JPH06333841A - Method and apparatus for forming non-single crystal silicon semiconductor film - Google Patents

Abstract

(57) [Abstract] [Purpose] To homogenize and improve various characteristics of a non-single-crystal silicon semiconductor film formed on a continuously moving strip-shaped substrate. A film-forming space is formed by a strip-shaped substrate for deposition (103) and a wall member (111) for film-forming space other than the substrate for deposition, and a source gas is introduced into the film-forming space and plasma is formed. In the method of forming a non-single crystal silicon based semiconductor film on the deposition target substrate while moving the deposition target substrate (103), the temperature of the wall member (111) during film formation is controlled by A method for forming a non-single crystal silicon based semiconductor film, characterized in that the temperature is kept lower than the temperature of the deposition substrate (103).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for forming a non-single crystal silicon semiconductor film, and particularly to a thin film having a large area, which is a functional deposition film used for a laminated element such as a photovoltaic element. The present invention relates to a method and an apparatus for continuously forming on a belt-shaped substrate.

[0002]

2. Description of the Related Art As a method for continuously forming a semiconductor functionally deposited film used for a photovoltaic element or the like on a substrate, an independent film forming chamber for forming various semiconductor layers is provided and each of these film forming films is formed. A method is known in which the chambers are connected by a load lock method via a gate valve, and the substrate is sequentially moved to each film forming chamber to form various semiconductor layers. Then, as a method for remarkably improving the mass productivity, US Pat.
No. 409 describes roll-to-roll (roll t roll).
The continuous plasma CVD method employing the o Roll) method is disclosed. According to this method, by using the long strip-shaped member as a substrate, while depositing and forming the conductive type semiconductor layers required in the plurality of glow discharge regions, by continuously transporting the substrate in its longitudinal direction, It is said that elements having a semiconductor junction can be continuously formed.

However, it may take several hours to form a semiconductor layer on a substrate having a length of several hundred meters, and in order to form a high quality semiconductor deposited film with a high yield. During that time, the discharge state and the substrate temperature must be precisely maintained and controlled. For example, the substrate temperature during film formation must be controlled within a range of plus or minus 5 ° C. in order to guarantee the electrical characteristics of the semiconductor deposited film.

The substrate temperature is determined by heat radiation and heat conduction by a lamp heater, a sheath heater, a heat bath, heat conduction from plasma, heat radiation from a member around the substrate, and heat input and output by substrate surface reaction. When forming a film over a long period of time, it is necessary to pay sufficient attention to temperature control of members around the substrate. That is, the temperature and temperature distribution of the substrate surrounding member are controlled to be constant with respect to the film formation time,
The amount of heat that the substrate receives from these components must be constant. The parameters that control the discharge state are the gas flow rate,
Pressure, high frequency or microwave power supply, bias power,
It is the temperature of the member in contact with the plasma. When applying a DC or high frequency bias, there is a method of controlling the bias application state by controlling the current flowing through the application electrode to a constant bias. At this time, the secondary electron emission coefficient from the member in contact with the plasma must be kept constant, and the temperature control of the member requires particularly high precision.

[0005]

SUMMARY OF THE INVENTION The present invention overcomes the problems associated with the conventional large area functionally deposited film methods and apparatus as described above and is formed on a substrate, such as a continuously moving strip substrate. It is an object of the present invention to provide a forming method and an forming apparatus which can make various characteristics of a non-single crystal silicon semiconductor film uniform and improved.

[0006]

The above object can be achieved by the present invention described below.

According to the method of the present invention, a deposition space is formed by a deposition base and a deposition space wall member other than the deposition base, a source gas is introduced into the deposition space, and plasma is generated. Then, in the method of forming the non-single-crystal silicon-based semiconductor film on the substrate for deposition while moving the substrate for deposition, the temperature of the wall member at the time of film formation is higher than the temperature of the substrate for deposition. It is also a method of forming a non-single-crystal silicon-based semiconductor film, characterized in that

In the method of the present invention, it is particularly effective to adjust the temperature of the wall member during film formation so that the temperature distribution becomes lower in the moving direction of the deposition substrate.

In the apparatus of the present invention, a deposition space is formed by a deposition base and a wall member other than the deposition base, a source gas is introduced into the deposition space, and plasma is generated.
In a device for forming a non-single crystal silicon semiconductor film on a substrate for deposition while moving the substrate for deposition, the temperature of the wall member during film formation is kept lower than the temperature of the substrate for deposition. It is a non-single-crystal silicon-based semiconductor film forming apparatus characterized by having a means for

[0010]

In general, the temperature of the substrate is controlled to a desired temperature by heat radiation from a lamp heater or the like or heat transfer from a member in contact with the substrate. In the present invention, by keeping the temperature of the film forming space wall member that is in contact with the discharge and that surrounds the film forming space lower than the temperature of the substrate, the effect of heat radiation from the member to the substrate is reduced, The temperature control of the substrate by the lamp heater or the like becomes easy.

Particularly, high-quality amorphous Si and SiG
For forming the e film, the temperature of the substrate is set to 250 depending on the film forming conditions.
It is necessary to control to a constant temperature between 380 ° C. In the present invention, the temperature of the film forming space wall member that is in contact with the discharge having heat radiation to the substrate and partitions the discharge space is set to 200 to
By setting the temperature to 300 ° C., it becomes easy to control the temperature of the substrate at 250 to 380 ° C.

Further, when a deposited film is formed while the strip-shaped substrate is conveyed along a long film-forming space, the temperature of the strip-shaped substrate rises due to plasma and heat radiation from a member surrounding the film-forming space. To do. Therefore, in the present invention, the amount of heat radiation from the wall member is reduced by a mode in which the temperature of the wall member during film formation is adjusted to have a temperature distribution that decreases toward the moving direction of the deposition substrate. The temperature control of the substrate can be facilitated.

