JP2013055083A - Film forming condition setting method and method of manufacturing photoelectric conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film forming condition setting method of a crystalline silicon photoelectric conversion layer, for manufacturing a photoelectric conversion device of high performance.SOLUTION: SiHflow rate is increased for a film forming condition candidate, to form a photoelectric conversion layer 92 made from crystalline silicon, so that an area rate and in-substrate plane distribution of a high brightness reflection region of the photoelectric conversion layer 92 are obtained. In a case where the distribution is uniform, a film forming condition candidate is set to be a final film forming condition. In a case where the distribution is not uniform, a high frequency power density supplied to each power feeding point of a discharge electrode is adjusted and is set to be a final film forming condition. For the photoelectric conversion layer 92 having an arbitrary Raman peak ratio that is obtained in advance, a correlation between the change amount of the SiHflow rate and the area rate of high brightness reflection region is used as a base, to obtain the Raman peak ratio of the photoelectric conversion layer 92. In a case where the obtained Raman peak ratio satisfies a design value, the film forming condition candidate is set to be a final film forming condition. In a case where the Raman peak ratio strays from the design value, the SiHflow rate, a SiHdivision voltage or high frequency power density is adjusted, for setting a final film forming condition.

Description

  The present invention relates to a film forming condition setting method for forming a crystalline silicon layer in a photoelectric conversion device using a crystalline silicon layer as a power generation layer.

  As a photoelectric conversion device that converts sunlight energy into electric energy, plasma CVD is performed on thin films of p-type silicon semiconductor (p layer), i-type silicon semiconductor (i layer), and n-type silicon semiconductor (n layer). 2. Description of the Related Art A thin film silicon solar cell including a photoelectric conversion layer formed by a method or the like is known. In the thin film silicon solar cell, the advantages of the thin film silicon solar cell include that the area can be easily increased, the film thickness is as thin as about 1/100 that of the crystalline solar cell, and the material can be reduced. It is done. For this reason, the thin film silicon solar cell can be manufactured at a lower cost than the crystalline solar cell.

A film mainly composed of amorphous silicon or a film mainly composed of crystalline silicon is generally used for the photoelectric conversion layer used in the thin film silicon solar cell.
In Patent Document 1, as a guideline for evaluating the film quality of a photoelectric conversion layer mainly containing microcrystalline (crystalline) silicon, the peak intensity Ic of the crystalline silicon phase with respect to the peak intensity Ia of the amorphous silicon phase in the Raman spectrum obtained by Raman spectroscopy. Ratio (Raman peak ratio) Ic / Ia is used. Patent Document 2 discloses that the SiH ₄ / H ₂ flow rate ratio is controlled so that the Raman peak ratio falls within a predetermined range.
In Patent Document 2, as a method for setting the film forming conditions for improving the throughput while maintaining the battery performance, after setting a desired film forming speed, the film forming pressure, the SiH ₄ flow rate, the H ₂ flow rate, and the input high frequency power It is disclosed to set in this order.
In Patent Document 3, when a crystalline silicon i layer is formed using a large area substrate exceeding 1 m ² under the condition that the average value of Raman peak ratio is in the range of 3.5 or more and 8 or less, the power generation output of the photoelectric conversion device It is disclosed that when the average value of the Raman peak ratio is 2.5 or less, visible light is scattered, so that a region with high luminance (high luminance reflection region) is generated. In order to improve the power generation performance, it is necessary to suppress the area ratio of the high-brightness reflection region to 3% or less. In order to suppress the generation of the high-brightness reflection region, the high frequency power density and the SiH ₄ partial pressure are used. It is disclosed to adjust the initial conditions.

JP 2008-66343 A (Claims, [0022] to [0024], [0035] to [0050]) JP 2007-150151 A ([0046] to [0055], FIG. 6) International Publication No. 2010/050034 ([0006], [0011] to [0012], [0015] to [0016], [0033], [0036] to [0048], claims 1 and 3)

In carrying out the process of forming a crystalline silicon layer on a large-area substrate exceeding 1 m ² using a plasma CVD apparatus by the method disclosed in the above patent document, various crystalline film forming conditions are optimized to produce a crystalline silicon layer. Even if the film is formed, the conversion efficiency may be lower than expected. This is because, in order to individually set each film formation condition when adjusting the plasma generation state of the plasma CVD apparatus so as to make the plasma generation state uniform by dividing the discharge electrode for film formation into a plurality of areas, It was thought that this was caused by a deviation from the optimum film forming conditions due to unintended interference between the film forming conditions and the distribution of the film forming conditions within the substrate surface. For this reason, a method of more easily setting the film forming conditions optimized over the entire surface of the large area substrate exceeding 1 m ² is desired.

  This invention is made | formed in view of such a situation, Comprising: It aims at providing the film forming condition setting method of the crystalline silicon photoelectric converting layer for manufacturing the photoelectric conversion apparatus which has high performance.

In order to solve the above problems, the present invention provides a photoelectric conversion device having a photoelectric conversion layer made of crystalline silicon on a substrate, supplying high-frequency power to a plurality of feeding points of discharge electrodes of a film forming device, A method for setting film forming conditions for forming a layer, the method comprising: selecting a film forming condition candidate for the photoelectric conversion layer including at least a SiH ₄ flow rate and a high frequency power density supplied to each of the plurality of feeding points; The step of forming the photoelectric conversion layer on the substrate by setting the SiH ₄ flow rate to a value increased at a predetermined rate with respect to the selected film forming condition candidate, and forming the photoelectric conversion layer The substrate is divided into a predetermined number of evaluation sections in the first division, and the high-intensity reflective region of the photoelectric conversion layer formed by increasing the SiH ₄ flow rate for each of the evaluation sections in the first division Calculate area ratio And obtaining the distribution of the high-intensity reflective region on the substrate, determining the uniformity of the high-intensity reflective region generated in the photoelectric conversion layer based on the distribution, and the distribution is uniform. A step of setting the film-forming condition candidate as a final film-forming condition when it is determined that there is, and a plurality of feeding points among the film-forming condition candidates when it is determined that the distribution is non-uniform. A film forming condition setting method comprising: adjusting the high frequency power density supplied to the substrate to set a final film forming condition.

  In the above invention, the step of adjusting the high-frequency power density supplied to the plurality of feeding points and setting the final film-forming conditions includes the step of setting the high-frequency power density at a predetermined ratio with respect to the selected film-forming condition candidates. A step of forming the photoelectric conversion layer on the substrate by setting to an increased or decreased value, and dividing the substrate on which the photoelectric conversion layer is formed into a predetermined number of sections in a second division; Calculating an area ratio of a high-intensity reflective region of the photoelectric conversion layer formed by increasing or decreasing the high-frequency power density for each of the two divided evaluation sections; and for each second divided evaluation section The final value of the high-frequency power density that supplies the smallest value among the high-frequency power densities at which the area ratio of the high-intensity reflective region is a predetermined value or less to the feed point closest to the evaluation section among the plurality of feed points. Film forming conditions And a step of setting.

When the SiH ₄ flow rate is increased by a predetermined amount with respect to conditions (film formation condition candidates) in which each parameter is individually set so that a high performance can be obtained without generating a high-luminance reflection region, a high output is obtained. It has been found that the high-brightness reflection region is uniformly generated under the conditions where the above-mentioned conditions are obtained, and the high-brightness reflection region is unevenly generated under the conditions of low output (that is, not optimized). Based on such a phenomenon, the present invention verifies whether the film forming conditions individually examined and set are optimum, and if the film forming conditions deviate from the optimum values, the power supply of the discharge electrode closest to the corresponding evaluation section is performed. Fine adjustment of the high frequency power density at the point is performed to set final film forming conditions.
According to the present invention, it is possible to select an optimum film forming condition for a crystalline silicon photoelectric conversion layer to be a high-performance photoelectric conversion device.

