JP3295133B2 - Manufacturing method of amorphous semiconductor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

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

An amorphous semiconductor is generally manufactured by a plasma CVD (chemical vapor deposition) method using a plasma CVD apparatus shown in FIG.

In the above plasma CVD apparatus, a high frequency power supply 43 is connected to an anode 46 and a cathode 47. The above anode 4
A source gas is introduced from a source gas introduction pipe 50 into a reaction vessel 48 surrounding the cathode 6 and the cathode 47. The inside of the reaction vessel 48 is decompressed by exhaust air from an 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 source gas from the source gas inlet tube 50 is turned into plasma by the discharge between the anode 46 and the cathode 47, and the turned source gas is deposited on the substrate 42. Thus, an amorphous semiconductor thin film can be formed on the substrate 42.

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

Further, as another method of manufacturing an amorphous semiconductor, a photo-CVD method, an ECR (Electron Cyclotron Resonance) -C
There are a VD method, a reactive sputtering method, and the like.

For example, in the photo-CVD method, when amorphous hydrogenated silicon (a-Si: H) is formed, disilane (Si ₂
H ₄ ) is directly decomposed by ultraviolet light, or silane (Si
H ₄ ) is decomposed by mercury sensitization to produce amorphous hydrogenated silicon.

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 or the like is introduced, and plasma is generated under the electron cyclotron resonance conditions. Then, silane (SiH ₄ ) is decomposed by this plasma 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 or the like and introducing H ₂ .

Various methods have been proposed for producing an amorphous semiconductor in addition to the above, but the properties of the raw materials are different depending on the production method. Generally, amorphous hydrogenated silicon (a-Si: H) is used for solar cells and thin film transistors.
When applying to devices such as (TFT), plasma C
Since a high-quality thin film can be formed by the VD method, a plasma CVD apparatus used for the plasma CVD method is mainly used as a manufacturing apparatus for product development.

[0012]

However, in the above-mentioned conventional method for manufacturing an amorphous semiconductor, when a CVD method including a plasma CVD method and a photo CVD method is used, silane is used.
It is necessary to use a special material gas for semiconductors such as (SiH ₄ ).
That is, the above-described CVD method has a disadvantage that only an amorphous semiconductor that can supply 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-mentioned CVD method, the production of an amorphous semiconductor is safely performed,
In addition, in order to perform the process while preventing environmental pollution, it is necessary to add an equipment such as an exhaust gas treatment device to the manufacturing apparatus, so that there is a disadvantage that the product cost increases.

As described above, in the CVD method, an amorphous semiconductor that can be manufactured is limited to a material capable of supplying a raw material in a gaseous state, and a manufacturing facility is required in order to ensure safety of a working environment and safety. It has the disadvantage of increasing costs and, consequently, product costs.

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

However, the reactive sputtering method is
High discharge voltage compared to other manufacturing methods (several hundred V or more)
Therefore, according to the reactive sputtering method, there is a disadvantage that the amorphous semiconductor is easily damaged by plasma during the film formation.

Further, the above reactive sputtering method is used for 10 ^-3 T
Since an amorphous semiconductor is formed by sputtering at a pressure of about orr, impurities in the atmosphere are easily taken into the semiconductor film. For this reason, there is a disadvantage that it is difficult to form a high-quality amorphous semiconductor thin film applicable to a device.

Therefore, an object of the present invention is to use a solid as a material for an amorphous semiconductor, to produce an amorphous semiconductor in which supply of a gaseous material is difficult, and to maintain a safe working environment, It is an object of the present invention to provide a method for manufacturing an amorphous semiconductor which can produce a high-quality, low-cost amorphous semiconductor applicable to various devices.

[0019]

According to a first aspect of the present invention, there is provided a method for manufacturing an amorphous semiconductor, comprising introducing a gas into a plasma chamber and applying a microwave and a magnetic field to the plasma chamber. Then, the plasma chamber is set to an electron cyclotron resonance condition by an interaction between a microwave and a magnetic field, and electrons are accelerated to generate plasma of the introduced gas, and the plasma collides with a solid sputter target. And causing the sputtered atoms to fly out of the sputter target and depositing the sputtered atoms on a substrate, thereby forming an amorphous semiconductor on the substrate. The pressure is set to 10 ^-5 to 10 ^-3 Torr,
The temperature of the substrate is set at room temperature to 400 ° C., and rare gas series argon gas and hydrogen are used as the introduced gas,
The hydrogen partial pressure (H ₂ / (H ₂ + Ar)) was set to 5 to 10, silicon was used as the sputtering target, and amorphous hydrogenated silicon (a−) was used as an amorphous semiconductor on the substrate.
(Si: H).

