JPH0639688B2 - Method of forming silicon thin film - Google Patents

Description

The present invention relates to a method for forming a silicon thin film using a high frequency reactive ion plating method.

Usually, a silicon thin film is a single crystal,
It is classified into polycrystalline and amorphous. Amorphous silicon (hereinafter referred to as a-Si) has a large light absorption coefficient in the visible light region and the near-ultraviolet light region, and thus is widely applied to solar cells, optical sensors, image sensors, electrophotographic photoreceptors, and the like. ing. Further, since it is possible to form an a-Si thin film at a low temperature, a thin film transistor formed on a glass substrate or the like has been studied. It goes without saying that the single crystal and polycrystalline thin films are applied to various electronic devices including integrated circuits.

In general, the crystallographic properties of a silicon thin film depend on the substrate temperature at the time of forming the thin film, the type of substrate underlayer, the atmosphere and the forming conditions specific to the forming method, and are either single crystal, polycrystal, or amorphous thin film. It becomes a silicon thin film.

However, a silicon thin film having any crystallographic property cannot be used as a thin film for an active element of an electronic device. It is difficult to make electronic devices due to the extremely low carrier mobility and the inability to control valence electrons such as p-type, i-type, and n-type due to many defects in polycrystals and amorphouss with minute crystal grain sizes. That's why. The above-mentioned a, which has recently begun to be applied to electronic devices.
For the -Si thin film and some polycrystalline Si thin films, for this reason, a film in which the dangling bonds of the silicon network in the film that are defective are compensated by hydrogen atoms is used.

The silicon thin film in which the dangling bonds of silicon are compensated by hydrogen atoms has the Si—H bond energy of 3.1 eV, which is relatively small, and thus has various drawbacks described below. That is, hydrogen is released at a temperature of about 350 ° C., and it is weak against light energy. Therefore, the heat resistance of the hydrogen-added a-Si thin film is poor and the characteristics of the electronic device are significantly deteriorated. Due to this situation, polycrystalline Si
At the formation temperature, hydrogen is hardly added to the film, and even if the method of pushing atomic hydrogen from the surface after film formation is used, hydrogen can be added only to several thousand Å of the film surface. Moreover, the process for that is complicated. Even with hydrogenated polycrystals, the drawback of hydrogen desorbing at relatively low temperatures has not been solved. Further, hydrogen not only has a large diffusion coefficient in the silicon film, but also enhances the diffusion of impurities in the film, so that the interface characteristics between the electrode metal of the electronic device and the silicon thin film and the silicon layer doped with different impurities are improved. Deterioration, causing deterioration of device characteristics.

In recent years, an a-Si thin film in which a dangling bond is compensated as in the case of hydrogen by using a Si-F bond having a bond energy of 5.6 eV, which is larger than that of the Si-H bond, has begun to be studied. However, although the heat resistance of the a-Si thin film to which the fluorine atom is added is improved, the a-Si thin film has various problems as described below in the method of forming the film.

As a typical method of adding fluorine atoms to the a-Si thin film, a plasma discharge decomposition method (hereinafter referred to as GD method) using a gas of SiF ₄ gas and SiH ₄ or a mixture of SiF ₄ and H ₂ gas is used. ). This is a method in which H ₂ or SiH ₄ must be introduced because it is extremely difficult to form a film by the GD method using only SiF ₄ gas.

Another typical method is a sputtering method. Even in this case, a film having a hygroscopic property or a film in which a large amount of undecomposed SiF ₄ is incorporated is difficult to form a high quality film, and H ₂ or SiH ₄ is introduced as in the GD method. In addition, in the sputtering method, it is necessary to use an Ar atmosphere as sputtering atoms. Due to these restrictions on film formation, the conventional fluorine-added a-Si thin film was a film containing hydrogen which deteriorates heat resistance and Ar which induces film defects.

On the other hand, a method of forming an a-Si thin film which does not include these unnecessary atoms and which is purely fluorine-added, uses SiF ₄ gas and S
There is a GD method using a SiF ₄ gas intermediate gas that is generated after reacting with i. However, since SiF ₄ intermediate gas is generated by the thermal reaction of Si and SiF ₄ gas, the temperature of the reactor must be raised to 1100 ° C. or higher, and SiF _{4 which} is an unreacted component is taken into the film and becomes a defect. It had problems such as easiness.

