JP3098950B2 - Repair device for detecting leak location of photoelectric conversion element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting and repairing a leak point which is a defect in a thin film photoelectric conversion element such as an amorphous silicon solar cell.

[0002]

2. Description of the Related Art In the production of a thin-film photoelectric conversion element such as an amorphous silicon solar cell, pinholes or contamination are inevitably generated when a thin film is formed. A short circuit or minute current leakage occurs. Since these defects deteriorate the output characteristics, repair is performed by removing one electrode at the defective portion by, for example, laser irradiation or etching.

[0003] Detection of a leak location is performed by observing the entire surface with a microscope or the like, or applying a reverse bias to the photoelectric conversion element to generate heat at the defective location, and observing light emission at this time with the naked eye. Is being done. Further, in order to specify a heat generating portion, a so-called thermoviewer that detects infrared rays is used to specify a heat generating portion when a reverse bias is applied. After the leak location is found in this way, marking and the like are manually performed, and then the marked portion is irradiated with a laser beam having a certain size and shape using a repair laser irradiation device to perform repair. ing.

[0004]

However, as the area of the photoelectric conversion element increases, it is no longer possible to cope with the above-described conventional method of finding and repairing a leak point. That is, as the size of the photoelectric conversion element increases, the probability of occurrence of a leak location increases, and a large number of leak locations exist in one photoelectric conversion element, and detection with the naked eye using a microscope or the like. Also, accurate detection and repair cannot be performed by the naked eye detection using a thermoviewer.
In particular, when light emission due to heat generation is detected by applying a reverse bias, light emission is performed instantaneously. Therefore, when the number of light emitting locations increases, it is not possible to accurately detect a defective location.

SUMMARY OF THE INVENTION An object of the present invention is to provide a photoelectric conversion device capable of repairing a leak location of a photoelectric conversion element having a large area and reducing the occurrence of defective products by realizing efficient and accurate repair. An object of the present invention is to provide a repair device for detecting a leak location of an element.

[0006]

According to the present invention, there is provided a repair device for detecting a leak point of a photoelectric conversion element, comprising: a reverse bias applying means for applying a reverse bias to the photoelectric conversion element; An infrared detecting means for detecting and detecting infrared rays emitted from the surface in two-dimensional coordinates of the surface to be measured, and comparing an energy intensity of each infrared ray on the two-dimensional coordinates detected by the infrared detecting means with a reference value and detecting a leak point. Leak location determining means for determining whether or not there is a leak location; storage means for storing two-dimensional coordinate information of a location determined to be a leak location by the leak location determining means; Laser light irradiation position control means for controlling a laser light irradiation position on the photoelectric conversion element based on two-dimensional coordinate information of a leak point stored in the storage means for emitting light, and laser light With the leakage portion of the photoelectric conversion element positioned by the position control means morphism and a laser light irradiating means for irradiating laser light, the laser light irradiation position control means
Corresponds to the two-dimensional coordinates of the measured surface of the photoelectric conversion element.
Variable transmission area mask that can control the light transmission area
And the position on the two-dimensional coordinates of the detected leak location.
Control the light transmission area of the transmission area variable mask
By controlling the laser beam irradiation position,
The variable transmission area mask is a liquid crystal mask.
ing.

In the present invention, the laser beam irradiation position control means preferably moves in at least a two-dimensional direction.
It has a drive table for mounting the photoelectric conversion element. By controlling the drive of such a drive table, it is possible to control the laser light irradiation position on the photoelectric conversion element.

In the present invention, the leak location determining means determines whether or not the location is a leak location by comparing the absolute temperature corresponding to the detected infrared energy intensity with the room temperature as a reference value. I do. In such a comparison based on temperature, for example, when a difference of 10K or more is between room temperature and room temperature, it is determined to be a leak location.