According to a second aspect of the present invention, a gas is introduced into a plasma chamber, a microwave and a magnetic field are applied to the plasma chamber, and an electron cyclotron resonance is generated in the plasma chamber by an interaction between the microwave and the magnetic field. By setting the conditions and accelerating the electrons, the plasma of the introduced gas is generated, the plasma is caused to collide with a solid sputter target, the sputter atoms are ejected from the sputter target, and the sputter atoms are formed on the substrate. In the method for manufacturing an amorphous semiconductor in which an amorphous semiconductor is formed on the substrate by depositing on the substrate, the pressure in the plasma chamber is set to 10 ⁻⁵ to 10 ⁻³ Torr, Is set at room temperature to 400 ° C., a rare gas series gas and hydrogen are used as the introduction gas, and silicon is used as the sputtering target. Using a mixture of con and germanium, amorphous hydrogenated silicon germanium as an amorphous semiconductor on the substrate: it is characterized by making (a-SiGe H).

According to a third aspect of the present invention, a gas is introduced into a plasma chamber, a microwave and a magnetic field are applied to the plasma chamber, and an electron cyclotron resonance is generated in the plasma chamber by an interaction between the microwave and the magnetic field. By setting the conditions and accelerating the electrons, the plasma of the introduced gas is generated, the plasma is caused to collide with a solid sputter target, the sputter atoms are ejected from the sputter target, and the sputter atoms are formed on the substrate. In the method for manufacturing an amorphous semiconductor in which an amorphous semiconductor is formed on the substrate by depositing on the substrate, the pressure in the plasma chamber is set to 10 ⁻⁵ to 10 ⁻³ Torr, Is set at room temperature to 450 ° C., and a rare gas series gas, hydrogen, oxygen or carbon dioxide is used as the introduced gas, The silicon used as a sputter target, amorphous hydrogenated silicon oxide as an amorphous semiconductor on the substrate: is characterized by making (a-SiO H).

According to a fourth aspect of the present invention, a gas is introduced into a plasma chamber, a microwave and a magnetic field are applied to the plasma chamber, and an electron cyclotron resonance is generated in the plasma chamber by an interaction between the microwave and the magnetic field. By setting the conditions and accelerating the electrons, the plasma of the introduced gas is generated, the plasma is caused to collide with a solid sputter target, the sputter atoms are ejected from the sputter target, and the sputter atoms are formed on the substrate. In the method for manufacturing an amorphous semiconductor in which an amorphous semiconductor is formed on the substrate by depositing on the substrate, the pressure in the plasma chamber is set to 10 ⁻⁵ to 10 ⁻³ Torr, Is set at room temperature to 450 ° C., and a rare gas series gas, hydrogen, and a hydrocarbon gas are used as the introduction gas, and the sputtering target is used. As bets, a silicon, amorphous hydrogenated silicon carbide as an amorphous semiconductor on the substrate: is characterized by making (a-SiC H).

According to a fifth aspect of the present invention, a gas is introduced into a plasma chamber, a microwave and a magnetic field are applied to the plasma chamber, and an electron cyclotron resonance is generated in the plasma chamber by an interaction between the microwave and the magnetic field. By setting the conditions and accelerating the electrons, the plasma of the introduced gas is generated, the plasma is caused to collide with a solid sputter target, the sputter atoms are ejected from the sputter target, and the sputter atoms are formed on the substrate. In the method for manufacturing an amorphous semiconductor in which an amorphous semiconductor is formed on the substrate by depositing on the substrate, the pressure in the plasma chamber is set to 10 ⁻⁵ to 10 ⁻³ Torr, Is set at room temperature to 450 ° C., and a rare gas series gas, hydrogen, nitrogen or ammonia is used as the introduction gas, and As a sputtering target, a silicon or silicon nitride, amorphous hydrogenated silicon nitride as an amorphous semiconductor on the substrate (a-Si
N: H).

According to a sixth aspect of the present invention, a gas is introduced into a plasma chamber, a microwave and a magnetic field are applied to the plasma chamber, and an electron cyclotron resonance is generated in the plasma chamber by an interaction between the microwave and the magnetic field. By setting the conditions and accelerating the electrons, the plasma of the introduced gas is generated, the plasma is caused to collide with a solid sputter target, the sputter atoms are ejected from the sputter target, and the sputter atoms are formed on the substrate. In the method for manufacturing an amorphous semiconductor in which an amorphous semiconductor is formed on the substrate by depositing on the substrate, the pressure in the plasma chamber is set to 10 ⁻⁵ to 10 ⁻³ Torr, Is set at room temperature to 450 ° C., and a rare gas series gas, hydrogen, and nitrogen oxide or nitrogen and oxygen are used as the introduction gas. Using silicon, silicon oxide, silicon nitride, or a mixture of silicon oxide and silicon nitride as the sputter target, forming amorphous hydrogenated silicon oxide nitride (a-SiO: N: H) as the amorphous semiconductor It is characterized by doing.