The embodiments of the present invention will be described in detail below.

In the present invention, the substrate for deposition is a substrate for forming a deposited film on its surface, and its shape is a shape suitable for continuous film formation by movement, for example, a band shape. This substrate for deposition is one (one surface) of the member that surrounds the film formation space. The film forming space wall member is a member other than the deposition target substrate and is a member (a conductive member or the like) that surrounds the film forming space. The space surrounded by the deposition substrate and the film forming space wall member becomes the film forming space. The shape of the film forming space is not particularly limited, but a rectangular parallelepiped-like shape is typical. The normal position of the film forming space wall member is fixed. On the other hand, the substrate to be deposited moves in a desired direction during film formation, for example, in the longitudinal direction in the case of a strip shape. During film formation, a raw material gas is introduced into the film formation space from the outside of the film formation space by a gas introduction means, and further high-frequency or microwave power is input to cause and maintain discharge. For example, the film forming space wall member is provided with an exhaust hole for discharging the gas introduced into the film forming space to the outside of the film forming space, and the gas is exhausted by a pump outside the apparatus. Here, the pressure in the film formation space during film formation is preferably about 10 ⁻⁴ to 1 (Torr), and the pressure in the outer space for film formation, which will be described in detail later, is preferably 1 (Torr) or higher.

The substrate during film formation is controlled to a desired temperature by heat radiation from a lamp heater or the like or heat transfer from a member in contact with the substrate. Furthermore, in the present invention,
The temperature of the wall member during film formation is controlled to be lower than the temperature of the substrate.

As this control method, there is provided a fin that can be housed on the surface of the wall member for film formation space that is not in contact with the film formation space (the surface outside the film formation space), and the projection length of this fin is adjusted to the outside. There is a method of adjusting the surface area exposed at, and a method of adjusting the pressure and / or the gas flow rate of the gas atmosphere in contact with the fin. That is, by providing the fin on the outer surface of the film forming space of the wall member, it is possible to radiate heat from the member and suppress an increase in temperature, and to adjust the protrusion amount of the fin to change the surface area. The amount of heat emitted can be controlled. When the pressure of the gas atmosphere in contact with the fins is increased, heat is transferred to the gas by convection, and the effect of suppressing the temperature rise of the member surrounding the film formation space is increased. Further, the effect is further enhanced by increasing the flow velocity of the gas or replacing the gas.

As another control method, there is a method in which a heat bath is provided on the surface side of the wall member for film formation space which is not in contact with the film formation space, and the heat bath is adjusted according to the presence or absence of contact between the wall member and the wall member. That is, it is a method of contacting the wall member with a heat bath to exchange heat. For example, when the heater is embedded in the wall member and the temperature is controlled, the control response speed becomes slow due to the large heat capacity of the member and the high heater temperature. Embedding a water cooling tube for cooling with a heater is 100
It is difficult at high temperatures above ℃. Therefore, in the aspect of the present invention, heat is exchanged by bringing the surface temperature of the wall member into contact with or away from the heat bath. This heat bath is formed of, for example, a block-shaped member having a high thermal conductivity and a large heat capacity, and a cooling pipe or a heater through which a cooling medium such as water or gas flows is attached to the inside of the heat bath. It is constantly controlled by an output controller or a cooling medium flow controller. Also, the hot bath is moved by a mechanical drive mechanism to contact or leave the wall member. The surface temperature of the wall member on the film formation space side is monitored by a thermocouple and fed back to the drive control circuit of the heat bath. In this case, it is desirable to reduce the wall thickness of the wall member to reduce the heat capacity and increase the control response speed.

Further, when the method of the present invention is carried out by a film forming method by a microwave plasma CVD method in which a DC bias is applied, the temperatures of the bias applying electrode, the substrate and the wall member for the film forming space are controlled to be constant. As a result, it is possible to improve the accuracy of monitoring the effective microwave power supplied to the discharge space with the bias current value. Therefore, by controlling the microwave power so that the bias current becomes constant while controlling the temperature of the substrate and the bias electrode as well as the temperature of the wall member for the film formation space to be constant, the control accuracy of the film formation conditions can be improved. It is possible to improve, and thus further improve the film quality. Similarly, in the case of performing the film formation method by the microwave plasma CVD method in which the RF bias is applied, while controlling the temperature of the member surrounding the film formation space to be constant,
By adjusting the microwave power or the RF power so that the bias current becomes constant, the control accuracy of the film forming conditions is improved, and thus the film quality can be further improved.

FIG. 1 is a sectional view showing a functional deposited film forming apparatus by a microwave plasma CVD method, which is a characteristic of the present invention. In the figure, 101 is a film forming container, 1
Reference numeral 02 denotes a wall member of the film forming container, 103 denotes a strip-shaped substrate (deposition substrate) that moves through the film forming container 101, 104,
Reference numeral 105 denotes a gas gate which connects the film forming container and a feed-out container for a strip-shaped substrate (not shown) or a winding container for the strip-shaped substrate, which is not shown. Reference numeral 106 is a lamp heater for heating the strip-shaped substrate, 107, 108 and 109 are thermocouples for measuring the temperature of the strip-shaped substrate, and 110 is a heat bath for exchanging heat in contact with the strip-shaped substrate. 111 is a member that surrounds the film formation space in contact with the discharge (wall member for film formation space), 112 is a fin, 113 is a baking heater, and 114, 115 and 116 are thermocouples that measure the temperature of the wall member for film formation space. 117 is a film forming space. Further, 118 is a means for supplying a raw material gas for forming a deposited film,
Reference numeral 119 is a gas exhaust pipe of the film forming space, 120 is a microwave applicator and a microwave permeable member for introducing microwaves into the film forming space, and 121 is a bias rod. 1
Reference numeral 22 denotes a film-forming outer space separated from the film-forming space, 123 denotes a means for supplying a gas to the film-forming outer space, and 124 denotes a film-forming outer space 1.
22 is a gas exhaust pipe.

