JP2022049049A - Solar cell manufacturing device and management method thereof - Google Patents

Abstract

To provide a solar cell manufacturing device capable of reducing a defect in a photoelectric conversion structure.SOLUTION: A solar cell manufacturing device according to an embodiment of the present invention includes a transport device that transports a semiconductor wafer, a photoelectric conversion structure forming device that forms a photoelectric conversion structure of a solar cell on the semiconductor wafer, an imaging device that captures a photoluminescence image of the semiconductor wafer, and a determination device that determines the necessity of maintenance of the transfer device on the basis of the brightness of a target region set in the photoluminescence image corresponding to the position where the transfer device of the semiconductor wafer abuts.SELECTED DRAWING: Figure 1

Description

The present invention relates to a solar cell manufacturing apparatus and a method for managing a solar cell manufacturing apparatus.

In the manufacture of a solar cell, a photoluminescence image of a semiconductor wafer forming a photoelectric conversion structure of a plurality of solar cells may be taken to confirm a defect in the photoelectric conversion structure (see, for example, Patent Document 1). By providing such a process, the performance of each finally obtained solar cell element can be predicted relatively easily, and by excluding the semiconductor wafer having a high defect rate before forming the electrode structure. It is also possible to reduce the manufacturing cost as a whole.

JP-A-2015-38481

As in Patent Document 1, a proposal has been made for analyzing a photoluminescence image to accurately predict the performance of a solar cell element, but the analysis result of the photoluminescence image is fed back to a solar cell manufacturing apparatus for photoelectric conversion. There is no technology to reduce structural defects. Therefore, it is an object of the present invention to provide a solar cell manufacturing apparatus and a solar cell manufacturing apparatus management method capable of reducing defects in the photoelectric conversion structure.

The solar cell manufacturing apparatus according to one aspect of the present invention includes a transport device for transporting a semiconductor wafer, a photoelectric conversion structure forming device for forming a photoelectric conversion structure of a solar cell on the semiconductor wafer, and a photoluminescence image of the semiconductor wafer. Judgment of determining the necessity of maintenance of the transport device based on the brightness of the target region set in the photoluminescence image corresponding to the position where the image pickup device to be imaged and the transfer device of the semiconductor wafer abut. It is equipped with a device.

In the solar cell manufacturing apparatus, the determination device is described when the ratio of the average brightness of the target area to the average brightness of the contrast area that does not overlap with the target area of the photoluminescence image is equal to or less than a predetermined determination threshold value. It may be determined that maintenance of the transport device is necessary.

The solar cell manufacturing apparatus may include a plurality of the transfer devices, and the determination device may determine the necessity of maintenance based on the brightness of the target area corresponding to each transfer device.

The method for managing a solar cell manufacturing apparatus according to one aspect of the present invention involves maintenance of a solar cell manufacturing apparatus including a transporting apparatus for transporting a semiconductor wafer and a solar cell manufacturing apparatus for forming a solar cell structure on the semiconductor wafer. It is a method of managing a solar cell manufacturing apparatus to be managed, and corresponds to a step of taking a photoluminescence image of a semiconductor wafer on which a photoelectric conversion structure of a solar cell is formed and a position where the transport device of the semiconductor wafer abuts. A step of determining whether or not maintenance of the transport device is necessary based on the brightness of the target region set in the photoluminescence image is provided.

According to the solar cell manufacturing apparatus and the solar cell manufacturing apparatus management method according to the present invention, defects in the photoelectric conversion structure can be reduced.

It is a schematic diagram which shows the structure of the solar cell manufacturing apparatus which concerns on one Embodiment of this invention. It is a figure which illustrates the photoluminescence image in the solar cell manufacturing apparatus of FIG. It is a figure which shows the target area set in the photoluminescence image in the solar cell manufacturing apparatus of FIG. It is a figure which illustrates the photoluminescence image when the 1st transport device is worn in the solar cell manufacturing apparatus of FIG. It is a figure which illustrates the photoluminescence image when the 2nd transport device is worn in the solar cell manufacturing apparatus of FIG. It is a flowchart which shows the procedure of the solar cell manufacturing apparatus management method which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing a configuration of a solar cell manufacturing apparatus 1 according to an embodiment of the present invention. The solar cell manufacturing apparatus 1 is an apparatus for forming a plurality of solar cell structures (a photoelectric conversion structure related to photoelectric conversion and an electrode structure for outputting power from the photoelectric conversion structure) that performs photoelectric conversion on the semiconductor wafer W. The "luminance" in this case refers to the radiance of the amount of radiation.