According to a seventh aspect of the present invention, a gas is introduced into a plasma chamber, a microwave and a magnetic field are applied to the plasma chamber, and an electron cyclotron resonance is generated in the plasma chamber by an interaction between the microwave and the magnetic field. By setting the conditions and accelerating the electrons, the plasma of the introduced gas is generated, the plasma is caused to collide with a solid sputter target, the sputter atoms are ejected from the sputter target, and the sputter atoms are formed on the substrate. In the method for manufacturing an amorphous semiconductor in which an amorphous semiconductor is formed on the substrate by depositing on the substrate, the pressure in the plasma chamber is set to 10 ⁻⁵ to 10 ⁻³ Torr, Is set at room temperature to 400 ° C., and a rare gas series gas and hydrogen are used as the introduced gas. Using a mixture of silicon and tin, amorphous hydrogenated silicon tin as an amorphous semiconductor on the substrate (a
-SiSn: H).

[0026]

According to the first aspect of the present invention, the sputtering target is silicon, the rare gas series argon gas and hydrogen are used as the introduced gas, and the pressure in the plasma chamber is set to 10 ^-5 to 10 ^-3 T.
orr, the temperature of the substrate was set at room temperature to 400 ° C., and the hydrogen partial pressure (H ₂ / (H ₂ + Ar)) was set at 5 to 10. ~ 1.8 eV
A thin film of amorphous hydrogenated silicon having an optical gap before and after can be manufactured.

According to the second aspect of the present invention, the sputter target is a mixture of silicon and germanium,
Since rare gas series gas and hydrogen were used as the introduction gas, the pressure in the plasma chamber was set at 10 ^-5 to 10 ^-3 Torr, and the temperature of the substrate was set at room temperature to 400 ° C., low-damage and high-quality amorphous A thin film of hydrogenated silicon germanium can be produced.

According to the third aspect of the present invention, the sputter target is silicon, a rare gas series gas, hydrogen and oxygen or carbon dioxide are introduced, and the pressure in the plasma chamber is 10 ^-5 to 10 ^-3 Torr. , And the temperature of the substrate is set at room temperature to 450 ° C., so that a thin film of amorphous hydrogenated silicon oxide with low damage and good quality can be manufactured.

According to the fourth aspect of the present invention, the sputter target is made of silicon, a rare gas series gas, hydrogen and a hydrocarbon gas are used as introduced gases, and the pressure in the plasma chamber is set at 1
0 ^-5 to 10 ^-3 Torr, and the substrate temperature is set to room temperature to 4
Since the temperature is set to 50 ° C., a high-quality amorphous hydrogenated silicon carbide thin film with low damage can be produced.

According to the fifth aspect of the present invention, the sputter target is silicon or silicon nitride, a rare gas series gas, hydrogen, nitrogen, or ammonia is used as the introduced gas, and the pressure in the plasma chamber is 10 ⁻⁵ to 10 ^{−. 3} Torr
, And the temperature of the substrate is set at room temperature to 450 ° C., so that a thin film of amorphous hydrogenated silicon nitride having low damage and good quality can be manufactured.

According to the sixth aspect of the present invention, the sputter target is silicon, silicon oxide, silicon nitride, or a mixture of silicon oxide and silicon nitride, and a rare gas series gas, hydrogen and nitrogen oxide, or nitrogen and oxygen are used. And the pressure in the plasma chamber is set to 10 ⁻⁵ to 10 ⁻³ Torr, and the temperature of the substrate is set to room temperature to
Since the temperature is set at 450 ° C., a thin film of amorphous hydrogenated silicon oxide nitride having low damage and good quality can be manufactured.

According to the seventh aspect of the present invention, the sputter target is a mixture of silicon and tin, the rare gas series gas and the hydrogen are the introduced gases, and the pressure in the plasma chamber is 10 ⁻⁵ to 10 ^{−. Since 3} Torr was set and the temperature of the substrate was set at room temperature to 400 ° C., a thin film of amorphous silicon tin hydride with low damage and good quality can be manufactured.

According to the present invention, since the source of the amorphous semiconductor is supplied by sputtering the solid target, unlike the CVD method, it is not necessary to supply the above source material in a gaseous state. An amorphous semiconductor that is difficult to supply in a state can be easily manufactured, and extra equipment for gas leakage countermeasures is unnecessary.