As a method for forming an a-Si thin film containing only fluorine, we also proposed a method using an ion plating method (Japanese Patent Application No. 55-104518), but as a result of further detailed examination, It was found that undecomposed SiF _x is included because of the difficulty in decomposing the SiF ₄ gas. Si
Increasing the discharge power, increasing the ion accelerating voltage, and increasing the substrate temperature in order to accelerate the decomposition of F ₄ gas also has the effect of deteriorating the film quality, and therefore, a high quality a
It was difficult to obtain a -Si thin film. As mentioned above,
The conventional method has a problem that it is difficult to obtain a good quality a-Si thin film.

An object of the present invention is to eliminate the above-mentioned problems and provide a method for forming a silicon thin film that can obtain a good quality silicon thin film.

The first method for forming a silicon thin film according to the present invention is to generate an electron beam on a high vacuum side in which a pressure difference is generated by a differential exhaust plate that partitions a reaction chamber and an electron beam generation chamber of a high frequency reactive ion plating apparatus. An evaporator installed in the chamber is charged with a silicon mass, the silicon mass is vaporized by electron beam heating, and the vaporized silicon gas is introduced into the reaction chamber on the low vacuum side of the differential exhaust plate, And a mixed gas consisting of fluorine gas and an impurity doping gas such as phosphorus or boron, which are separately introduced into the reaction chamber, are discharged into the discharge plasma generated in the reaction chamber to react with each other, and the thin film deposited in the reaction chamber is deposited. Forming a silicon thin film to which fluorine has been added on a substrate for use.

The second method for forming a silicon thin film according to the present invention is to generate an electron beam on the high vacuum side in which a pressure difference is generated by a differential exhaust plate partitioning a reaction chamber and an electron beam generation chamber of a high frequency reactive ion plating apparatus. In the evaporator installed in the chamber, tin, germanium, lead, aluminum, gallium, indium,
A solid solution mass of a metal selected from arsenic and antimony and silicon is charged, the solid solution mass is vaporized by electron beam heating, and the vaporized silicon and metal gases are reacted on the low vacuum side of the differential exhaust plate. Introduced into the chamber, the silicon and metal gases and a mixed gas consisting of an inert gas such as fluorine gas and helium, which are separately introduced into the reaction chamber, are released into the discharge plasma generated in the reaction chamber and reacted. Forming a fluorine-added silicon thin film on the thin film deposition substrate loaded in the reaction chamber.

The third method for forming a silicon thin film of the present invention is to generate an electron beam on the high vacuum side in which a pressure difference is generated by a differential exhaust plate partitioning the reaction chamber and the electron beam generation chamber of the high frequency reactive ion plating apparatus. An evaporator loaded with a metal block selected from tin, germanium, lead, aluminum, gallium, indium, arsenic, and antimony and an evaporator loaded with a silicon block were installed in the chamber, and vaporized by heating an electron beam. The vaporized silicon gas and metal gas are introduced into the reaction chamber on the low vacuum side of the differential exhaust plate, and the silicon gas and the metal gas are separately introduced into the reaction chamber. Is discharged into the discharge plasma generated in the reaction chamber to react therewith, and fluorine is deposited on the thin film deposition substrate loaded in the reaction chamber. Configured to include forming an added silicon thin film.

A fourth method for forming a silicon thin film according to the present invention is to generate an electron beam on a high vacuum side in which a pressure difference is generated by a differential exhaust plate that partitions a reaction chamber and an electron beam generation chamber of a high frequency reactive ion plating apparatus. An evaporator installed in the chamber is charged with a silicon mass, the silicon mass is vaporized by electron beam heating, and the vaporized silicon gas is introduced into a reaction chamber on the low vacuum side of the differential exhaust plate, and the silicon gas is introduced. And a thin film loaded in the reaction chamber by releasing fluorine gas and an impurity doping gas such as phosphorus or boron introduced into the reaction chamber from separate independent systems into the discharge plasma generated in the reaction chamber to cause reaction. It comprises forming a fluorine-doped silicon thin film on a substrate for deposition.