In this apparatus, the film forming space 117 is arranged along the strip-shaped substrate 103 in the longitudinal direction of the strip-shaped substrate, that is, in the transport direction. The film forming space 117 is formed by the strip-shaped substrate 10
It has a rectangular parallelepiped shape in which 3 is one surface and the other surface is surrounded by a conductive member (the film forming space wall member 111 whose position is fixed). A raw material gas is introduced into the film forming space 117 from the outside of the film forming space by a gas introducing means, and electric power is further applied to the microwave to generate and maintain a discharge.

Further, in this apparatus, a bobbin around which the strip-shaped substrate 103 is wound is set in a feeding container having a strip-shaped substrate feeding mechanism (not shown) on the left side of the drawing, and the strip-shaped substrate 103 is set to the gas gate 104, the film forming container 101, and the gas gate. The film is passed through 105 to a winding container having a belt-shaped substrate winding mechanism (not shown) on the right side of the drawing, tension is adjusted, and the film is conveyed at a constant speed.

Output of lamp heater 106 and heat bath 11
The temperature of 0 is controlled by the thermocouple 10 by an output controller (not shown).
The temperature of the strip-shaped substrate 103 measured by 7, 108 and 109 is controlled to be constant. The temperature of the heat bath 110 is adjusted by a heater and cooling water embedded in the heat bath.
The film forming container 101 can be evacuated to a reduced pressure by a rotary pump, a mechanical booster pump, and a diffusion pump (not shown) connected to the exhaust pipes 119 and 124. Further, the film forming space 117 and the film forming outside space 122 can be adjusted to a predetermined pressure by a throttle valve (not shown) provided on the exhaust pipes 119 and 124. Into the film forming space 117, a deposited film forming raw material gas or an inert gas can be introduced by the gas supply means 118. Microwaves can be introduced into the film formation space 117 from a microwave power source (not shown) through a waveguide (not shown), a microwave applicator, and a microwave transparent member 120 to generate a discharge.

The bias rod 121 is connected to the D
C voltage or RF power can be applied, and the microwave power can be controlled by a feedback circuit (not shown) so that the current flowing from the bias rod 121 to the ground is constant. Baking heater 113
Thus, the member 111 that is in contact with the discharge and surrounds the film formation space can be heated and degassed. The heat of the wall member 111 is radiated to the space outside the film formation by the fins 112 installed on the film forming space wall member 111 in contact with the discharge. Further, the temperature of the wall member 111 can be controlled by adjusting the protruding length of the fin 112. Gas supply means 1 is provided in the outer space 122 for film formation.
An inert gas or hydrogen gas can be introduced according to 23. By adjusting the opening degree of a throttle valve (not shown) on the exhaust pipe 124, it is possible to increase the pressure in the outer space for film formation and increase the efficiency of transferring heat from the fins 112 to the gas in the outer space for film formation.

FIG. 2 is a sectional view showing an apparatus for forming a functional deposited film by a high frequency plasma CVD method, which shows the features of the present invention well. In the figure, 201 is a film forming container, and 202
Is a wall member of the film deposition container, 203 is a strip-shaped substrate (deposited substrate) that moves through the film deposition container 201, 204, 20
Reference numeral 5 denotes a gas gate which connects the film forming container 201 to a film forming container (not shown) adjacent to the film forming container, a container for feeding the belt-shaped substrate, or a container for winding the belt-shaped substrate. Reference numeral 206 is a lamp heater for heating the strip-shaped substrate, and 207 and 208 are thermocouples for measuring the temperature of the strip-shaped substrate. 209 is a member that is in contact with the discharge and surrounds the film formation space (wall member for film formation space), 210 is a fin, 2
Reference numeral 11 is a baking heater, 212 is a thermocouple for measuring the temperature of the member 211, and 213 is a film forming space. Reference numeral 214 is a means for supplying a raw material gas for forming a deposited film, 215 is a gas exhaust pipe for the film forming space, and 216 is a high-frequency electrode. Reference numeral 218 is an outer space for film formation, and 219 is an exhaust pipe for gas in the outer space 218 for film formation.

In this apparatus, a bobbin around which the belt-shaped substrate 203 is wound is set in a feeding container having a belt-shaped substrate feeding mechanism (not shown) on the left side of the drawing, and the belt-shaped substrate 203 is set to the gas gate 204, the film forming container 201, and the gas gate 205. The tension can be adjusted by passing it through a winding container having a strip-shaped substrate winding mechanism on the right side of the drawing (not shown), and it can be conveyed at a constant speed. The output of the lamp heater 206 is measured by thermocouples 207 and 208 by an output controller (not shown).
The temperature of 3 is controlled to be constant. Film forming container 20
1 can be evacuated to a reduced pressure by a rotary pump or a mechanical booster pump (not shown) connected to the exhaust pipes 215 and 219. Further, the film forming space and the film forming outside space can be adjusted to a predetermined pressure by a throttle valve (not shown) provided on the exhaust pipes 115 and 219. Film formation space 2
A raw material gas for forming a deposited film or an inert gas can be introduced into 13 by a gas supply means 214.