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, highly ionized plasma can be formed without electrodes at a low gas pressure. Can be generated. For this reason, a large ion current of low energy can be applied to the solid target. Therefore, there is an advantage that an amorphous semiconductor can be formed at a lower temperature than the ordinary reactive sputtering method.

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

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

That is, the present invention has the following advantages.

An amorphous semiconductor which is difficult to supply a raw material in a gas state can be easily manufactured.

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 a low temperature.

The damage caused by plasma to the amorphous semiconductor film is low.

An amorphous semiconductor film with low stress can be manufactured.

[0044]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 shows the structure of an electron cyclotron resonance sputtering apparatus used in an embodiment of the method for producing an amorphous semiconductor according to the present invention. A first embodiment of the method for producing 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 from the inlet 12, and
The pressure is set to ^-5 to 10 ^-3 Torr.

Next, microwave (2.45 GHz) power is applied, and the microwave 13 is transmitted through the rectangular waveguide 14.
It is introduced into the plasma chamber 11. At the same time, the magnetic coil 1
6, the plasma chamber 11 is set to an electron cyclotron resonance (ECR) condition by giving a magnetic flux density of 875 Gauss (Gauss) to the plasma chamber 11, thereby accelerating the electrons and generating a plasma based on the introduced gas. Generate

The magnetic field distribution by the magnetic coil 16 is designed to be a divergent magnetic field distribution that becomes weaker in the direction from the plasma chamber 11 to the substrate holder 19.
Electrons moving 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 sputter power source 21 connected to a sputter target 18 disposed so as to surround the plasma flow 17 is turned on, and a part of ions in the plasma flow 17 are caused to collide with the sputter target 18 to be sputtered. I do. The sputter particles generated from the sputter target 18 pass through the plasma flow 17 and are supplied to the surface of the substrate 22.

Thus, by depositing the sputter 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 embodiment, since the solid sputter target 18 is sputtered to supply sputter particles which are the raw material of the amorphous semiconductor, the CV
Unlike D method, there is no need to supply raw materials in gaseous state,
An amorphous semiconductor in which it is difficult to supply a raw material in a gaseous state can be easily manufactured. Moreover, no extra equipment is required for gas leakage countermeasures, and the cost of the product can be reduced.

Further, according to the above embodiment, since electrons are accelerated by utilizing electron cyclotron resonance to generate plasma, unlike the plasma CVD method, highly ionized plasma can be generated with no electrodes and a low gas pressure. . For this reason,
A large ion current of low energy can be applied to the solid sputter target 18. Therefore, there is an advantage that an amorphous semiconductor can be formed at a low temperature as compared with the reactive sputtering method.

Further, as compared with the reactive sputtering method, an amorphous semiconductor can be formed in a high vacuum state and the plasma flow 17 does not spread in the reaction chamber 20 over a wide range. Impurities are less taken in, and a high-purity amorphous semiconductor thin film can be manufactured.

In general, the voltage applied to the sputtering target 18 is lower than that of the reactive sputtering method (10 to 5).
(Approximately 0 V), so that plasma does not damage the amorphous semiconductor thin film more than in the reactive sputtering method. Therefore, according to this embodiment, a high-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 formed as an amorphous semiconductor thin film, a quartz substrate is used as the substrate 22 and the plasma chamber 11 Argon (Ar) and hydrogen as introduced gas
(H ₂ ) may be used, and silicon may be used as the solid sputtering target 18. The optical band gap of the amorphous hydrogenated silicon thin film can be controlled by changing the hydrogen partial pressure ratio during the formation of the amorphous silicon hydrogenated film. As shown in FIG. 2, the hydrogen partial pressure ratio (H ₂ / (H ₂
When + Ar)) is increased, 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 within a range from room temperature to 400 ° C. As a result, a thin film of amorphous silicon hydride having good optical and electrical properties could be produced.

If a sputter target obtained by adding phosphorus or boron to silicon is used as the sputter target 18, the amorphous hydrogenated silicon (a-S
i: H) can be doped with an impurity, and the amorphous silicon hydride can be made an n-type or p-type semiconductor, and the impurity can be controlled. Further, impurities can also be controlled by adding other group III or group V elements to the sputtering target 18.

As a gas introduced into the plasma chamber 11, in addition to argon, a rare gas series gas (He, Ne, Kr,
Xe) can also be used.

