JP3461314B2 - Substrate processing method and substrate processing apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a substrate processing method and a substrate processing apparatus. The present invention also relates to a deposited film forming method and a deposited film forming apparatus. The present invention also relates to a deposited film forming method and a deposited film forming apparatus for continuously forming a deposited film on the surface of a substrate by a plasma CVD method or a sputtering method. Furthermore, the present invention relates to a method and an apparatus for manufacturing a photovoltaic element.

[0002]

2. Description of the Related Art Conventionally, as a method of depositing a functional thin film on the surface of a substrate using a plurality of processing chambers, a semiconductor device manufacturing apparatus for continuously forming a thin film on the surface of a strip substrate, for example, a roll.・ Two Roll
A manufacturing apparatus by a continuous deposition film forming method adopting the method 1) is known and disclosed in US Pat. No. 4,400,409. This apparatus has a double chamber structure in which a film forming chamber is provided in a plurality of communicating processing chambers, and a belt-shaped substrate having a desired width and sufficiently long is provided along a path for sequentially communicating the processing chambers. It is described that an element or the like having a semiconductor junction can be continuously formed by continuously conveying the strip-shaped substrate in the longitudinal direction.
Further, the film forming chamber is installed in a processing chamber that maintains a depressurized state, but in order to prevent the process gas used for forming each thin film layer from diffusing and mixing into another film forming chamber, There is a gas gate in. The gas gate is one in which each processing chamber is connected by a slit-shaped separation passage, and a flow of a separation gas such as Ar or H ₂ is formed in the separation passage. In the processing chamber, a means for introducing a process gas into the film forming chamber, an exhaust pipe for exhausting the film forming chamber,
By applying energy such as an exhaust means such as a vacuum pump and high frequency power, plasma is generated in the film forming chamber to generate CV.
A means for performing plasma processing such as D and sputtering, and a heating means such as a heater for heating a member forming the film forming chamber and the belt-shaped substrate to a desired temperature to form a deposited film are provided.

By using the plurality of processing chambers, thin films of different substances or different compositions can be continuously laminated on the substrate. As an example of the configuration of such an apparatus including a plurality of processing chambers, a case where one film forming chamber is installed in one processing chamber to deposit one kind of thin film, and a plurality of processing chambers are formed in one processing chamber. When a film chamber is installed to sequentially deposit thin films of the same type or similar types, or in one processing chamber, heating is performed without depositing a film on a strip substrate,
When performing processing such as cooling or etching, etc. may be considered. For example, as disclosed in Japanese Patent Application Laid-Open No. 9-191120, when a pin-type photovoltaic element is deposited, a p-type semiconductor layer is formed using a plurality of film forming chambers under different conditions. It is said that the characteristics of the device can be improved thereby. In the apparatus of the publication, the p-type layer is formed by a plurality of processing chambers each including a film forming chamber, and it can be said that the apparatus has the above-mentioned apparatus configuration. Further, since the process gases in the film forming chambers are of the same type, it is possible to adopt the above-mentioned apparatus configuration in which a film forming chamber for a plurality of p-type layers is included in one processing chamber. To be As another example, when the film thickness of the deposited film in one film forming chamber is insufficient, the above-mentioned apparatus configuration, that is, a plurality of film forming chambers having the same film forming conditions are combined into one processing chamber. By including the film inside, it is possible to obtain a desired film thickness. Particularly, in the device configuration of (1), the number of processing chambers and gas gates can be reduced, so that the device can be simplified and the cost can be reduced.

[0004]

As described above, the deposition film forming method in which a plurality of processing chambers are connected to each other, such as the roll-to-roll method, is used for semiconductor devices such as photovoltaic elements and functionalities. Although it is a method suitable for mass production of thin films,
Particularly, in order to popularize a large number of photovoltaic elements, further improvement in photoelectric conversion efficiency, characteristic stability and characteristic uniformity, and reduction in manufacturing cost are desired. Regarding the film forming conditions such as exhaust and pressure adjustment of the processing chamber or the film forming chamber, which is one of the important factors for that, the conventional one has the following problems. As a conventional method for exhausting the film forming chamber to adjust the pressure, a pressure regulator is used to compare the measured pressure value in the processing chamber or the film forming chamber with the set target pressure value, There is a method of changing the opening of the variable valve so that they match. An example of an apparatus using the pressure adjusting means according to this method is shown in FIGS. In the case of FIG. 3, there is a problem in that the exhaust speed of the gas exhausted from each film forming chamber is unbalanced, and in the case of FIG. 4, the film forming conditions cannot be easily changed. Etc. had a problem.

Explaining this point in more detail, in the method using the apparatus shown in FIG. 3, the exhaust pipe 108a of a plurality of adjacent processing spaces (film forming spaces) 104a to 104c in the processing chamber (film forming chamber) 103 is used. To c respectively, the variable valve 109a-c is connected, for example, the pressure regulator 1 which has a valve control function.
The measurement values of the pressure gauges 106a to 106c are respectively input to 10a to 10c to adjust the opening of the variable valves 109a to 109c to adjust the pressure in the film forming spaces 104a to 104c, and feedback control is independently performed in the film forming spaces. However, in the apparatus configuration shown in FIG. 3, the balance of the opening rates of the variable valves 109a to 109c may be disturbed, and the balance of the exhaust speeds of the respective film formation spaces may be disturbed. There is a problem in that. As such a problem, it is understood that the respective film forming spaces are installed in the same film forming chamber and are spatially continuous. , It is considered to be caused by a difference between the pressure recognized by the pressure regulator and the pressure recognized by the pressure regulator. The causes are (1) deviation of the zero point of the pressure gauge and the error range of linearity, (2) error range of the pressure setting value of the pressure regulator or deviation of the setting value, and (3) long-term error. Variation in pressure measurement value due to output drift of the pressure gauge itself and temperature change during film processing, (4) Process gas reaction state change due to abnormal discharge or discharge interruption in discharge space, (5) Discharge due to substrate vibration Changes in the tightness of the space,
(6) There are electrical noises and the like that affect the pressure adjustment, and these change the actual pressure in a certain film formation space.