The solar cell manufacturing device 1 includes a first transport device 10, a photoelectric conversion structure forming device 20, a second transport device 30, an image pickup device 40, a determination device 50, and an electrode structure forming device 60. It should be noted that these devices need not be functionally distinguishable and do not have to be independent devices from each other. In particular, a part or all of the first transfer device 10 and the second transfer device 30 are photoelectric conversion. It can be configured and controlled integrally with the structure forming apparatus 20, the image pickup apparatus 40, or the electrode structure forming apparatus 60.

The first transfer device 10 conveys the semiconductor wafer W. The first transfer device 10 is configured so that the contact position with the semiconductor wafer W is limited. As an example, the first transfer device 10 is a conveyor for transporting a semiconductor wafer W by two parallel-arranged, endless loop-shaped ropes or narrow belts rotating at the same speed, a specific region of the semiconductor wafer W. It may be composed of a belt having a support projection for supporting the wafer, a conveyor having a bucket or the like, a robot that grips a specific region of the semiconductor wafer W, and holds the semiconductor wafer W by suction.

The wear and dirt of the portion of the first transfer device 10 in contact with the semiconductor wafer W may cause scratches or stains on the semiconductor wafer W, thereby causing a defect in the photoelectric conversion structure of the semiconductor wafer W. Therefore, it is preferable that the first transfer device 10 is configured so that only the portion in contact with the semiconductor wafer W can be exchanged. As a result, the first transport device 10 can replace only the portion of the semiconductor wafer W that can cause a defect in the photoelectric conversion structure, so that maintenance is facilitated.

The photoelectric conversion structure forming apparatus 20 forms a plurality of photoelectric conversion structures on a semiconductor wafer by patterning and laminating a plurality of types of semiconductor layers on the semiconductor wafer W. As an example, the photoelectric conversion structure forming apparatus 20 may include one or a plurality of sputtering apparatus, vacuum vapor deposition apparatus, chemical vapor deposition apparatus, and the like for laminating semiconductor layers. Further, the photoelectric conversion structure forming apparatus 20 can be equipped with a printing apparatus, a photolithography apparatus, an etching apparatus, and the like in order to pattern the semiconductor layer by laminating resist patterns or selectively removing each layer.

The second transfer device 30 conveys the semiconductor wafer W in the same manner as the first transfer device 10, but it is preferable that the contact position with the semiconductor wafer W is different from that of the first transfer device 10. Like the first transfer device 10, the second transfer device 30 is also preferably configured so that only the portion in contact with the semiconductor wafer W can be exchanged.

The image pickup apparatus 40 captures a photoluminescence image of the semiconductor wafer W on which the photoelectric conversion structure is formed by the photoelectric conversion structure forming apparatus 20. Specifically, the image pickup apparatus 40 irradiates the semiconductor wafer W with light to excite carriers inside the semiconductor wafer W, and photographs the light emitted when the carriers recombine and return to the ground state. Therefore, the image pickup device 40 can have a light irradiation unit having a light source and an image pickup unit having an image pickup element.

The imaging device 40 can be shared with a configuration related to imaging of a well-known inspection device that detects defects in the photoelectric conversion structure formed by the photoelectric conversion structure forming device 20 by a photoluminescence method.

The determination device 50 is an image processing device that analyzes a photoluminescence image taken by the image pickup device 40. The determination device 50 can be realized by causing a computer having a CPU, a memory, or the like to execute an appropriate image processing program. The determination device 50 may be realized by adding a program to a computer that performs image processing of the inspection device that detects defects in the photoelectric conversion structure.

The determination device 50 determines whether or not maintenance of the transfer devices 10 and 30 is necessary based on the brightness of the target area set in the photoluminescence image corresponding to the position where the transfer devices 10 and 30 of the semiconductor wafer W abut. do. That is, when the brightness of the target region is lowered, the determination device 50 causes an increase in defects in the local photoelectric conversion structure due to the contact of the transfer devices 10 and 30 with the semiconductor wafer W, so that the transfer device 50 is transferred. It is determined that maintenance of the devices 10 and 30 is necessary.

The target region is preset as a fixed region in the luminescence image in consideration of variations in the contact positions of the transport devices 10 and 30 with respect to the semiconductor wafer W, variations in the existing region of the semiconductor wafer W in the photoluminescence image, and the like. Can be done. Further, the target region may be set for each photoluminescence image according to the arrangement of the existing region of the semiconductor wafer W in the luminescence image. That is, the determination device 50 identifies the existing region of the semiconductor wafer W in the photoluminescence image by pattern recognition, and sets the target region as a dynamic region preset with respect to the pattern of the specified semiconductor wafer W existing region. May be set.