In the above embodiment, the amorphous semiconductor thin film was made of amorphous silicon germanium hydride (a-S
In the case of producing iGe: H), a Corning 7059 substrate (trade name) is used as the substrate 22, and argon (Ar) and hydrogen (H ₂ ) are introduced into the plasma chamber 11 as gas.
And a mixed material of silicon and germanium was used as the solid sputtering target 18. By changing the mixing ratio of silicon and germanium, the optical band gap of the produced amorphous silicon germanium hydride can be changed. That is, the optical band gap can be increased by increasing the mixing ratio of 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 was set to 10 ⁻⁵ to 10 ⁻³ Torr, and the temperature of the substrate 22 was set in a range from room temperature to 400 ° C. As a result, amorphous silicon germanium hydride (a-SiGe: 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 a mixed material of silicon and germanium, the above-mentioned amorphous silicon germanium hydride (a-SiGe: H) can be doped with impurities, and the above amorphous silicon germanium hydride can be doped. Can be an n-type or p-type semiconductor, and impurities can be controlled. Also, other Group III or V elements
Impurity can also be controlled by adding it to the sputtering target 18.

As a gas introduced into the plasma chamber 11, in addition to argon, a rare gas series gas (He, Ne, Kr,
Xe) can also be used.

In the above embodiment, the amorphous hydrogenated silicon oxide (a-Si
O: H), a 7059 substrate (trade name) manufactured by Corning Co., Ltd.
Argon (Ar), hydrogen (H ₂ ), and oxygen (O ₂ ) are used as the gas to be introduced into 1, and silicon is used as the solid sputtering target 18. In this case, by changing the oxygen partial pressure ratio, the composition ratio x of the amorphous hydrogenated silicon oxide, a-Si _1-x O _x : H, can be changed,
Increasing the oxygen partial pressure ratio can increase the optical band gap. 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 of the plasma chamber 11 is set to 10 ^−5.
And to 10 ^-3 Torr, 450 the temperature of the substrate 22 from room temperature
° C range. As a result, an amorphous hydrogenated silicon oxide (a-SiO: H) having good optical and electrical properties could be produced.

The impurity doping to a-SiO: H is performed by using the above-mentioned amorphous hydrogenated silicon oxide as the solid-state sputtering target 18 by using a sputtering target obtained by adding phosphorus or boron to silicon.
Type or p-type semiconductor and impurity control. Also,
The impurities can also be controlled by adding other group III or group V elements to the sputtering target 18.

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

As a gas introduced into the plasma chamber 11, in addition to argon, a rare gas series gas (He, Ne, Kr,
Xe) can also be used.

In the above embodiment, when amorphous hydrogenated silicon carbide (a-SiC: H) is used, as the substrate 22, a 7059 substrate (trade name) manufactured by Corning Incorporated is used. As a gas introduced into the chamber 11, argon (Ar), hydrogen (H ₂ ) and ethylene (C ₂ H ₄ ) were used, and silicon was used as the solid sputtering target. By changing the partial pressure ratio of the ethylene (C ₂ H ₄ ), the amorphous hydrogenated silicon carbide (a-Si _{1 -X} C _X : H)
Can be changed. Increasing the ethylene partial pressure ratio can increase the optical band gap. Further, when the composition ratio x 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 to a range from room temperature to 450 ° C. As a result, 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 sputtering target obtained by adding phosphorus or boron to silicon, the above-mentioned amorphous hydrogenated silicon carbide (a-SiC: H) can be doped with impurities.
The above amorphous hydrogenated silicon carbide is converted into n-type or p-type.
It can be a type semiconductor and can control impurities. In addition, other I
A group II or group V element is added to the sputtering target 18
Can also be controlled by adding it to the substrate.

The amorphous hydrogenated silicon carbide (a-
As the carbon (C) supply gas at the time of producing SiC: H), hydrocarbon gas such as methane, ethane, propane, and acetylene can be used in addition to ethylene. As the sputter target 18, a SiC target can be used in addition to a silicon target.

As a gas introduced into the plasma chamber 11, in addition to argon, a rare gas series gas (He, Ne, Kr,
Xe) can also be used.

In the above embodiment, the amorphous hydrogenated silicon nitride (a-S
In the case of manufacturing 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 into the plasma chamber 11 as gas.
And nitrogen (N ₂ ) using a solid sputter target 18
Was used as silicon. By changing the nitrogen partial pressure ratio, the amorphous hydrogenated silicon nitride (a-
The composition ratio x of (Si _1−X N _x : H) can be changed. Increasing the nitrogen partial pressure ratio can increase the optical band gap. 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 of the plasma chamber 11 is set to 10 ⁻⁵ to 1
At 0 ^-3 Torr, the temperature of the substrate 22 was set in a range from room temperature to 450 ° C. 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,
By using a sputter target in which phosphorus or boron is added to silicon, the above-mentioned amorphous hydrogenated silicon nitride (a-SiN: H) can be doped with impurities. Type or p-type semiconductor and impurity control. Also, impurities can be controlled by adding other group III or group V elements.