Further, the present invention provides a photoelectric conversion device having a photoelectric conversion layer made of crystalline silicon on a substrate for forming a film of the photoelectric conversion layer by supplying high-frequency power to a plurality of feeding points of a discharge electrode of the film forming device. In the film forming condition setting method, when the ratio of the Raman peak intensity of the crystalline silicon phase to the Raman peak intensity of the amorphous silicon phase in the photoelectric conversion layer is defined as the Raman peak ratio, any Raman peak ratio Obtaining a correlation between the change rate of the SiH ₄ flow rate and the area rate of the high-intensity reflective region for the photoelectric conversion layer having the above, and supplying at least the SiH ₄ flow rate, the SiH ₄ partial pressure, and each of the plurality of feeding points A step of selecting candidate film forming conditions for the photoelectric conversion layer including a high frequency power density to be increased, and a flow rate of SiH ₄ is increased at a predetermined rate with respect to the selected film forming condition candidate A step of forming the photoelectric conversion layer on the substrate, and dividing the substrate on which the photoelectric conversion layer is formed into a predetermined number of evaluation sections in a third division, Calculating the area ratio of the high-intensity reflective region of the photoelectric conversion layer formed by increasing the SiH ₄ flow rate for each of the evaluation sections; and SiH increased at a predetermined ratio with respect to the film forming condition candidates _The flow rate and the calculated area ratio of the high-intensity reflective region are compared with the correlation to obtain a Raman peak ratio for each of the evaluation sections of the formed photoelectric conversion layer; and the evaluation When the Raman peak ratio acquired for each of the sections satisfies a design value, the step of setting the film forming condition candidate as the final film forming condition; and the Raman peak ratio acquired for each of the evaluation sections Different The case, the SiH ₄ flow rate, film manufactured by a step of setting at least one adjustment to the final film forming conditions of the high frequency power density supplied to each of the SiH ₄ partial pressure and the plurality of feed points Provides a condition setting method.

In the present invention, the step of setting a final film forming condition when the Raman peak ratio acquired for each of the evaluation sections is different from the design value is based on the calculated area ratio of the high-intensity reflective region. Obtaining a distribution of the high-intensity reflective region on the substrate; determining a uniformity of the high-intensity reflective region generated in the photoelectric conversion layer based on the distribution; and determining that the distribution is uniform When the Raman peak ratio is higher than the design value, the SiH ₄ flow rate is increased with respect to the film forming condition candidates so that the Raman peak ratio of the photoelectric conversion layer satisfies the design value. and setting the value to the final casting conditions, wherein when the Raman peak ratio is lower than the design value, as the Raman peak ratio of the photoelectric conversion layer satisfies the design value, the SiH And setting a value obtained by decreasing the flow rate to the film forming conditions candidates in the final film forming conditions, when the distribution is determined to be non-uniform, the substrate on which the photoelectric conversion layer is formed first The area ratio of the high-intensity reflective region of the photoelectric conversion layer formed by dividing the predetermined number of sections into four sections and increasing or decreasing the high-frequency power density for each of the evaluation sections in the fourth section is calculated. And, for each evaluation section of the fourth division, the smallest value among the high-frequency power densities at which the area ratio of the high-intensity reflective region is a predetermined value or less is set to the evaluation section among the plurality of feeding points. It is preferable to include a step of setting the final film-forming conditions of the high-frequency power density supplied to the feeding point closest to.

Raman peak ratio in the present invention measures the Raman spectrum obtained by Raman scattering spectroscopy, Raman peak intensity of the crystalline silicon phase in the vicinity of 520 cm ^-1 to the peak intensity Ia of the amorphous silicon phase in the vicinity of 480 cm ^-1 Ic Is defined as the ratio Ic / Ia.
The Raman peak ratio is one of the indexes for evaluating the film quality of the photoelectric conversion layer made of crystalline silicon. When the Raman peak ratio is about 2.5 or less, a high-intensity reflective region is generated. Usually, it is an index obtained by measuring a Raman spectrum using a spectroscopic device for a substrate on which a crystalline silicon photoelectric conversion layer is formed. When the substrate area was large, it was necessary to move the substrate to another evaluation location, divide the substrate, and measure the Raman spectrum.
The inventors of the present application have found that the state of occurrence of the high-intensity reflective region differs when the SiH ₄ flow rate is varied depending on the Raman peak ratio of the crystalline silicon photoelectric conversion layer. That is, as the Raman peak ratio is higher, there is a tendency that a high-intensity reflective region is less likely to occur even when the SiH ₄ flow rate is increased with respect to the film forming condition candidates. Based on such a phenomenon, the present invention estimates the Raman peak ratio of the crystalline silicon photoelectric conversion layer formed under certain conditions without dividing the substrate or measuring the Raman spectrum with another apparatus. When the Raman peak ratio is different from the design value, readjustment of the film forming conditions is performed to set the final film forming conditions.
According to the present invention, the Raman peak ratio of the crystalline silicon photoelectric conversion layer can be obtained by a simple method, and the film forming conditions of the crystalline silicon photoelectric conversion layer having a desired Raman peak ratio can be selected. it can.

Further, the present invention is a method for manufacturing a photoelectric conversion device having a photoelectric conversion layer made of crystalline silicon on a substrate by a plasma CVD device, and at least the final film formation conditions set by the film formation condition setting method described above, The photoelectric conversion layer is formed.
According to the present invention, since the optimum film-forming conditions for the crystalline silicon photoelectric conversion layer are selected over the entire surface of the large-area substrate exceeding 1 m ² , the produced photoelectric conversion device has high performance. . In addition, the yield can be improved and the production efficiency can be improved.

  According to the present invention, the validity of the film forming conditions (film forming condition candidates) after completion of the initial adjustment can be confirmed. For this reason, it is possible to avoid the problem that the performance of the photoelectric conversion device is deteriorated because the film forming condition candidates deviate from the optimum conditions, and it is possible to reliably manufacture a high-performance photoelectric conversion device.

It is the schematic showing the structure of the photoelectric conversion apparatus of the tandem structure manufactured by this invention. It is the schematic explaining one Embodiment which manufactures a solar cell panel as a photoelectric conversion apparatus. It is the schematic explaining one Embodiment which manufactures a solar cell panel as a photoelectric conversion apparatus. It is the schematic explaining one Embodiment which manufactures a solar cell panel as a photoelectric conversion apparatus. It is the schematic explaining one Embodiment which manufactures a solar cell panel as a photoelectric conversion apparatus. It is the schematic explaining the generation | occurrence | production state of a high-intensity reflective area | region when a film forming condition candidate is suitable, (a) is film-forming with SiH ₄ flow volume of film forming condition candidate, (b) is SiH ₄ flow volume. Is formed by increasing the film formation condition candidates by 10%. It is the schematic explaining the generation | occurrence | production state of a high-intensity reflective area | region when a film forming condition candidate is not suitable, (a) is film-forming with SiH ₄ flow volume of film forming condition candidate, (b) is SiH ₄ flow volume. This is a case where the film is formed by increasing the film forming condition candidate by 10%. It is the schematic which shows the electrode structure of the thin film manufacturing apparatus used in order to form a 2nd cell layer. It is a figure explaining the generation | occurrence | production condition of the high-intensity reflective area | region of the 2nd cell layer formed into a film with various high frequency power densities. It is a graph showing the correlation between the SiH ₄ flow rate increase amount and the area ratio of the high-intensity reflective region for crystalline silicon films having different Raman peak ratios.

FIG. 1 is a schematic diagram illustrating a configuration of a photoelectric conversion apparatus. The photoelectric conversion device 100 is a tandem silicon solar cell, and includes a substrate 1, a transparent electrode layer 2, a first cell layer 91 (amorphous silicon system) and a second cell layer 92 ( Crystalline silicon), intermediate contact layer 5 and back electrode layer 4. Here, the silicon-based is a generic name including silicon (Si), silicon carbide (SiC), and silicon germanium (SiGe). Further, the crystalline silicon system means a silicon system other than the amorphous silicon system, and includes microcrystalline silicon and polycrystalline silicon.
Although the tandem solar cell has been described as the solar cell in the above embodiment, the present invention is not limited to this example. For example, the present invention can be similarly applied to a single solar cell and a triple solar cell to which crystalline silicon including microcrystalline silicon is applied as a photoelectric conversion layer.

  The method for manufacturing the photoelectric conversion device in FIG. 1 will be described by taking a process for manufacturing a solar cell panel as an example. 2 to 5 are schematic views showing a method for manufacturing the solar cell panel of the present embodiment.