Specifically, the determination device 50 determines that maintenance of the transfer devices 10 and 30 is necessary when the absolute value (for example, average value, total value, etc.) of the brightness of the target area becomes a certain value or less. However, when the ratio of the average luminance of the target region (hereinafter referred to as the luminance ratio) to the average luminance of the contrast region that does not overlap with the target region of the photoluminescence image is equal to or less than a predetermined determination threshold value, the transport devices 10 and 30 may be used. It may be determined that maintenance is required. That is, the determination device 50 is influenced by the transfer devices 10 and 30 using the photoluminescence image to determine whether or not the emission intensity is lowered due to the photoluminescence of the photoelectric conversion structure of the target region with which the transfer devices 10 and 30 are in contact. It can be determined based on the emission intensity by photoluminescence of the photoelectric conversion structure in the non-contrast region. As a result, it is possible to relatively accurately determine the decrease in the emission intensity of the photoelectric conversion structure by the transfer devices 10 and 30 by offsetting the change in the emission intensity of the image pickup apparatus 40, the change in the ambient brightness, and the like.

FIG. 2 shows an example of a photoluminescence image when the transport devices 10 and 30 are not worn or soiled, and FIG. 3 shows a first target area A1 and a second transport device corresponding to a position where the first transport device 10 abuts. The second target area A2 corresponding to the position where 30 abuts is shown. In FIG. 2, the brightness ratio of the average brightness of the first target area A1 to the average brightness of the areas other than the first target area A1 is 0.90, and the average brightness of the second target area A2 is other than the second target area A2. The luminance ratio to the average luminance of the region is 1.00.

FIG. 4 shows an example of a photoluminescence image when the first transport device 10 is worn. In this example, the brightness ratio of the average brightness of the first target area A1 to the average brightness of the area other than the first target area A1 is 0.39, and the average brightness of the second target area A2 is other than the second target area A2. The luminance ratio to the average luminance of the region is 1.00. As described above, since the brightness ratio of the average brightness of the first target area A1 to the average brightness of the area other than the first target area A1 is small, it can be determined that the maintenance of the first transfer device 10 is necessary.

Further, FIG. 5 shows an example of a photoluminescence image when the second transport device 30 is worn. In this example, the brightness ratio of the average brightness of the first target area A1 to the average brightness of the area other than the first target area A1 is 1.00, and the average brightness of the second target area A2 is other than the second target area A2. The luminance ratio to the average luminance of the region is 0.41. As described above, since the brightness ratio of the average brightness of the second target area A2 to the average brightness of the area other than the second target area A2 is small, it can be determined that the maintenance of the second transfer device 30 is necessary.

The contrast region may be a region excluding a preset target region from the entire photoluminescence image, but from the entire photoluminescence image, for example, a region outside the semiconductor wafer W, a photoelectric conversion structure in the semiconductor wafer W Excludes regions that are not formed, regions where defects in the photoelectric conversion structure may be particularly large due to factors other than the transport devices 10 and 30 to be determined (regions where the transport device or other device that is not the target of determination abuts on the semiconductor wafer W), etc. By setting the area as the surface, it is possible to more accurately determine the necessity of maintenance of the transfer devices 10 and 30.

The determination device 50 sets a corresponding target area for each of the transfer devices 10 and 30 for one photoluminescence image, and maintenance of the corresponding transfer devices 10 and 30 is necessary based on the brightness of each target area. May be determined individually. In this case, as described above, by making the transport devices 10 and 30 come into contact with different positions of the semiconductor wafers W, the accuracy of determining the necessity of maintenance of the individual transport devices 10 and 30 can be improved.

The determination device 50 may determine the necessity of maintenance of the transfer devices 10 and 30 based on the brightness of the target region of a plurality of photoluminescence images obtained by photographing different semiconductor wafers W. As an example, in the determination device 50, maintenance of the transfer devices 10 and 30 is performed when the average value of the luminance ratios of the latest predetermined number of semiconductor wafers W and the moving average of the luminance ratio, that is, the moving average of the luminance ratio becomes equal to or less than the determination threshold value. It may be determined that it is necessary. As a result, when defects in the target region increase due to a primary cause such as a defect of the semiconductor wafer W, it is possible to prevent maintenance of the transport devices 10 and 30 which are originally unnecessary.

