JPH0649636A - Production of amorphous semiconductor - Google Patents

Abstract

PURPOSE:To enable the production of the amorphous semiconductor with which supply of materials in a gaseous state is difficult and to produce the amorphous semiconductor which has good quality, is inexpensive and is applicable to various kinds of devices while maintaining safe working environment. CONSTITUTION:Plasma flow 17 based on the gas introduced into a plasma chamber 11 is generated by accelerating electrons under an electron cyclotron resonance condition by the interaction of microwaves and magnetic fields. This plasma flow 17 is brought into collision against a solid sputtering target 18 to jump sputtered atoms out of the sputtering target 18. The sputtered atoms are deposited on a substrate 22, by which the amorphous semiconductor thin film is formed on the substrate 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor element and a method for producing an amorphous semiconductor used in an applied device incorporating the semiconductor element.

[0002]

2. Description of the Related Art Amorphous semiconductors such as amorphous silicon hydride (a-Si: H) are used as semiconductor device materials.
It is used in devices such as solar cells, thin film transistors (TFTs), image scanners, and photosensitive drums.

Amorphous semiconductors are generally manufactured by a plasma CVD (chemical vapor deposition) method using a plasma CVD apparatus shown in FIG.

In the plasma CVD apparatus, a high frequency power source 43 is connected to an anode 46 and a cathode 47. The anode 4
A raw material gas is introduced from a raw material gas introduction pipe 50 into a reaction vessel 48 surrounding the cathode 6 and the cathode 47. The inside of the reaction container 48 is decompressed by the exhaust from the exhaust port 51. The anode 46 is heated by the heater 41. The substrate 42 is mounted on the anode 46.

According to the plasma CVD method, the raw material gas from the raw material gas introducing pipe 50 is turned into plasma by the discharge between the anode 46 and the cathode 47, and the turned raw material gas is placed on the substrate 42. By depositing on the substrate 42, a thin film of an amorphous semiconductor can be formed on the substrate 42.

In the plasma CVD method, the source gas is selected according to the type of amorphous semiconductor to be produced.
That is, in the case of producing amorphous silicon hydride, silane (SiH ₄ ) and hydrogen are mainly used as the source gas.
(H ₂ ) is used. Further, when producing amorphous silicon germanium hydride, silane (SiH ₄ ) and germane (Ge) are used.
H ₄ ) and hydrogen (H ₂ ) are used. When producing amorphous hydrogenated silicon oxide, silane is used as a source gas.
(SiH ₄ ), carbon dioxide (CO ₂ ), and H ₂ are mainly used. When making other amorphous semiconductors,
The source gas is selected according to the type of amorphous semiconductor.

Further, as another method for manufacturing an amorphous semiconductor, a photo CVD method, an ECR (electron cyclotron resonance) -C method is used.
There are a VD method, a reactive sputtering method and the like.

For example, in the photo-CVD method, when forming amorphous silicon hydride (a-Si: H), disilane (Si ₂
H ₄ ) can be decomposed directly by UV light, or silane (Si
Amorphous silicon hydride is produced by decomposing H ₄ ) by a mercury sensitization method.

Further, ECR (electron cyclotron resonance)-
In the CVD method, a magnetic field is applied while introducing a microwave into a plasma chamber into which a rare gas series gas is introduced, and plasma is generated under electron cyclotron resonance conditions. Then, this plasma decomposes silane (SiH ₄ ) to produce an amorphous semiconductor.

In the reactive sputtering method, an amorphous semiconductor is produced by sputtering a silicon target with a gas such as a rare gas series gas and introducing H ₂ .

Various methods other than the above have been proposed as a method for manufacturing an amorphous semiconductor, but the properties of the raw materials differ depending on the manufacturing method. Generally, amorphous silicon hydride (a-Si: H) is used for solar cells and thin film transistors.
When applied to devices such as (TFT), plasma C
Since a good quality thin film can be formed by the VD method, the plasma CVD apparatus used for the plasma CVD method is mainly used as a manufacturing apparatus for product development.

[0012]

However, when the CVD method including the plasma CVD method and the photo CVD method is used in the conventional method for manufacturing an amorphous semiconductor, silane is used.
It is necessary to use a special material gas for semiconductors such as (SiH ₄ ).
That is, the above-mentioned CVD method has a drawback that only an amorphous semiconductor capable of supplying a raw material in a gas state can be manufactured.