For example, in the conventional device shown in FIG. 3, the set value of the pressure regulator 110b is shifted by any of the above factors,
Assuming that the actual pressure in the film forming space 104b has increased, the process gas in the film forming space 104b flows into the adjacent film forming spaces 104a and 104c, and as a result, the film forming space 1
The pressure of the pressure controller 104a and the pressure of the pressure controller 104c are increased.
a, 104c are variable valves 109a, 109 for reducing the pressures in the film forming spaces 104a, 104c.
Increase the opening of c. If the pressure adjustment operation is continuously performed in such a state that the mutual balance is lost, the variable valve for exhausting the film forming chamber, which may be extreme, may be fully opened and the variable valve for exhausting the adjacent film forming chamber may be opened. In some cases, it may be fully opened. As described above, since the film forming spaces are spatially continuous with each other, in the worst case, a process in which a pressure value in each film forming space is a target value but is supplied to a certain film forming space The gas may be exhausted through the adjacent film forming spaces and the process gas may be mixed into the mutual film forming spaces, and the same may be said when the gas for separation is supplied to the gas gate 101. The phenomenon occurs.

The above problems due to such factors are the same when the film forming spaces are provided in different processing chambers and communicate with each other through gas gates (for example, in the case of the positional relationship shown in FIG. 4). Is.

In addition, the method shown in FIG.
The exhaust pipes 108a to 108c of the processing spaces (film forming spaces) 104a to 104c inside the accumulators 03a to 103c are assembled, the variable valve 109 is installed between the collecting portion and the exhaust means, and one of the pressure gauges 106a to 106c. The opening degree of the variable valve 109 is adjusted by the pressure adjuster 110 based on the output, and the film forming spaces 104a to 104c are formed.
This is a method of adjusting the pressure inside and collecting the exhaust gas to exhaust it. In this method, the inside of the film forming spaces 104a to 104c can be set to a desired pressure by inserting an orifice or the like and optimizing the exhaust speed through the exhaust pipes 108a to 108c. However, when the film forming conditions are changed, for example, when the process gas flow rate in a part of the film forming space is changed,
There is a difference in pressure between the film forming spaces 104a to 104c,
Since a desired gas flow path cannot be formed, for example, a process gas is mixed in an adjacent film forming space, the film forming conditions that can be set are limited. In other words, there is a case that the apparatus configuration may need to be changed in order to change the growth condition, so that the film forming condition cannot be easily changed.

The same problem can occur not only when a thin film is formed but also when the substrate is processed by carrying the substrate over a plurality of processing spaces. An example of substrate processing in which such a problem may occur is sputtering vapor deposition CVD.
Film forming treatment, etching treatment, thermal annealing treatment and the like. In particular, when the gas composition, pressure, etc. of the atmosphere are different between the adjacent processing spaces, the above-mentioned problem is likely to occur.

Therefore, the present invention solves the above-mentioned problems in the prior art, and by optimizing the flow of the process gas in the processing space, it is possible to obtain an element having good characteristics, and the reliability is improved for a long time. (EN) Provided are a substrate processing method and a substrate processing apparatus capable of forming a deposited film having high and stable characteristics, a low production cost, and a high productivity, particularly a functional deposited film such as a photovoltaic element. The purpose is to do.

[0011]

In order to achieve the above object, the present invention provides a substrate processing method and a substrate processing apparatus configured as in the following (1) to (22). (1) In a substrate processing method including a step of transporting a substrate over a plurality of processing spaces and processing the substrate in each processing space, based on a pressure of one of the processing spaces, A substrate processing method comprising controlling the pressure of at least one other processing space. (2) The substrate according to (1) above, wherein the control of the pressure in the one processing space and the pressure in the other at least one processing space is performed by controlling the exhaust speed of each processing space. Processing method. (3) The substrate processing method according to (2), wherein each of the exhaust speeds is controlled by adjusting an opening of an exhaust valve in an exhaust pipe connected to each of the processing spaces. . (4) The substrate processing method according to (3), wherein the opening degree of the exhaust valve in the exhaust pipe connected to each of the processing spaces is controlled to be the same. (5) The above-mentioned (3), wherein the exhaust valves in the exhaust pipes connected to the respective processing spaces are controlled in conjunction with each other so that the opening degrees of the exhaust valves are constant. Substrate processing method. (6) The substrate processing method according to (1), wherein the one processing space and the other one processing space are present in the same processing chamber. (7) The substrate processing method according to (1) above, wherein the one processing space and the other processing space are connected via a gas gate. (8) The at least one other processing space includes a processing space other than the processing space and a processing space adjacent to the one processing space, (1) to (7).
The substrate processing method according to any one of the above. (9) The substrate processing method as described in (1) above, wherein the processing includes film forming processing. (10) The substrate processing method as described in (9) above, wherein the processing includes sputtering. (11) The substrate processing method as described in (9) above, wherein the processing includes CVD. (12) The substrate processing method as described in (1) above, wherein a strip substrate is used as the substrate. (13) A plurality of processing spaces, a substrate transfer mechanism that transfers a substrate over the plurality of processing spaces, a pressure gauge that measures one pressure in the plurality of processing spaces, and based on information obtained from the pressure gauges. And a control unit for controlling the pressure in at least one other processing space. (14) Each of the plurality of processing spaces has an exhaust pipe,
The substrate processing apparatus according to (13) above, wherein a variable valve is provided in each of the exhaust pipes, and the control unit directly or indirectly controls the opening degree of the variable valve. (15) Each of the variable valves has a pressure regulator for controlling the opening of each variable valve, and each of the pressure regulators of the variable valves connected based on a signal from the control unit. The substrate processing apparatus according to (14) above, wherein the opening is controlled. (16) The substrate processing apparatus according to (13), wherein the one processing space and the other one processing space are present in the same processing chamber. (17) The substrate processing apparatus according to (13), wherein the one processing space and the other processing space are connected via a gas gate. (18) The at least one other processing space includes a processing space other than the processing space and a processing space adjacent to the one processing space.
The substrate processing apparatus according to any one of (17). (19) The substrate processing apparatus according to (13) above, wherein at least one of the processing spaces has a film forming means. (20) The substrate processing apparatus according to the above (19), wherein the film forming means includes a process gas introducing means and a voltage applying means. (21) The substrate processing apparatus according to (19), wherein the film forming means is a sputtering means. (22) The substrate processing apparatus according to the above (19), wherein the film forming means is a CVD means.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention, which has the above-described structure, has been a problem in the prior art as described above.
Deviation of pressure gauge zero point or linearity error range. (2) Error range of pressure setting value of pressure regulator or deviation of setting value.
(3) Fluctuation of pressure measurement value due to output drift of the pressure gauge itself or temperature change during substrate processing for a long time. It is possible to minimize the effect of such as the above, and it is possible to further stabilize the processing conditions.Therefore, especially for equipment that is operated for a long time or for a long time, such as mass production equipment, a processed substrate with stable characteristics should be used. It becomes possible to obtain.