(1) FIG. 2 (a)
As the substrate 1, a large soda float glass substrate (for example, 1.4 m × 1.1 m × plate thickness: 3.0 mm to 4.5 mm) having an area exceeding 1 m ² is used. The end face of the substrate is preferably subjected to corner chamfering or R chamfering to prevent damage due to thermal stress or impact.

(2) FIG. 2 (b)
As the transparent electrode layer 2, a transparent conductive film having a thickness of about 500 nm to 800 nm and having tin oxide (SnO ₂ ) as a main component is formed at about 500 ° C. with a thermal CVD apparatus. At this time, a texture with appropriate irregularities is formed on the surface of the transparent electrode film. As the transparent electrode layer 2, an alkali barrier film (not shown) may be formed between the substrate 1 and the transparent electrode film in addition to the transparent electrode film. As the alkali barrier film, a silicon oxide film (SiO ₂ ) is formed at a temperature of about 500 ° C. in a thermal CVD apparatus at 50 nm to 150 nm.

(3) FIG. 2 (c)
Thereafter, the substrate 1 is placed on an XY table, and the first harmonic (1064 nm) of the YAG laser is irradiated from the film surface side of the transparent electrode film as indicated by an arrow in the figure. The laser power is adjusted so as to be suitable for the processing speed, and the transparent electrode film is moved relative to the direction perpendicular to the series connection direction of the power generation cells 7 to move the substrate 1 and the laser beam to form the groove 10. Thus, laser etching is performed in a strip shape having a predetermined width of about 6 mm to 15 mm.

(4) FIG. 2 (d)
As the first cell layer 91, a p layer, an i layer, and an n layer made of an amorphous silicon thin film are formed by a plasma CVD apparatus. Using SiH ₄ gas and H ₂ gas as main raw materials, the amorphous silicon p layer 31 from the side on which sunlight is incident on the transparent electrode layer 2 at a reduced pressure atmosphere: 30 Pa to 1000 Pa and a substrate temperature: about 200 ° C. Then, an amorphous silicon i layer 32 and an amorphous silicon n layer 33 are formed in this order. The amorphous silicon p layer 31 is mainly made of amorphous B-doped silicon and has a thickness of 10 nm to 30 nm. The amorphous silicon i layer 32 has a thickness of 200 nm to 350 nm. The amorphous silicon n layer 33 is mainly P-doped silicon containing microcrystalline silicon in amorphous silicon, and has a thickness of 30 nm to 50 nm. A buffer layer may be provided between the amorphous silicon p layer 31 and the amorphous silicon i layer 32 in order to improve interface characteristics.

  Next, a crystalline silicon p layer 41, a crystalline silicon i layer 42, and a crystalline silicon n layer 43 as the second cell layer 92 are sequentially formed on the first cell layer 91 using a plasma CVD apparatus. Film. The crystalline silicon p layer 41 is mainly made of B-doped microcrystalline silicon and has a thickness of 10 nm to 50 nm. The crystalline silicon i layer 42 is mainly made of microcrystalline silicon and has a film thickness of 1.2 μm or more and 3.0 μm or less. The crystalline silicon n layer 43 is mainly made of P-doped microcrystalline silicon and has a thickness of 20 nm to 50 nm. The crystalline silicon n layer may be replaced with an amorphous silicon n layer.

  In forming the i-layer film mainly composed of microcrystalline silicon by the plasma CVD method, the distance d between the plasma discharge electrode and the surface of the substrate 1 is preferably 3 mm or more and 10 mm or less. If it is smaller than 3 mm, it is difficult to keep the distance d constant from the accuracy of each component device in the film forming chamber corresponding to the large substrate, and there is a possibility that the discharge becomes unstable because it is too close. When it is larger than 10 mm, it is difficult to obtain a sufficient film forming speed (1 nm / s or more), and the uniformity of the plasma is lowered and the film quality is lowered by ion bombardment.

  An intermediate contact layer 5 serving as a semi-reflective film is provided between the first cell layer 91 and the second cell layer 92 in order to improve the contact property and achieve current matching. As the intermediate contact layer 5, a ZnO film doped with Ga or Al having a film thickness of 20 nm to 100 nm is formed by sputtering using a target: Ga-doped ZnO sintered body or Al-doped ZnO sintered body. Further, the intermediate contact layer 5 may not be provided.

(5) FIG. 2 (e)
The substrate 1 is placed on an XY table, and the second harmonic (532 nm) of the laser diode-pumped YAG laser is irradiated from the film surface side of the photoelectric conversion layer 3 as indicated by an arrow in the figure. Pulse oscillation: 10 kHz to 20 kHz, laser power is adjusted so as to be suitable for the processing speed, and laser etching is performed so that grooves 11 are formed on the lateral side of the laser etching line of the transparent electrode layer 2 from about 100 μm to 150 μm. To do. Further, this laser may be irradiated from the substrate 1 side. In this case, the photoelectric conversion layer is formed by utilizing a high vapor pressure generated by the energy absorbed in the amorphous silicon-based first cell layer of the photoelectric conversion layer 3. Since 3 can be etched, a more stable laser etching process can be performed. The position of the laser etching line is selected in consideration of positioning tolerances so as not to intersect with the etching line in the previous process.

(6) FIG. 3 (a)
An Ag film / Ti film is formed as the back electrode layer 4 by a sputtering apparatus at a reduced pressure atmosphere and at a film forming temperature of 150 ° C. to 200 ° C. In this embodiment, an Ag film: 150 nm or more and 500 nm or less, and a Ti film having a high anticorrosion effect: 10 nm or more and 20 nm or less are stacked in this order to protect them. Alternatively, the back electrode layer 4 may have a laminated structure of an Ag film having a thickness of 25 nm to 100 nm and an Al film having a thickness of 15 nm to 500 nm. In addition, in the case where a long wavelength side reflected light of 600 nm or more is required, such as a tandem solar cell, a laminated structure of a Cu film having a thickness of about 100 nm to 450 nm and a Ti film having a thickness of about 5 nm to 150 nm It is also good.
For the purpose of reducing the contact resistance between the n layer 43 and the back electrode layer 4 and improving the light reflection, Ga or Al having a film thickness of 50 nm or more and 100 nm or less is formed between the photoelectric conversion layer 3 and the back electrode layer 4 by a sputtering apparatus. Alternatively, a ZnO film doped with may be formed.

(7) FIG. 3 (b)
The substrate 1 is placed on an XY table, and the second harmonic (532 nm) of the laser diode-pumped YAG laser is irradiated from the substrate 1 side as indicated by the arrow in the figure. The laser light is absorbed by the photoelectric conversion layer 3, and the back electrode layer 4 is exploded and removed using the high gas vapor pressure generated at this time. Pulse oscillation: 1 kHz to 50 kHz, laser power is adjusted so as to be suitable for the processing speed, and laser etching is performed so that grooves 12 are formed on the lateral side of the laser etching line of the transparent electrode layer 2 from 250 μm to 400 μm. .

(8) FIG. 3 (c) and FIG. 4 (a)
The power generation region is divided, and the film edge around the substrate edge is laser-etched to prevent a short circuit at the serial connection portion. The substrate 1 is placed on an XY table, and the second harmonic (532 nm) of the laser diode pumped YAG laser is irradiated from the substrate 1 side. The laser light is absorbed by the transparent electrode layer 2 and the photoelectric conversion layer 3, and the back electrode layer 4 explodes using the high gas vapor pressure generated at this time, and the back electrode layer 4 / photoelectric conversion layer 3 / transparent electrode layer 2 is removed. Pulse oscillation: 1 kHz or more and 50 kHz or less, the laser power is adjusted so as to be suitable for the processing speed, and the position of 5 mm to 20 mm from the end of the substrate 1 is placed in the X-direction insulating groove as shown in FIG. Laser etching is performed to form 15. In addition, in FIG.3 (c), since it becomes X direction sectional drawing cut | disconnected in the direction in which the photoelectric converting layer 3 was connected in series, the back surface electrode layer 4 / photoelectric conversion is originally in the position of the insulating groove 15 Although there should be a state (see FIG. 4A) corresponding to the peripheral film removal region 14 where the layer 3 / transparent electrode layer 2 has been polished and removed, description of processing to the end of the substrate 1 For the sake of convenience, the insulating groove formed to represent the Y-direction cross section at this position will be described as the X-direction insulating groove 15. At this time, the Y-direction insulating groove does not need to be provided because the film surface polishing removal processing of the peripheral film removal region of the substrate 1 is performed in a later process.

