JP3126176B2 - Semiconductor thin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for forming a crystalline semiconductor thin film having a low absorption of visible light and a high carrier density in an ultra-thin state in a high-performance amorphous solar cell. .

[0002]

2. Description of the Related Art Amorphous solar cells have already been put into practical use as energy sources with a small output for driving calculators and watches. However, as an energy source with a large output of 0.1 W or more, such as for photovoltaic power generation, its performance and stability are not sufficient, and various studies have been conducted with the aim of improving performance. I have. Therefore, the photoelectric conversion efficiency of the solar cell is the open-circuit voltage,
It is expressed by the product of the short-circuit photocurrent and the fill factor. As a result of various studies, with regard to the short-circuit photocurrent and fill factor, the current achieved value has approached the theoretically expected value.
That is, the open-circuit voltage has not been sufficiently improved. In recent years, in order to improve the reliability of a solar cell, a pin-type amorphous solar cell having a p-layer on the light incident side has been studied. In this amorphous solar cell, in order to improve the open-circuit voltage, p
There is a technical difficulty in that the photoelectric characteristics of the mold semiconductor thin film must be improved, and in particular, the enlargement of the optical band gap and the improvement of the electric conductivity must be performed simultaneously. A microcrystalline thin film has been proposed as a material that satisfies these conditions. Attempts have been made to form a thin film using a conventional technique such as a plasma CVD method under conditions where a p-type microcrystalline thin film should be formed on a transparent electrode. However, as a result, the open-circuit voltage of the amorphous solar cell has not been improved. It has been reported that the reason for this is that it is difficult to form a p-type microcrystalline thin film on a transparent electrode at a film thickness of 50 to 300 ° necessary and sufficient as a p-type amorphous solar cell p-layer. (For example, Be.
Goldstein et al., "Characteristics of p-type SiC: H Microcrystalline Thin Film Formed by Normal RF Glow Discharge," Applied Physics Letter, vol. 53, pp. 2672 to 2674, published in 1988 of p + microcrystal
line films of SiC: H deposited by conventional rf g
low discharge ", Applied Physics letters, 53, p2672
~ 2674 (1988)). In other words, at a film thickness of 50 to 300 °, crystallization does not occur, the resistance is increased, the fill factor is low, and the improvement of the open-circuit voltage cannot be obtained. On the other hand, ECR (Electron Cy
(clotron Resonane) When a p-layer is formed by plasma CVD, improvements in open-circuit voltage and photoelectric conversion efficiency have been reported.However, in this method, the underlying material is severely damaged by ion bombardment. At present, the properties of the p-type microcrystalline thin film obtained by the method have not been fully exploited (for example, Yutaka Hattori et al., "Highly efficient amorphous heterojunction using p-type microcrystalline SiC film formed by ECR-CVD" Solar Cell "Technical Digest of
International PVSEC-3, pages 171 to 174, published in 1987 (Y. Hattori et al., "High Efficiency Amorphous
Heterojunction Solar cell Employing ECR-CVD Produc
ed p-Type MicrocrystallineSiC Film ", Technical Dig
est of the International PVSEC-3, p.171-174 (198
7) See).

In recent years, it has been reported that a microcrystalline thin film can be obtained by repeatedly treating a film with atomic hydrogen generated by microwave plasma, high-frequency plasma or the like after film formation. For these, a total film thickness of 3
It is not mentioned whether microcrystallization is possible even below 00 ° (for example, A. Asano, "Effect of hydrogen atoms on network structure of hydrogenated amorphous silicon and microcrystalline silicon thin film", Applied Physics Letter, 56
Volume, pp. 533-535, 1990 (A. Asano, "Effects of
hydrogen atoms on the network structure of hydro
genated amorphous and microcrystalline silicon thi
n films ", Applied Physics letters, 56, pp. 533-535
(1990)), Isamu. Shimizu et al., "Chemical Reaction Control for Crystalline Silicon Growth at Low Substrate Temperature," Material Research Society Symposium Proceeding, Volume 164, pp. 195-204, 1990 (I. Shimizu et al.)
al., "Control of Chemical Reactions for Growth of C
rystalline Si at Low Substrate Temperature, Matir
ials Research Society Symposium Proceeding Vol.16
4, p.195-204 (1990)).