Next, embodiments of the present invention will be described with reference to the drawings.

[Embodiment 1] This embodiment is the first embodiment of the first invention.

FIG. 1 is a schematic view of a high frequency reactive ion plating apparatus used in the embodiment of the first invention.

As shown in FIG. 1, the reaction chamber 1 for forming a thin film and the electron beam generating chamber 3 are partitioned by a stainless steel differential exhaust plate 2 for producing a pressure difference, and the electron beam generating chamber 3 is exhausted. It is connected to an exhaust system of 10 ⁻⁶ Toor or less through a tube 4 and kept in a high vacuum for generating an electron beam. Fluorine gas is introduced into the reaction chamber 1 via the gas introduction pipe 5 through the mass flow controller for fluorine gas 16, and impurities for setting the conductivity type of the thin film to be formed to p, i, or n type. A small amount of a doping gas such as PH ₃ (phosphine), B ₂ H ₆ (diborane), which is a hydride of phosphorus or boron, or BF _3, which is a fluoride, is introduced through the mass flow controller 17 for the doping gas as needed. It In the electron beam generating chamber 3, an electron beam 7 is generated by an electron beam heater for heating and evaporating an evaporation source to heat the silicon mass 6 of the thin film forming material,
Evaporate. The evaporated silicon gas 18 flies into the reaction chamber 1, holds the substrate 8 for depositing a thin film, and heads toward the substrate holder 9 which is heated and to which a potential for ion acceleration is applied. A vapor gas between the evaporation source and the substrate holder, a high frequency coil 10 for ionizing the gas
Is provided. The inside of the reaction chamber 1 is about 3 × 10 ⁻⁴ Torr to 3 × depending on the partial pressure of the evaporated gas and the partial pressure of the introduced gas.
A vacuum of about 10 ^-2 Torr is maintained and discharge plasma is generated. Here, since the plasma is electromagnetically shielded by the differential exhaust plate 2, the electron beam generating chamber 3 is shielded from the plasma generated in the reaction chamber 1. As external power sources, a high frequency power source 11 connected to a high frequency circuit matching box 12, an electron beam power source 13, a substrate heating power source 14, and an ion acceleration power source 15 are provided.

A Si wafer having a specific resistance of about 10 Ω-cm was used as a substrate and set on the substrate holder 9. After evacuating the reaction chamber 1 to a vacuum level of 10 ^-5 Torr or less,
Mass flow controller for fluorine gas 1 from gas inlet pipe 5
6 to adjust the degree of vacuum in the reaction chamber 1 to 5 by introducing fluorine gas.
It was set to × 10 ^-3 Torr. At this time, the degree of vacuum in the electron beam generating chamber 3 is about 10 ⁻³ T due to the action of the differential exhaust plate 2.
Unless kept below orr, the degree of vacuum is lowered and an electron beam cannot be generated. The degree of vacuum in the reaction chamber is 3 × 10 ^{−4 at} the total gas pressure of silicon gas and introduced gas.
Stable plasma discharge can be obtained when it is set in the range of Torr to 3 × 10 ^-2 Torr. Substrate 8 is power source 1 for heating
4 and kept at 350 ° C. Resistivity of about 1000 inserted in electron beam heating evaporation source as evaporation silicon material
The electron beam power source 13 is used for the n-type silicon block 6 of about Ω-cm.
The electron beam 7 was heated by the above operation to evaporate.
At this time, the high-frequency coil 10 is supplied with about 13.
00 W of power was supplied. As a result, plasma discharge occurs, and the vaporized silicon gas and the introduced fluorine gas are ionized or decomposed. Further, an ion acceleration voltage of 200 V is applied to the substrate holder 9 by the power source 15, and the ions generated on the substrate are irradiated to obtain a thin film to which fluorine atoms are added.

FIG. 2 is an infrared absorption spectrum distribution diagram of the silicon thin film formed by Example 1 and the conventional method.