In the film formation space 213, high frequency power is supplied from a high frequency power source (not shown) outside the film formation container 201 to the high frequency electrode 216.
Can be applied to generate a discharge. The microwave power can be controlled by a feedback circuit (not shown) so that the current flowing from the high frequency electrode 216 to the ground is constant. The wall member 209 can be heated and degassed by the baking heater 211. In addition, the fins 210 installed on the wall member 209 radiate the heat of the member to the outside film formation space 218. Also fin 210
2 for adjusting the protrusion length of the film to contact the discharge and enclose the film formation space
The temperature of 09 can be controlled. Furthermore, the exhaust pipe 2
By adjusting the opening degree of a throttle valve (not shown) on 19, it is possible to raise the pressure of the film-deposition outer space 218 and increase the efficiency of transferring heat from the fins 210 to the gas of the film-deposition outer space 218.

FIG. 3 is a sectional view showing a functional deposited film forming apparatus by the microwave plasma CVD method, which is a characteristic of the present invention. In the figure, 301 is a film forming container, 3
Reference numeral 02 denotes a wall member of the film forming container, 303 denotes a belt-shaped substrate (deposition substrate) that moves through the film forming container 301, 304 and 30.
Reference numeral 5 denotes a gas gate that connects the film forming container and a film forming container (not shown) adjacent to the film forming container, a container for feeding the belt-shaped substrate, or a container for winding the belt-shaped substrate. Reference numeral 306 is a lamp heater for heating the strip-shaped substrate, and 307, 308, 309 are thermocouples for measuring the temperature of the strip-shaped substrate. Reference numeral 310 denotes a member that is in contact with the discharge and surrounds the film formation space (wall member for film formation space), 311 is a baking heater that is a member that contacts the discharge and surrounds the film formation space, 312.
˜318 is a thermocouple for measuring the temperature of the member 310, 319
˜325 is a heat bath for controlling the temperature of the member 310, 32
6 to 332 are cooling tubes for controlling the temperature of the heat bath, and 333 to 339.
Is a straight line introduction machine for bringing the heat baths 319 to 325 into contact with or away from the member 310 surrounding the film formation space, 340 is a temperature controller for the member surrounding the film formation space whose position is fixed in contact with discharge, and 341 is film formation It is a space. Reference numeral 346 is a means for supplying a raw material gas for forming a deposited film, 347 is a gas exhaust pipe of the film forming space, 342 and 344 are microwave applicators and microwave permeable members for introducing microwaves into the film forming space,
343 and 345 are bias rods. Reference numeral 348 is a space outside the film formation.

In the above structure, the strip-shaped substrate 3 is provided in the feeding container having the strip-shaped substrate delivery mechanism on the left side of the drawing (not shown).
No. 03 wound bobbin is set, and the strip-shaped substrate 3
03 can be passed through the gas gate 304, the film forming container 301, and the gas gate 305 to a winding container having a belt-shaped member winding mechanism (not shown) on the right side of the drawing to adjust the tension, and can be conveyed at a constant speed. . The output of the lamp heater 306 is controlled by an output controller (not shown) so that the temperature of the belt-shaped substrate 303 measured by the thermocouples 307, 308, 309 becomes constant. The temperature of the heat baths 319 to 325 is adjusted by a heater and cooling water embedded in the heat bath. The film forming container 301 is the exhaust pipe 3
A rotary pump, a mechanical booster pump, and a diffusion pump (not shown) connected to 47 can be used to reduce the pressure. Further, the film forming space and the film forming outside space can be adjusted to a predetermined pressure by a throttle valve (not shown) provided on the exhaust pipe 347. A deposition film forming source gas or an inert gas can be introduced into the film formation space 341 by the gas supply unit 346. Microwaves can be introduced into the film formation space 341 from a microwave power source (not shown) through a waveguide (not shown), a microwave applicator, and microwave transmitting members 342 and 344 to generate a discharge. DC voltage or RF power can be applied to the bias rods 343 and 345 from an external power supply.
The bias rod 3 is provided by a feedback circuit (not shown).
The microwave power can be controlled so that the current flowing from 43, 345 to ground is constant. The baking heater 311 can heat and degas the member 310 that is in contact with the discharge and surrounds the film formation space. Member 31
The temperature adjustment of 0 is performed by adjusting the temperature of the heating baths 319 to 325, or bringing the members into contact with or leaving the members 310.

FIG. 4 is a sectional view showing an apparatus for forming a functional deposited film by the high frequency plasma CVD method, which shows the features of the present invention well. In the figure, 401 is a film forming container and 402
Is a wall member of the film forming container, 403 is a strip-shaped substrate (deposition substrate) that moves through the film forming container 401, and 404 and 405 are film-depositing containers (not shown) adjacent to the film forming container or a feed-out container for the strip-shaped substrate. Alternatively, it is a gas gate that connects the winding container of the strip-shaped substrate. Reference numeral 406 is a lamp heater for heating the strip-shaped substrate, and 407 and 408 are thermocouples for measuring the temperature of the strip-shaped substrate. Reference numeral 409 denotes a member that is in contact with the discharge and surrounds the film formation space (film member for the film formation space), 410 is a baking heater that is a member that contacts the discharge and surrounds the film formation space, and reference numerals 412 to 415 are thermocouples that measure the temperature of the member 410. 416 to 419 are heat baths for controlling the temperature of the member 409, 420 to 423 are cooling tubes for controlling the temperature of the heat baths 416 to 419, 4
Reference numerals 24 to 427 are linear introduction machines for bringing the heat baths 416 to 419 into contact with and separating from the member 409 surrounding the film formation space, 428 is a temperature controller of the member surrounding the film formation space, and 429 is a film formation space. Reference numeral 430 is a means for supplying a raw material gas for forming a deposited film, 433 is a gas exhaust pipe for forming a film,
431 high frequency electrodes 432 are high frequency introduction terminals. Four
Reference numeral 34 is the outside of the film formation.