[0004] It has also been reported that a microcrystalline thin film can be obtained by forming a silicon thin film of 900 to 1000 ° and then treating it with an ion beam.
It must be irradiated with high-energy ions of the order of ~ MeV (for example, J. S. Im et al., "Crystal nucleation by ion irradiation in amorphous silicon thin film", Applied Physics Letter, vol. 57, pp. 1766-1768)
Page, 1990 (JSImet al., "Ion irradiation enh
anced crystal nucleation in amorphous Si thin film
s ", Applied Physics letters, 57, p. 1766-1768 (19
90)), Sea. Spinella et al., "Grain Growth Mechanism of Amorphous Silicon by Chemical Vapor Deposition under Ion Beam Irradiation," Applied Physics Letter, 57, 554-
556 pages, 1990 (C. Spinella et al., "Grain growt
h kinetics during ion beam irradiation of chemical
vapor deposited amorphous silicon ", Applied Physi
cs letters, 57, p.554-556 (1990)), damage to the underlying material occurs, and the equipment becomes extremely large and expensive, making it impractical.

[0005]

SUMMARY OF THE INVENTION The present invention provides a type semiconductor thin film having crystallinity in an extremely thin film state (300 ° or less), low resistance, and high carrier density, which has been impossible in the past. The purpose is to gain.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, introduced a gas containing a hydrocarbon compound or an organic silicon compound gas into the ion generator, and grown the growth surface. After forming an ultra-thin film of 100 mm or less while irradiating low-energy ions of preferably 1 keV or less, crystallization of the film is promoted by further continuing ion irradiation. The present inventors have found that it is possible to form a semiconductor thin film having crystallinity even at a large thickness, and having low absorption and high carrier density, and completed the present invention.

The present invention provides a method for forming a silicon-based thin film by supplying a silicon-based thin film forming raw material in an atmosphere containing charged particles obtained by discharging a mixed gas of a hydrocarbon compound or an organic silicon compound and a non-deposition gas. (Hereinafter, abbreviated as a film forming step), and stopping the supply of the silicon-based thin film forming raw material, and discharging a mixed gas of a hydrocarbon compound or an organic silicon compound and a non-deposition gas. Exposing the surface on which the thin film is formed to an atmosphere containing charged particles (hereinafter, abbreviated as a modifying step), and the thickness of the silicon-based thin film formed in one repetition is 1 to 100 °. A gist is a crystalline semiconductor thin film having a total thickness of 300 mm or less.

In the present invention, the film forming step is most characterized in that the thin film is grown in an atmosphere containing charged particles generated by discharging a mixed gas of a hydrocarbon compound or an organic silicon compound and a non-deposition gas. The means for supplying a raw material for forming a thin film and the film forming means itself are not particularly limited. Specifically, vacuum deposition, sputtering,
Physical film formation methods such as ion plating and optical CV
D. This is performed by a chemical vapor deposition (CVD) method such as plasma CVD. An atmosphere containing charged particles refers to a cation or an anion of a hydrocarbon compound or an organic silicon compound and / or a non-deposited gas generated by discharging a mixed gas of a hydrocarbon compound or an organic silicon compound and a non-deposited gas. The atmosphere contains ions. In the present invention, this is guided (collides) with the surface of the thin film formed on the substrate during the film formation process by means such as applying a bias voltage to the substrate.

On the other hand, the reforming step is to stop supplying the thin film forming raw material in the film forming step and discharge the mixed gas of the hydrocarbon compound or the organic silicon compound and the non-deposition gas to generate charged particles. In this step, only the atmosphere containing the thin film is continued (exposed) to the surface on which the thin film formed on the substrate is formed, and the properties of the semiconductor thin film formed in the film forming step are modified. In addition,
At this time, the effect of the present invention is not impeded even if the hydrocarbons or the species produced by decomposition of the organic silicon compound cover the surface of the thin film. Of course, the hydrocarbon compound and the organic silicon compound may be used in combination.