As shown in FIG. 2, the solid line 21 represents the spectral distribution of the silicon thin film formed in Example 1. Absorption peak is 82
It was observed only at 0 cm ⁻¹ and it was confirmed that only a Si—F single bond was generated. Dotted line 22 is conventional SiF ₄
The spectral distribution of the silicon thin film formed by the method using gas is shown. This spectrum is 920 cm ^-1 , 965c
It shows that at m ⁻¹ , 1015 cm ⁻¹ , there are many high-order bonds of Si—F ₂ , Si—F ₃ , and Si—F ₄ , which are considered to be undecomposed components of SiF ₄ . Further, in the case of a conventional thin film formed with a high discharge power or a high ion acceleration voltage in order to accelerate the decomposition of SiF ₄ , as shown by a broken line 23, although the above-mentioned higher-order bonds are reduced, a small absorption peak is generated. It was observed, and a new absorption peak appeared at 750 cm ^-1 . This is because contamination by carbon or the like is caused or silicon clusters are formed, and the film quality is not improved so much. On the other hand, in the case of the film using the fluorine gas (F ₂ ) as in this embodiment, since the F ₂ is easily decomposed, there is no formation of the above-mentioned higher-order bonds or contamination, and no formation of clusters. As a result, a good-quality silicon thin film with few defects in the film could be formed.

[Embodiment 2] This embodiment is the second embodiment of the first invention.

The same high frequency reactive ion plating device as in Example 1 was used. The basic thin film forming conditions were set similarly. However, the substrate temperature was changed in the range of 100 ° C. to 750 ° C. to form a fluorine-added silicon thin film. The content of fluorine contained in these thin films is analyzed by IMA (ion microanalyzer), and the results are shown in FIG.
Indicate. Further, the particle size of the silicon thin film deposited on the metal mesh covered with the carbon support film under the same conditions as the formation of the thin film was observed by TEM (transmission electron microscope), and the result is shown by a curve 32 in FIG. The amount of fluorine contained in the film tended to decrease as the substrate temperature increased, but even with a silicon thin film deposited at a high temperature of around 700 ° C, 1
% Content was above. Further, when the substrate temperature was 500 ° C. or lower, the crystal grain size was several hundred liters or less, which was a so-called amorphous silicon thin film. When the substrate temperature exceeded 600 ° C., the crystal grain size suddenly increased and a polycrystalline silicon thin film was formed. When the substrate temperature was around 500 ° C. to 600 ° C., the silicon thin film was mainly composed of fine crystals with a crystal grain size of around 1000 Å.

[Embodiment 3] This embodiment is the third embodiment of the first invention.

The same high frequency reactive ion plating device as in Example 1 was used. The basic thin film forming conditions were set as in Example 1. However, a glass substrate was used as the substrate, and the substrate temperature was set to 300 ° C. Further, the amount of fluorine gas introduced was changed variously with respect to the partial pressure of the vaporized silicon gas. The partial pressure of silicon gas is adjusted to 3 × 10 ^-5 by adjusting the electron beam current.
The range of Torr to 9 × 10 ^-4 Torr, the partial pressure of fluorine gas is adjusted by adjusting the mass flow controller to change the introduction amount to 1
The range is from × 10 ^-4 Torr to 3 × 10 ^-2 Torr, and P
_{The F2} / P _{(Si + F2)} ratio was changed from 1.0 to 99.9%. An aluminum electrode is formed on the silicon thin film formed under the above conditions, and the exposed silicon thin film between the two electrodes is irradiated with light to measure the photoconductivity. The results are shown in FIG. A film having good photoconductive properties was obtained when the partial pressure of F ₂ was high. In particular, when the silicon vapor pressure is set to about 8 × 10 ⁻³ Torr and the introduced gas pressure of F ₂ is set to about 4 × 10 ⁻³ Torr, the photoconductivity exceeds 10 ⁻⁴ (Ω-cm) ^−1. It was found that the more obtained the properties, the better. Here, the doping gases such as diborane and phosphine are both 0.
1 to 1000 ppm (preferably about several 100 ppm)
It was possible to obtain p-type or n-type conductivity.

