientation) of the film and the generation of the conical structure, it is necessary to treat the surface of the substrate so that the film structure and the film structure can obtain desired characteristics. Is desirable.

FIG. 1 shows an example of an apparatus suitable for embodying the deposited film forming method of the present invention.

The deposited film forming apparatus shown in FIG. 1 is roughly divided into three parts: an apparatus main body, an exhaust system and a gas supply system.

A reaction space and a film formation space are provided in the apparatus body.

101 to 108 are cylinders filled with gas used for film formation, 101a to 108a are gas supply pipes, 101b to 108b are mass flow controllers for adjusting the flow rate of gas from each cylinder, 101
c-108c are gas pressure gauges, 101d-108, respectively.
d and 101e to 108e are valves, and 101f to 1
Reference numerals 08f are pressure gauges showing the pressures inside the corresponding gas cylinders.

Reference numeral 120 denotes a vacuum chamber having a structure in which a gas introducing pipe is provided in an upper portion thereof, and a reaction space is formed in the downstream of the pipe, and the substrate 1 faces the gas outlet of the pipe.
It has a structure in which a film formation space in which the base holder 112 is provided so that 18 is installed is formed. The gas introduction pipe has a triple concentric circle arrangement structure, and the first gas introduction pipe 109 into which the gas from the gas cylinders 101 and 102 is introduced and the second gas from the gas cylinders 103 to 105 are introduced from the inside. Gas introduction pipe 110 and gas cylinder 1
It has a third gas introduction pipe 111 into which the gas from 06 to 108 is introduced.

For the gas discharge to the reaction space of each gas introduction pipe, it is designed such that the inner pipe is located farther from the surface position of the substrate. That is, the respective gas introduction pipes are arranged so that the outer pipes surround the inner pipes.

The supply of gas from the pipe cylinders to the respective introduction pipes is performed by gas supply pipelines 123 to 125, respectively.

The gas introduction pipes, the gas supply pipelines, and the vacuum chamber 120 are vacuum-exhausted by a vacuum exhaust device (not shown) via the main vacuum valve 119.

The substrate 118 is installed at a desired distance from the position of each gas introduction pipe by moving the substrate holder 112 up and down.

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

Reference numeral 113 denotes a substrate heating heater that heats the substrate 118 to an appropriate temperature during film formation, preheats the substrate 118 before film formation, and further heats after film formation to anneal the film. is there.

The substrate heater 113 is connected to the power source 115 via the conductor 114.
Is supplied with electric power.

Reference numeral 116 is a thermocouple for measuring the temperature of the substrate temperature (Ts), which is electrically connected to the temperature display device 117.

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

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

The SiH ₄ gas with which the cylinder 103 is filled has a flow rate of 20.
B ₂ H ₆ gas (diluted to 1% with H ₂ gas) charged in the cylinder 104 at a sccm of ₂ sccm is supplied from the gas introduction pipe 110 to the F ₂ gas charged in the cylinder 106 at a flow rate of ₂ sccm and the cylinder 108. Filled in
Gas was introduced into the vacuum chamber 102 through the gas introduction pipe 111 at a flow rate of 40 sccm.

At this time, the pressure in the vacuum chamber 120 was adjusted to 800 mTorr by adjusting the opening / closing degree of the vacuum valve 119. Quartz glass (15 cm × 15 cm) was used as the substrate, and the distance between the gas inlet 111 and the substrate was set to 3 cm. SiH ₄
Pale white emission was strongly observed in the mixed region of gas and F ₂ gas.
The substrate temperature (Ts) was set between room temperature and 400 ° C. as shown in Table 1 for each sample.

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

The unevenness of the film thickness distribution was within ± 5%. It was confirmed by electron beam diffraction that all of the formed Si: H: F: B films were amorphous.

On the amorphous Si: H: F: B film of each sample, a comb-shaped electrode (gap length 200 μm) of Al was vapor-deposited to prepare a sample for conductivity measurement. Place each sample in a vacuum cryostat and apply a voltage of 100 V, and use a micro ammeter (YHP4140).
The current was measured in B) to determine the dark conductivity (σd). Again 6
The photoconductivity (σp) was obtained by irradiating with light of 00 nm, 0.3 mw / cm ² . Further, the optical bandgap (Eg ^opt ) was determined from the absorption of light. The results are shown in Table 1.
In addition, all of these films showed P-type conduction in measurement of thermoelectromotive force.