  The insulating groove 15 has an effective effect in suppressing moisture permeation from the outside into the solar cell module 6 from the end of the solar cell panel by terminating the etching at a position of 5 mm to 15 mm from the end of the substrate 1. This is preferable.

  In addition, although the laser beam in the above process is made into a YAG laser, there exists what can use a YVO4 laser, a fiber laser, etc. similarly.

(9) FIG. 4 (a: view from the solar cell film side, b: view from the substrate side of the light receiving surface)
Since the laminated film around the substrate 1 (peripheral film removal region 14) has a step and is easy to peel off in order to ensure a sound adhesion / seal surface with the back sheet 24 via EVA or the like in a later process, The film is removed to form a peripheral film removal region 14. In removing the film over the entire circumference of the substrate 1 at 5 to 20 mm from the end of the substrate 1, the X direction is closer to the substrate end than the insulating groove 15 provided in the step of FIG. The back electrode layer 4 / photoelectric conversion layer 3 / transparent electrode layer 2 are removed by using grinding stone polishing, blast polishing, or the like on the substrate end side with respect to the groove 10 near the side portion.
Polishing debris and abrasive grains are removed by cleaning the substrate 1.

(10) FIGS. 5 (a) and 5 (b)
A solar cell panel using a copper foil to collect current from the back electrode layer 4 of the power generation cell 7 at one end arranged in series and the back electrode layer 4 of the current collecting cell connected to the power generation cell 7 at the other end It processes so that electric power can be taken out from the part of the terminal box 23 on the back side. In order to prevent short circuit with each part, the copper foil for current collection arrange | positions an insulating sheet wider than copper foil width.
After the current collecting copper foil or the like is disposed at a predetermined position, an adhesive filler sheet made of EVA (ethylene vinyl acetate copolymer) or the like is disposed so as to cover the entire solar cell module 6 and not protrude from the substrate 1. .
A back sheet 24 having a high waterproofing effect is installed on the adhesive filler sheet. In this embodiment, the back sheet 24 has a three-layer structure of PET sheet / Al foil / PET sheet so that the waterproof and moisture-proof effect is high.
An opening through window is provided at the attachment portion of the terminal box 23 of the back sheet 24 to take out the copper foil for current collection. In the opening through window portion, an insulating material is provided in a plurality of layers between the back sheet 24 and the back electrode layer 4 to suppress intrusion of moisture and the like from the outside.
The one with the back sheet 24 in place is degassed in a reduced pressure atmosphere with a laminator and pressed at about 150 to 160 ° C., and the adhesive filler sheet (EVA) is cross-linked and tightly sealed. Process.
The adhesive filler sheet is not limited to EVA, and an adhesive filler having a similar function such as PVB (polyvinyl butyral) can be used. In this case, the processing is performed by optimizing the conditions such as the pressure bonding procedure, temperature and time.

(11) FIG. 5 (a)
The terminal box 23 is attached to the back side of the solar cell module 6 with an adhesive.
(12) FIG. 5 (b)
The copper foil and the output cable of the terminal box 23 are connected by solder or the like, and the inside of the terminal box 23 is filled with a sealing agent (potting agent) and sealed. Thus, the solar cell panel 50 is completed.
(13) FIG. 5 (c)
A power generation inspection and a predetermined performance test are performed on the solar cell panel 50 formed in the steps up to FIG. The power generation inspection is performed using a solar simulator of AM1.5 and solar radiation standard sunlight (1000 W / m ² ). The power generation inspection may be performed after the solar battery panel 50 is completely completed, or may be performed before the aluminum frame frame is attached.
(14) FIG. 5 (d)
Before and after the power generation inspection (FIG. 5C), a predetermined performance inspection is performed including an appearance inspection.

An aluminum frame frame that adds strength to the solar cell module 6 and serves as a mounting seat is attached around the solar cell module 6. It is preferable to securely hold the solar cell module 6 and the aluminum frame frame through a rubber gasket or the like while maintaining elasticity.
Thus, the solar cell panel 50 is completed.

<First Embodiment>
The film forming condition setting method according to the first embodiment will be described below. In the first embodiment, when the second cell layer 92 that is a microcrystalline silicon layer is formed by the plasma CVD apparatus, whether the film forming conditions of the second cell layer 92 set individually by a known method are appropriate. Judgment is made and fine adjustment is performed on the film forming conditions in the entire surface of the large-area substrate.
In the first embodiment, the second cell layer (crystalline silicon p layer 41, crystalline silicon i layer 42, and crystalline silicon n layer 43) is manufactured by the following steps (1-1) to (1-8). Film conditions are set.
The plasma CVD apparatus used for forming the second cell layer 92 according to this embodiment includes a discharge electrode shown in FIG. That is, the plasma CVD apparatus used in the present embodiment includes eight discharge electrodes, and eight feeding points are provided above and below the discharge electrodes, respectively.

(1-1) Selection of Film Formation Condition Candidate Film formation condition candidates for forming the second cell layer 92 are selected. The method for selecting candidate film forming conditions can follow the method disclosed in, for example, Japanese Patent Application Laid-Open No. 2007-150151. Examples of film forming conditions include SiH ₄ flow rate, film forming pressure, hydrogen dilution rate, high frequency power density, distance between substrate and discharge electrode, substrate temperature, and the like. Specific example condition ranges are as follows. The SiH ₄ flow rate is appropriately determined from the film forming pressure, the hydrogen dilution rate, the size of the film forming chamber, and the like to obtain the target film forming speed and the necessary film quality.
Film-forming pressure: 3000 Pa or less Hydrogen dilution rate: SiH ₄ : H ₂ = 1: 45-75
Plasma generation frequency: 40 MHz to 100 MHz High frequency power density: 1.0 to 1.15 W / cm ²
Substrate-electrode distance: 3 to 10 mm
Substrate temperature: about 200 ° C

(1-2) is set to a value film SiH ₄ flow rate of the second cell layer is increased a predetermined amount from the film forming conditions candidates in terms of increasing the SiH ₄ flow rate, other conditions of film formation condition candidate Similarly, the second cell layer 92 is formed on the first cell layer 91 (or on the intermediate contact layer 5) of the substrate 1. For example, the set value of the SiH ₄ flow rate is a value increased by 10% with respect to the film forming condition candidates. SiH ₄ If even flow increase can not be visually confirmed high-brightness reflective regions, which will be described later, may be increased SiH ₄ flow rate with respect to film forming condition candidate for example more than 15%. However, if the high-brightness reflective region cannot be visually confirmed even if the SiH ₄ flow rate is increased by more than 20% with respect to the deposition condition candidate, conditions such as high-frequency power density may be inappropriate. Therefore, the above-described film forming condition candidates are reset.

(1-3) Calculation of Area Ratio of High Brightness Reflection Area and Acquisition of Distribution As described above, the high brightness reflection generated for the second cell layer 92 formed by increasing the SiH ₄ flow rate from the film formation condition candidates as described above. While calculating the area ratio of the region, the distribution in the substrate plane is acquired.
In order to determine the occurrence state of the high-intensity reflective region in the substrate surface, the substrate on which the second cell layer 92 is formed is divided into a predetermined number of divisions as the first division evaluation division. In the first division, the substrate is preferably divided into three or more divisions on each side so that the uniformity at the end portion and the central portion of the substrate can be confirmed. That is, the substrate is divided into at least nine sections. In addition, when carrying out visual detection and evaluation of a high-intensity reflective area, from the viewpoint of work efficiency and certainty of judgment, the upper limit is that it is divided into 6 sections by dividing the long side and short side of the substrate into 6 sections. Is done. The number of divisions may be the same or different between the long side and the short side of the substrate. When detecting a high-intensity reflection area by image processing, there is no upper limit to the number of evaluation sections, but if the number of evaluation sections is set appropriately so that it is suitable for evaluating the distribution status of the generated high-intensity reflection area in the substrate surface good. For example, in order to more accurately evaluate the situation in which the high-intensity reflective region is unevenly distributed when the substrate area is as large as 1 m ² or more, the number of evaluation sections is increased to 100 sections or more, that is, the area of one evaluation section is reduced. Smaller is better.