Further, in general, the above-mentioned special material gas for semiconductors often has flammability and toxicity. Therefore,
In the above CVD method, the production of amorphous semiconductor can be safely performed.
In addition, in order to carry out efforts to prevent environmental pollution, it is necessary to add equipment such as an exhaust gas treatment apparatus to the manufacturing apparatus, which has a disadvantage of increasing product cost.

As described above, in the CVD method, the amorphous semiconductors that can be produced are limited to those that can supply the raw material in a gas state, and the manufacturing equipment is required to ensure the safety and safety of the working environment. There is a drawback that the cost is increased and the product cost is increased.

By the way, according to the above-mentioned reactive sputtering method, since a solid is used as a raw material of an amorphous semiconductor without using a gas, the disadvantage of the CVD method that requires the use of gas as the raw material is solved. You can

However, the above reactive sputtering method is
Higher discharge voltage than other manufacturing methods (several 100V or more)
Therefore, the reactive sputtering method has a drawback that it is easily damaged by plasma during film formation of an amorphous semiconductor.

Further, the above reactive sputtering method uses 10 ^-3 T
Since an amorphous semiconductor is formed by sputtering at a pressure of about orr, impurities in the atmosphere can be easily taken into the semiconductor film. Therefore, there is a drawback that it is difficult to form a high-quality amorphous semiconductor thin film applicable to devices.

Therefore, an object of the present invention is to use an amorphous semiconductor material as a solid material to produce an amorphous semiconductor in which it is difficult to supply a material in a gas state, while maintaining a safe working environment. An object of the present invention is to provide a method for producing an amorphous semiconductor, which can be applied to various devices and which can produce a high-quality and low-cost amorphous semiconductor.

[0019]

In order to achieve the above object, a method for producing an amorphous semiconductor according to the present invention comprises introducing a gas into a plasma chamber and applying a microwave and a magnetic field to the plasma chamber, By setting the electron cyclotron resonance condition in the plasma chamber by the interaction between the microwave and the magnetic field,
By accelerating electrons, plasma of the introduced gas is generated, the plasma is made to collide with a solid sputter target, and sputter atoms are ejected from the sputter target, and the sputter atoms are deposited on a substrate. It is characterized in that an amorphous semiconductor is formed on the substrate.

Further, a rare gas series gas and hydrogen are used as the introduction gas, silicon is used as the sputtering target, and amorphous hydrogenated silicon (a-Si: a-Si: It is desirable to make H).

Further, a rare gas series gas and hydrogen are used as the introduction gas, a mixture of silicon and germanium is used as the sputter target, and amorphous hydrogenated silicon as an amorphous semiconductor is formed on the substrate. It is desirable to make germanium (a-SiGe: H).

A rare gas series gas, hydrogen, and oxygen or carbon dioxide are used as the introduction gas, silicon is used as the sputter target, and amorphous hydrogenation is performed as an amorphous semiconductor on the substrate. It is desirable to make silicon oxide (a-SiO: H).

A rare gas series gas, hydrogen, and a hydrocarbon gas are used as the introduction gas, silicon is used as the sputtering target, and an amorphous hydrogenated silicon car is used as an amorphous semiconductor on the substrate. Byte (a-SiC:
It is desirable to make H).

A rare gas series gas, hydrogen, and nitrogen or ammonia are used as the introduction gas, silicon or silicon nitride is used as the sputter target, and an amorphous semiconductor is formed on the substrate as an amorphous semiconductor. It is desirable to make a hydrogenated silicon nitride (a-SiN: H).

Further, a rare gas series gas, hydrogen, and nitrogen oxide or nitrogen and oxygen are used as the introduction gas, and silicon or silicon oxide or silicon nitride or silicon oxide and silicon nitride is used as the sputtering target. Using the mixture, amorphous hydrogenated silicon oxide nitride (a-Si
It is desirable to make O: N: H).

Further, a rare gas series gas and hydrogen are used as the introduced gas, and the sputter target is
It is desirable to form amorphous hydrogenated silicon tin (a-SiSn: H) as an amorphous semiconductor on the substrate using a mixture of silicon and tin.

[0027]

According to the invention of claim 1, since the raw material of the amorphous semiconductor is supplied by sputtering the solid target, unlike the CVD method, it is not necessary to supply the raw material in a gas state, and the raw material is supplied. Amorphous semiconductors that are difficult to supply in a gas state can be easily manufactured, and no extra equipment is required for gas leakage countermeasures.