[0009] The present invention Contact information, and <br/> with transparently region variable mask, are used liquid crystal mask. In such a liquid crystal mask, by applying a voltage between electrodes sandwiching the liquid crystal,
By aligning the liquid crystal molecules, a transmission state or a non-transmission state can be realized. By using such a transmission area variable mask, it is possible to control the light transmission area of the transmission area variable mask corresponding to the position on the two-dimensional coordinates of the detected leak location, and thereby control the laser beam irradiation position. it can. Further, by using such a transmission region variable mask, the size and shape of the laser beam can be controlled in accordance with the shape and size of the leak location, and the increase in the ineffective area due to repair can be suppressed. Thus, efficient repair can be realized.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a functional block diagram showing a basic configuration of a repair device for detecting a leak point according to the present invention.
According to the present invention, a reverse bias is applied by the reverse bias applying means 2 between electrodes sandwiching the semiconductor layer of the photoelectric conversion element 1. As a result, the current is short-circuited at the leak location and heat is generated, so that infrared rays are emitted. The emitted infrared light is detected by the infrared detecting means 3. At this time, the two-dimensional coordinates of the infrared emission point on the surface to be measured of the photoelectric conversion element 1 are specified, and infrared light is detected. The energy intensity of each infrared ray on the two-dimensional coordinates detected by the infrared detecting means 3 is compared with a reference value by the leak location determining means 4,
It is determined whether or not it is a leak location. As mentioned above,
For example, it is possible to determine whether or not there is a leak by converting the energy intensity of infrared rays into an absolute temperature in accordance with Planck's law of heat radiation and calculating the difference between the absolute temperature and the room temperature.

When the leak location is determined to be a leak location by the leak location determining means 4, two-dimensional coordinate information of the leak location is stored in the storage means 5. Next, based on the two-dimensional coordinate information of the leak location stored in the storage means 5, the laser light irradiation position control means 6 causes the laser light emitted from the laser light irradiation means 7 to be applied to the leak location. The laser beam irradiation position is determined. Specifically, the positioning may be performed by, for example, moving the position of the photoelectric conversion element 1 or by changing the optical path of the laser light emitted from the laser light emitting means 7. In addition, positioning may be performed using both of these methods. Further, when a transmission area variable mask such as a liquid crystal mask is used as described above, the irradiation position of the laser light from the laser light irradiation means 7 and the beam shape and size of the laser light are controlled and positioned. Is also good.

As described above, the leak portion can be repaired by irradiating the leak portion of the photoelectric conversion element 1 with the laser beam and, for example, removing one electrode of the leak portion.

FIG. 2 is a configuration diagram showing a leak point detecting and repairing apparatus according to a reference example . Referring to FIG. 2, photoelectric conversion element 10 is mounted on workpiece drive table 17. The photoelectric conversion element 10 is formed by stacking a first electrode layer, a semiconductor layer, and a second electrode layer on a substrate. The semiconductor layer of the photoelectric conversion element 10 has a pinhole 10a, and the pinhole 10a becomes a leak location. The first electrode layer and the second electrode layer of the photoelectric conversion element 10
When a reverse bias is applied to the electrode layer by the bias applying device 11, the portion of the pinhole 10a generates heat, and infrared rays are emitted from this portion. The reverse bias is usually set to 0.
A voltage of about 1 to 5.0 V is applied.

The infrared light emitted from the pinhole 10a is detected by the infrared sensor 12. The infrared sensor is not particularly limited as long as it can specify two-dimensional coordinates and measure infrared energy intensity.
Examples of such an infrared sensor include a scanning infrared sensor or an infrared sensor capable of specifying two-dimensional coordinates of a surface to be measured, such as an IRCDD. Further, a thermoelectric radiation thermometer, a photoelectric radiation thermometer, or An array sensor in which these are arranged in an array shape is exemplified.

The signal detected by the infrared sensor 12 is sent to a control computer 13. In the present embodiment, the bias application device 11 is also connected to the control computer 13, and the control computer 13 controls the timing of applying the reverse bias. The detection signal sent from the infrared sensor 12 includes the information of the energy intensity of the detected infrared rays together with the X-axis coordinate information and the Y-axis coordinate information of the detection location as the two-dimensional coordinates of the photoelectric conversion element 10. The signal is sent to the control computer 13. The control computer 13 calculates a temperature corresponding to the energy intensity of the infrared ray from the energy intensity of the infrared ray. If the difference between the temperature and the room temperature is equal to or more than a predetermined value, the control computer 13 determines that the leak location exists. The coordinate information of the axis and the Y axis is stored. Thus, all the two-dimensional coordinate information of the leak location of the photoelectric conversion element 10 is stored, and the repair is performed based on the two-dimensional coordinate information.

In the repair, first, a signal for moving the drive table based on the two-dimensional coordinate information is sent from the control computer 13 to the workpiece drive table 17. As a result, the workpiece drive table 17 moves. The workpiece drive table 17 includes an excimer laser 14.
To the position where the laser beam reflected by the mirror 16 passes through the metal mask 15 to the position where the pinhole 10a, which is the leak point, is located. When the movement is completed, a signal is sent from the control computer 13 to the excimer laser 14, and the excimer laser 14 emits a laser beam. The irradiated laser beam passes through the metal mask 15 and is reflected by the mirror 16, and is applied to the portion of the second electrode layer on the pinhole 10a. By this laser light irradiation, the second electrode layer above the pinhole 10a is removed, and the leak location is repaired. In this manner, the workpiece drive table 17 is sequentially moved based on the two-dimensional coordinate information of the leak location stored in the control computer 13, and the leak location is repaired by irradiating a laser beam.