Next, the substrate temperature was fixed at 300 ° C., and the film thicknesses of the samples, σd, σp, when various flow rates of SiH ₄ were prepared.
The results of Eg ^opt are shown in Table 2.

At this time, the time for which the gas was flown was 3 hours for all the samples. In addition, all the samples were F ₂ gas flow rate ₂ sccm, He
The gas flow rate was 40 sccm and the internal pressure was 800 mTorr.

Next, the substrate temperature is 300 ° C., the SiH ₄ gas flow rate is 20 sc
cm, F ₂ gas flow rate ₂ sccm, B ₂ H ₆ gas flow rate (1
% H ₂ gas dilution) ₂ sccm, internal pressure 800 mTorr, He gas flow rate was variously changed, and each gas was flowed for 3 hours, and the film thickness of each sample obtained, σd, σp, Eg
Table 3 shows the values of ^opt .

Next, the substrate temperature is 300 ° C., the SiH ₄ gas flow rate is 20 sc
cm, F ₂ gas flow rate ₂ sccm, B ₂ H ₆ gas (H ₂ gas dilution to 1%) flow rate ₂ sccm, He gas flow rate 40 sc
Table 4 shows the film thickness, σd, σp, and Eg ^opt of each sample prepared by changing the internal pressure to various values in cm.

The samples shown in Tables 2 to 4 are all P
It showed type conduction.

The unevenness of the film thickness distribution of each sample shown in Tables 1 to 4 depended on the distance between the gas introducing pipe 111 and the substrate, the gas flow rate flowing through the gas introducing pipes 110 and 111, and the internal pressure. In each film formation, by adjusting the distance between the gas introduction tube and the substrate, the unevenness of the film thickness could be controlled within ± 5% in the substrate of 15 cm × 15 cm. This position almost always corresponded to the position of maximum emission intensity. In addition, the deposited S
It was confirmed that the i: H: F: B films of all samples were amorphous according to the result of electron diffraction.

Example 2 A film was formed by introducing F ₂ gas and Cl ₂ gas from a 107 cylinder in Example 1 (Sample 2).

The film forming conditions at this time are as follows.

SiH ₄ 20 sccm F _{2 2} sccm Cl _{2 2} sccm B ₂ H ₆ (1% H ₂ dilution) ₂ sccm He 40 sccm Internal pressure 800 mTorr Base temperature 300 ° C. Distance between gas outlet and base 3 cm As in Example 1, SiH ₄ gas and (F Strong blue emission was observed in the region where the ₂ + Cl ₂ ) gas merged. After blowing out the gas for 3 hours, about 2.6 μm AS on the quartz glass substrate.
An i: H: F: Cl: B film was deposited.

It was confirmed by electron diffraction that the film was amorphous.

After vacuum-depositing an Al comb-shaped electrode (gear length 200 μm) on the A-Si: H: F: Cl: B film, the sample was placed in a vacuum cryostat, and the dark conductivity (σd), 60
Conductivity (σ when irradiated with light of 0 nm and 0.3 mw / cm ²
p) and the optical bandgap (Eg ^opt ) were measured from the measurement of optical absorption, respectively.

The obtained value was σd = 3 × 10 ⁻⁸ S / cm σp = 7 × 10 ⁻⁷ S / cm Eg ^opt = 1.75 eV. Moreover, the measurement result of the thermoelectromotive force showed P type.

Example 3 Instead of introducing SiH ₄ gas in Example 1, 10
Si ₂ H ₆ gas was introduced from 5 cylinders to form a film (Sample 3).

The film forming conditions at this time are as follows.

Si ₂ H ₆ 20 sccm F ₂ 5 sccm B ₂ H ₆ (1% H ₂ dilution) ₂ sccm He 40 sccm Internal pressure 800 mTorr Base temperature 300 ° C. Distance between gas outlet and base 3 cm Region where Si ₂ H ₆ gas and F ₂ gas meet A strong blue luminescence was seen at. After blowing out the gas for 1 hour, an A-Si: H: F film of about 1.9 μm was deposited on the quartz glass substrate.

It was confirmed by electron diffraction that the film was amorphous.