Further, according to the manufacturing method of the present invention, since electrons are accelerated by utilizing electron cyclotron resonance to generate plasma, unlike the plasma CVD method, there is no electrode and low gas pressure, and high ionized plasma is generated. Can be generated. Therefore, it is possible to irradiate a solid target with a large ion current of low energy. Therefore, there is an advantage that the amorphous semiconductor can be formed at a low temperature as compared with the usual reactive sputtering method.

Further, as compared with the reactive sputtering method, the amorphous semiconductor can be formed in a high vacuum state, and the plasma does not spread over a wide area in the reaction chamber, so that impurities are taken into the amorphous semiconductor film. And a high-purity amorphous semiconductor thin film can be manufactured.

Further, since the voltage applied to the sputter target is usually about 10 to 50 V, plasma damage to the amorphous semiconductor thin film is less than in the reactive sputtering method. Therefore, according to the present invention, a good quality amorphous semiconductor thin film applicable to various devices can be formed.

That is, the present invention has the following advantages. It is possible to easily manufacture an amorphous semiconductor in which it is difficult to supply the raw material in a gas state. A high-purity amorphous semiconductor film can be manufactured. A highly reactive amorphous semiconductor film can be manufactured. An amorphous semiconductor film can be manufactured at low temperature. The damage that plasma gives to the amorphous semiconductor film is low. An amorphous semiconductor film with low stress can be manufactured.

When a rare gas series gas and hydrogen are used as the introduction gas and silicon is used as the sputter target, amorphous silicon hydride ( a-Si: H) can be produced.

When a rare gas series gas and hydrogen are used as the introduced gas and a mixture of silicon and germanium is used as the sputter target, an amorphous semiconductor as an amorphous semiconductor is formed on the substrate. Hydrogenated silicon germanium (a-SiGe: H) can be prepared.

When a rare gas series gas, hydrogen, and oxygen or carbon dioxide are used as the introduced gas and silicon is used as the sputter target, a non-crystalline semiconductor is formed on the substrate as an amorphous semiconductor. Amorphous hydrogenated silicon oxide (a-SiO: H) can be prepared.

When a rare gas series gas, hydrogen, and a hydrocarbon gas are used as the introduction gas and silicon is used as the sputtering target, an amorphous semiconductor is formed on the substrate as an amorphous semiconductor. Hydrogenated Silicon Carbide
(a-SiC: H) can be produced.

When a rare gas series gas, hydrogen, and nitrogen or ammonia are used as the introduction gas and silicon or silicon nitride is used as the sputter target, amorphous is formed on the substrate. Amorphous hydrogenated silicon nitride (a-SiN: H) as semiconductor
Can be produced.

Further, a rare gas series gas, hydrogen, and nitrogen oxide or nitrogen and oxygen are used as the introduction gas, and silicon or silicon oxide or silicon nitride or silicon oxide and silicon nitride is used as the sputtering target. When a mixture is used, amorphous hydrogenated silicon oxide nitride (a-SiO: N: H) can be prepared as the amorphous semiconductor material.

Further, a rare gas series gas and hydrogen are used as the introduced gas, and the sputter target is
When a mixture of silicon and tin is used, amorphous silicon tin hydride (a-Si) is used as an amorphous semiconductor on the substrate.
Sn: H) can be produced.

[0039]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 shows the structure of an electron cyclotron resonance sputtering apparatus used in an embodiment of the method for producing an amorphous semiconductor of the present invention. A first embodiment of the method for manufacturing an amorphous semiconductor according to the present invention will be described with reference to FIG.

First, a gas such as Ar (argon) is introduced into the plasma chamber 11 through the inlet 12, and the plasma chamber 10 is filled with the gas.
Set the pressure to ^-5 to 10 ^-3 Torr.

Next, microwave (2.45 GHz) electric power is applied and the microwave 13 is passed through the rectangular waveguide 14.
It is introduced into the plasma chamber 11. At the same time, magnetic coil 1
6, the plasma chamber 11 is set to electron cyclotron resonance (ECR) conditions by giving a magnetic flux density of 875 Gauss to the plasma chamber 11 to accelerate electrons, and a plasma based on the introduced gas is introduced. To generate.