Next, P _F2 / P _{(Si + F2)} was set to 0.84, the other conditions were set as in Example 1, and the ion acceleration voltage was set to 0 to 10.
A silicon thin film was formed by changing the voltage in the range of 00V. The result of measuring the photoconductivity of these films is shown by a solid line 51 in FIG. 5, and the case of using the conventional SiF ₄ gas is also shown by a broken line 52. F ₂ compared with the case of using conventional SiF ₄ gas
In the case of the present example using gas, the optimum photoconductive property is shown at a lower accelerating voltage, and the value is improved by about one digit. Especially when the ion acceleration voltage is zero, the difference is remarkable, and
When iF ₄ gas is used, the characteristics are poor and it cannot be used.
_When formed using _two gases, a silicon thin film that can withstand sufficient use could be formed.

[Embodiment 4] This embodiment is an embodiment of the second invention.

A high frequency reactive ion plating device similar to that of Example 1 was used. The basic conditions for forming a thin film are the same as in Example 1, except that the introduced fluorine gas is a mixture of an inert gas, helium gas, as a diluent gas, and is inserted into an evaporation source. The sources are different. The silicon ingot and the small pieces of high-purity aluminum were inserted into the evaporation source at a mixing ratio such that the weight ratio of aluminum to silicon was 10% or less. Prior to the deposition of the silicon thin film, the above-mentioned mixed source is melted by electron beam heating and uniformly mixed. Even if the mixing weight ratio is 10% or more, it can be easily co-melted. Sn, G which is a solid doping material other than aluminum
Even in the case of e, Ga, In, As, Sb, etc., if the mixing ratio with respect to silicon is several tens% or less by weight, uniform melting and mixing can be performed. When depositing a silicon thin film, the solid solution of the silicon and the doping metal is electron beam heated to form a silicon thin film doped with the metal and doped with fluorine atoms. The results of measuring the resistivity of the silicon thin film deposited by doping Al and Sb at a substrate temperature of 500 ° C. are shown in FIG. Curve 61 is Al
And the curve 62 shows the resistivity of each of Sb-doped and Sb-doped. A wide range of changes in resistivity was obtained for each. Similar results were obtained for Ga, In and As, but in the case of Sn and Ge, the effect of lowering the resistance was small, but there was a phenomenon in which the optical absorption edge changed. Fluorine gas with helium as a diluent gas was used, but since helium is inert and does not react during discharge film formation, it may not be taken into the film or cause troubles during the film formation process. There wasn't.

[Embodiment 5] This embodiment is an embodiment of the third invention.

FIG. 7 is a schematic view of a high frequency reactive ion plating apparatus used in the embodiment of the third invention, and the basic points have the same constitution and function as those used in the embodiment 1.

As shown in FIG. 7, an evaporator 73 exposed from a differential exhaust plate 72 is provided in a reaction chamber 71 for forming a thin film,
It has two independent evaporation sources. The differential exhaust plate is provided with a small hole through which an electron beam for heating penetrates. The release of the fluorine gas or the like introduced through the gas introduction pipe 74 surrounds the two types of evaporation sources in order to uniformly mix the vaporized silicon and the doping element with the two types of evaporation sources. A method of discharging gas from a small hole provided inside is used by using the circumferential gas discharger 75 provided as described above. In the evaporator 73, a silicon block and Sn,
A metal block selected from Ge, Pb, Al, Ga, In, As, Sb, etc. is inserted. These are electron beam-heated by the two power sources 76 and 77 respectively independently provided, so that the vapor pressure of silicon and the vapor pressure of the dopant can be controlled independently, so that precise control can be performed. It is also extremely effective when forming a multilayer film of an undoped silicon thin film and a doped thin film. Other basic configurations and conditions were set in the same manner as in Example 4.
Now, an example in which a silicon block and a germanium block are inserted will be described. The silicon lump and the germanium lump are independently heated, and the generated vapor pressure is measured with a vacuum gauge,
A silicon thin film was formed at a substrate temperature of 400 ° C. by changing each partial pressure ratio. Optical absorption edge E of this thin film
The result of measuring o is shown in FIG. As the doping amount of Ge increased, a mixed crystal of Si and Ge was formed, and Eo tended to decrease. Thus, when solid Ge was used, control with good reproducibility could be performed. Also, when other solid dopants were used, the control of the film resistivity could be controlled with good reproducibility.

[Embodiment 6] This embodiment is an embodiment of the fourth invention.