The electrode structure forming apparatus 60 forms an electrode structure for further outputting electric power on the semiconductor wafer W on which the photoelectric conversion structure is formed. The electrode structure forming device 60 includes a device for printing a conductor pattern with silver paste or the like, a device for laminating metal layers by sputtering, plating, or the like, forming a resist pattern, and then etching to selectively remove the metal layer. Can be used.

Since the solar cell manufacturing device 1 having the above configuration includes a determination device 50 for determining the necessity of maintenance of the transfer devices 10 and 30, the photoelectric conversion structure can be obtained by appropriately performing the maintenance of the transfer devices 10 and 30. Defects can be reduced. Therefore, the solar cell manufacturing apparatus 1 can manufacture a solar cell having excellent quality (output) with a high yield.

Subsequently, the management method of the solar cell manufacturing apparatus 1 of FIG. 1 will be described. FIG. 6 is a flowchart showing a procedure of a solar cell manufacturing apparatus management method according to an embodiment of the present invention, which can be applied to the solar cell manufacturing apparatus 1. The solar cell manufacturing device management method of the present embodiment is a method of managing the maintenance of the solar cell manufacturing device 1, particularly the maintenance of the transport devices 10 and 30.

The solar cell manufacturing apparatus management method of the present embodiment includes a step of photographing a photoluminescence image of the semiconductor wafer W (step S1: photographing step) and a step of determining the necessity of maintenance of the transporting devices 10 and 30 (step S2 :). Judgment step) and.

In the photographing step of step S1, the image pickup apparatus 40 photographs a photoluminescence image of the semiconductor wafer W on which the photoelectric conversion structure is formed.

In the determination step of step S2, the determination device 50 determines whether or not maintenance of the transfer devices 10 and 30 is necessary based on the brightness of the target area set in the photoluminescence image.

As described above, in the solar cell manufacturing apparatus management method of the present embodiment, since the necessity of maintenance of the transport devices 10 and 30 is determined based on the photoluminescence image, the photoelectric conversion structure caused by the transport devices 10 and 30 is determined. It is possible to recognize the occurrence of defects at an early stage, and it is possible to suppress the increase of defects in the photoelectric conversion structure.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and modifications can be made.

As an example, when a plurality of transfer devices have the same configuration and the wear of the members in contact with the semiconductor wafer progresses substantially equally, the determination device sets a single target area for the plurality of transfer devices. By doing so, the necessity of maintenance of a plurality of transport devices may be collectively determined. In this case, the members that come into contact with the semiconductor wafer can be replaced all at once in the plurality of transport measures that are collectively determined. Further, the shape of the target region is not limited to the strip shape, and may be set according to the shape of the portion of the transport device that abuts on the semiconductor wafer.

The determination device may determine the necessity of maintenance of at least one transfer device. As an example, a photoelectric conversion structure forming device often cooperates with a transfer device that positions a semiconductor wafer using a rigid jig, but such a transfer device has extremely small wear of a member that comes into contact with the semiconductor wafer. Therefore, it does not have to be the target of constant monitoring by the determination device.

1 Solar cell manufacturing device 10 1st transfer device 20 Photoelectric conversion structure forming device 30 2nd transfer device 40 Imaging device 50 Judgment device 60 Electrode structure forming device

Claims (4)

A transport device that transports semiconductor wafers,
A photoelectric conversion structure forming apparatus for forming a photoelectric conversion structure of a solar cell on the semiconductor wafer,
An image pickup device that captures a photoluminescence image of the semiconductor wafer, and
A determination device for determining the necessity of maintenance of the transfer device based on the brightness of the target region set in the photoluminescence image corresponding to the position where the transfer device of the semiconductor wafer abuts.
A solar cell manufacturing device. The determination device requires maintenance of the transfer device when the ratio of the average brightness of the target area to the average brightness of the comparison area that does not overlap with the target area of the photoluminescence image is equal to or less than a predetermined determination threshold value. The solar cell manufacturing apparatus according to claim 1, which is determined to be present. Equipped with a plurality of the above-mentioned transport devices,
The solar cell manufacturing device according to claim 1 or 2, wherein the determination device determines the necessity of maintenance based on the brightness of the target area corresponding to each transfer device. A solar cell manufacturing device management method for managing maintenance of a solar cell manufacturing device including a transport device for transporting a semiconductor wafer and a solar cell manufacturing device for forming a solar cell structure on the semiconductor wafer.
The process of taking a photoluminescence image of a semiconductor wafer on which a photoelectric conversion structure of a solar cell is formed, and
A step of determining the necessity of maintenance of the transport device based on the brightness of the target region set in the photoluminescence image corresponding to the position where the transport device of the semiconductor wafer abuts.
A solar cell manufacturing equipment management method.

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