The above amorphous hydrogenated silicon nitride (a
In addition to nitrogen, ammonia (NH ₃ ) can be used as a nitrogen (N) supply source at the time of producing —SiN: H). As the sputter target 18, a SiN target can be used in addition to a silicon target.

As a gas introduced into the plasma chamber 11, a rare gas series gas (He, Ne, Kr,
Xe) can also be used.

Further, in the above embodiment, the 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 gases to be introduced into the plasma chamber 11. And (N ₂ O), and silicon was used as the solid sputtering 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 Target band gap can be increased. Further, when the compositions x and y are 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 is
The temperature of the substrate 22 was set to a range from room temperature to 450 ° C. at 10 ⁻⁵ to 10 ⁻³ Torr. As a result, amorphous hydrogenated silicon oxide nitride (a-S
iO: N: H).

As the solid sputter target 18,
By using a sputter target in which phosphorus or boron is added to silicon, the above-mentioned amorphous hydrogenated silicon oxide nitride (a-SiO: N: H) can be doped with impurities. To
It can be an n-type or p-type semiconductor and can control impurities. Further, by adding another group III or group V element to the sputtering target 18, the impurity can be controlled.

[0075] 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. As the sputter target 18, a SiO target, a SiN target, or a mixed target of SiO and SiN can be used in addition to a silicon target.

As a gas introduced into the plasma chamber 11, in addition to argon, a rare gas series gas (He, Ne, Kr,
Xe) can also be used.

In the above embodiment, when amorphous silicon tin hydride (a-SiSn: H) is formed as the amorphous semiconductor thin film, the substrate 22 is a 7059 substrate (Corning). (Trade name), argon (Ar) and hydrogen (H ₂ ) were used as gases introduced into the plasma chamber 11, and a mixed material of silicon and tin was used as the solid sputtering 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 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 in the plasma chamber 11 was set to 10 ⁻⁵ to 10 ⁻³ Torr, and the temperature of the substrate 22 was set in a range from 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 a sputter target obtained by adding phosphorus or boron to a mixed material of silicon and tin as the solid sputter target 18 to thereby form the amorphous silicon tin hydride. , N-type or p-type semiconductor, and impurity control can be performed.
Further, by adding another group III or group V element to the sputtering target 18, the impurity can be controlled.

As a gas introduced into the plasma chamber 11, a rare gas series gas (He, Ne, Kr,
Xe) can also be used.

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

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

In the above embodiment, an amorphous semiconductor thin film is formed by sputtering one sputter target, but amorphous silicon germanium hydride (a-S
In the case where a mixed sputter target composed of two or more materials is required, such as in the case of manufacturing iGe: H), a sputter target composed of silicon and a sputter target composed of germanium are required. Or two or more kinds of sputter targets may be simultaneously sputtered to produce an amorphous semiconductor thin film.

[0083]

As is apparent from the above description, according to the first aspect of the present invention, the sputter target is made of silicon, and the rare gas series argon gas and hydrogen are used as the introduction gas.
The pressure in the plasma chamber is set at 10 ^-5 to 10 ^-3 Torr, the temperature of the substrate is set at room temperature to 400 ° C., and the hydrogen partial pressure is set.
Since (H ₂ / (H ₂ + Ar)) was set to 5 to 10, a thin film of amorphous hydrogenated silicon having a low damage, good quality and a practical optical gap of about 1.7 to 1.8 eV was produced. it can.

According to the second aspect of the present invention, the sputter target is a mixture of silicon and germanium,
Since rare gas series gas and hydrogen were used as the introduction gas, the pressure in the plasma chamber was set at 10 ^-5 to 10 ^-3 Torr, and the temperature of the substrate was set at room temperature to 400 ° C., low-damage and high-quality amorphous A thin film of hydrogenated silicon germanium can be produced.

According to the third aspect of the present invention, the sputter target is made of silicon, a rare gas series gas, hydrogen and oxygen or carbon dioxide are used as introduced gases, and the pressure in the plasma chamber is set to 10 ^-5 to 10 ^-3 Torr. , And the temperature of the substrate is set at room temperature to 450 ° C., so that a thin film of amorphous hydrogenated silicon oxide with low damage and good quality can be manufactured.

According to the fourth aspect of the present invention, the sputter target is made of silicon, a rare gas series gas, hydrogen and a hydrocarbon gas are used as introduced gases, and the pressure in the plasma chamber is set to one.
0 ^-5 to 10 ^-3 Torr, and the substrate temperature is set to room temperature
Since the temperature is set to 50 ° C., a high-quality amorphous hydrogenated silicon carbide thin film with low damage can be produced.