Embodiments of the present invention will be described below with reference to the drawings. The substrate processing method of the present invention includes a method of carrying a substrate by carrying the substrate over a plurality of processing spaces. Further, the substrate processing apparatus of the present invention includes an apparatus having a plurality of processing spaces and a substrate transfer mechanism that transfers a substrate over the plurality of processing spaces.

The present invention is preferably used when the gas composition and / or pressure in at least one set of atmospheres in adjacent processing spaces are different from each other. In the following, a method and an apparatus for forming a film on a belt-shaped substrate will be specifically described, but the substrate does not need to be in the shape of a belt in applying the present invention, and various types such as a disk shape and a square shape can be used. The present invention can be applied to the substrate processing of. Further, the substrate processing method of the present invention includes a film forming method such as a sputtering method, a vapor deposition method, a CVD method, an etching method, and a thermal annealing method. The substrate processing apparatus of the present invention includes a sputtering apparatus, a vapor deposition apparatus, a CVD apparatus. Film forming equipment, etching equipment, etc.
Includes thermal annealing equipment.

In a preferred mode of the processing apparatus of the present invention, as shown in FIG. 1, a plurality of processing spaces 1 are provided in the processing chamber 103.
04a to c are built in, and the respective processing spaces are connected to exhaust means (not shown) through exhaust pipes 108a to 108c and variable valves 109a to 109c. Further, pressure gauges 106a to 106c and process gas introduction pipes 107a to 107c are connected to the respective processing spaces. Control unit 11
1 (for example, an arithmetic unit such as a calculation unit) is one of the pressure gauges 106a to 106c (106 in the example of FIG. 1).
The opening degree of the variable valves 109a-c is controlled by determining the opening degree of the variable valves 109a-c based on the pressure value of b) and controlling the pressure regulators 110a-c, and the processing space 10
Adjust the pressure within 4a-c. Further, in detail, the pressure regulators 110a to 110c control the opening degrees of the variable valves 109a to 109c based on the pressure signals sent from the pressure gauges 106a to 106c, respectively, to control the pressure inside the processing spaces 104a to 104c. And a function of controlling the opening degree of the variable valves 109a to 109c based on the opening degree signal sent from the control unit 111. These signals are controlled by a signal from the control unit 111. Functions can be switched. The control unit 111 has a function of outputting a pressure signal sent from any of the pressure gauges 106a to 106c (106b in the example of FIG. 1) to one of the pressure regulators 110a to 110c (110b in the example of FIG. 1). And the variable valve 109a
A function of receiving the current value of the opening, which is deviated by 109c (109b in the example of FIG. 1) through the pressure regulator, and outputting the opening signal to another pressure regulator (110a and 110c in the example of FIG. 1). And have. Furthermore, the control unit 1
Reference numeral 11 denotes a pressure regulator 1 by adding a calculation described later to the opening signal.
It also has a function of outputting to 10a to 110c. For example, in the processing spaces 104a to 104c, all processing spaces have the same conditions (flow rate and composition of process gas, pressure, temperature,
When performing processing for the film forming chamber shape and size and the exhaust pipe shape and size from the processing space to the variable valve (for example, when designing to obtain a similar deposited film), the control unit 111 controls the pressure. By outputting the opening signal received from the regulator 110b to the pressure regulators 110a and 110c with the same value, and interlocking the variable valves 109a to 109c at the same opening, the exhaust speed of the process gas from each processing space is increased. The same processing conditions can be realized because the same can be obtained. In addition, since the variable valves have the same opening, it is possible to always maintain a desired processing condition without causing the difference in opening and losing the balance of the exhaust speed as in the conventional example. Furthermore, since a plurality of variable valves are adjusted in conjunction with each other based on the pressure measurement value at one location and one pressure set value, the pressure gauge and the pressure set value are less susceptible to variations, so that a very stable pressure can be obtained. It becomes possible to control.