FIG. 3 is a flowchart for explaining the operation of the apparatus shown in FIG. Referring to FIG. 3, first, a reverse bias voltage is applied to the photoelectric conversion element (S1). Next, infrared rays are emitted from the photoelectric conversion element by application of a reverse bias voltage. z indicates the total number of defects (S
2). The energy of infrared light emitted from the photoelectric conversion element is detected by the infrared sensor together with the two-dimensional coordinate information of the photoelectric conversion element. In the present embodiment, the temperature is measured as the temperature corresponding to the energy intensity (S
3).

Next, the difference between the temperature measured by the infrared sensor and the room temperature is 10K on the control computer.
It is determined whether it is the above or not, and if it is 10K or more, the coordinate information on the location of the leak, that is, the defect is determined to be a defect. Next, it is determined whether the detection by the infrared sensor has scanned the entire surface of the measured surface of the photoelectric conversion element. If the full-surface scanning has not been completed, the detection by the infrared sensor is repeated again (S
4).

After recording the two-dimensional coordinate information of the leak location on the entire surface of the measured surface of the photoelectric conversion element, that is, defect coordinate information, repair of the leak location is performed. Based on the recorded defect existence coordinate data, the workpiece drive table moves to the position to be irradiated with the laser (S
5). When the movement is completed, laser light is oscillated by the laser oscillator, the laser light is applied to the defective portion of the photoelectric conversion element, and the defect is repaired (S6).

The control computer determines whether all the defects have been repaired. If all the defects have not been repaired, the movement of the workpiece drive table and the repair by laser irradiation are repeated. The operation ends when the repair of all the defects is completed (S7).

In the embodiment shown in the above flowchart,
Although the corresponding temperature is measured from the energy intensity of the infrared ray, the present invention is not limited to this, and the energy intensity of the infrared ray is directly compared with the reference value of the energy intensity to determine whether or not it is a leak location. You may.

FIG. 4 is a plan view for explaining sampling intervals in the X-axis direction and the Y-axis direction of the two-dimensional coordinates. As shown in FIG. 4, if the sampling interval T corresponds to the diameter of the laser spot 31, the sampling interval T
The defect 30 inside can be covered by the laser spot 31. Therefore, the sampling interval T is preferably equal to or less than the diameter of the laser spot. In addition, the defect 30 shown in FIG. 4 has shown the defect made by the scratch.

FIG. 5 is a block diagram showing a leakage portion detecting repair apparatus of the slave power sale implementation form the present invention. In FIG. 5, the photoelectric conversion element 10 is placed on the workpiece drive table 17 such that the substrate of the photoelectric conversion element 10 is located above and the second electrode layer is located below. In the photoelectric conversion element 10 shown here, the microcrystallized portion 10b is formed in the semiconductor layer.
Exists, and this portion is a leak location.
In the present embodiment, a beam expander 19 is provided in front of the exit side of the excimer laser 18, and the laser beam from the beam expander 19 is applied to the liquid crystal mask 2.
0, the light is reflected by the mirror 16 and the photoelectric conversion element 10
Irradiated on top. The liquid crystal mask 20 is capable of freely controlling the size and shape of the light transmitting region, that is, the opening. As shown in FIG. Once formed, a plurality of laser beams can be irradiated on the photoelectric conversion element 10 at the same time to perform repair.

FIG. 6 is a perspective view for explaining the control of the laser irradiation area by the liquid crystal mask 20. As shown in FIG. In the two-dimensional coordinates 40 corresponding to the photoelectric conversion elements, the leak locations, that is, the coordinates determined to be defective, are shown with hatching. In addition, each pixel of the liquid crystal mask 20 is provided corresponding to each coordinate. In this case, a laser beam is applied to a coordinate which is hatched at a coordinate 40 and is determined as a defect, and therefore, as shown in FIG. The lower two right-hand sides are irradiated with laser light with the apertures in the open state. The hatched pixels are closed pixels. As described above, by using a mask such as a liquid crystal mask that can control the light transmission region, the irradiation region of the laser beam can be controlled according to the size and shape of the defective portion. Therefore, it is possible to reduce a region that becomes invalid due to laser irradiation even though there is no defect. The pixel size (dot size) of the liquid crystal mask is usually several hundred μm, and is generally in the range of 100 μm to 1.0 mm.