According to the fifth aspect of the present invention, the sputtering target is silicon or silicon nitride, a rare gas series gas, hydrogen, nitrogen, or ammonia is used as the introduction gas, and the pressure in the plasma chamber is 10 ⁻⁵ to 10 ^{−. 3} Torr
, And the temperature of the substrate is set at room temperature to 450 ° C., so that a thin film of amorphous hydrogenated silicon nitride having low damage and good quality can be manufactured.

According to the sixth aspect of the present invention, the sputter target is silicon, silicon oxide, silicon nitride, or a mixture of silicon oxide and silicon nitride, and a rare gas series gas, hydrogen and nitrogen oxide or nitrogen and oxygen are used. And the pressure in the plasma chamber is set to 10 ⁻⁵ to 10 ⁻³ Torr, and the temperature of the substrate is set to room temperature to
Since the temperature is set at 450 ° C., a thin film of amorphous hydrogenated silicon oxide nitride having low damage and good quality can be manufactured.

Further, according to the invention of claim 7, the sputter target is a mixture of silicon and tin, the rare gas series gas and hydrogen are the introduced gases, and the pressure in the plasma chamber is 10 ⁻⁵ to 10 ^{−. Since 3} Torr was set and the temperature of the substrate was set at room temperature to 400 ° C., a thin film of amorphous silicon tin hydride with low damage and good quality can be manufactured.

According to the present invention, the raw material of the amorphous semiconductor is supplied by sputtering the solid target. Therefore, unlike the CVD method, it is not necessary to supply the raw material in a gaseous state. An amorphous semiconductor that is difficult to supply in a state can be easily manufactured, and extra equipment for gas leakage countermeasures is unnecessary.

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, highly ionized plasma can be formed at no electrode and low gas pressure. Can be generated. For this reason, a large ion current of low energy can be applied to the solid target. Therefore, there is an advantage that an amorphous semiconductor can be formed at a lower temperature than the ordinary reactive sputtering method.

Further, as compared with the reactive sputtering method, an amorphous semiconductor can be formed in a high vacuum state, and since the plasma does not spread over a wide range in the reaction chamber, 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, the plasma causes less damage to the amorphous semiconductor thin film than the reactive sputtering method. Therefore, according to the present invention, a high-quality amorphous semiconductor thin film applicable to various devices can be formed.

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

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an apparatus for performing sputtering using electron cyclotron resonance used in an embodiment of a method for manufacturing an amorphous semiconductor according to the present invention.

FIG. 2 is a characteristic diagram showing a relationship between a hydrogen partial pressure ratio and an optical band gap when amorphous hydrogenated silicon (a-Si: H) is produced.

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 tube, 14: waveguide,
15: quartz window, 16: magnetic coil, 17: plasma flow,
18 ... sputter target, 19 ... substrate holder, 20
... Reaction chamber, 21 ... Sputter power supply, 22 ... Substrate, 23 ... Gas introduction pipe.

Continuation of front page (56) References JP-A-3-28367 (JP, A) JP-A-4-21774 (JP, A) JP-A-1-240648 (JP, A) JP-A-61-26771 (JP) JP-A-1-298153 (JP, A) JP-A-4-66663 (JP, A) JP-A-4-173970 (JP, A) JP-A-60-50167 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C23C 14/00-14/58 H01L 21/203 H01L 21/205

Claims (7)