Next, in the processing spaces 104a to 104c, in the processing conditions, for example, when the processing gas flow rate in the processing space 104b is set to be twice the flow rate flowing in the processing spaces 104a and 104c, the variable valve 109b is used. A desired processing condition can be realized by setting the opening of the variable valves 109a and 109c to an opening that provides twice the exhaust speed and by interlocking the opening of the variable valves 109a to 109c at a constant ratio. . When the correlation between the opening of the variable valve and the exhaust speed of the gas passing through the variable valve is non-linear, the relationship between the opening and the exhaust speed at the desired pressure is calculated or measured in advance to determine the calculation formula. Incidentally, for example, in the film forming chambers 104a to 104c, when the flow rate of the process gas is different among the film forming conditions, the control unit 111 is substituted by substituting the pressure measurement value at any one position into the calculation formula.
By calculating and controlling the opening of each of the variable valves 109a to 109c, it is possible to realize more precise control of processing conditions. For example, when processing is performed with the flow rate of the process gas introduced into the processing spaces 104a to 104c being twice the flow rate introduced into the processing space 104b, the control unit 111 first causes the variable valve 109b controlled by the pressure regulator 110b. Is received, the opening of the variable valve capable of obtaining a double exhaust speed is calculated in the control unit 111, and the opening signal is output to the pressure regulators 110a and 11a.
Output to 0c. As the calculation method of the opening degree, the relational expression between the opening degree of the variable valve and the exhaust speed can be calculated by simulating by numerical calculation based on the shape and size of the device, or by actually measuring using an actual device. Then, a method of determining the opening degree of the variable valve can be given. By the control as described above, the process gas introduction pipes 107a to
The process gas introduced from 107c into the processing spaces 104a to 104c can be exhausted through the exhaust pipes 108a to 108c, respectively, so that proper process gas passages can be formed. In the present invention, when the control unit 111 itself also has a function of directly controlling the opening degree of the variable valves 109a to 109c based on the pressure signal from the pressure gauges 106a to 106c to adjust the pressure, the pressure adjustment is performed. The containers 110a to 110c are unnecessary. Further, in the film forming chambers 104a to 104c, even when it is desired to set different pressures in the film forming chamber among the film forming conditions, one of the pressure measurement values is substituted into the calculation formula to control unit 111. Variable valve 109a-
A desired film forming condition can be realized by calculating and controlling each opening degree.

An example in which the above-described structure of the present invention is applied to a manufacturing apparatus for continuously depositing thin films to form an element will be described with reference to the drawings. A roll-to-roll system device is an example of a manufacturing device for forming an element by continuously depositing thin films, which is one embodiment of the present invention. In this apparatus, the strip-shaped substrate is continuously conveyed in the longitudinal direction of the strip-shaped substrate through a plurality of film forming chambers to form elements. A plasma CVD method, a sputtering method, or the like can be given as a film deposition method performed by this apparatus. Also,
Examples of the element to be formed include various photovoltaic elements such as semiconductor integrated circuits, various semiconductor sensors, and solar cells. In particular, the substrate processing method and the substrate processing apparatus of the present invention can be suitably used for manufacturing a photovoltaic element that requires a large-area light receiving section. The photovoltaic element has, for example, the layer structure shown in FIG. 8, that is, on the surface of the substrate 800,
Back surface reflection layer 801, transparent conductive film 802, n-type semiconductor layer 8
03, i-type semiconductor layer 804, p-type semiconductor layer 805, and transparent conductive film 806 are sequentially deposited, and a collector electrode 807 is formed thereon.

Next, a roll-to-roll system device capable of forming such an element will be described with reference to FIG. FIG. 5 is a schematic sectional view showing an example of a roll-to-roll type plasma CVD film forming apparatus. In FIG. 5, 501, 502, and 503 are processing chambers (deposition chambers) by a plasma CVD method in which n, i, and p type semiconductor layers are deposited, respectively, 500 is a strip substrate delivery chamber, and 504 is a winding chamber. Is. The respective processing chambers are connected by a gas gate 101. Reference numeral 100 is a strip-shaped substrate, which is 3 before being transported from the delivery chamber to the winding chamber.
After passing through one processing chamber (four processing spaces (film forming space)), a pin-structured photovoltaic layer is formed on the surface thereof.
In this example, each processing space is formed by being surrounded by a tank-shaped member opened to the upper side and a substrate provided so as to cover the upper side. There is a gap between the tank-shaped member and the substrate.
Each of the processing spaces 104a to 104 of the processing chambers 501 to 503
A lamp heater unit (not shown) for preheating the strip-shaped substrate, a heater 105 for heating the strip-shaped substrate, and a process gas introduction pipe for introducing a process gas supplied from a gas supply means (not shown) into the processing space are provided on the upper side of d. 107, an exhaust pipe 108a for exhausting the processing space by an exhaust unit (not shown)
~ D, variable valve 109a for adjusting the pressure in the processing space
To d, a high-frequency electrode (not shown) that supplies energy to process gas in the processing space to generate electric power to generate plasma discharge, pressure gauges 106a to 106d to measure the pressure in the processing space 104a to 104d, and the processing space are formed. A wall heater (not shown) for heating the member to be heated is provided, and the deposited film is formed by the plasma CVD method.

In the roll-to-roll system, the strip-shaped substrate 100 wound on the delivery core 505 arranged in the delivery chamber 500 is unwound and passed through a plurality of film forming spaces to form a winding chamber. It is conveyed so as to be wound into a coil around a winding core 506 provided in 504. It is important that the strip-shaped substrate is conveyed at a constant speed to the plurality of film forming chambers without causing wrinkles, twists, warps, and the like in its surface as much as possible. When the belt-shaped substrate 100 is magnetized, a rotatable magnetic roller (not shown)
By supporting the strip-shaped substrate by using, it becomes possible to convey the strip-shaped substrate along a desired path while keeping it in a constant shape. The transfer speed is appropriately selected depending on the film forming conditions (film thickness of semiconductor film, forming speed, etc.), but is preferably 200 mm / min to 5000 mm / min.