The liquid crystal mask 20 shown in FIG. 6 uses a liquid crystal element driven by a TFT. However, the liquid crystal mask is not limited to this, and a liquid crystal mask driven by a simple matrix or the like can be used. Further, the transmission area variable mask is not limited to the liquid crystal mask, and other masks can be used as long as the mask can control the irradiation area.

In the embodiment shown in FIG . 5, the laser beam irradiation position is controlled by moving the photoelectric conversion element using the workpiece drive table, but the present invention is not limited to this. For example, as long as the entire surface of the photoelectric conversion element can be covered by a transmission region variable mask such as a liquid crystal mask, the laser beam irradiation region can be controlled only by such a transmission region variable mask.

In the above embodiment, an excimer laser is used as a laser for repairing a leak location. However, the present invention is not limited to this, and other lasers such as a YAG laser may be used depending on the material of the repair location. Can also be used.

[0028]

According to the present invention, even if a large number of leak locations exist, all the leak locations can be measured within a short period of time when a reverse bias is applied to the photoelectric conversion element to emit light. After the measurement, repair can be performed by irradiating a laser beam. Therefore, efficient and highly accurate repair can be realized, and the occurrence of defective products can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a basic configuration of the present invention.

FIG. 2 is a configuration diagram showing a leak point detection repair device of a reference example .

FIG. 3 is a flowchart showing the operation of the apparatus shown in FIG. 2;

FIG. 4 is a plan view for explaining sampling intervals in the present invention.

Configuration diagram illustrating a leakage portion detecting repair apparatus of the slave power sale implementation form the present invention; FIG.

FIG. 6 is a perspective view for explaining control of a light transmitting region of a liquid crystal mask used in the embodiment shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Photoelectric conversion element 2 ... Reverse bias application means 3 ... Infrared detection means 4 ... Leak point determination means 5 ... Storage means 6 ... Laser light irradiation position control means 7 ... Laser light irradiation means 10 ... Photoelectric conversion element 10a ... Pinhole 11 ... Bias application device 12 ... Infrared sensor 13 ... Control computer 14 ... Excimer laser 15 ... Metal mask 16 ... Mirror 17 ... Workpiece drive table 18 ... Excimer laser 19 ... Beam expander 20 ... Liquid crystal mask 30 ... Defect 31 ... Laser beam Spot 40: two-dimensional coordinates corresponding to the photoelectric conversion element

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 31/04-31/078

Claims (3)

(57) [Claims] 1. A device for detecting and repairing a leak point of a photoelectric conversion element, comprising: a reverse bias applying means for applying a reverse bias to the photoelectric conversion element; Infrared detecting means for identifying and detecting infrared light emitted from the surface to be measured by the two-dimensional coordinates of the surface to be measured, and comparing the energy intensity of each infrared light on the two-dimensional coordinates detected by the infrared detecting means with a reference value Leak location determining means for determining whether or not the location is a leak location; storage means for storing two-dimensional coordinate information of the location determined to be a leak location by the leak location determination means; In order to irradiate a laser beam to a leak point, a laser beam irradiation position on the photoelectric conversion element is controlled based on two-dimensional coordinate information of the leak point stored in the storage unit. That the laser light irradiation position control means, and a laser beam irradiating means for irradiating a laser beam to leakage portion of the photoelectric conversion element is positioned by the laser light irradiation position control means, said laser beam irradiating position control means, Of the photoelectric conversion element
The light transmission area is controlled according to the two-dimensional coordinates of the surface to be measured.
It has a transparent area variable mask that can
Corresponding to the position on the two-dimensional coordinates of the leak location
By controlling the light transmission area of the over-area variable mask,
Laser light irradiation position can be controlled,
Strange mask leakage portion detecting repair apparatus of the liquid crystal mask der Ru photoelectric conversion element. 2. The apparatus according to claim 1, wherein the laser beam irradiation position control means includes a drive table for mounting the photoelectric conversion element, the drive table moving at least two-dimensionally, and controlling the drive of the drive table. The repair device for detecting a leak point of a photoelectric conversion element according to claim 1, wherein the laser light irradiation position on the conversion element is controlled. 3. The leak location determining means compares an absolute temperature corresponding to the detected infrared energy intensity with a room temperature as a reference value, and determines a location on a two-dimensional coordinate having a difference of 10K or more as a leak location. Claim 1 or 2 which determines that there is.
3. A repair device for detecting a leak point of a photoelectric conversion element according to item 1.