First, an effective physical film forming method will be described below. As described above, the generation of an atmosphere containing charged particles generated by discharging a mixed gas of a hydrocarbon compound or an organic silicon compound and a non-deposited gas in the film formation step is as follows.
This method is performed in conjunction with a physical film formation method and a chemical vapor deposition method described below, but can be controlled independently. Thus, this is the same generation method as the generation method of the atmosphere including the charged particles generated by discharging the mixed gas of the hydrocarbon compound or the organic silicon compound and the non-depositable gas in the reforming step, An effective generation method and the like will be described in a specific section of the reforming step described later. As a starting material for forming a film, an element, compound, or alloy of silicon such as silicon, silicon carbide, silicon nitride, a silicon-germanium alloy or a composite powder, a silicon-tin alloy, or a composite powder can be effectively used. The film forming conditions are not particularly limited, except that the film is formed while being exposed to an atmosphere containing charged particles during the growth of the thin film, and rare gases such as argon, xenon, helium, neon, krypton, hydrogen, and carbon are used. The film can be formed in an atmosphere of hydrogen, fluorine, nitrogen, oxygen gas, or the like. As specific conditions, the gas flow rate is 0.1 to 100 sccm, and the reaction pressure is 0.00
The range is from 01mtorr to 100mtorr. In addition, film forming conditions such as a flow rate, a pressure, and an electric power are appropriately selected according to a film forming speed. The film formation temperature is controlled by controlling the substrate temperature during film formation. Although the temperature range is not basically limited, it is preferable to set the temperature in accordance with the reforming step. Specifically, it is selected in a temperature range of 500 ° C. or less.

Next, a specific example of an effective chemical vapor deposition method will be described. As a source gas for film formation, a general formula Si _n H
_A silane compound such as monolan, disilane, trisilane, and tetrasilane represented by _{2n + 2} (n is a natural number), fluorinated silane, organic silane, hydrocarbon, and germane compound are used. As a diluent gas, a gas such as hydrogen, deuterium, fluorine, chlorine, helium, argon, neon, xenon, krypton, or nitrogen may be introduced together with the source gas. When these gases are used, it is effective to use them in the range of 0.01 to 100% (volume ratio) with respect to the raw material gas, which is appropriately selected in consideration of the film forming speed and film characteristics. . Like the physical film forming method, the film forming conditions are not particularly limited except that the film is formed in an atmosphere containing charged particles during the growth of the thin film. Specific conditions are disclosed below. In the photo CVD, a source gas is decomposed by using an ultraviolet light source having a wavelength of 350 nm or less, such as a low-pressure mercury lamp, a deuterium lamp, or a rare gas lamp, to form a film. The conditions at the time of film formation are as follows: gas flow rate 1 to 100 sccm, reaction pressure 15
mtorr to atmospheric pressure, substrate temperature 200 to 600 ° C, considering the heat resistance of the substrate, the film forming time considered from the film forming speed, the temperature of the reforming step, etc., more preferably, appropriately in the range of 300 to 500 ° C. Is done. Further, the plasma CVD is specifically described below. As a discharge method, a method such as a high-frequency discharge, a DC discharge, a microwave discharge, and an ECR discharge can be effectively used. Source gas flow rate 1 ~ 900sccm, reaction pressure 0.001mtorr ~ atmospheric pressure, electric power 1
A range of mW / cm ² to 10 W / cm ² is sufficient. These film forming conditions are appropriately changed according to the film forming speed and the discharge method. The substrate temperature is from 200 to 600C, more preferably from 300 to 500C.