The magnetic field distribution by the magnetic coil 16 is designed so as to be a divergent magnetic field distribution that becomes weaker from the plasma chamber 11 toward the substrate holder 19.
Electrons that move circularly at high speed by R (electron cyclotron resonance) move toward the substrate holder 19. As a result, the plasma flow 17 reaches the surface of the substrate 22 mounted on the substrate holder 19 mounted in the reaction chamber 20. Then, a sputtering power source 21 connected to a sputter target 18 arranged so as to surround the plasma flow 17 is turned on to collide some of the ions in the plasma flow 17 with the sputter target 18 to carry out sputtering. I do. The sputtered particles generated from the sputter target 18 pass through the plasma flow 17 and are supplied to the surface of the substrate 22.

By depositing the sputtered particles generated from the sputter gate 18 on the substrate 22, an amorphous semiconductor thin film can be formed on the substrate 22.

When a reactive gas is introduced during the film formation, low-energy ion irradiation of reactive gas ions can be performed, and a reactive sputtered film can be formed.

According to the above-mentioned embodiment, since the sputtered particles which are the raw material of the amorphous semiconductor are supplied by sputtering the solid sputter target 18, the CV is used.
Unlike the method D, it is not necessary to supply the raw material in a gas state,
An amorphous semiconductor in which it is difficult to supply the raw material in a gas state can be easily manufactured. In addition, no extra equipment is required for gas leakage measures, and the cost of the product can be reduced.

Further, according to the above-described embodiment, since electrons are accelerated by utilizing electron cyclotron resonance to generate plasma, unlike the plasma CVD method, highly ionized plasma can be generated without electrodes and at low gas pressure. . For this reason,
A large ion current of low energy can be applied to the solid sputter target 18. Therefore, as compared with the reactive sputtering method, there is an advantage that an amorphous semiconductor can be formed at a low temperature.

Further, as compared with the reactive sputtering method, the amorphous semiconductor can be formed in a high vacuum state, and the plasma flow 17 does not spread over a wide area in the reaction chamber 20, so that the amorphous semiconductor film is formed. Impurities are rarely incorporated, and a high-purity amorphous semiconductor thin film can be manufactured.

The voltage applied to the sputter target 18 is usually lower than that of the reactive sputtering method (10 to 5).
Since it is about 0 V), the damage that the plasma gives to the amorphous semiconductor thin film is less than that in the reactive sputtering method. Therefore, according to this embodiment, a good quality amorphous semiconductor thin film applicable to various devices can be formed.

In the above embodiment, when an amorphous silicon hydride (a-Si: H) is produced as the amorphous semiconductor thin film, a quartz substrate is used as the substrate 22, and the quartz chamber is used as the substrate 22. Argon (Ar) and hydrogen as introduced gases
(H ₂ ) may be used, and silicon may be used as the solid sputtering target 18. The optical bandgap of the amorphous silicon hydride thin film can be controlled by changing the hydrogen partial pressure ratio during the film formation of the amorphous silicon hydride. As shown in FIG. 2, the hydrogen partial pressure ratio (H ₂ / (H ₂
By increasing + Ar)), the optical band gap can be increased. During the film formation, the plasma chamber 11
Was set at 10 ^-5 to 10 ^-3 Torr, and the temperature of the substrate 22 was set at room temperature to 400 ° C. As a result, an amorphous silicon hydride thin film having good optical and electrical properties could be produced.

If a sputter target in which phosphorus or boron is added to silicon is used as the sputter target 18, the amorphous silicon hydride (a-S) is used.
(i: H) can be doped with impurities, the amorphous hydrogenated silicon can be made into an n-type or p-type semiconductor, and impurities can be controlled. The impurities can also be controlled by adding another group III or group V element to the sputter target 18.

In addition to argon as a gas to be introduced into the plasma chamber 11, rare gas series gases (He, Ne, Kr,
Xe) can also be used. In addition, in the above-mentioned embodiment, when an amorphous silicon germanium hydride (a-SiGe: H) is produced as the amorphous semiconductor thin film, the substrate 2
For No. 2, a 7059 substrate (trade name) manufactured by Corning Inc. is used, and argon (A
r) and hydrogen (H ₂ ) using solid sputter target 1
A mixed material of silicon and germanium was used as 8.
The optical band gap of the produced amorphous silicon hydride germanium can be changed by changing the mixing ratio of silicon and germanium. That is, the optical bandgap can be increased by increasing the mixing ratio of the silicon.
Furthermore, when the mixing ratio of silicon and germanium is kept constant, the optical band gap can be increased by increasing the hydrogen partial pressure ratio during film formation. During the film formation, the pressure in the plasma chamber 11 is set to 10 ⁻⁵ to 10 ⁻³ T.
Orr was used and the temperature of the substrate 22 was set in the range of room temperature to 400 ° C. As a result, amorphous hydrogenated silicon germanium (a-SiGe: H) having good optical and electrical properties could be produced.