After vacuum-depositing a comb-shaped electrode (gap length 200 μm) of Al on the A-Si: H: F: B film, it was placed in a vacuum cryostat and dark conductivity (σd), 600 nm, 0.3 m.
The optical bandgap (Eg ^opt ) was measured by measuring the electrical conductivity (σp) at the time of light irradiation of w / cm ² and the optical absorption.

The obtained value was σd = 8 × 10 ⁻⁸ S / cm σp = 2 × 10 ⁻⁷ S / cm Eg ^opt = 1.75 eV. Moreover, the measurement result of the thermoelectromotive force showed P-type conduction.

Example 4 Instead of introducing SiH ₄ gas in Example 1, 10
GeH ₄ gas was introduced from 5 cylinders to form a film (Sample 4).

The film forming conditions at this time are as follows.

GeH ₄ 20 sccm F ₂ 4 sccm B ₂ H ₆ (1% H ₂ dilution) ₂ sccm He 40 sccm Inner pressure 800 mTorr Base temperature 300 ° C. Distance between gas outlet and base 3 cm At this time, the confluence of GeH ₄ gas and F ₂ gas is strong blue. Light emission was observed. After blowing out the gas for 2 hours, an about 1.7 μm A-Ge: H: F film was deposited on the quartz glass substrate. It was confirmed by electron diffraction that the film was amorphous.

A comb-shaped electrode of Al (gear length 200 μm) was vacuum-deposited on the A-Ge: H: F: B film, and then placed in a vacuum cryostat, and the dark conductivity (σd), 600 nm, 0.3 nm.
The optical bandgap (Eg ^opt ) was measured by measuring the electrical conductivity (σp) at the time of light irradiation of mw / cm ² and the optical absorption.

The obtained value was σd = 3 × 10 ⁻⁶ S / cm σp = 5 × 10 ⁻⁶ S / cm Eg ^opt = 1.1 eV. Moreover, the measurement result of the thermoelectromotive force showed P-type conduction.

Example 5 Introducing SiH ₄ gas in Example 1 and
GeH ₄ gas was introduced from 5 cylinders to form a film (Sample 5).

The film forming conditions at this time are as follows.

SiH ₄ 20 sccm GeH ₄ 5 sccm B ₂ H ₆ (1% H ₂ dilution) 3 sccm F ₂ 5 sccm He 40 sccm Inner pressure 800 mTorr Base temperature 300 ° C. Distance between gas outlet and substrate 3 cm Strong blue emission near the outlet of the gas outlet at this time Was seen. After blowing out the gas for 2 hours, an A-SiGe: H: F film of about 1.9 μm was deposited on the quartz glass substrate. It was confirmed to be amorphous by electron beam diffraction.

After vacuum-depositing a comb-shaped electrode of Al (gear length 200 μm) on the A-SiGe: H: F: B film, a sample 5 was placed in a vacuum cryostat, and the dark conductivity (σd), 6
Electrical conductivity (σ when irradiated with light of 00 nm, 0.3 mw / cm ²
The optical bandgap (Eg ^opt ) was measured from p) and the measurement of optical absorption, respectively.

The obtained value was σd = 5 × 10 ⁻⁸ S / cm σp = 2 × 10 ⁻⁷ S / cm Eg ^opt = 1.4 eV. Moreover, it was confirmed by measurement of thermoelectromotive force that the conduction was P-type conduction.

Example 6 Instead of introducing GeH ₄ gas in Example 5, 10
C ₂ H ₄ gas was introduced from 5 cylinders to form a film (Sample 6).

The film forming conditions at this time are as follows.

SiH ₄ 20 sccm C ₂ H ₄ 5 sccm B ₂ H ₆ (1% H ₂ dilution) 3 sccm F ₂ 5 sccm He 40 sccm Internal pressure 800 mTorr Substrate temperature 300 ° C. Distance between gas outlet and substrate 3 cm 3 hours after gas blowing, quartz glass substrate About 1.1μ above
m A-SiC: H: F: B film was deposited. It was confirmed by electron diffraction that the film was amorphous.

After vacuum-depositing a comb-shaped electrode of Al (gear length 200 μm) on the A-SiC: H: F: B film, sample 6 was placed in a vacuum cryostat, and the dark conductivity (σd), 600
nm, conductivity (σp) when irradiated with light of 0.3 mw / cm ² ,
And optical bandgap (Eg
^opt ) was measured respectively.