In the above structure, the strip-shaped substrate 4 is provided in the feeding container having the strip-shaped substrate delivery mechanism on the left side of the drawing (not shown).
No. 03 wound bobbin is set, and the strip-shaped substrate 4
03 can be passed through the gas gate 404, the film forming container 401, and the gas gate 405 to a winding container having a belt-shaped substrate winding mechanism (not shown) on the right side of the drawing to adjust the tension, and can be conveyed at a constant speed. . The output of the lamp heater 406 is measured by thermocouples 407 and 408 by an output controller (not shown).
The temperature of 3 is controlled to be constant. Film deposition container 40
1 can be exhausted to a reduced pressure by a rotary pump or a mechanical booster pump (not shown) connected to exhaust pipes 415 and 419. Further, a film formation space and a film formation outside space can be adjusted to a predetermined pressure by a throttle valve (not shown) provided on the exhaust pipe 433. A deposition gas forming source gas or an inert gas can be introduced into the film formation space 429 by the gas supply unit 430. Film formation space 42
In FIG. 9, high-frequency power can be applied to the high-frequency electrode 431 from a high-frequency power source (not shown) outside the film formation container 401 to cause discharge. By a feedback circuit not shown,
The microwave power can be controlled so that the current flowing from the high frequency electrode 431 to the ground becomes constant. The baking heater 410 can heat and degas the member 409 that is in contact with the discharge and surrounds the film formation space. The temperature of the member 410 is adjusted by adjusting the temperature of the heat baths 316 to 319, and bringing the member 410 into contact with or away from the member.

[0031]

EXAMPLES Examples of the present invention will be described in detail below, including experiments conducted by the present inventors to complete the present invention.

[Experiment 1: Temperature Control of Strip-shaped Substrate] A microwave plasma was generated by using the apparatus shown in FIG. 1 and an amorphous silicon semiconductor was formed over a length of 100 (m) on the strip-shaped substrate 103 made of SUS430BA which continuously moves. A thin film (Si film) and an amorphous silicon germanium semiconductor thin film (SiGe film) were formed. The film forming conditions are the source gas Si
H ₄ flow rate 200 (SCCM), H ₂ 200 (SCC
M), or SiH ₄ 120 (SCCM), GeH ₄ 9
0 (SCCM), H ₂ 200 (SCCM), film formation space pressure 5 (mTorr), microwave power 300 (W) fixed, and RF (13.56M) for the bias rod.
Bias is applied, RF power is controlled so that the bias current flowing from the bias rod to the ground is 2.5 (A) (about 500 (W)), and the deposition length of the deposition space is 200 (mm). )

In forming the deposited film, the strip-shaped substrate 10 is used.
The temperature of No. 3 was kept constant (300 ° C., 350 ° C., 400 ° C.), and the temperature of the film forming space wall member 111 was variously set. In addition, the moving speed of the substrate is from zero (stationary) to 2000.
Various settings were made up to mm / min. As a result, the film-forming space wall member 11 capable of controlling the band-shaped substrate 103 at a set temperature.
The upper limit of the temperature of 1 is the case where the substrate is stationary, and the values are shown in Table 1 below.

[0034]

[Table 1] The temperature shown in Table 1 is a value peculiar to the apparatus system, and there is an upper limit in other general apparatuses.

As is clear from the results shown in Table 1, unless the temperature of the film-forming space-like wall member 111 is not higher than the temperature of the strip-shaped substrate 103, it becomes difficult to control the temperature of the strip-shaped substrate due to heat radiation from the film-forming space member. Become.

[Experiment 2: Temperature control of wall member for film formation space]
In this experiment, the same apparatus as in Experiment 1 was used, and the strip-shaped substrate 103 made of SUS430BA that continuously moved in the same procedure was used.
While forming an amorphous silicon semiconductor thin film over the length of 100 (m) under the same conditions as in Experiment 1, the protruding length (surface area) of the fins installed in the film forming space wall member, the surface temperature of the wall member, and the strip-shaped substrate The correlation with temperature was investigated. Furthermore, the correlation between the pressure in the space outside the film formation, the temperature of the member surrounding the film formation space, and the temperature of the strip-shaped substrate was investigated. The results of the experimental conditions are shown as graphs in FIGS. 5 and 6.

As shown in FIG. 5, when the protruding length of the fins is increased (the surface area is increased), the radiation amount of heat increases and the temperature of the member surrounding the film formation space decreases. Further, as shown in FIG. 6, when the pressure in the outer space for film formation is increased, the amount of heat transferred from the fins to the gas is increased, and the temperature of the member surrounding the film formation space is lowered.

[Experiment 3: Bias current, temperature of wall member,
Correlation of Film Properties] In this experiment, an amorphous silicon semiconductor thin film was formed by a microwave CVD method over a length of 100 (m) on a SUS430BA strip-shaped substrate 103 that continuously moved in the same procedure using the same apparatus as in Experiment 1. Formed. In the experiment, a high frequency or DC bias was applied to the discharge, and the correlation between the bias current flowing between the bias rod (bias application electrode) and the ground, the temperature of the wall member for film formation space, and the characteristics of the deposited film was investigated. It was However, the temperature of the strip-shaped substrate was kept constant. The experimental conditions and the results are shown in FIGS. 7 and 8 and Table 2 below.