In the present invention, the atmosphere containing these charged particles obtained by discharging a mixed gas of a hydrocarbon compound or an organosilicon compound and a non-depositable gas in the reforming step and the film forming step is defined as a hydrocarbon. By discharge using a mixed gas of a compound or an organic silicon compound and a non-deposition gas,
This is an atmosphere in which charged particles composed of cations or anions of a hydrocarbon compound or an organosilicon compound and / or a non-deposition gas are generated and exposed to the growth surface. Even if there is something that is not ionized in that atmosphere,
It does not hinder the effects of the present invention. Exposure of the substrate (upper thin film) to the discharge atmosphere, application of a bias voltage to the substrate, and effective introduction of ionized components onto the substrate are more preferable means as a modification method. As a method of generating a discharge, a high-frequency discharge, a DC discharge, a microwave discharge, an ECR discharge, or the like can be effectively used. It is also a useful method in the present invention to effectively generate ions by an ion generator and guide the ions to the substrate surface. Specifically, various ion generators such as a Kauffman ion gun and an ECR ion gun are used.

In the present invention, the hydrocarbon compound or organic silicon compound gas includes saturated hydrocarbon compounds such as methane and ethane, unsaturated hydrocarbon compounds such as ethylene and acetylene, methylsilane, dimethylsilane, disilylmethane, dimethyldisilane and the like. Of these gases, if necessary, hydrogen gas, deuterium gas, hydrogen fluoride gas, fluorine gas, nitrogen trifluoride,
Mixing a non-deposition gas such as carbon tetrafluoride, argon gas, neon gas, helium gas, xenon gas, and krypton gas does not hinder the present invention and is a more preferable embodiment. The mixing ratio between the hydrocarbon compound or organic silicon compound gas and the other gas is adjusted according to the desired thin film absorption coefficient, conductivity, and carrier density.
Although it is selected, it is usually mixed in the range of 100 ppm to 100%, more preferably 1% to 50%. If the mixing ratio is too low, the absorption coefficient will be high. If the mixing ratio is too high, crystallization will be hindered, and the carrier density will decrease, resulting in a film with high resistance. As described above, the hydrocarbon compound and the organic silicon compound may be used in combination. In this case, the mixing ratio is set to be in the above range in total of both.

Next, specific conditions for the reforming step will be disclosed. When the discharge is used, a discharge power of 1 to 500 W, a mixed gas of a hydrocarbon compound or an organic silicon compound and a non-deposition gas is generated and maintained at a flow rate of 5 to 500 sccm and a pressure of 0.001 mtorr to atmospheric pressure. When using an ion gun, the flow rate of a mixed gas of a hydrocarbon compound or an organic silicon compound and a non-deposition gas is 0.1 to 50 sccm, and the pressure is 0.0001 mtorr.
A pressure range from r to 100 mtorr with ion generation and sufficient lifetime is used. The ion energy in the range of 10 to 1000 eV is sufficient, and preferably 100 to 600 eV. If the energy of the ions is increased beyond this range, the damage due to the ions and the sputtering phenomenon become more intense than the effect of the modification, which is not effective.
Temperature conditions in the reforming step are managed and controlled by the temperature of the substrate. This substrate temperature is the same as or lower than the substrate temperature in the film forming step, and is from room temperature to 600 ° C, preferably 200 to 500 ° C. In one film forming process,
It is formed to a thickness of 1 to 100 °, preferably 3 to 50 °.
When the thickness exceeds 100 °, the effect of the present invention is reduced. On the other hand, a film thickness of less than 1 mm is not preferred because the number of times of film formation and modification is increased from the viewpoint of practicality. The time required for one cycle is not particularly limited, but is within 1000 seconds.

In order to increase the carrier density and reduce the resistance, it is also a preferable embodiment to introduce a gas imparting a p-type or a gas imparting an n-type in addition to the above-mentioned gases. These gases may be introduced together with the film forming raw material, or may be mixed with a gas of a hydrocarbon compound or an organic silicon compound and introduced into the ion generator. p
Examples of the mold-providing gas include boron hydrides such as diborane, boron halide compounds such as boron trifluoride,
A gas such as an organic boron compound such as trimethyl boron is used. On the other hand, as the gas for imparting the n-type, a gas such as a phosphorus hydrogen compound such as phosphine, an arsenic hydrogen compound such as arsine, an organic phosphorus compound such as trimethyl phosphorus or trimethyl arsenic, or an organic arsenic compound is used. Of course, these gases can be used by mixing with non-depositing gases such as hydrogen, deuterium, argon, helium, xenon, neon, and krypton, which is a more preferable embodiment.