As the solid sputter target 18,
The amorphous hydrogenated silicon germanium (a-SiGe: H) can be doped with impurities by using a sputter target obtained by adding phosphorus or boron to a mixed material of silicon and germanium. Can be an n-type or p-type semiconductor, and impurities can be controlled. In addition, other group III or V elements,
Impurities can also be controlled by adding them to the sputter target 18.

In addition to argon as a gas to be introduced into the plasma chamber 11, a rare gas series gas (He, Ne, Kr,
Xe) can also be used. In addition, in the above-described embodiment, when amorphous hydrogenated silicon oxide (a-SiO: H) is produced as the amorphous semiconductor thin film, the substrate 22 is used.
As a substrate, a Corning 7059 substrate (trade name) is used, and argon (Ar) is used as a gas to be introduced into the plasma chamber 11.
And hydrogen (H ₂ ) and oxygen (O ₂ ) are used, and silicon is used as the solid sputter target 18. In this case, the composition ratio x of the amorphous hydrogenated silicon oxide a-Si _1- xOx: H can be changed by changing the oxygen partial pressure ratio. The gap can be increased. Further, when the composition ratio x is constant, the optical band gap can be increased by increasing the hydrogen partial pressure ratio during film formation. During the film formation, the plasma chamber 11
Was set to 10 ⁻⁵ to 10 ⁻³ Torr, and the temperature of the substrate 22 was set in the range of room temperature to 450 ° C. As a result, amorphous hydrogenated silicon oxide (a-
It was possible to produce SiO: H).

The impurity doping of a-SiO: H is performed by using a sputter target in which phosphorus or boron is added to silicon as the solid sputter target 18.
Type or p-type semiconductor, and control of impurities. Also,
Impurities can also be controlled by adding other Group III or Group V elements to the sputter target 18.

The above amorphous hydrogenated silicon oxide (a-
In addition to oxygen, carbon dioxide (CO ₂ ) can be used as an oxygen supply source when producing SiO: H).

In addition to argon as a gas to be introduced into the plasma chamber 11, rare gas series gases (He, Ne, Kr,
Xe) can also be used. Further, in the above embodiment, when amorphous hydrogenated silicon carbide (a-SiC: H) is used, the substrate 22 is made of Corning 7
Using a 059 substrate (trade name), argon (Ar) and hydrogen (H ₂ ) and ethylene (C ₂ ) are used as introduction gases into the plasma chamber 11.
H ₄ ), and silicon was used as the solid sputtering target 18. The ethylene (C ₂ H ₄₎ in by changing the voltage dividing ratio, the amorphous hydrogenated silicon carbide (a-
The composition ratio x of Si _1- xCx: H) can be changed. The optical band gap can be increased by increasing the ethylene partial pressure ratio. Furthermore, when the composition ratio x is constant, the optical band gap can be increased by increasing the hydrogen partial pressure ratio during film formation. During the film formation, the pressure in the plasma chamber 11 is set to 10 ⁻⁵ to 10 ⁻³ T.
Orr was used and the temperature of the substrate 22 was set in the range of room temperature to 450 ° C. As a result, an amorphous hydrogenated silicon carbide (a-SiC: H) having good optical and electrical properties could be produced.

As the solid sputter target 18,
By using a sputter target in which phosphorus or boron is added to silicon, the amorphous hydrogenated silicon carbide (a-SiC: H) can be doped with impurities,
The amorphous hydrogenated silicon carbide can be made into an n-type or p-type semiconductor, and impurities can be controlled. Also, other II
Impurities can also be controlled by adding a group I or group V element to the sputter target 18.

The amorphous hydrogenated silicon carbide (a-
As a carbon (C) supply gas at the time of producing SiC: H, a hydrocarbon gas such as methane, ethane, propane, and acetylene can be used in addition to ethylene. Further, as the sputter target 18, a SiC target other than a silicon target can be used. Also, the plasma chamber 1
In addition to argon, a rare gas series gas (He, Ne, Kr, Xe) can also be used as a gas to be introduced into 1.