There are cases where a plurality of thin film layers made of different materials are formed by continuously providing a plurality of film forming chambers.
At this time, it is preferable to provide a gas gate 101, which will be described later, between each film forming chamber to prevent the influence of adjacent film forming.
The gas gate 101 separates the feeding chamber, the winding chamber, and the film forming chambers of the strip-shaped substrate so that the gases in the chambers do not mix with each other, and the strip-shaped substrate is continuously passed through them. It is provided for the purpose of carrying the material. The gas gate has a structure in which the strip-shaped substrate 100 is penetrated into a slit-shaped space, and a predetermined gap is provided between the deposition surface of the strip-shaped substrate. This gap is preferably set to a width of, for example, 1 to 5 mm for the purpose of reducing the conductance and preventing the diffusion and mixing of the gas between the film forming chambers. Further, the separation gas is introduced into the gas gate from the separation gas introduction pipe 102, and the process gas that enters the gas gate from the film forming chamber is pushed back. Examples of the separation gas include Ar, He, Ne, Kr, and
Examples include rare gases such as Xe and Rn, or diluent gases such as H ₂ for forming a semiconductor film. The flow rate of the separation gas is appropriately determined by the conductance of the entire gas gate,
For example, if a point where the pressure becomes maximum is provided in the substantially central part of the gas gate, the separation gas flows from the central part of the gas gate to the film forming chambers on both sides, and the mutual gas between the film forming chambers on both sides is separated. Diffusion can be minimized.

The strip-shaped substrate used in the present invention is preferably one which has a small amount of deformation and distortion at a temperature required for producing a deposited film, has a desired strength, and has electrical conductivity. Specifically stainless steel,
A thin metal plate such as aluminum or its alloy, iron or its alloy, copper or its alloy, or a composite thereof is preferably used. In addition, the surface of heat-resistant resinous sheet such as polyimide, polyamide, polyethylene terephthalate, epoxy, etc. can be made conductive by a method such as sputtering, vapor deposition, plating, coating, etc. with a simple metal or alloy, and transparent conductive oxide (TCO). The processed product is also preferably used. In addition, the thickness of the belt-shaped substrate is as thin as possible in consideration of cost, storage space, etc., as long as it is within a range in which the path and shape formed during the transportation by the transportation means can be maintained. Is preferable. Specifically, it is preferably 0.01 mm to 1 mm, and most preferably 0.05 mm to 0.
It is preferably 5 mm. When a thin plate made of metal or the like is used as the substrate, desired strength can be easily obtained even if the thickness is relatively thin. The width of the strip-shaped substrate is not particularly limited and is determined by the size of the deposited film forming means, the container thereof or the like. The length of the strip-shaped substrate is not particularly limited and may be such a length that it can be wound into a roll, and a long one is further lengthened by welding or the like. Is also good. In the present invention, it is possible to use a substrate other than the strip-shaped substrate, but when the strip-shaped substrate is used as in the present embodiment, it is difficult to completely separate adjacent processing spaces from each other. The effect of is more prominent.

Next, a preferred embodiment of the deposited film forming apparatus which is the substrate processing apparatus of the present invention will be further described with reference to FIGS. 1 and 2. FIG. 1 is a schematic sectional view showing a part of the deposited film forming apparatus of the present invention. In FIG. 1, 100 is a belt-shaped substrate, 101 is a gas gate, 102 is a separation gas introduction tube, 103 is a film forming chamber as a processing chamber, 104a to c are film forming spaces as processing spaces, 105a to c are heaters, and 106a to 106a.
c is a pressure gauge, 107a-c are process gas introduction pipes, 10
8a to c are exhaust pipes, 109a to c are variable valves, 110
a to c are pressure regulators, and 111 is a control unit. First, the strip substrate 100 is transported from the delivery chamber, passes through the gas gate 101, and then enters the film forming chamber 103. Process gases are introduced into the film forming spaces 104a to 104c installed in the film forming chamber 103 through process gas introducing pipes 107a to 107c, and exhaust gases (not shown) are passed through exhaust pipes 108a to 108c and variable valves 109a to 109c. Exhausted to means. Film forming chamber 104a
The pressures in to c are adjusted by the pressure regulators 110a to 110c adjusting the opening of the variable valve based on the opening of the variable valve 109a to 109 calculated by the control unit 111. For example, when the flow rate of the process gas is the same in all the film forming chambers 104a, 104b, 104c and the composition, the control unit 111 causes the pressure regulator 110b to control the variable valve 109b based on the pressure signal of the pressure gauge 106b.
Control the pressure regulators 110a and 110c.
With regard to the above, the opening degree of the variable valves 109a and 109c may be controlled so as to match the opening degree of the variable valve 109b. As a result, the gases passing through the variable valves 109a to 109c all have the same evacuation rate. For example, when the shape, size, and capacity of the film forming chamber, the exhaust pipe, and the exhaust means are the same except for the variable valve, the film forming chamber 104a. The pressures of to c are also the same, and proper gas flow paths are formed, so that the process gas does not flow into the film forming chambers adjacent to each other. here,
The proper gas flow passage means the process gas introduction pipe 107a (1
That is, all the process gas introduced from 07b, 107c) is exhausted through the exhaust pipe 108a (108b, 108c).

When the flow rate or composition of the process gas to be introduced differs depending on the film forming chamber, the relation between the opening of the variable valve and the exhaust speed of the gas passing through the variable valve is calculated or measured in advance to obtain a calculation formula. Then, the film-forming chambers 104a to 104c are adjusted by adjusting the opening ratio of each variable valve so as to maintain the ratio of the opening ratios obtained from the above-mentioned calculation formulas and adjusting any one pressure measurement value to a desired pressure. The pressure can be made the same to form an appropriate flow path. As a calculation formula,
The degree of opening can be obtained by using a function of second order or higher or by creating a conversion table in advance. In the present invention, the control unit 111 may also serve as a pressure regulator. In that case, the pressure regulator 110a-
c is unnecessary.

FIG. 2 is a schematic cross-sectional view showing a part of another embodiment of the deposited film forming apparatus which is the processing apparatus according to the present invention. The difference from FIG. 1 is that each of the film forming space chambers 104a to 104c is different. It is installed in another film forming chamber 103a-c. In this device configuration, each film forming space 103a,
Although the gas gate 101 is installed between b and c, performing the same control as in FIG. 1 has the effect of obtaining an appropriate gas flow rate. In the film formation spaces 104a to 104c, electric power is supplied by an electric power supply unit (not shown) to decompose and excite the process gas, and a deposited film is formed on the surface of the strip substrate 100 by plasma CVD processing or sputtering processing. The exhaust gas after film formation is exhausted to an exhaust means (not shown) through an exhaust pipe and a variable valve.