[0039]

[Table 2]

As is clear from the results shown in FIGS. 7 and 8 and Table 2 above, as the temperature of the wall member 111 increased, the bias current increased and the characteristics of the deposited film changed. Even if the RF bias or the microwave power is adjusted so that the bias current is constant, the characteristics of the deposited film change when the temperature of the member changes.

When applying an RF bias,
When the RF bias power is controlled so that the bias current becomes constant while maintaining the temperature of the member surrounding the film formation space constant, the characteristics of the deposited film do not change. When a DC bias is applied, the characteristics of the deposited film do not change if the microwave electrode is controlled so that the bias current becomes constant while the temperature of the member surrounding the film formation space is kept constant.

Next, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1 Amorphous silicon pin type photovoltaic element 900 having a layer structure as schematically shown in FIG.
Was prepared as follows. This photovoltaic element 900
Is a photovoltaic element in which a lower electrode 902, an n-type semiconductor layer 903, an i-type semiconductor layer 904, a p-type semiconductor layer 905, a transparent electrode 906, and a collector electrode 907 are sequentially deposited and formed on a belt-shaped substrate 901. The photovoltaic element 9 of this example
In 00, it is premised that light is incident from the transparent electrode 906 side.

First, SUS43 that has been thoroughly degreased and washed
A strip-shaped substrate made of 0BA (width 12 cm × length 100 m × thickness 0.2 mm) was set in a continuous sputtering apparatus, and Ag (9
A thin film of 1000 Å of Ag using the 9.99%) electrode as a target and ZnO (9
1.2 (μ)
The ZnO thin film of m) was sputter-deposited to form a lower electrode.

Subsequently, the strip-shaped substrate on which the lower electrode was formed was set in the continuous deposited film forming apparatus 1000 shown in FIG.

First, the bobbin 1003 on which the strip-shaped substrate 1002 is wound is set in a vacuum container 1001 having a substrate delivery mechanism, and the strip-shaped substrate 1002 is attached to the gas gate 1.
008, 1013, 1018, 1023 and film forming container 1
The tension was adjusted to such an extent that there was no slack by passing it through the transport mechanism in 010, 1015, 1020 to the vacuum container 1025 having a belt-shaped substrate winding mechanism.

The vacuum vessels 1001 and 1025 and the film forming vessels 1010, 1015, and 1020 are roughly evacuated by a rotary pump (not shown), and then a mechanical booster pump (not shown) is activated to evacuate to a pressure of about 10 ^-3 (Torr). After that, He gas was introduced to adjust the pressure to 1 (Torr), the baking heater (not shown) in the film forming containers 1010, 1015, and 1020 was operated, and this state was maintained for about 3 hours.

When the gas was sufficiently degassed, the supply of He gas was stopped, and the film forming container 1015 was started to be evacuated by an oil diffusion pump (not shown). Next, the raw material gas for forming a deposited film was introduced from each gas introduction pipe under the conditions shown in Table 3 below, and the opening degree of the throttle valve provided on the pipe leading from each film formation container to the exhaust pump was adjusted. The film forming space pressure in each film forming container was maintained as shown in Table 3 below.
Further, RF or microwave plasma is generated in each film forming space, and when the discharge or the like is stabilized, the strip-shaped substrate 100 is formed.
2 was conveyed from the left side to the right side in the drawing at a conveyance speed of 600 (mm / min), and n, i, p-type semiconductor layers were continuously laminated.

Further, the film forming containers 1010, 1015, 10
A temperature control means (not shown) for a wall member that surrounds the film formation space similar to that shown in FIGS. 1 and 2 is provided inside 20, and the temperature is controlled to a temperature lower than the temperature of the strip-shaped substrate.

[0050]

[Table 3] After a semiconductor layer is laminated and formed over the entire length of the belt-shaped substrate 1002, it is cooled, taken out, set in a continuous sputtering device, and an ITO thin film of 700 (angstrom) is vapor-deposited using an ITO (99.99%) electrode as a target. A transparent electrode was formed. 12 (cm) × 30 (cm) solar cell modules were continuously produced by a continuous modularization device.

The solar cell module thus produced was subjected to characteristic evaluation under AM1.5 (100 mW / cm ² ) light irradiation, and a photoelectric conversion efficiency of 8 (%) or more was obtained. There are 5 variations in the characteristics of
It was within (%). Also, AM1.5 (100
The rate of change of the photoelectric conversion efficiency with respect to the initial value after continuous irradiation with mW / cm ² ) light for 500 hours was measured to be 9.5.
It came within (%). FIG. 11 shows the relationship between the film formation time of the photovoltaic element and the cell characteristics.

<Embodiment 2> Using the apparatus shown in FIG.
An amorphous germanium pin type photovoltaic element 900 having the layer structure shown in the schematic sectional view of FIG. 9 was produced in the same manner as in Example 1. The production conditions are shown in Table 4 below.

[0053]

[Table 4] Regarding the solar cell module thus manufactured,
When the characteristics were evaluated under irradiation with M1.5 (100 mW / cm ² ) light, a photoelectric conversion efficiency of 9 (%) or more was obtained.
Furthermore, the variation in characteristics between modules was within 5 (%). In addition, AM1.5 (100 mW / cm ² )
The rate of change of the photoelectric conversion efficiency with respect to the initial value after continuous irradiation with light for 500 hours was measured and found to be within 9.5 (%). FIG. 12 shows the relationship between the film formation time of the photovoltaic element and the cell characteristics.