FIG. 9 is a schematic diagram of a high-frequency reactive ion plating apparatus used in the fourth embodiment of the invention, and basically has the same configuration and function as those used in the first embodiment.

As shown in FIG. 9, it is provided inside a gas discharger 94 provided so as to surround the evaporation source via independent gas introduction pipes 92 and 93 in a reaction chamber 91 for forming a thin film. Gas is released from the small hole 95. The two gas introduction pipes 92, 93 and the gas discharge pipe 94 are connected at different positions. Fluorine gas is introduced from one gas introduction pipe 92 through a fluorine gas flow rate controller 96, doping gas is introduced from the other gas introduction tube 93 through a doping gas flow rate controller 97, and discharged through a gas discharger 94. Each gas is released into the plasma. As a result, for example, even when the fluorine gas and the doping gas which is hydrogen or hydride are introduced, no reaction occurs in the gas system before the introduction into the reaction chamber 91, no trouble occurs, and the doping element does not disappear. Therefore, stable doping could be performed. First, the basic device configuration and formation conditions were set in the same manner as in Example 1, the substrate temperature was set to 450 ° C., and boron was doped to form a silicon thin film. The measurement results of the resistivity of the obtained thin film are shown in FIG. Curve 101 shows the case of using BF ₃ as a doping gas,
A curve 102 shows the result when B ₂ H ₆ is used and the doping amount is represented by each flow rate ratio with respect to the fluorine gas flow rate. The resistance of B ₂ H ₆ is lower than that of BF ₃ even with the same doping amount. This seems to be because B ₂ H ₆ is more easily decomposed than BF ₃ due to the effect of F ₂ . Next, the substrate temperature was set to 600 ° C., and a polycrystalline silicon thin film doped with PH ₃ was deposited on the quartz substrate. The deposited silicon thin film was formed into a stripe shape, and a NiCr / Au electrode was formed to prepare a thermoelectric element. The heat resistance of the film was investigated using this device.

FIG. 11 shows 1 with respect to the temperature of the atmosphere in which this device is placed.
It shows a change in thermoelectromotive force per 00 ° C. 10
29 mV is obtained per 0 ° C., which is an extremely large electromotive force compared with 4 mV of an alumel-chromel thermocouple, which has a relatively large thermoelectromotive force with a normal thermocouple. However, although it has been considered that the use of PH ₃ may introduce hydrogen atoms into the film and cause deterioration of the element, the number of hydrogen atoms in the film is extremely small, and as shown in FIG. It could be used as a thermoelectric element.

As described above, when F ₂ gas is used, both the ease of decomposition of F ₂ gas itself and the ease of decomposition of hydride because F ₂ easily bonds with hydrogen of hydride are achieved and doped. The effect of facilitating the formation of the silicon thin film is great.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a high-frequency ion plating apparatus used in the embodiment of the first invention, FIG. 2 is an infrared absorption spectrum distribution diagram of a silicon thin film formed by Embodiment 1 and the conventional method, and FIG. Correlation diagram of the fluorine content and crystal grain size of the silicon thin film formed in Example 2 with respect to the substrate temperature, FIG. 4 is a correlation diagram of photoconductivity of the silicon thin film formed in Example 3 with respect to gas pressure, and FIG. Correlation diagram of photoconductivity of the silicon thin film formed in Example 3 with respect to ion acceleration voltage, FIG. 6 is a correlation diagram of resistivity of the silicon thin film formed in Example 4 with respect to doping amount, and FIG. 7 is a third invention. 8 is a schematic diagram of a high frequency reactive ion plating apparatus used in the embodiment of FIG. 8, FIG. 8 is a correlation diagram with respect to the doping amount of the optical absorption edge of the silicon thin film formed in Embodiment 5, and FIG. 9 is an embodiment of the fourth invention. High frequency used for Schematic view of ion plating apparatus, Figure 10 is a correlation diagram for the doping amount of resistivity of the silicon thin film formed in Example 6, FIG. 11 Example 6
It is a correlation diagram with respect to the temperature of the thermoelectromotive force of the silicon thin film formed in. 1 ... Reaction chamber, 2 ... Differential exhaust plate, 3 ... Electron beam generating chamber, 4 ... Exhaust pipe, 5 ... Gas introduction pipe, 6 ... Silicon mass, 7 ... Electron beam, 8 ... Substrate, 9 ... Substrate holder, 10 ... High frequency coil, 11 ... High frequency power source, 1
2 ... Etching box, 13 ... Electron beam power supply,
14 ... Heating power supply, 15 ... Ion acceleration power supply, 16
...... F ₂ flow rate controller, 17 …… doping gas flow rate controller, 18 ・ ・ ・ silicon substrate, 71 ・ ・ ・ reaction chamber, 72
...... Differential exhaust plate, 73 …… Evaporator, 74 …… Gas introduction pipe, 75 …… Gas discharger, 76,77 …… Electron beam power source, 91 …… Reaction chamber, 92,93 …… Gas introduction pipe , 94
...... Gas discharger, 95 …… Gas discharge head, 96 …… F ₂
Flow controller, 97 ... Doping gas flow controller.