For each evaluation section, the area ratio of the high-intensity reflective region of the second cell layer 92 is calculated. The high-intensity reflective area is detected by visual observation or image processing.
In the case of visual observation, the high-intensity reflective area is observed as an area having high brightness and shining white. In the visual evaluation, the generation ratio of the high-intensity reflection region is calculated with reference to the limit sample.
The detection of the high-intensity reflective region and the calculation of the area ratio by image processing are performed by the following steps. The substrate is photographed from the film surface of the second cell layer 92 using a CCD camera, and an RGB two-dimensional image is acquired. The acquired RGB two-dimensional image is transmitted to the computer. The computer converts the RGB two-dimensional image into the CIE-XYZ color system, and then converts into the CIE-L * a * b * color system. Thereby, the L * value (luminance) in the two-dimensional image is acquired. The computer compares the L * value with a preset threshold value for each pixel captured by the camera, and determines an area equal to or higher than the threshold value as a high-intensity reflective area. The computer calculates the area ratio of the high-intensity reflective area to the area of the entire substrate.

The area ratio of the high-intensity reflective region in each evaluation section is evaluated using, for example, the following four stages A to D in Table 1. Based on the evaluation of each evaluation section, the generation distribution of the high-intensity reflection region when the SiH ₄ flow rate in the entire substrate is increased by a predetermined amount is acquired.
In addition, even in visual evaluation, the occurrence of high-intensity reflective areas in B, C, and D is clearly different, and the area ratio shown in Table 1 can be evaluated by referring to the limit sample. It is.

(1-4) Determination of Uniformity of High Brightness Reflection Area Based on the distribution of the high brightness reflection area obtained as described above, the uniformity of the generated high brightness reflection area is determined. The determination is performed according to the following criteria.

As a first criterion, there is an evaluation section (an evaluation section in which the area ratio of the high-intensity reflective region is greater than 3%) determined as C or D according to Table 1 when the SiH ₄ flow rate over the entire substrate is increased by a predetermined amount. It is required to be 80% or more of the total number of evaluation sections.
When it is divided into 12 sections (3 sections × 4 sections) or more and the area per section is larger than 2.8% and 10% or less of the substrate area, the second criterion is It is required that two or more sections determined as A or B (evaluation sections in which the area ratio of the high luminance reflection region is 3% or less) are not continuous. 36 or more and less than 100 divisions, that is, when the area per division is more than 1.0% and less than 2.8%, the evaluation determined as A or B by Table 1 It is required that three or more partitions are not continuous. When the area per section is 1.0% or less of the substrate area (100 sections or more), a plurality of sections are integrated to be less than 100 sections, and two or more are the same as above according to the area ratio after integration. Alternatively, it is required that three or more evaluation sections determined as A or B are not continuous. In addition, it integrates so that the area ratio of each division after integration may become uniform.

When the first standard is satisfied in 9 sections, and the first standard and the second standard are satisfied in 12 sections or more, it is determined that the high-intensity reflective region is uniformly generated in the substrate surface.
When the first standard is not satisfied in nine sections, and when at least one of the first standard and the second standard is not satisfied in twelve sections or more, the high-intensity reflective region is not uniform in the substrate plane. Is determined to have occurred.
Note that the above evaluation is an example, and the number of evaluation stages in Table 1, the numerical range of the area ratio in each stage, and the above-described uniformity according to the accuracy required for determining the uniformity of the generated high-intensity reflective region The numerical value of the area ratio of the high-intensity reflective region, which is the boundary of the sex determination criterion, can be set as appropriate.

(1-5) Configuration Figure 6 and 7 of the final film forming conditions, (a) manufactured by the second cell layer was formed into a film with SiH ₄ flow rate of film condition candidate, and, (b) SiH ₄ flow rate of film forming conditions It is a figure explaining an example of the generation | occurrence | production situation of the high-intensity reflective area | region of the 2nd cell layer formed into a film by increasing 10% from a candidate. 6 and 7, the substrate is divided into 4 sections × 4 sections, for a total of 16 sections. FIG. 6 shows a case where the selected film forming condition candidate is appropriate and the output when the solar cell panel is obtained is 91 W / m ² . FIG. 7 shows a case where the selected film forming condition candidate is inappropriate and the output when the solar cell panel is used is as low as 88 W / m ² .

As shown in FIGS. 6 (a) and 7 (a), when film formation is performed with the SiH ₄ flow rate as a film formation condition candidate, there is almost no difference in the occurrence state of the high-intensity reflective region, and evaluation is performed in any evaluation section. A or B (the area ratio of the high-intensity reflective region was 3% or less).

When the film forming condition candidates are appropriate and the SiH ₄ flow rate is increased by 10% from the film forming condition candidates, the evaluation becomes D in 80% or more evaluation sections as shown in FIG. Only the evaluation section I-4 was determined to be B, and two or more evaluation sections determined to be A or B were not continuously generated.
On the other hand, in FIG. 7B where the film forming condition candidates are inappropriate, the evaluation section determined as C or D was less than 80%. In addition, two or more evaluation sections determined as A or B were continuously generated. Even if the SiH ₄ flow rate is increased by a predetermined amount, it can be estimated that the increase in the high-brightness reflection region is small because the film-forming reference conditions were selected under the film-forming conditions where the Raman peak is high and the crystallization rate is high.

Therefore, when it is determined in (1-4) that the SiH ₄ flow rate is increased by a predetermined amount from the film forming condition candidates and the high-intensity reflective region is uniformly generated, it is selected in (1-1). The film forming condition candidates are determined to be appropriate, and the film forming condition candidates are determined as the final film forming conditions. In the production of the solar cell panel of FIG. 1, the second cell layer 92 is formed under the determined final film formation conditions.

  When it is determined in (1-4) that the high-brightness reflective region is not uniform, the film forming condition candidates selected in (1-1) are considered inappropriate. The film forming condition candidates determined to be inappropriate are optimized by adjusting the high-frequency power density supplied to each feeding point according to steps (1-6) to (1-8).

(1-6) Film formation of second cell layer under conditions in which high-frequency power density is changed With respect to the high-frequency power density supplied to each feeding point, a predetermined amount is increased or decreased step by step with respect to the film formation condition candidates. Each of the set values is set. The high-frequency power density supplied to each feeding point increases or decreases with respect to the film forming condition candidates in increments of 0.05 to 0.1 W / cm ² -30 in consideration of the plasma generation distribution of the discharge electrode 103. % To + 30%. For example, as a reference value 1.15 W / cm ² is deposition conditions candidates of this embodiment, the 0.1 W / cm ² increments, the film forming conditions candidates vicinity is increased or decreased to 0.05 W / cm ² increments Value is set. The lower and upper limits of the high-frequency power density are the production time (film forming speed), the output of the manufactured solar cell panel, and the electrical stability of the high-frequency power supply system, along with the occurrence of the high-intensity reflective area. Etc. are also taken into consideration.
The second cell layer 92 is formed on the first cell layer 91 (or on the intermediate contact layer 5) of the substrate 1, assuming that the conditions other than the high frequency power density are the same as the candidate film forming conditions.

(1-7) Calculation of Area Ratio of High-Brightness Reflective Region The generated high-brightness reflective region for the second cell layer 92 formed by increasing or decreasing the high-frequency power density by a predetermined amount from the film-forming condition candidates as described above The area ratio is calculated.

  FIG. 8 is a schematic view showing an electrode structure of a thin film manufacturing apparatus used for forming the second cell layer in the present embodiment. The discharge electrode 103 of the present embodiment includes eight discharge electrodes 103a to 103h, each of which is provided between two horizontal electrodes extending in the X direction substantially parallel to each other and between the two horizontal electrodes. A plurality of rod-like vertical electrodes extending in the Z ′ direction in parallel. Further, it may be divided into a plurality of electrode units. When the discharge electrode 103 is divided and formed, it is preferably divided and formed according to the number of feeding points.