<Example 3> An a-Si / a-SiGe / a-SiGepin type photovoltaic element 1300 having a layer structure as schematically shown in FIG. 13 was produced as follows. This photovoltaic element 1300 has a lower electrode 1307, a lower a-SiGe cell 1302, an intermediate a- on a strip-shaped substrate 1301.
This is a photovoltaic device in which a SiGe cell 1303, an upper a-Si cell 1304, a transparent electrode 1305, and a collector electrode 1306 are sequentially deposited. Each cell is formed by depositing n, i, and p-type semiconductor layers in this order from the side of the belt-shaped substrate. Further, also in this embodiment, it is premised that light is incident from the transparent electrode 1305 side.

First, a strip-shaped substrate (width 12 cm × length 100 m × thickness 0.2 mm) having a lower electrode formed thereon in the same manner as in Examples 1 and 2 is shown in FIG.
I set it to 00. The bobbin 1423 around which the belt-shaped substrate 1422 is wound is set in a vacuum container 1401 having a substrate delivery mechanism, and the belt-shaped substrate 1422 is set to the gas gates 1402, 1404, 1406, 1408, 141.
0,1412,1414,1416,1418,142
0 and film forming containers 1403, 1405, 1407, 140
9, 1411, 1413, 1415, 1417, 141
The vacuum mechanism 1421 having a belt-shaped substrate winding mechanism was passed through the transport mechanism in No. 9 to adjust the tension so that there was no slack.

Vacuum containers 1401 and 1421 and film forming containers 1403, 1405, 1407, 1409 and 141
1, 1413, 1415, 1417, 1419 are roughly evacuated by a rotary pump (not shown), and then a mechanical booster pump (not shown) is activated to evacuate to about 10 ⁻³ (Torr), and then He gas is introduced. Set the pressure to 1 (To
rr), a baking heater (not shown) in the film forming container was operated, and this state was maintained for about 3 hours.

When the degassing is sufficiently performed, the supply of He gas is stopped and the film forming containers 1405, 1411, 141
In No. 7, exhaust was started by an oil diffusion pump (not shown). Next, the raw material gas for forming a deposited film was introduced from each gas introduction pipe under the conditions shown in Table 7 below, and the opening degree of the throttle valve provided on the pipe leading from each film formation container to the exhaust pump was adjusted. The film forming space pressure in each film forming container was maintained as shown in Table 5 below.

Further, RF or microwave plasma is generated in each film forming space, and when the discharge or the like is stabilized, the strip-shaped substrate is conveyed from the left side to the right side in the figure at a conveying speed of 60 (cm / min), and is continuously formed. As a result, n, i, and p-type semiconductor layers were laminated.

[0059]

[Table 5] After stacking the semiconductor layers over the entire length of the strip-shaped substrate,
It was cooled, taken out, and further set in a continuous sputtering apparatus, and an ITO (99.99%) electrode was used as a target to deposit a 700 (angstrom) ITO thin film to form an upper electrode. Furthermore, a solar cell module of 12 (cm) × 30 (cm) was continuously produced by a continuous modularization device.

Regarding the manufactured solar cell module, A
When the characteristics were evaluated under irradiation with M1.5 (100 mW / cm ² ) light, a photoelectric conversion efficiency of 10 (%) or more was obtained, and the variation in characteristics between modules was within 5 (%). . In addition, AM1.5 (100 mW / cm
² ) The rate of change of the photoelectric conversion efficiency with respect to the initial value after continuous irradiation with light for 500 hours was measured and found to be within 10 (%). FIG. 15 shows the relationship between the film formation time of the photovoltaic element and the cell characteristics.

[0061]

According to the present invention, at the time of film formation, the temperature of the wall member surrounding the film formation space is kept lower than the temperature of the substrate to form the deposited film, whereby the temperature is controlled by a lamp heater or the like. It is possible to improve the temperature control accuracy of the strip-shaped substrate, reduce film defects and impurity contamination due to film peeling and gas release from the member, and improve the film quality. Further, the yield can be improved.

Further, by controlling the temperature of the member surrounding the film forming space so as to decrease in the conveying direction of the strip-shaped substrate, it is possible to improve the controllability of the temperature of the strip-shaped substrate which moves while being exposed to the discharge.

Further, by providing a fin outside the member surrounding the film forming space and exchanging heat with the gas outside the discharge space, the temperature of the member surrounding the film forming space can be controlled.

Further, in the film formation by the microwave plasma CVD method applying a DC or RF bias,
By controlling the microwave power so that the bias current flowing from the bias applying electrode to the ground becomes constant while keeping the temperature of the member surrounding the film forming space constant, the control accuracy of the film forming conditions is improved, Further improvement of the film quality and uniformity of the film quality can be achieved.

[Brief description of drawings]

FIG. 1 is a sectional view of an apparatus for forming a functional deposited film by a microwave plasma CVD method according to the present invention.

FIG. 2 is a sectional view of an apparatus for forming a functional deposited film by a high frequency plasma CVD method according to the present invention.

FIG. 3 is another microwave plasma CV embodying the present invention.
It is an apparatus for forming a functional deposited film by the D method.

FIG. 4 is a functional deposited film forming apparatus by another high frequency plasma CVD method embodying the present invention.

FIG. 5 is a graph showing the relationship between the fin protrusion length and the temperature of the member surrounding the film formation space described in Experiment 2;

FIG. 6 is a graph showing the relationship between the discharge external space pressure and the temperature of a member surrounding the film formation space described in Experiment 2;

FIG. 7 is a graph showing the relationship between the temperature of the member surrounding the film formation space and the bias current when the DC bias described in Experiment 3 is applied.

FIG. 8 is a graph showing the relationship between the temperature of the member surrounding the film formation space and the bias current when the RF bias described in Experiment 3 was applied.

FIG. 9 is a schematic sectional view of the photovoltaic elements manufactured in Examples 1 and 2.