Further, in the above embodiment, the amorphous semiconductor thin film is formed of amorphous hydrogenated silicon nitride (a-S).
In the case of producing iN: H), a 7059 substrate (trade name) manufactured by Corning Co., Ltd. is used as the substrate 22, and argon (Ar) and hydrogen (H ₂ ) are introduced as gas to be introduced into the plasma chamber 11.
And nitrogen (N ₂ ) using a solid sputter target 18
Silicon was used as. By changing the nitrogen partial pressure ratio, the amorphous hydrogenated silicon nitride (a-
The composition ratio x of Si _1- xNx: H) can be changed. The optical bandgap can be increased by increasing the nitrogen partial pressure ratio. Further, when the composition ratio x is constant, the optical band gap can be increased by increasing the hydrogen partial pressure ratio during film formation.
During the film formation, the pressure in the plasma chamber 11 is set to 10 ⁻⁵ to 1
The temperature of the substrate 22 was set in the range of room temperature to 450 ° C. at 0 ⁻³ Torr. As a result, amorphous hydrogenated silicon nitride (a-SiN: H) having good optical and electrical properties could be produced.

As the solid sputter target 18,
The amorphous hydrogenated silicon nitride (a-SiN: H) can be doped with impurities by using a sputter target in which phosphorus or boron is added to silicon. Type or p-type semiconductor, and control of impurities. Impurities can also be controlled by adding other group III or group V elements.

The amorphous hydrogenated silicon nitride (a
In addition to nitrogen, ammonia (NH ₃ ) can be used as a nitrogen (N) supply source during the production of —SiN: H). Further, as the sputter target 18, a SiN target can be used in addition to the silicon target. In addition to argon, a rare gas series gas (He, Ne, Kr, Xe) can also be used as a gas to be introduced into the plasma chamber 11.

In addition, in the above-described embodiment, the amorphous semiconductor thin film is formed of amorphous hydrogenated silicon oxide nitride (a).
In the case of producing (SiO: N: H), a 7059 substrate (trade name) manufactured by Corning Co., Ltd. is used as the substrate 22, and argon (Ar) and hydrogen (H ₂ ) are introduced as gas to be introduced into the plasma chamber 11. And (N ₂ O) were used, and silicon was used as the solid sputter target 18. By varying the N ₂ O partial pressure ratio, the amorphous hydrogenated silicon oxide nitride composition of (a-SiOx:: Ny H ) x, it can be changed y, increasing the N ₂ O partial pressure ratio optical The band gap can be increased. Further, when the compositions x and y are constant, the optical band gap can be increased by increasing the hydrogen partial pressure ratio during film formation. During the film formation, the pressure in the plasma chamber 11 is set to 1
0 ^-5 to 10 ^-3 Torr, and the temperature of the substrate 22 from room temperature to 4
The range was 50 ° C. As a result, amorphous hydrogenated silicon oxide nitride (a-Si) having good optical and electrical properties is obtained.
O: N: H) could be created.

As the solid sputter target 18,
The amorphous hydrogenated silicon oxide nitride (a-SiO: N: H) can be doped with impurities by using a sputter target in which phosphorus or boron is added to silicon. To
It can be an n-type or p-type semiconductor and can control impurities. Also,
Impurities can also be controlled by adding other Group III or Group V elements to the sputter target 18.

[0064] The above amorphous hydrogenated silicon oxide nitride (a-SiO: N: H ) oxygen O at producing other N ₂ O as a source of nitrogen N, can use the N _2, O ₂ it can. In addition to the silicon target, a SiO target, a SiN target, or a mixed target of SiO and SiN can be used as the sputter target 18. In addition to argon, a rare gas series gas (He, Ne, Kr, Xe) can also be used as a gas to be introduced into the plasma chamber 11.

Further, in the above embodiment, when amorphous silicon tin hydride (a-SiSn: H) is produced as the amorphous semiconductor thin film, the substrate 22 is a 7059 substrate manufactured by Corning Incorporated ( (Trade name), argon (Ar) and hydrogen (H ₂ ) were used as introduction gases to the plasma chamber 11, and a mixed material of silicon and tin was used as the solid sputter target 18. By changing the mixing ratio of silicon and tin, the optical band gap of the produced amorphous silicon tin hydride can be changed. That is, the optical band gap can be increased by increasing the mixing ratio of the silicon. Further, when the mixing ratio of silicon and tin is kept constant, the optical band gap can be increased by increasing the hydrogen partial pressure ratio during film formation. During the film formation, the pressure of the plasma chamber 11 was set to 10 ⁻⁵ to 10 ⁻³ Torr, and the temperature of the substrate 22 was set in the range of room temperature to 400 ° C. As a result, an amorphous silicon tin hydride (a-SiSn: H) having good optical and electrical properties could be produced.