The substrate on which the semiconductor thin film of the present invention is formed comprises:
There are no limiting conditions other than withstanding the process temperatures of the present invention. Transparent materials such as blue plate glass, borosilicate glass, and quartz glass, metals, ceramics, heat-resistant polymer materials, and the like can be used as the substrate. In addition, it goes without saying that a substrate on which electrodes used for a solar cell, a sensor, and the like are formed is also effectively used in the present invention. FIG. 1 shows an example of a semiconductor thin film manufacturing apparatus preferable for carrying out the present invention. Here, 1 is an electron beam evaporation apparatus, 2
Is an ion beam generator, 3 is a shutter, 4 is a substrate,
Reference numeral 5 denotes a substrate heater, 6 denotes a turbo molecular pump, 7 denotes an oil rotary pump, 8 denotes a gas flow meter, and 9 denotes a substrate bias power supply. In the following Examples and Comparative Examples, experiments were performed using this device.

[0017]

EXAMPLE 1 FIG. 1 shows an apparatus for carrying out the present invention. The apparatus includes an electron beam evaporation apparatus 1 for depositing silicon and an ion generator 2 for generating ions. A shutter 3 is provided in the electron beam evaporation apparatus and the ion generator, and film formation and modification can be repeated by opening and closing the shutter. As a starting material, high-purity silicon was set in a crucible, irradiated with an electron beam, and evaporated. The substrate temperature was set to 200 ° C., which is the temperature for the next reforming step. Hydrogen gas 10 sccm, 2% diborane / hydrogen dilution gas 0.5 sccm, and methane gas 0.2 sccm as a hydrocarbon compound were introduced into the ion generator, and the pressure was adjusted to 1 × 10 ^-3 torr.
An ion beam voltage of 300 V and an acceleration voltage of 50 V were applied to generate an ion beam, the shutter of the ion beam was opened, and the substrate 4 was irradiated with the ion beam. Here, the presence of ions by the probe near the substrate surface, that is,
It was confirmed that the substrate surface had an atmosphere containing charged particles. At the same time, set the shutter of the electron beam evaporation system to 20
After a few seconds, a 20 ° silicon thin film was deposited on the substrate (deposition process). Next, close the shutter of the electron beam evaporation device,
Only ion beam irradiation was performed for 10 seconds (reforming step). Thus, opening and closing of the shutter of the electron beam evaporation apparatus were repeated at each time interval. About 200Å after 10 repetitions
Was obtained. As the substrate used here, a quartz glass substrate or a glass substrate coated with tin oxide was used. In order to examine the presence or absence of crystallization of these samples, evaluation by Raman scattering spectrum was performed. The result is shown in FIG. As is clear from the figure, in this sample, a Raman scattering spectrum of 520 cm ⁻¹ due to the silicon crystal was observed,
It was confirmed that a crystalline thin film could be obtained even at a film thickness of. In addition, the dark conductivity, carrier density,
When the mobility was measured, they were 1.5 S / cm and 3 ×, respectively.
High conductivity, high carrier density and high hole mobility of 10 ¹⁹ cm ^-3 and 1 cm ² / Vs were confirmed. Furthermore, the optical band gap was 2.3 eV and the absorption was extremely low in the wavelength region of 300 to 700 nm.