Claims (4)

[Claims] 1. A vaporizer installed in a high vacuum side electron beam generating chamber in which a pressure difference is generated by a differential exhaust plate partitioning the reaction chamber of the high frequency reactive ion plating device and the electron beam generating chamber. A lump is charged, the silicon lump is vaporized by electron beam heating, and the vaporized silicon gas is introduced into the reaction chamber on the low vacuum side of the differential exhaust plate, and is introduced into the reaction chamber separately from the silicon gas. A mixed gas of fluorine gas and an impurity doping gas such as phosphorus or boron is released into the discharge plasma generated in the reaction chamber to react with each other, and fluorine is added to the thin film deposition substrate loaded in the reaction chamber. Method for forming a silicon thin film, comprising: forming a thinned silicon thin film. 2. A tin is attached to an evaporator installed in a high vacuum side electron beam generating chamber in which a pressure difference is generated by a differential exhaust plate partitioning the reaction chamber of the high frequency reactive ion plating device and the electron beam generating chamber. , Germanium, lead, aluminum,
A solid solution mass of a metal selected from gallium, indium, arsenic, and antimony and silicon is loaded, the solid solution mass is vaporized by electron beam heating, and the vaporized silicon and metal gas is reduced to a low temperature of the differential exhaust plate. Introduced into the reaction chamber on the vacuum side, the silicon and metal gases and a mixed gas consisting of fluorine gas and an inert gas such as helium, which are separately introduced into the reaction chamber, are released into the discharge plasma generated in the reaction chamber. And reacting to form a silicon thin film to which fluorine is added on the substrate for thin film deposition loaded in the reaction chamber. 3. A high-vacuum-side electron beam generating chamber in which a pressure difference is generated by a differential exhaust plate partitioning the reaction chamber of the high-frequency reactive ion plating apparatus and the electron beam generating chamber is filled with tin, germanium, lead, An evaporator loaded with a metal mass selected from aluminum, gallium, indium, arsenic, and antimony and an evaporator loaded with a silicon mass are installed, and vaporized by heating an electron beam, and the vaporized silicon gas and metal gas Each of them is introduced into the reaction chamber on the low vacuum side of the differential exhaust plate, and the reaction is performed with the silicon gas and the metal gas and a mixed gas consisting of a fluorine gas and an inert gas such as helium, which are separately introduced into the reaction chamber. The silicon thin film added with fluorine is formed on the substrate for thin film deposition, which is discharged into the discharge plasma generated in the chamber and reacted therewith. Method of forming a silicon thin film characterized by comprising. 4. An evaporator installed in a high vacuum side electron beam generating chamber in which a pressure difference is generated by a differential exhaust plate partitioning the reaction chamber of the high frequency reactive ion plating device and the electron beam generating chamber. A lump is charged, the lump of silicon is vaporized by electron beam heating, the vaporized silicon gas is introduced into the reaction chamber on the low vacuum side of the differential exhaust plate, and the silicon gas reacts from a system independent from the silicon gas. The fluorine gas introduced into the chamber and the impurity doping gas such as phosphorus or boron are released into the discharge plasma generated in the reaction chamber to cause a reaction, and fluorine is deposited on the substrate for thin film deposition loaded in the reaction chamber. A method of forming a silicon thin film, comprising forming an added silicon thin film.