The impurity doping of a-SiSn: H is performed by using, as the solid-state sputter target 18, a sputter target obtained by adding phosphorus or boron to a mixed material of silicon and tin and adding the amorphous silicon tin hydride. , N-type or p-type semiconductor, and can control impurities. The impurities can also be controlled by adding another group III or V element to the sputter target 18. In addition to argon, a rare gas series gas (He, Ne, Kr, X) is introduced as a gas to be introduced into the plasma chamber 11.
e) can also be used.

In the above example, the case of producing a hydrogenated amorphous semiconductor has been described. However, when the substrate temperature is set to a high temperature or the hydrogen source is not supplied, the non-hydrogenated amorphous semiconductor is used. Can be manufactured.

As another method for impurity doping, equipment such as an exhaust gas treatment device is required, but doping with a gas such as phosphine (PH ₃ ) or diborane (B ₂ H ₆ ) is required. it can.

In the above embodiment, one sputter target was sputtered to form an amorphous semiconductor thin film. However, amorphous silicon germanium hydride (a-S) was used.
When a mixed sputter target composed of binary or higher materials is required as in the case of producing (iGe: H), etc., a sputter target composed of silicon and a sputter target composed of germanium are used. The above two different sputter targets may be used, and two or more kinds of sputter targets can be simultaneously sputtered to form an amorphous semiconductor thin film.

[0070]

As is clear from the above description, the method for producing an amorphous semiconductor according to the present invention is different from the CVD method in that the amorphous semiconductor raw material is supplied by sputtering a solid target. It is not necessary to supply the raw material in a gas state, and it is possible to easily manufacture an amorphous semiconductor in which the raw material is difficult to supply in a gas state.
No extra equipment is required to prevent gas leaks.

Further, according to the manufacturing method of the present invention, electrons are accelerated by utilizing electron cyclotron resonance to generate plasma. Therefore, unlike the plasma CVD method, there is no electrode and low gas pressure, and high ionized plasma is generated. Can be generated. Therefore, a large ion current of low energy can be applied to the solid target. Therefore, there is an advantage that the amorphous semiconductor can be formed at a low temperature as compared with the usual reactive sputtering method.

Further, compared with the reactive sputtering method, an amorphous semiconductor can be formed in a high vacuum state, and since plasma does not spread over a wide area in the reaction chamber, impurities are incorporated into the amorphous semiconductor film. And a high-purity amorphous semiconductor thin film can be manufactured.

Further, since the voltage applied to the sputter target is usually about 10 to 50 V, the plasma damage to the amorphous semiconductor thin film is less than in the reactive sputtering method. Therefore, according to the present invention, a good quality amorphous semiconductor thin film applicable to various devices can be formed.

That is, according to the present invention, by using a solid as a material of the amorphous semiconductor, it is possible to manufacture an amorphous semiconductor in which it is difficult to supply a material in a gas state, and it is possible to maintain a safe working environment. In addition, a high-quality, low-cost amorphous semiconductor that can be applied to various devices can be manufactured.

When a rare gas series gas and hydrogen are used as the introduction gas and silicon is used as the sputtering target, amorphous hydrogenated silicon ( a-Si: H) can be produced.

When a rare gas series gas and hydrogen are used as the introduced gas and a mixture of silicon and germanium is used as the sputter target, an amorphous semiconductor as an amorphous semiconductor is formed on the substrate. Hydrogenated silicon germanium (a-SiGe: H) can be prepared.

When a rare gas series gas, hydrogen, and oxygen or carbon dioxide are used as the introduced gas and silicon is used as the sputter target, a non-crystalline semiconductor is formed on the substrate as an amorphous semiconductor. Amorphous hydrogenated silicon oxide (a-SiO: H) can be prepared.

When a rare gas series gas, hydrogen, and a hydrocarbon gas are used as the introduction gas and silicon is used as the sputtering target, an amorphous semiconductor is formed on the substrate as an amorphous semiconductor. Hydrogenated Silicon Carbide
(a-SiC: H) can be produced.

When a rare gas series gas, hydrogen, and nitrogen or ammonia are used as the introduction gas and silicon or silicon nitride is used as the sputtering target, the amorphous substance is deposited on the substrate. Amorphous hydrogenated silicon nitride (a-SiN: H) as semiconductor
Can be produced.