Example 2 In Example 1, only the deposition thickness per one time and the modification time were changed to about 4 ° and 6 seconds, respectively.
The deposition thickness was changed by changing the time for opening the shutter of the electron beam deposition apparatus. In Example 1, since the deposition rate by electron beam deposition was found to be about 1 秒 / sec, in this example, one deposition time was set to 4 seconds. Evaporation process-approx.
A 200 mm thin film was obtained. As a result of measuring the same Raman scattering spectrum as in Example 1, a Raman scattering spectrum peculiar to the silicon crystal at 520 cm ⁻¹ was obtained as in Example 1. This embodiment is very effective, deposition - many as the number of modified more than five times in the first embodiment Narri, and, 520 cm for Raman scattering spectra of the 480 cm ^-1 due to the amorphous silicon ^{- Since} the ratio of the Raman scattering spectrum of ¹ was reduced by half, it is determined that the crystallization ratio was reduced.
Further, to reduce the crystallization rate, the dark conductivity was one digit, and the carrier density and the hole mobility were about half the values. Also, the optical band gap was slightly reduced to 2.2 eV.

Example 3 In Example 1, only the deposition thickness per one time and the modification time were changed to about 80 ° and 10 seconds, respectively.
The deposition thickness was changed by changing the time for opening the shutter of the electron beam deposition apparatus. In Example 1, since the deposition rate by electron beam deposition was found to be about 1Å / sec, one deposition time was set to 80 seconds in this example. Approximately 2
A 40 mm thin film was obtained. As a result of measuring the same Raman scattering spectrum as in Example 1, a Raman scattering spectrum peculiar to the silicon crystal at 520 cm ⁻¹ was obtained as in Example 1. This embodiment is very effective, and the number of film formation-modifications
However, the ratio of the 520 cm ^-1 Raman scattering spectrum to the 480 cm ^-1 Raman scattering spectrum attributable to amorphous silicon has been reduced to 1/4. It was determined that the density had decreased, and the dark conductivity decreased by about two orders, and the carrier density and the hole mobility decreased by about one order. The optical band gap also decreased slightly by 2.1 eV, and the absorption coefficient slightly increased.

Comparative Example 1 In Example 1, the thickness was reduced to 200 mm without going through a reforming step using only the ion irradiation in which the film formation was interrupted (that is, without performing the ion irradiation and the film formation). Formed up to. That is, the shutters of the ion beam evaporation apparatus and the electron beam evaporation apparatus were simultaneously opened, and in Example 1, the deposition rate by electron beam evaporation was found to be about 1 mm / sec. After 200 seconds, both shutters were closed to complete the formation. did. When the Raman scattering spectrum of this sample was measured in the same manner as in the example, as shown in FIG. 3, a Raman scattering spectrum peculiar to the silicon crystal at 520 cm ⁻¹ was not observed. The dark conductivity of this thin film is 4 × 10 ^-13 S / cm, the carrier density is 3 × 10 ¹² cm ^-3 , the hole mobility is 0.0003 cm ² / Vs, and the resistance is high, the carrier density is low, and the hole mobility is low. It was the characteristic of.
This comparative example shows that it is essential to repeat the film formation and the modification only by ion irradiation in order to obtain a crystalline thin film in a state where the total film thickness is 300 mm or less.

Comparative Example 2 A thin film was formed in the same manner as in Example 1 except that methane gas was not introduced into the ion generator and the other conditions were exactly the same. The Raman scattering spectrum of the thin film obtained under these conditions was similar to that of Example 1, and it was confirmed that a crystalline thin film was obtained. However, since a hydrocarbon compound was not introduced, optical spectroscopy was not performed. The band gap decreased to 1.9 eV and the absorption coefficient increased significantly. In this comparative example, in order to obtain a crystalline thin film, repetition of film formation and modification by ion irradiation may be repeated.
This indicates that a hydrocarbon compound or an organic silicon compound needs to be introduced.

Comparative Example 3 In Example 1, after forming a Si thin film to a thickness of 200 °, only ion irradiation was continued. Only irradiation time is 10
00 seconds. In the Raman scattering spectrum of the thin film obtained under these conditions, a spectrum specific to the silicon crystal at 520 cm ^-1 was not observed. Therefore, the electrical characteristics were high resistance and low carrier density. In this comparative example,
This shows that there is an upper limit to the film thickness per cycle in the repetition of the reforming process.