The obtained value was σd = 7 × 10 ^-10 S / cm σp = 8 × 10 ^-9 S / cm Eg ^opt = 1.9 eV. Moreover, the measurement result of the thermoelectromotive force showed P-type conduction.

Example 7 Introducing SiH ₄ gas in Example 1 and
Si ₂ H ₆ gas was introduced from 5 cylinders to form a film (Sample 7).

The film forming conditions at this time are as follows.

SiH ₄ 20 sccm Si ₂ H ₆ 5 sccm B ₂ H ₆ (1% H ₂ dilution) 3 sccm F ₂ 5 sccm He 40 sccm Internal pressure 800 mTorr Base temperature 300 ° C. Distance between gas outlet and substrate 3 cm Blue near the gas outlet at this time Strong light emission was observed. After blowing out the gas for 1 hour, about 1
A 1.4 μm A-Si: H: F: B film was deposited. It was confirmed by electron diffraction that the film was amorphous.

After vacuum-depositing a comb-shaped electrode of Al (gear length 200 μm) on the A-Si: H: F: B film, sample 7 was placed in a vacuum cryostat, and the dark conductivity (σd), 600 n.
The optical bandgap (E) was measured by measuring the electrical conductivity (σp) at the time of light irradiation of m, 0.3 mw / cm ² and optical absorption.
g ^opt ) was measured for each.

The obtained value was σd = 3 × 10 ⁻⁹ S / cm σp = 5 × 10 ⁻⁷ S / cm Eg ^opt = 1.65 eV. Further, it was found from the results of the thermoelectromotive force that it was P-type conduction.

Example 8 In Example 7, F ₂ gas was introduced and Cl ₂ was introduced from the cylinder 107 to form a film (Sample 8).

The film forming conditions at this time are as follows.

SiH ₄ 20 sccm Si ₂ H ₆ 5 sccm F ₂ 5 sccm Cl _{2 2} sccm B ₂ H ₆ (1% H ₂ dilution) 3 sccm He 40 sccm Internal pressure 800 mTorr Base temperature 300 ° C. Distance between gas outlet and base 3 cm When gas is flowed, gas A strong blue emission was observed at the confluence point of. After blowing out the gas for 1 hour, about 1
A 1.8 μm A-Si: H: F: Cl: B film was deposited.
It was confirmed by electron diffraction that the film was amorphous.

After vacuum-depositing a comb-shaped electrode of Al (gear length 200 μm) on the A-Si: H: F: Cl: B film, a sample 8 was placed in a vacuum cryostat, and the dark conductivity (σd), 6
Electrical conductivity (σ when irradiated with light of 00 nm, 0.3 mw / cm ²
p), and the optical bandgap (Eg ^opt ) was measured by measuring the optical absorption.

The obtained value was σd = 7 × 10 ⁻⁹ S / cm σp = 3 × 10 ⁻⁷ S / cm Eg ^opt = 1.70 eV. Further, it was found from the measurement result of the thermoelectromotive force that it was P-type conduction.

Example 9 In Example 1, the substrate temperature was set to 600 ° C. to form a film (Sample 9).

The film forming conditions at this time are as follows.

SiH ₄ 20 sccm F ₂ 5 sccm B ₂ H ₆ (1% H ₂ dilution) ₂ sccm He 40 sccm Internal pressure 800 mTorr Distance between gas outlet and substrate 3 cm Similar to Example 1, strong blue color at confluence of SiH ₄ gas and F ₂ gas Light emission was observed. After blowing out the gas for 3 hours, about 1.0 μm of poly-Si: H: F: on the quartz glass substrate.
Film B was deposited. When the deposited film was measured by electron diffraction, a diffraction peak of Si was observed, and it was found that the film was polycrystallized.

After vacuum-depositing a comb-shaped electrode of Al (gear length of 200 μm) on the poly-Si: H: F: B film, sample 9 was put in a vacuum cryostat, and dark conductivity (σd) and optical absorption Optical bandgap (E
g ^opt ) was measured respectively.

The obtained value was σd = 8 × 10 ⁻³ S / cm Eg ^opt = 1.4 eV.

Example 10 In the example 1, SiH ₄ gas was introduced, and 10
SnH ₄ gas was introduced from one cylinder to form a film (Sample 10).

The film forming conditions at this time are as follows.