  The matching units 113a (113aa to 113ha) and 113b (113ab to 113hb) match the impedance on the output side, and from a high-frequency power source (not shown) via the high-frequency power transmission lines 114a (114aa to 114ha) and 114b (114ab to 114hb). High-frequency power is transmitted to the discharge electrodes 103 (103a to 103h) via the high-frequency power transmission paths 112a (112aa to 112ha) and 112b (112ab to 112hb). In FIG. 8, only the matching devices 113aa, 113ah, and 113ba are shown.

  In the film formation of the second cell layer 92 in the step (1-6), the high-frequency power density transmitted to each discharge electrode 103 is substantially the same for each value set above. Each of the discharge electrodes 103a to 103h is substantially uniformly supplied with a source gas from a feed gas pipe connected to each of the feed points 153a to 153h and the feed points 154a to 154h in the vicinity of both ends along the vertical electrode, This source gas is discharged substantially uniformly from a plurality of locations in the direction indicated by the arrow in the figure (on the opposite electrode side). In FIG. 8, only the feeding points 153a and 154a are shown. As described above, when the high-frequency power and the gas are supplied to the discharge electrode 103, plasma is generated between the discharge electrode 103 and the counter electrode facing the discharge electrode 103. The source gas is decomposed by this plasma, and a crystalline silicon film as the second cell layer 92 is formed on the substrate 1 during film formation.

The substrate on which the second cell layer 92 is formed is divided into a predetermined number of sections as the second division, and the detection of the high luminance reflection area and the calculation of the area ratio are performed for each evaluation section.
In the second division, the division may be made to coincide with the first division of (1-3) above. Or you may differ from a 1st division | segmentation according to the electrode structure of the film forming apparatus which forms a 2nd cell layer. When the electrode having the structure shown in FIG. 8 is used, the substrate on which the second cell layer is formed is divided into two evaluation sections on the feeding point 153a side and the feeding point 154a side. Further, the substrate is divided into eight evaluation sections in the direction in which the discharge electrodes 103a to 103h are arranged in parallel. That is, in this embodiment, it is divided into 16 sections according to the structure of the discharge electrode.
For example, if the first division is divided into 4 divisions × 4 divisions, and the second division is divided into 8 divisions on the long side of the substrate and 2 divisions on the short side of the substrate corresponding to the electrode structure of FIG. It is possible to associate the evaluation section by and the evaluation section by the second division. For example, the region obtained by combining I-1 and II-1 in FIG. 6 matches the region obtained by combining I-1 and I-2 in FIG. If it carries out like this, the area | region when determining the film-forming condition candidate of process (1-2)-(1-5) and the area | region when adjusting the conditions of process (1-6)-(1-8) will be obtained. The correspondence relationship is preferable because the adjustment accuracy can be improved.

  The high-intensity reflective area is detected by the same method as in (1-3) above. Table 1 is used to evaluate the area ratio of the high-intensity reflective region in each section. By this evaluation, the generation distribution of the high-intensity reflective region when the high-frequency power density is changed is obtained.

(1-8) Setting of Final Film Formation Conditions for High-Frequency Power Density FIG. 9 is a diagram for explaining an example of the state of occurrence of a high-brightness reflection region of the second cell layer 92 formed at various high-frequency power densities. FIG. 9 shows a case where evaluation is performed by dividing into 16 sections corresponding to the electrode structure of FIG. 9, I-1 to I-8 correspond to the feeding points 153a to 153h in FIG. 8, and II-1 to II-8 correspond to the feeding points 154a to 154h in FIG. In FIG. 9, the high frequency power density supplied to each feeding point is set to the same value, (a) is 1.0 W / cm ² , (b) is 1.1 W / cm ² , (c) is 1 .15 W / cm ² , (d) is 1.2 W / cm ² , (e) is 1.3 W / cm ² , and (f) is 1.4 W / cm ² .
According to FIG. 9, the higher the high-frequency power density, the smaller the generation area of the high-intensity reflective region. 9A to 9F, the evaluation section indicated by diagonal lines is evaluated B when the evaluation becomes A at the smallest high-frequency power density, or at the upper limit of 1.4 W / cm ² in this example. Shows the time when In this example, the upper limit value of the high frequency power density is 1.4 W / cm ² , but this is a value determined in consideration of the film forming time (film forming speed) and the output of the manufactured solar cell panel. is there.

For example, evaluation compartments I-8 is, 1.1 W / cm ² (to FIG. 9 (b)) the evaluation is A, and the even evaluated as 1.15 W / cm ² or more remains A. Thus, in the evaluation section where the high-intensity reflection area disappears at a certain high-frequency power density, the high-intensity reflection area does not occur even if the high-frequency power density is further increased. If the high-frequency power density is too high, the Raman peak ratio increases, that is, crystallization progresses too much and the voltage of the solar cell panel decreases, causing a decrease in output. For this reason, it is preferable that the high-frequency power density is low in a range where the high-brightness reflective region is 3% or less with respect to the required film forming speed.

Therefore, the value of the minimum high frequency power density that can achieve the evaluation A in each evaluation section, or the upper limit value (that is, the value of the high frequency power density when each evaluation section is represented by diagonal lines in FIG. 9) The final film-forming condition of the high-frequency power density supplied to the feeding point closest to the evaluation section is determined. For example, the high-frequency power density supplied to the feeding point 153h corresponding to (i.e., the nearest) the I-8 evaluation section is 1.1 W / cm ² . Regarding the other film forming conditions, the film forming condition candidates selected in the above (1-1) are determined as the final film forming conditions.
In the production of the solar cell panel of FIG. 1, the second cell layer 92 is formed under the determined final film formation conditions.

For example, in the electrode structure of FIG. 8, feed points 153 and 154 are provided above and below the discharge electrode 103. That is, feeding points 153 and 154 are arranged along the long side of the substrate. A high-intensity reflective region may occur corresponding to such a power feeding structure. Specifically, when the second cell layer 92 is formed, a high-brightness reflection region is generated at the two end portions on the long side of the substrate 1 but not at the center portion of the substrate 1, or at the center portion of the substrate 1. In some cases, a high-intensity reflective region is generated, and no high-intensity reflective region is generated at the two ends on the long side.
When the distribution of the high luminance reflection region obtained in the steps (1-4) and (1-7) corresponds to the power feeding structure, the phase of the high frequency power supplied to the discharge electrode 103 is modulated. The phase modulation is preferably used in combination with the adjustment of the high frequency power density.

  In order to set the final film-forming conditions of the high-frequency power density, it is preferable that the occurrence of the high-intensity reflective region is evaluated as A or B in all evaluation sections. There may be an evaluation section where the value does not fall below the predetermined value (3% in Table 1). In such a case, the high-frequency power density is further increased from the above upper limit within the range where the high-frequency power supply oscillates abnormally or the protection circuit does not operate due to thermal abnormality, etc. The condition for reducing the area ratio of the region is defined as the final film forming condition.

If the evaluation based on Table 1 does not achieve A or B in all evaluation sections even if steps (1-6) to (1-8) are performed, the flow returns to step (1-1) and another SiH ₄ gas flow rate is obtained. Is set as a film forming condition candidate. Alternatively, when the high-brightness reflection region is generated in an area exceeding the predetermined value in the entire substrate, the setting state of each component inside the thin film manufacturing apparatus is reset, or the film forming condition candidates selected in (1-1) above Will be re-selected. After reselection of conditions and resetting of the setting state, steps (1-2) to (1-8) are performed. In this case, steps (1-1) to (1-8) are repeated until final film forming conditions are determined.

  In the present embodiment, first, the validity of the film forming condition candidates can be determined. Since the adjustment is performed in consideration of the interference between the film forming conditions and the distribution of the film forming conditions in the substrate surface, the final film forming conditions are optimized over the entire surface of the substrate.