Comparative Example 4 In Example 1, a film was formed without performing ion irradiation in the film forming process. In other words, after opening the shutter of the electron beam evaporation system for 20 seconds, depositing a 20 mm silicon thin film on the substrate
(Film forming step), the shutter of the electron beam evaporation apparatus was closed, and the ion beam shutter was opened, and ion beam irradiation was performed for 10 seconds (reforming step). Next, the shutter for the ion beam is closed, and the shutter of the electron beam evaporation apparatus is opened again to form a film. By repeating this film formation and modification ten times, a thin film of about 200 mm was obtained. As a result of measuring the thin film formed under these conditions by Raman scattering spectrum, a Raman scattering spectrum peculiar to silicon crystal at 520 cm ⁻¹ was not observed. It was also found that the electrical characteristics were characteristics of high resistance and low carrier density. In this comparative example, the condition of the film thickness per one time was selected within the range specified in the present invention, and even if the film forming-modifying step was repeated, in the case of no ion irradiation in the film forming step, Clearly shows no effect.

[0024]

As is clear from the above Examples and Comparative Examples, the semiconductor thin film produced by using this method has a thickness of 300
Å Even at the following film thickness, it is a thin film having crystallinity,
In addition, it was confirmed that the film had characteristics of low absorption, high carrier density and high hole mobility. This makes it possible to apply a microcrystalline semiconductor thin film to a p-layer or an n-layer of an amorphous solar cell, which has been difficult in the past. It leads to improvement of the nature. Therefore, the present invention can provide a powerful technology that enables high conversion efficiency and high reliability required for power solar cells, for the energy industry,
It must be said that this is a very useful invention. In addition,
It is believed that the technical matters disclosed by the present invention have a great impact on those skilled in the art to which the present invention pertains.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a semiconductor thin film manufacturing apparatus for carrying out the present invention.

FIG. 2 is a Raman scattering spectrum chart of a semiconductor thin film formed by the method shown in Example 1.

FIG. 3 is a Raman scattering spectrum chart of a semiconductor thin film formed under the conditions shown in Comparative Example 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electron beam vapor deposition apparatus 2 Ion beam generator 3 Shutter 4 Substrate 5 Substrate heater 6 Turbo molecular pump 7 Oil rotary pump 8 Gas flow meter 9 Substrate bias power supply

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-245849 (JP, A) JP-A-2-271995 (JP, A) JP-A-3-32018 (JP, A) JP-A-3-32018 60025 (JP, A) JP-A-5-24999 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/18-21/20 H01L 21/205

Claims (3)

(57) [Claims] 1. A raw material for forming a thin film of silicon, a silicon compound or a silicon alloy is supplied in an atmosphere containing charged particles obtained by discharging a mixed gas of a hydrocarbon compound or an organic silicon compound and a non-deposition gas. A step of forming a thin film of silicon, a silicon compound or a silicon alloy, and stopping the supply of the raw material for forming the thin film to discharge a mixed gas of a hydrocarbon compound or an organic silicon compound and a non-deposited gas; Repeating the step of exposing the surface on which the thin film is formed to an atmosphere containing particles, and wherein the thickness of the silicon, silicon compound or silicon alloy thin film formed in one cycle is 1 to 100 mm and the total thickness is 300 mm or less. Crystalline semiconductor thin film. 2. A gas mixture of a hydrocarbon compound or an organic silicon compound and a non-sedimentable gas is introduced into an ion generator, and a thin film having a thickness of 1 to 100 ° is irradiated with low-energy ions on the surface on which the thin film is formed. 2. The crystalline semiconductor thin film according to claim 1, wherein the step of forming and the step of stopping the supply of the deposition gas and continuing the ion irradiation are repeated. 3. The crystalline semiconductor thin film according to claim 2, wherein low energy ions irradiated to the thin film growth surface are 1 KeV or less.