Next, the belt-shaped substrate 100 is conveyed to the winding chamber and wound on a winding bobbin together with a slip sheet (not shown) used for protecting the surface of the belt-shaped substrate. As the material of the interleaving paper, heat-resistant resin such as polyimide, Teflon, and glass wool is preferably used. As described above, particularly when manufacturing an element having a thin film such as a photovoltaic element, by using the apparatus for continuously forming a deposited film of the present invention, the above problems can be solved and It is possible to stably manufacture a high-quality functional deposited film that satisfies the requirements.

[0026]

EXAMPLES Examples of forming a photovoltaic element by the deposited film forming apparatus as a substrate processing apparatus of the present invention will be described below, but the present invention is not limited to these examples. [Example 1] In Example 1, a roll-to-roll type plasma CVD apparatus shown in FIG. 5 was used, and a pin-type amorphous silicon photovoltaic element was formed on the surface of a strip substrate under the following conditions. It was made. In FIG. 5, as the strip substrate 100, a thin film of aluminum (thickness 0.1 μm) is used as a back surface reflection layer on the strip substrate 100 by a roll-to-roll type sputtering film forming apparatus (not shown) in advance.
And a thin film of zinc oxide (ZnO) (thickness 1.0 μm) deposited, width 350 mm, length 300 m, thickness 0.2 m
m SUS430 substrate was used.

In this embodiment, first, the strip substrate 100 is
The film was set to be sent out from the delivery chamber 500, passed through the three film forming chambers 501 to 503 connected to the gas gate 101, and wound in the winding chamber 506. Next, the film forming spaces 104a to 104d are evacuated through the variable valves 109a to 109d to 1 Torr level by an evacuation means (not shown), and then continuously evacuated from the process gas introduction pipe 107 to He.
Flowing gas at 100 sccm each, variable valve 1
The pressure in each of the film forming spaces 104a to 104d was measured by the pressure gauges 106a to 106d and maintained at 1.0 Torr by controlling 09. Further, each heater 105 was heated to 300 ° C. and baked in this state for 5 hours to desorb the impurity gas. Next, the He gas flowing from the process gas introduction pipe 107 is stopped, and a raw material gas having a composition shown in Table 1 is introduced from a gas mixer (not shown) into the film forming chambers 104a to 104d through the process gas introduction pipe 107. did. Each gas gate 1
H ₂ gas was flowed to 01 through the separation gas introduction pipe 102 at 1000 sccm. The transport speed of the strip substrate 100 was 1000 mm / min. Further, a high-frequency oscillator (not shown) applies power to high-frequency electrodes (not shown) in each of the film forming chambers 104a to 104d to generate plasma discharge, and an n, i, p-type amorphous silicon film is formed on the strip substrate. Were continuously formed. Table 1 shows the production conditions for stable film formation in each film formation chamber.

In this embodiment, the p-type layer has two film formation spaces 1
04c and 104d were used to deposit a film having good film characteristics in the respective film forming spaces, and by stacking two layers of the films, a p-type layer having a large film thickness and good film characteristics could be formed. As for the method of exhausting the film forming spaces 104c and 104d, the variable valve 109c, using only the measurement value of the pressure gauge 106c,
The pressure in the film forming chamber was adjusted while keeping the opening of 109d the same, and the pressure shown in Table 1 could be constantly maintained during the film forming process. As a film-forming process, film formation is continuously performed for about 5 hours, and 25 of the lots of strip-shaped substrates (total length 300 m) are used.
The semiconductor film could be formed at 0 m. Furthermore, the take-up core 506 was removed, an empty take-up core 506 was set, a delivery core 505 on which a strip-shaped substrate was newly wound was set, and the film forming step was performed for a total of 10 lots. . After that, when the inside of each of the film forming chambers 501 to 503 was observed, there was no deposition film or by-product attached to the wall surfaces of the film forming chambers 501 to 503.

Further, the strip-shaped substrate on which the amorphous silicon film obtained by the above procedure was deposited was taken out from the winding chamber 504, and an ITO transparent conductive film (film pressure 800 Å) was formed by a sputtering system film forming device (not shown). After that, the strip substrate 10
0 is sent out by a cutting machine (not shown) and cut every 100 mm in the carrying direction to form a sample, and a collector electrode is formed by screen-printing an Ag paste, and the photovoltaic power shown in the schematic cross-sectional view of FIG. A device was produced.
By measuring the photoelectric conversion rate η when the formed photovoltaic element is irradiated with pseudo sunlight having an AM value of 1.5 and an energy density of 100 mW / cm ² , the photoelectric conversion efficiency of each element is averaged. The characteristics were evaluated. The evaluation results are shown in Table 2.

Comparative Example 1 The same film formation as in Example 1 was performed, but in Comparative Example 1, the film forming spaces 104c and 104d were formed.
As for the exhaust method, the pressure was adjusted for each film forming chamber. That is, in the film formation space 104c, the variable valve 1 is operated by the pressure adjuster 110c using the measurement value of the pressure gauge 106c.
The opening degree of 09c is controlled, and the pressure gauge 10 is set in the film forming chamber 104d.
The opening of the variable valve 109d was controlled by the pressure regulator 110d using the measured value of 6d. Other film forming conditions are the same as in Table 1. In Comparative Example 1 as well as in Example 1, after performing the film forming process for a total of 10 lots, each film forming chamber 501
When the inside of ~ 503 was observed, the film formation chamber 503
A large amount of by-products were attached to the wall surface of the film and the wall surfaces of the film forming spaces 104c and 104d. In particular, the film formation spaces 104c and 104
A large amount of by-products adhered during the period d and around the path through which the strip substrate 100 passes. It takes a long time to remove the by-products, and when the device is used for production, the maintenance time is extended and the operation rate is reduced. In this comparative example,
During the film forming process, the opening degrees of the variable valves 109c and 109d, which are supposed to match in design, do not match, and the opening ratio is 1: 1.1 for the first lot and 1:11 for the tenth lot. It changed with time to 1.2. From this, the cause of the generation of by-products is that the process gas is formed from the film forming space 104c through the film forming chamber 503 into the film forming space 104d, and the process gas is formed in the film forming space 104c. It is considered that this is because the process gas that has become the active species in step S3 leaks into the processing space 503. The evaluation method is the same as in Example 1,
The evaluation results are shown in Table 2.