Second Embodiment
The film forming condition setting method according to the second embodiment will be described below. The second embodiment is a film forming condition setting method for optimizing the Raman peak ratio of the second cell layer 92. The film forming condition setting method of the second embodiment may be carried out alone or in combination with the film forming condition setting method of the first embodiment. In this case, it is preferable that the film forming condition setting of the second embodiment is performed after the film forming condition setting of the first embodiment is performed in consideration of work efficiency.
In the second embodiment, the film forming conditions for the second cell layer 92 are set by the following steps (2-1) to (2-7).

(2-1) Correlation between the area ratio of the acquisition SiH ₄ flow rate change amount and the high-brightness reflective regions of the correlation between the area ratio of the SiH ₄ flow rate change amount and the high-brightness reflective regions are acquired in advance.
The sample in which the crystalline silicon film is formed on the substrate is manufactured by increasing or decreasing the SiH ₄ flow rate with reference to the film forming condition candidate (1-1). Similarly, a sample in which a crystalline silicon film is formed by increasing or decreasing the SiH ₄ flow rate by a predetermined amount when the high frequency power density or the like is changed with respect to the film forming candidate conditions. By changing the high frequency power density or the like, a crystalline silicon film having different Raman peak ratios can be obtained even at the same SiH ₄ flow rate. With respect to this film formation, the crystalline silicon film may be formed on the first cell layer (amorphous silicon layer) or the intermediate contact layer as in the case of forming the solar cell panel of FIG. It may be formed directly on the top. In order to measure the Raman peak ratio, the correlation is preferably obtained using a test piece cut out from the large-area substrate as described above, for example, a small test piece of about 50 mm × 50 mm.

  For each sample, the area ratio of the high-intensity reflective region is acquired. The acquisition of the area ratio of the high-intensity reflective region in this step is the same as that in the above step (1-3). However, since the substrate is a small area substrate, it is not necessary to evaluate the substrate separately.

A Raman peak ratio is acquired for each sample formed at a SiH ₄ flow rate as a film forming condition candidate. The Raman peak ratio is a ratio of the Raman peak intensity Ic of the crystalline silicon phase near 520 cm ⁻¹ to the peak intensity Ia of the amorphous silicon phase near 480 cm ⁻¹ by measuring a Raman spectrum obtained by Raman scattering spectroscopy. / Ia.

The change rate of the SiH ₄ flow rate as a film forming condition candidate is set to 0%. For each Raman peak ratio, the change rate of the SiH ₄ flow rate from the film forming condition candidate is obtained, and a graph representing the correlation between the change rate of the SiH ₄ flow rate and the area ratio of the high-intensity reflective region is obtained. The case where the SiH ₄ flow rate increases is represented as +, and the case where the SiH ₄ flow rate decreases is represented as −.
FIG. 10 is an example of a graph representing the correlation. In this figure, the horizontal axis represents the area ratio of the SiH ₄ flow rate of increase, and the vertical axis the high-brightness reflective region when relative to the SiH ₄ flow rate of deposition conditions candidates in step (1-1). FIG. 10 shows the case where the Raman peak ratio is 3.0 to 3.5, 3.5 to 5.0, and 5.0 to 8.0 when the SiH ₄ flow rate change rate is 0%. In the example of FIG. 10, the Raman peak ratio of 3.5 to 5.0 is set as the design value. The set values of these Raman peak ratio ranges are appropriately set according to the Raman peak ratio required for the second cell layer 92, evaluation accuracy, and the like.

When the SiH ₄ flow rate change rate is 0%, even if the Raman peak ratio is different from 3.0 to 3.5, 3.5 to 5.0, or 5.0 to 8.0, the area ratio of the high brightness reflective region There is almost no difference with 1% or less. As can be seen from FIG. 10, the smaller the Raman peak ratio, the greater the area ratio of the high-brightness reflective region with a slight increase in the SiH ₄ flow rate. For example, when the SiH ₄ flow rate is increased by 3%, the area ratio of the high-intensity reflective region is about 6% in a crystalline silicon film having a Raman peak ratio of 3.0 to 3.5. On the other hand, when the Raman peak ratio is 3.5 to 5.0 and 5.0 to 8.0, it is 3% or less. When the SiH ₄ flow rate is increased by 6%, the crystalline silicon film having a Raman peak ratio of 3.5 to 5.0 has an area ratio of the high-intensity reflective region of about 8%, but the Raman peak ratio is 5.0 to 8 In the crystalline silicon film of 0.0, the area ratio is about 3%.

(2-2) Selection of Film Formation Condition Candidate Film formation condition candidates for forming the second cell layer 92 are selected. The film forming condition candidates selected in this step may be the same conditions as those in the step (1-1) of the first embodiment, or may be the final candidate conditions determined by the steps of the first embodiment.

(2-3) Film formation of crystalline silicon film under conditions where SiH ₄ flow rate is changed SiH ₄ flow rate is set to a value obtained by increasing 3% and 6% from the candidate film formation conditions, and other conditions are film formation As the same condition candidate, the second cell layer 92 is formed on the first cell layer 91 (or on the intermediate contact layer 5) of the substrate 1.
Here, the increase rate of the SiH ₄ flow rate was set to 3% and 6%. However, based on the acquired correlation graph, the design value of the Raman peak ratio and the case of deviating from the design value of the high luminance reflection region An increasing rate of the SiH ₄ flow rate is set so that a clear difference is made in the numerical value of the area ratio.

(2-4) Calculation of Area Ratio of High Brightness Reflection Area The area ratio of the high brightness reflection area of the second cell layer 92 formed by increasing the SiH ₄ flow rate by 3% and 6% from the deposition condition candidates is Calculated. The area ratio of the high-intensity reflective region is calculated for each evaluation section by dividing the substrate into a predetermined number of evaluation sections as the third division. The third division may be the same as or different from the first division in the step (1-3). In this step, the area ratio of the high luminance reflection region is calculated by the image processing described in the step (1-3).
In addition, by this step, the substrate in-plane distribution of the high-intensity reflective region when each SiH ₄ flow rate increase rate is set is acquired.

(2-5) Determination of Raman peak ratio The area ratio of the high-intensity reflective region when the SiH ₄ flow rate is increased by 3% and 6% is collated with the correlation obtained in the step (2-1). Thereby, the Raman peak ratio range in each evaluation section is acquired for the second cell layer 92 formed with the film forming condition candidates set in the step (2-2).

(2-6) Setting of final film forming conditions If the acquired Raman peak ratio range is a design value in all evaluation sections, the film forming condition candidates set in step (2-2) are the final film forming conditions. To be determined. In the production of the solar cell panel of FIG. 1, the second cell layer 92 is formed under the determined final film formation conditions.
If there is an evaluation section in which the estimated Raman peak ratio range is different from the design value, the film forming condition candidates set in step (2-2) are adjusted.

(2-7) Adjustment of film forming condition candidates When it is determined in step (2-6) that there is an evaluation section having a Raman peak ratio range different from the design value, the same as step (1-4) of the first embodiment By this method, the uniformity of the distribution of the high-intensity reflective region is determined.

When it is determined that the high-intensity reflective area is uniform, adjustment of the SiH ₄ flow rate or the SiH ₄ partial pressure is performed. Specifically, when the Raman peak ratio range is lower than the design value and the high-brightness reflection region is uniform, the SiH ₄ flow rate or the SiH ₄ partial pressure is reduced from the film forming condition candidates. When the Raman peak ratio range is higher than the design value and the high-brightness reflective region is uniform, the SiH ₄ flow rate or the SiH ₄ partial pressure is increased with respect to the film forming condition candidates. The amount of increase or decrease from the film forming condition candidates may be a predetermined value. Alternatively, it may be increased at a predetermined ratio with respect to the film forming condition candidates (specifically, within a range of −5% to 20% with respect to the film forming condition candidates).
After increasing or decreasing the SiH ₄ flow rate or the SiH ₄ partial pressure, the steps (2-2) to (2-6) are performed using the conditions as film forming condition candidates. The film forming condition candidates in this step are adjusted until it is determined that the Raman peak ratio range of the second cell layer 92 after adjusting the SiH ₄ flow rate or the SiH ₄ partial pressure satisfies the design value.