FIG. 10 is an apparatus for continuously forming a large-area functional deposited film used in Examples 1 and 2.

FIG. 11 is a graph showing the relationship between the film formation time and cell characteristics of the photovoltaic element manufactured in Example 1.

FIG. 12 is a graph showing the relationship between the film formation time and the cell characteristics of the photovoltaic element manufactured in Example 2.

FIG. 13 is a schematic cross-sectional view of the photovoltaic element manufactured in Example 3.

14 is an apparatus for continuously forming a large-area functional deposited film used in Example 3. FIG.

FIG. 15 is a graph showing the relationship between the film formation time and cell characteristics of the photovoltaic element manufactured in Example 3.

[Explanation of symbols]

101, 201, 301, 401 Film forming container 102, 202, 302, 302 Wall member of film forming container 103, 203, 303, 403, 901, 1002
1301 band-shaped substrate 104, 105, 204, 205, 304, 305, 4
04,405 Gas gate 106,206,306,406 Lamp heater 107,108,109,207,208,307,3
08,309,407,408 Thermocouple for lamp heater control 110,319,320,321,322,323,3
24, 325, 416, 417, 418, 419 Heat bath 111, 209, 310, 409 Member surrounding a film forming space fixed in contact with discharge (film forming space wall member) 112, 210 Fin 113, 211 , 311,410 Baking heater 114,115,116,212,312,313,3
14,315,316,317,318,412,41
4,415 Thermocouple 117, 213, 341, 429 Film forming space 118, 214, 346, 430 Deposition film forming source gas supply means 119, 215, 347, 433 Gas exhaust pipe of film forming space 120, 342, 344 Microwave applicator and microwave permeable member 121, 343, 345 Bias rod 122, 218, 348, 434 Outside film forming space 123 Means for supplying gas to outside film forming space 124 Gas exhaust pipe 216 of outside film forming space 431 High-frequency electrode 217, 411 Insulator 219 Gas exhaust pipe 220, 432 High-frequency introduction terminal 326, 327, 328, 329, 330, 331, 3
32,420,421,422,423 Cooling pipe 333,334,335,336,337,338,3
39,424,425,426,427 Linear introduction machine 340,428 Temperature controller 900,1300 Photovoltaic element 902,1307 Lower electrode 903,1308,1311,1314 n-type semiconductor layer 904,1309,1312,1315 i-type semiconductor Layers 905, 1310, 1313, 1316 p-type semiconductor layers 906, 1305 Transparent electrodes 907, 1306 Current collecting electrodes 1001, 1025, 1401, 1421 Vacuum containers 1003, 1026, 1423, 1424 Bobbins 1004, 1027, 1425, 1426 Conveying rollers 1005 , 1028 Pressure gauge 1006, 1011, 1016, 1021, 1029
Exhaust pipe 1007, 1012, 1017, 1022, 1030
Throttle valve 1008, 1013, 1018, 1023, 1402
1404, 1406, 1408, 1410, 1412,
1414, 1416, 1418, 1420 Gas gate 1009, 1014, 1019, 1024 Gas gate introduction piping 1010, 1403, 1409, 1415 n-type semiconductor layer deposition container 1015, 1405, 1411, 1417 i-type semiconductor layer deposition container 1020, 1407, 1413, 1419 p-type semiconductor layer deposition container

Claims (10)

[Claims] 1. A film-forming space is formed by a substrate for deposition and a wall member for a film-forming space other than the substrate for deposition, a source gas is introduced into the film-forming space, and plasma is generated to generate a film. A method of forming a non-single-crystal silicon semiconductor film on a substrate for deposition while moving the substrate for deposition, wherein the temperature of the wall member during film formation is kept lower than the temperature of the substrate for deposition. A method of forming a non-single-crystal silicon-based semiconductor film, comprising: 2. The method according to claim 1, wherein the temperature of the film forming space wall member during film formation is adjusted to have a temperature distribution that decreases in the moving direction of the deposition substrate. 3. The film forming space wall member is provided with a fin on a surface not in contact with the film forming space, and the temperature of the wall member during film formation is adjusted by adjusting the protrusion length of the fin.
The method described. 4. A fin is provided on a surface of the wall member for film forming space which is not in contact with the film forming space, and the pressure and / or the gas flow rate of a gas atmosphere in contact with the fin is adjusted so that the wall member for film formation is formed. The method according to claim 1, 2 or 3, wherein the temperature is adjusted. 5. A heating bath is provided on a surface side of the film forming space wall member which is not in contact with the film forming space, and the temperature of the wall member at the time of film formation depends on whether or not the heating bath and the wall member are in contact with each other. The method according to claim 1 or 2, wherein 6. A deposition base is formed by a deposition base and a wall member other than the deposition base, a source gas is introduced into the deposition space, and plasma is generated to form the deposition base. An apparatus for forming a non-single-crystal silicon-based semiconductor film on a substrate for deposition while moving, comprising means for keeping the temperature of the wall member at the time of film formation lower than the temperature of the substrate for deposition. A non-single crystal silicon-based semiconductor film forming apparatus characterized by: 7. The apparatus according to claim 6, wherein the means includes a fin provided on a surface of the wall member for a film forming space that is not in contact with the film forming space. 8. The apparatus of claim 7, wherein the protruding length of the fin is adjustable. 9. The apparatus according to claim 7, wherein the means includes means for adjusting the pressure and / or the gas flow rate of the gas atmosphere in contact with the fins. 10. The method according to claim 6, wherein the means includes a heat bath which is provided on a surface side of the film forming space wall member which is not in contact with the film forming space and is capable of adjusting contact / non-contact with the wall member. apparatus.