Further, a rare gas series gas, hydrogen, and nitrogen oxide or nitrogen and oxygen are used as the introduction gas, and silicon or silicon oxide or silicon nitride or silicon oxide and silicon nitride is used as the sputtering target. When a mixture is used, amorphous hydrogenated silicon oxide nitride (a-SiO: N: H) can be prepared as the amorphous semiconductor material.

Further, a rare gas series gas and hydrogen are used as the introduced gas, and the sputter target is
When a mixture of silicon and tin is used, amorphous silicon tin hydride (a-Si) is used as an amorphous semiconductor on the substrate.
Sn: H) can be produced.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an apparatus for performing sputtering by using electron cyclotron resonance used in an example of a method for producing an amorphous semiconductor of the present invention.

FIG. 2 is a characteristic diagram showing a relationship between a hydrogen partial pressure ratio and an optical bandgap at the time of producing amorphous silicon hydride (a-Si: H).

FIG. 3 is a configuration diagram of a plasma CVD apparatus used in a conventional example.

[Explanation of symbols]

11 ... Plasma chamber, 12 ... Gas introduction pipe, 14 ... Waveguide,
15 ... Quartz window, 16 ... Magnetic coil, 17 ... Plasma flow,
18 ... Sputter target, 19 ... Substrate holder, 20
... Reaction chamber, 21 ... Sputtering power source, 22 ... Substrate, 23 ... Gas introduction tube.

Claims (8)

[Claims] 1. A gas is introduced into the plasma chamber, a microwave and a magnetic field are applied to the plasma chamber, and the plasma chamber is set to electron cyclotron resonance conditions by the interaction between the microwave and the magnetic field. By generating a plasma of the introduced gas, by colliding the plasma with a solid sputter target, to eject sputter atoms from the sputter target, by depositing the sputter atoms on the substrate, A method of manufacturing an amorphous semiconductor, comprising forming an amorphous semiconductor on the substrate. 2. The method for producing an amorphous semiconductor according to claim 1, wherein a rare gas series gas and hydrogen are used as the introduction gas, silicon is used as the sputter target, and amorphous is formed on the substrate. A method for producing an amorphous semiconductor, which comprises producing amorphous silicon hydride (a-Si: H) as a high quality semiconductor. 3. The method for producing an amorphous semiconductor according to claim 1, wherein a rare gas series gas and hydrogen are used as the introduction gas, and a mixture of silicon and germanium is used as the sputtering target. Amorphous silicon germanium hydride (a-
A method for producing an amorphous semiconductor, which comprises producing SiGe: H). 4. The method for producing an amorphous semiconductor according to claim 1, wherein a rare gas series gas, hydrogen, and oxygen or carbon dioxide are used as the introduction gas, and silicon is used as the sputtering target. , Amorphous hydrogenated silicon oxide (a
A method for manufacturing an amorphous semiconductor, which comprises producing —SiO: H). 5. The method for producing an amorphous semiconductor according to claim 1, wherein a rare gas series gas, hydrogen and a hydrocarbon gas are used as the introduction gas, and silicon is used as the sputtering target. A method for producing an amorphous semiconductor, characterized by producing amorphous hydrogenated silicon carbide (a-SiC: H) as an amorphous semiconductor thereon. 6. The method for producing an amorphous semiconductor according to claim 1, wherein a rare gas series gas, hydrogen, and nitrogen or ammonia are used as the introduction gas, and silicon or nitriding is used as the sputtering target. A method for producing an amorphous semiconductor, which comprises using silicon to produce amorphous hydrogenated silicon nitride (a-SiN: H) as an amorphous semiconductor on the substrate. 7. The method for producing an amorphous semiconductor according to claim 1, wherein the introduction gas is a rare gas series gas,
Hydrogen and nitrogen oxides or nitrogen and oxygen are used, as the sputter target, silicon, silicon oxide, silicon nitride, or a mixture of silicon oxide and silicon nitride is used, and as the amorphous semiconductor, amorphous hydrogenated silicon oxide. A method for producing an amorphous semiconductor, which comprises producing a nitride (a-SiO: N: H). 8. The method for producing an amorphous semiconductor according to claim 1, wherein a rare gas series gas and hydrogen are used as the introduction gas, and a mixture of silicon and tin is used as the sputtering target. A method for producing an amorphous semiconductor, characterized by producing amorphous silicon tin hydride (a-SiSn: H) as an amorphous semiconductor on the substrate.