When it is determined that the high-intensity reflective area is non-uniform, the high-frequency power density is adjusted. The adjustment of the high frequency power density is performed in the same steps as the steps (1-6) to (1-8) of the first embodiment.
The substrate on which the second cell layer 92 is formed is divided into a predetermined number of evaluation sections as a fourth division. The fourth division may be the same as or different from the second division. At this time, as described in the step (1-7), it is preferable to divide the evaluation section based on the third division and the evaluation section based on the fourth division so that the adjustment accuracy is improved.

For each evaluation section, the high-frequency power density is adjusted so that the high-intensity reflection area is uniformly generated. Specifically, as in (1-8), the high frequency power density is increased or decreased in increments of 0.1 W / cm ^{2 with} respect to the candidate film forming conditions, and in increments of 0.05 W / cm ² near the candidate film forming conditions. The second cell layer 92 is formed by setting the value as described above. And the 2nd cell layer 92 is divided | segmented into a predetermined evaluation division, and the area ratio of the high-intensity reflective area | region in each evaluation division is acquired. In each evaluation section, the minimum high-frequency power density value at which the evaluation of the high-intensity reflective area is A is set as a high-frequency power density condition that is supplied to the feeding point closest to the evaluation section. Steps (2-2) to (2-6) are performed using the set conditions as film forming condition candidates. The film forming condition candidates in this step are adjusted until it is determined that the Raman peak ratio range of the second cell layer 92 after the high frequency power density adjustment satisfies the design value.

According to the present embodiment, the Raman peak ratio of the second cell layer 92 can be evaluated by a simple method. In addition, the film forming conditions for the second cell layer 92 having a desired Raman peak ratio are selected over the entire surface of the large-area substrate surface exceeding 1 m ² . For this reason, a high-performance photoelectric conversion device (solar cell panel) can be produced with a high yield, and the production efficiency can be improved.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Transparent electrode layer 3 Photoelectric conversion layer 4 Back electrode layer 5 Intermediate contact layer 6 Solar cell module 7 Power generation cell 31 Amorphous silicon p layer 32 Amorphous silicon i layer 33 Amorphous silicon n layer 41 Crystalline silicon p layer 42 crystalline silicon i layer 43 crystalline silicon n layer 50 solar cell panel 91 first cell layer 92 second cell layer 100 photoelectric conversion device 103 discharge electrode

Claims (5)

A film forming condition setting method for forming a film of the photoelectric conversion layer by supplying high-frequency power to a plurality of feeding points of a discharge electrode of the film forming apparatus in a photoelectric conversion device having a photoelectric conversion layer made of crystalline silicon on a substrate Because
Selecting a film forming condition candidate of the photoelectric conversion layer including at least a SiH ₄ flow rate and a high-frequency power density supplied to each of the plurality of feeding points;
Setting the SiH ₄ flow rate to a value increased at a predetermined rate with respect to the selected film forming condition candidate, and forming the photoelectric conversion layer on the substrate;
The photoelectric conversion layer formed by dividing the substrate on which the photoelectric conversion layer is formed into a predetermined number of evaluation sections in a first division and increasing the flow rate of the SiH ₄ for each of the evaluation sections in the first division. Calculating the area ratio of the high-intensity reflective region, and obtaining the distribution of the high-intensity reflective region on the substrate;
Determining the uniformity of the high-intensity reflective region generated in the photoelectric conversion layer based on the distribution;
When the distribution is determined to be uniform, the step of setting the film forming condition candidate as the final film forming condition;
Forming a final film-forming condition by adjusting the high-frequency power density supplied to the plurality of feeding points among the film-forming condition candidates when it is determined that the distribution is non-uniform Condition setting method. The step of adjusting the high-frequency power density supplied to the plurality of feeding points to set the final film forming conditions,
Setting the high-frequency power density to a value increased or decreased at a predetermined rate with respect to the selected film-forming condition candidates, and forming the photoelectric conversion layer on the substrate;
The photoelectric conversion formed by dividing the substrate on which the photoelectric conversion layer is formed into a predetermined number of sections in a second division and increasing or decreasing the high-frequency power density for each of the evaluation sections in the second division Calculating the area ratio of the high brightness reflective region of the layer;
For each evaluation section of the second division, the power supply closest to the evaluation section among the plurality of feeding points is set to the smallest value among the high-frequency power densities in which the area ratio of the high-intensity reflective region is a predetermined value or less. The film forming condition setting method according to claim 1, further comprising: setting the final film forming condition of the high-frequency power density supplied to a point. A film forming condition setting method for forming a film of the photoelectric conversion layer by supplying high-frequency power to a plurality of feeding points of a discharge electrode of the film forming apparatus in a photoelectric conversion device having a photoelectric conversion layer made of crystalline silicon on a substrate Because
When the ratio of the Raman peak intensity of the crystalline silicon phase to the Raman peak intensity of the amorphous silicon phase in the photoelectric conversion layer is defined as the Raman peak ratio, SiH _{4 is used} for the photoelectric conversion layer having an arbitrary Raman peak ratio. Obtaining a correlation between the flow rate change ratio and the area ratio of the high-intensity reflective region;
Selecting a film forming condition candidate of the photoelectric conversion layer including at least a SiH ₄ flow rate, a SiH ₄ partial pressure, and a high-frequency power density supplied to each of the plurality of feeding points;
Setting the SiH ₄ flow rate to a value increased at a predetermined rate with respect to the selected film forming condition candidate, and forming the photoelectric conversion layer on the substrate;
The photoelectric conversion layer formed by dividing the substrate on which the photoelectric conversion layer is formed into a predetermined number of evaluation sections in a third division and increasing the SiH ₄ flow rate in each of the evaluation sections of the third division. Calculating the area ratio of the high-intensity reflective region of
The SiH ₄ flow rate increased at a predetermined ratio with respect to the film forming condition candidate and the calculated area ratio of the high-intensity reflective region are collated with the correlation, and the photoelectric conversion layer of the formed photoelectric conversion layer Obtaining a Raman peak ratio for each of the evaluation sections;
When the Raman peak ratio acquired for each of the evaluation sections satisfies a design value, the step of setting the film forming condition candidates as final film forming conditions;
When the Raman peak ratio acquired for each of the evaluation sections is different from a design value, at least one of the SiH ₄ flow rate, the SiH ₄ partial pressure, and the high-frequency power density supplied to each of the plurality of feeding points. And a step of setting final film forming conditions by adjusting the film forming conditions. A step of setting final film forming conditions when the Raman peak ratio acquired for each of the evaluation sections is different from the design value,
Obtaining a distribution of the high-intensity reflective region on the substrate based on the calculated area ratio of the high-intensity reflective region;
Determining the uniformity of the high-intensity reflective region generated in the photoelectric conversion layer based on the distribution;
When it is determined that the distribution is uniform,
When the Raman peak ratio is higher than the design value, a value obtained by increasing the SiH ₄ flow rate with respect to the film formation condition candidates so that the Raman peak ratio of the photoelectric conversion layer satisfies the design value is obtained as a final product. A step of setting the film conditions;
When the Raman peak ratio is lower than the design value, a value obtained by reducing the SiH ₄ flow rate with respect to the film formation condition candidates is set to a final product so that the Raman peak ratio of the photoelectric conversion layer satisfies the design value. A step of setting the film conditions;
When it is determined that the distribution is non-uniform, the substrate on which the photoelectric conversion layer is formed is divided into a predetermined number of sections in a fourth division,
Calculating an area ratio of a high-intensity reflective region of the photoelectric conversion layer formed by increasing or decreasing the high-frequency power density for each of the evaluation sections of the fourth division;
For each evaluation section of the fourth division, the power supply closest to the evaluation section among the plurality of power supply points is set to the smallest value among the high-frequency power densities in which the area ratio of the high-intensity reflective region is a predetermined value or less. The film forming condition setting method according to claim 3, further comprising: setting the final film forming condition of the high-frequency power density supplied to a point.   It is a manufacturing method of the photoelectric conversion apparatus which has a photoelectric converting layer which consists of crystalline silicon on a board | substrate, Comprising: The last manufacture set by the film forming condition setting method of any one of Claim 1 thru | or 4 The manufacturing method of the photoelectric conversion apparatus which forms the said photoelectric converting layer on film | membrane conditions.

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