SiH ₄ 20 sccm SnH ₄ 5 sccm F _{2 3} sccm B ₂ H ₆ (1% H ₂ dilution) 3 sccm He 40 sccm Inner pressure 800 mTorr Base temperature 300 ° C. Distance between gas outlet and base 3 cm At this time, strong blue emission near gas outlet Was seen. After the gas was blown for 2 hours, an A-SiSn: H: F: B film of about 1.8 μm was deposited on the quartz glass substrate. It was confirmed by electron diffraction that this film was amorphous.

Sample 10 was formed by vacuum-depositing a comb-shaped electrode of Al (gear length 200 μm) on the A-SiSn: H: F: B film.
In a vacuum cryostat, dark conductivity (σd),
Conductivity (σ when irradiated with light of 600 nm and 0.3 mw / cm ²
The optical bandgap (Eg ^opt ) was measured from p) and the measurement of optical absorption, respectively.

The obtained value was σd = 4 × 10 ⁻⁷ S / cm σp = 5 × 10 ⁻⁷ S / cm Eg ^opt = 1.2 eV. Further, it was found from the measurement result of the thermoelectromotive force that it was P-type conduction.

Example 11 Instead of introducing F ₂ in Example 1, Cl ₂ gas was introduced from a 107 cylinder to form a film (Sample 1).
1).

The film forming conditions at this time are as follows.

SiH ₄ 20 sccm Cl _{2 2} sccm B ₂ H ₆ (1% H ₂ dilution) ₂ sccm He 40 sccm Internal pressure 800 mTorr Base temperature 300 ° C. Distance between gas outlet and base 3 cm At this point, SiH ₄ gas and Cl ₂ gas merge Strong light emission was observed. After blowing out the gas for 3 hours, an A-Si: H: Cl: B film of about 1.4 μm was deposited on the quartz glass substrate. It was confirmed by electron diffraction that the film was amorphous.

A comb electrode of Al (gear length 200 μm) was vacuum-deposited on the A-Si: H: Cl: B film, and then the sample 11 was placed in a vacuum cryostat, and the dark conductivity (σd), 60
Conductivity (σ when irradiated with light of 0 nm and 0.3 mw / cm ²
p), and the optical bandgap (Eg ^opt ) was measured by measuring the optical absorption.

The obtained value was σd = 1 × 10 ⁻⁹ S / cm σp = 5 × 10 ⁻⁸ S / cm Eg ^opt = 1.70 eV. Moreover, it was found from the measurement of thermoelectromotive force that it was P-type conduction.

Example 12 Instead of introducing B ₂ H ₆ gas in Example 1, 10
PH ₃ gas (1% H ₂ gas diluted) was introduced from 4 cylinders to form a film (Sample 12).

The film forming conditions at this time are as follows.

SiH ₄ 20 sccm F ₂ 5 sccm PH ₃ (1% H ₂ gas diluted) ₂ sccm He 40 sccm Inner pressure 800 mTorr Base temperature 300 ° C. Distance between gas outlet and base 3 cm SiH ₄ Gas and intense F ₂ gas emit intense blue light. It was seen. After blowing out the gas for 1 hour, an A-Si: H: F: P film of about 1.2 μm was deposited on the quartz glass substrate.

It was confirmed by electron diffraction that the film was amorphous.

After vacuum-depositing a comb-shaped electrode of Al (gap length 200 μm) on the A-Si: H: F: P film, put it in a vacuum cryostat, and dark conductivity (σd), 600 nm, 0.3 m.
The optical bandgap (Eg ^pot ) was measured by measuring the conductivity (σp) at the time of light irradiation of w / cm ² and the optical absorption.

The obtained value was σd = 8 × 10 ⁻⁷ S / cm σp = 3 × 10 ⁻⁶ S / cm Eg ^pot = 1.7 ev. The measurement of thermoelectromotive force revealed that it was n-type conduction.

Example 13 In Example 12, SiH ₄ gas was introduced, and 1
GeH ₄ gas was introduced from a 05 cylinder to form a film (Sample 13).

The film forming conditions at this time are as follows.

SiH ₄ 20sccm GeH ₄ 5sccm PH ₃ (1% H ₂ gas dilution) 3sccm F ₂ 5sccm He 40sccm Inner pressure 800mTorr Base temperature 300 ° C Distance between gas outlet and substrate 3cm At this time, strong blue light emission near gas outlet It was seen. After blowing out the gas for 2 hours, an about 1.8 μm A-SiGe: H: F: P film was deposited on the quartz glass substrate. It was confirmed to be amorphous by electron beam diffraction.