[0031]

[Table 1]

[0032]

[Table 2] As shown in Table 2, in Comparative Example 1, the photoelectric conversion efficiency was improved in Example 1. When the surfaces of the deposited films of Comparative Example 1 and Example 1 were observed, a large number of powders adhered in Comparative Example 1 and the appearance was cloudy in white. This powder is a by-product generated in the film forming chamber 503, and it is considered that this powder causes a decrease in light transmittance and a leakage current, which causes a decrease in photoelectric conversion efficiency. To be
In Example 1, such powder and turbidity were not observed.

[Embodiment 2] In Embodiment 2, as in Embodiment 1, film formation was performed with the apparatus configuration shown in FIG. 5, but the difference is in the process gas flow rate for forming the p-type layer. The flow rate of the space 104c was set to 1/2 of 104d. Table 3 shows the film forming conditions at that time. Also, the variable valves 109c, d
The control unit 111 is operated so that the opening rate of the film is maintained at ½ of that of the exhaust speed of 109d, and only the measurement value of the pressure gauge 106c is used to form the film formation space 10.
The pressure of 4c and d was adjusted. After performing the film forming process for a total of 10 lots as in the first embodiment, each film forming chamber 50
When the inside of Nos. 1 to 503 was observed, byproducts and the like did not adhere to the wall surfaces of any of the film formation chambers and the space wall of the film formation chamber. Alternatively, the same evaluation as in Example 1 was performed. The evaluation results are shown in Table 4.

Comparative Example 2 In Comparative Example 2, the film formation was carried out by controlling the variable valves in the apparatus configuration shown in FIG. 6 as in Comparative Example 1 based on the pressure measurement values of the corresponding film forming spaces. The film forming conditions are the same as in Example 2, and are as shown in Table 3. After performing the film forming process for a total of 10 lots in the same manner as in Example 2, the inside of each of the film forming chambers 501 to 503 was observed. As a result, it was confirmed that the film forming chambers 503 and the wall surfaces of the film forming spaces 106c and 106d were observed. Adhesion of a large amount of by-products was observed. Moreover, the same evaluation as in Example 1 was performed.
The evaluation results are shown in Table 4.

[0035]

[Table 3]

[0036]

[Table 4] As shown in Table 4, the photoelectric conversion efficiency was improved in Example 2 as compared with Comparative Example 2. When the surfaces of the deposited films of Comparative Example 2 and Example 2 were observed in the same manner as in Comparative Example 1, Comparative Example 2
In this case, many powders were attached and the appearance was cloudy in white. This powder is a by-product generated in the film forming chamber 503, and it is considered that this powder causes a decrease in light transmittance and a leakage current, which causes a decrease in photoelectric conversion efficiency. To be In Example 2, such powder and turbidity were not observed.

[Embodiment 3] In Embodiment 3, the same film formation as in Embodiment 1 was performed using the apparatus shown in FIG. Example 1
The difference is that the film formation chamber 502 for forming the i-type layer is expanded,
Forming a deposited film by providing three film formation spaces 104b to 104d therein and increasing the film thickness of the i-type layer,
The point is to improve the film characteristics of the i-type layer by changing the film forming conditions to reduce the deposition rate. Further, the pressure in the film forming spaces 104b to 104d is adjusted by using only the measured value of the pressure gauge 106c while keeping the opening of the variable valves 109b to 109d the same, and the pressures shown in Table 5 are constantly applied during the film forming process. I was able to keep it. Table 5 shows other film forming conditions. After performing the film forming process for a total of 10 lots in the same manner as in Example 1, the inside of each of the film forming chambers 501 to 503 was observed. No by-products were attached.

[0038]

[Table 5] [Example 4] In Example 4, the same film formation as in Example 3 was performed by using the apparatus shown in FIG. The difference from Example 3 is the film forming condition of the film forming space 104d for forming the third i-type layer, and this layer forms an interface with the p-type layer, but it is better by optimizing the film quality. To form a different P / i interface. Specifically, H in the film formation space 104d
₂ Increased dilution amount and increased RF power. That is, in the film formation space 104d, the flow rate and composition of the process gas are set to 10
4b and 104c. If the composition is different, the relationship between the opening degree of the variable valve and the exhaust speed is not a constant ratio. Therefore, the opening degrees of the variable valves 109b to 109d and the exhaust speed are measured in advance and approximated by a cubic equation. Pressure gauge 106c
The control unit 111 determines the openings of the variable valves 109b to 109d using only the measured values of the above, adjusts the pressure of the film forming space, and adjusts the pressure shown in Table 6 during the film forming process. I could always keep it. Table 6 shows other film forming conditions.

After the film forming process was performed for a total of 10 lots as in Example 1, the inside of each film forming chamber 501 to 503 was observed. No by-products were attached to the wall surface.