(57) [Claims] A gas is introduced into a plasma chamber, a microwave and a magnetic field are applied to the plasma chamber, and the plasma chamber is set to an electron cyclotron resonance condition by an interaction between the microwave and the magnetic field. By accelerating, the plasma of the introduction gas is generated, the plasma is caused to collide with a solid sputter target, the sputter atoms are ejected from the sputter target, and the sputter atoms are deposited on the substrate, In the method for manufacturing an amorphous semiconductor in which an amorphous semiconductor is formed on the substrate, the pressure in the plasma chamber is set to 10 ⁻⁵ to 10 ⁻³ Torr, and the temperature of the substrate is set to room temperature to 400 ° C. set, as the gas introduced, using argon gas and hydrogen noble gas series, the hydrogen partial pressure _{(H 2 / (H 2 +} Ar)), is set to 5 to 10 As the sputter target, a silicon, amorphous hydrogenated silicon as the amorphous semiconductor on the substrate (a
-Si: H) is produced. 2. 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 an electron cyclotron resonance condition by an interaction between the microwave and the magnetic field. By accelerating, the plasma of the introduction gas is generated, the plasma is caused to collide with a solid sputter target, the sputter atoms are ejected from the sputter target, and the sputter atoms are deposited on the substrate, In the method for manufacturing an amorphous semiconductor in which an amorphous semiconductor is formed on the substrate, the pressure in the plasma chamber is set to 10 ⁻⁵ to 10 ⁻³ Torr, and the temperature of the substrate is set to room temperature to 400 ° C. Using a rare gas series gas and hydrogen as the above introduced gas,
Using a mixture of silicon and germanium as the sputtering target, producing an amorphous silicon germanium hydride (a-SiGe: H) as an amorphous semiconductor on the substrate. Manufacturing method. 3. 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 an electron cyclotron resonance condition by an interaction between the microwave and the magnetic field. By accelerating, the plasma of the introduction gas is generated, the plasma is caused to collide with a solid sputter target, the sputter atoms are ejected from the sputter target, and the sputter atoms are deposited on the substrate, In the method for manufacturing an amorphous semiconductor in which an amorphous semiconductor is formed on the substrate, the pressure in the plasma chamber is set to 10 ⁻⁵ to 10 ⁻³ Torr, and the temperature of the substrate is set to room temperature to 450 ° C. Using a rare gas series gas, hydrogen, oxygen or carbon dioxide as the introduced gas, A silicon Te, amorphous hydrogenated silicon oxide as an amorphous semiconductor on the substrate: amorphous semiconductor manufacturing method which is characterized by making (a-SiO H). 4. 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 an electron cyclotron resonance condition by an interaction between the microwave and the magnetic field. By accelerating, the plasma of the introduction gas is generated, the plasma is caused to collide with a solid sputter target, the sputter atoms are ejected from the sputter target, and the sputter atoms are deposited on the substrate, In the method for manufacturing an amorphous semiconductor in which an amorphous semiconductor is formed on the substrate, the pressure in the plasma chamber is set to 10 ⁻⁵ to 10 ⁻³ Torr, and the temperature of the substrate is set to room temperature to 450 ° C. Using a rare gas series gas, hydrogen and a hydrocarbon gas as the introduction gas, silicon as the sputtering target There, amorphous hydrogenated silicon carbide as an amorphous semiconductor on the substrate: amorphous semiconductor manufacturing method which is characterized by making (a-SiC H). 5. 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 an electron cyclotron resonance condition by an interaction between the microwave and the magnetic field. By accelerating, the plasma of the introduction gas is generated, the plasma is caused to collide with a solid sputter target, the sputter atoms are ejected from the sputter target, and the sputter atoms are deposited on the substrate, In the method for manufacturing an amorphous semiconductor in which an amorphous semiconductor is formed on the substrate, the pressure in the plasma chamber is set to 10 ⁻⁵ to 10 ⁻³ Torr, and the temperature of the substrate is set to room temperature to 450 ° C. Using a rare gas series gas, hydrogen, nitrogen or ammonia as the introduced gas, Te, a silicon or silicon nitride, amorphous hydrogenated silicon nitride as an amorphous semiconductor on the substrate: amorphous semiconductor manufacturing method which is characterized by making (a-SiN H). 6. A gas is introduced into a plasma chamber, a microwave and a magnetic field are applied to the plasma chamber, and the plasma chamber is set to an electron cyclotron resonance condition by an interaction between the microwave and the magnetic field. By accelerating, the plasma of the introduction gas is generated, the plasma is caused to collide with a solid sputter target, the sputter atoms are ejected from the sputter target, and the sputter atoms are deposited on the substrate, In the method for manufacturing an amorphous semiconductor in which an amorphous semiconductor is formed on the substrate, the pressure in the plasma chamber is set to 10 ⁻⁵ to 10 ⁻³ Torr, and the temperature of the substrate is set to room temperature to 450 ° C. The rare gas series gas, hydrogen, nitrogen oxide or nitrogen and oxygen are used as the introduced gas, and the sputtering target is used. Using silicon or silicon oxide or silicon nitride or a mixture of silicon oxide and silicon nitride to produce amorphous hydrogenated silicon oxide nitride (a-SiO: N: H) as the amorphous semiconductor. A method for producing an amorphous semiconductor. 7. A gas is introduced into a plasma chamber, a microwave and a magnetic field are applied to the plasma chamber, and the plasma chamber is set to an electron cyclotron resonance condition by an interaction between the microwave and the magnetic field. By accelerating, the plasma of the introduction gas is generated, the plasma is caused to collide with a solid sputter target, the sputter atoms are ejected from the sputter target, and the sputter atoms are deposited on the substrate, In the method for manufacturing an amorphous semiconductor in which an amorphous semiconductor is formed on the substrate, the pressure in the plasma chamber is set to 10 ⁻⁵ to 10 ⁻³ Torr, and the temperature of the substrate is set to room temperature to 400 ° C. 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. Used, amorphous hydrogenated silicon tin as an amorphous semiconductor on the substrate: amorphous semiconductor manufacturing method which is characterized by making (a-SiSn H).