Sample 13 was formed after vacuum-depositing a comb-shaped electrode of Al (gear length 200 μm) on the A-SiGe: H: F: P film.
In a vacuum cryostat, dark conductivity (σd),
Conductivity (σ when irradiated with light of 600 nm and 0.3 mw / cm ²
The optical bandgap (Eg ^opt ) was measured from p) and the measurement of optical absorption, respectively.

The obtained value was σd = 4 × 10 ⁻⁷ S / cm σp = 8 × 10 ⁻⁷ S / cm Eg ^opt = 1.4 eV. In addition, it was confirmed by measurement of thermoelectromotive force that it was n-type conduction.

〔effect〕

From the above detailed description and each example, according to the deposited film forming method of the present invention, it is possible to obtain a deposited film having a uniform physical property over a large area while achieving energy saving and easy control of film quality. In addition, it has excellent productivity and mass productivity, high quality and electrical,
A film having excellent physical properties such as optical properties and semiconductor properties can be easily obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a film forming apparatus used in an example of the present invention. 101-108 ... Gas cylinder, 101a-108a ... Gas introduction pipe, 101b-108b ... Mass flow meter, 101c-108c ... Gas pressure gauge, 101d-108d and 101e-108e ... Valve, 101f-108f ... ... Pressure gauge, 109, 110, 111 ... Gas introduction pipe, 112 ... Substrate holder, 113 ... Substrate heating heater, 116 ... Substrate temperature monitoring thermocouple, 118 ... Substrate, 119 ... Vacuum exhaust valve , And, respectively.

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01L 31/0248

Claims (18)

[Claims] 1. A gaseous raw material for forming a deposited film, a gaseous halogen-based oxidizer having a property of oxidizing the raw material, and a component serving as a valence electron control agent as constituent elements. (D) and (D) are introduced into the reaction space and brought into chemical contact with each other to generate a plurality of precursors including a precursor in an excited state, and at least one of these precursors is deposited to form a deposited film. A deposited film forming method characterized in that a deposited film is formed on a substrate in a film forming space as a supply source of elements. 2. The method for forming a deposited film according to claim 1, wherein light is emitted during film formation. 3. The deposited film forming method according to claim 1, wherein the gaseous raw material is a chain silane compound. 4. The deposited film forming method according to claim 3, wherein the chain silane compound is a straight chain silane compound. 5. The linear silane compound has the general formula Si _n
The deposited film forming method according to claim 4, which is represented by H _{2n + 2} (n is an integer of 1 to 8). 6. The deposited film forming method according to claim 3, wherein the chain silane compound is a branched chain silane compound. 7. The deposited film forming method according to claim 1, wherein the gaseous raw material is a silane compound having a silicon ring structure. 8. The deposited film forming method according to claim 1, wherein the gaseous raw material is a chain germane compound. 9. The chain-like germane compound has the general formula Ge _m
The deposited film forming method according to claim 8, which is represented by H _{2m + 2} (m is an integer of 1 to 5). 10. The method for forming a deposited film according to claim 1, wherein the gaseous source material contains a tin hydride compound. 11. The deposited film forming method according to claim 1, wherein the gaseous raw material is a tetrahedral compound. 12. The deposited film forming method according to claim 1, wherein the gaseous halogen-based oxidizing agent contains a halogen gas. 13. The deposited film forming method according to claim 1, wherein the gaseous halogen-based oxidizing agent contains fluorine gas. 14. The deposited film forming method according to claim 1, wherein the gaseous halogen-based oxidizing agent contains chlorine gas. 15. The gas-based halogen-based oxidizing agent is a gas containing a fluorine atom as a constituent.
The method for forming a deposited film according to item. 16. The method for forming a deposited film according to claim 1, wherein the gaseous halogen-based oxidizing agent contains halogen in a nascent state. 17. The substrate is arranged at a position facing the introduction direction of the gaseous raw material, the gaseous halogen-based oxidant, and the gaseous substance (D) into the reaction space. The deposited film forming method according to claim 1. 18. The method according to claim 1, wherein the gaseous raw material, the gaseous oxidant and the gaseous substance (D) are introduced into the reaction space through a transport pipe having a multi-tubular structure. Method for forming deposited film.