[0040]

[Table 6]

[0041]

As described above, according to the preferred embodiment of the present invention, the control means for determining the opening of the variable valve connected to each processing space can measure the pressure measurement value of one processing space. Based on this, the opening degree of the variable valve connected to each processing space is determined, and each variable valve connected to each processing space is linked to optimize the flow of the process gas in the processing space. It is possible to obtain a processed substrate with good characteristics, which makes it possible to obtain stable and reliable characteristics over a long period of time.
A substrate processing method such as a deposited film forming method and a substrate processing apparatus such as a deposited film forming apparatus capable of forming a deposited film having a low production cost and high productivity, particularly a functional deposited film such as a photovoltaic element. Can be realized. Further, according to a preferred aspect of the present invention, reliable and stable characteristics can be obtained for a long period of time, by-products can be prevented from being generated, the maintenance frequency of the apparatus can be reduced, and the operating rate can be improved. In addition, it is possible to form a functional deposited film such as a photovoltaic element with low production cost and high productivity.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a device configuration of the present invention.

FIG. 2 is a schematic diagram showing another device configuration of the present invention.

FIG. 3 is a schematic diagram showing a configuration of a conventional device.

FIG. 4 is a schematic diagram showing another conventional device configuration.

FIG. 5 is a schematic view showing a roll-to-roll type deposited film forming apparatus of the present invention.

FIG. 6 is a schematic view showing a conventional roll-to-roll system deposited film forming apparatus.

FIG. 7 is a schematic diagram showing a roll-to-roll type deposited film forming apparatus of the present invention.

FIG. 8 is a schematic cross-sectional view showing the structure of a photovoltaic element.

[Explanation of symbols]

100: Strip substrate 101: Gas gate 102: Separation gas introduction pipes 103, 103a to 103c: Processing chambers (deposition chamber) 104a to 104f: Processing space (deposition space) 105, 105a to 105c: Heaters 106a to 106f: Pressure Total 107, 107a-107c: Process gas introduction pipes 108a-108f: Exhaust pipes 109a-109f: Variable valves 110a-110f: Pressure regulator 111: Control unit (for example, arithmetic unit such as calculation unit) 500: Delivery chamber 501 To 503: processing chamber 504: winding chamber 505: delivery core 506: winding core 800: substrate 801: back surface reflection layer 802: transparent electrode 803: n-type semiconductor layer 804: i-type semiconductor layer 805: p-type semiconductor layer 806: Transparent electrode 807: Current collecting electrode

Front page continuation (51) Int.Cl. ⁷ Identification code FI H01L 31/04 H01L 31/04 TV (72) Inventor Naoto Okada 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72 ) Inventor Hiroshi Shimoda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Oozaki Hiroyuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masahiro Kanai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Reference JP-A-6-177060 (JP, A) JP-A-9-45628 (JP, A) JP-A 9-306851 (JP, A) JP-A-8-148539 (JP, A) JP-B-49-16221 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/205 H01L 21/302 C23C 14/54 C23C 14/56 C23C 16/44 C23C 16/52

Claims (22)

(57) [Claims] 1. A substrate is transported over a plurality of processing spaces,
In a substrate processing method including a step of processing a substrate in each processing space, controlling the pressure of the one processing space and the pressure of at least another processing space based on the pressure of one of the processing spaces. A substrate processing method, comprising: 2. The control of the pressure of the one processing space and the pressure of at least one other processing space is performed by controlling the exhaust speed of each processing space. Substrate processing method. 3. The substrate processing according to claim 2, wherein the control of each of the exhaust speeds is performed by adjusting an opening degree of an exhaust valve in an exhaust pipe connected to each of the processing spaces. Method. 4. The substrate processing method according to claim 3, wherein the opening degrees of the exhaust valves in the exhaust pipes connected to the respective processing spaces are controlled to be the same. 5. The exhaust valve connected to each of the processing spaces is controlled in conjunction with each other so that the opening degree of the exhaust valve in the exhaust pipe becomes a constant ratio. The substrate processing method described. 6. The substrate processing method according to claim 1, wherein the one processing space and the other processing space are present in the same processing chamber. 7. The substrate processing method according to claim 1, wherein the one processing space and the other processing space are connected via a gas gate. 8. The at least one other processing space includes a processing space other than the processing space and a processing space adjacent to the one processing space.
2. The substrate processing method according to any one of 1. 9. The substrate processing method according to claim 1, wherein the processing includes film forming processing. 10. The substrate processing method according to claim 9, wherein the processing includes sputtering. 11. The substrate processing method according to claim 9, wherein the processing includes CVD. 12. The substrate processing method according to claim 1, wherein a strip substrate is used as the substrate. 13. A plurality of processing spaces, a substrate transfer mechanism for transferring a substrate over the plurality of processing spaces, a pressure gauge for measuring one pressure in the plurality of processing spaces, and information obtained from the pressure gauges. A substrate processing apparatus comprising: a control unit that controls the pressure of the one processing space and at least another processing space based on the above. 14. The plurality of processing spaces each have an exhaust pipe, each exhaust pipe is provided with a variable valve, and the control unit directly or indirectly controls the opening degree of the variable valve. 14. The method according to claim 13, wherein
The substrate processing apparatus according to. 15. Connected to each of the variable valves,
7. A pressure regulator for controlling each opening, each of the pressure regulators controlling the opening of a variable valve connected thereto based on a signal from the control unit. 14. The substrate processing apparatus according to 14. 16. The substrate processing apparatus according to claim 13, wherein the one processing space and the other processing space are present in the same processing chamber. 17. The substrate processing apparatus according to claim 13, wherein the one processing space and the other processing space are connected via a gas gate. 18. The at least one other processing space comprises:
14. A processing space other than the processing space and a processing space adjacent to the one processing space are included.
17. The substrate processing apparatus according to any one of 1 to 17. 19. The substrate processing apparatus according to claim 13, wherein at least one of the processing spaces has a film forming means. 20. The substrate processing apparatus according to claim 19, wherein the film forming means comprises process gas introducing means and voltage applying means. 21. The substrate processing apparatus according to claim 19, wherein the film forming means is a sputtering means. 22. The substrate processing apparatus according to claim 19, wherein the film forming means is a CVD means.