JP2010080829A - Cleaning device, method of manufacturing substrate, and solar battery element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for cleaning a substrate sufficiently cleaning the substrate bonded to a base, to provide a method of manufacturing the substrate, and to provide a solar battery element with improved yield and superior characteristics. <P>SOLUTION: The method of manufacturing the substrate includes a slicing step wherein a plurality of substrates are formed by slicing a block bonded to a slicing base, a cleaning step wherein the substrate bonded to the slicing base is soaked in a cleaning tub containing cleaning liquid to clean, and a peeling step wherein the substrate is peeled from the slicing base after cleaning. In the manufacturing method, the substrate is so soaked in the cleaning tub that the slicing base becomes a side, and the cleaning liquid is ejected into the tub to the side opposite to the side having the slicing base of the substrate, from a nozzle having a plurality of openings provided to the lower part of the cleaning tub. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cleaning device, a substrate manufacturing method, and a solar cell element.

  Conventionally, when a substrate made of a semiconductor material, a magnetic material, ceramics, or the like is manufactured, these materials are bonded to a base in a block state, and then the block is sliced using a wire saw. A plurality of substrates can be obtained by peeling the sliced block from the base.

Usually, a wire saw cut | disconnects a block, supplying the grinding fluid containing an abrasive grain. For this reason, a large amount of grinding liquid containing abrasive grains adheres to the substrate after slicing, and it is necessary to clean the substrate. Such cleaning of the substrate is usually performed by immersing a block bonded and fixed to the base in a liquid (cleaning liquid) in a tank of the cleaning apparatus. Some of the conventional cleaning apparatuses include a tank storing a plurality of types of cleaning liquids, and the substrate is cleaned by immersing the substrates in the plurality of types of cleaning liquids. (For example, see Patent Document 1).
Japanese Patent Laid-Open No. 10-22239

  However, the substrate manufacturing process is performed in a state where the sliced block is adhered to the base, so that there is a problem that the substrates are likely to stick to each other and sufficient cleaning is difficult. In particular, when a silicon substrate used for a solar cell element is manufactured, in recent years, the silicon substrate has been thinned to 200 μm or less, the substrates are easily stuck to each other, and time is required for cleaning, and work efficiency is deteriorated. Such a silicon substrate tends to reduce the yield when manufacturing the solar cell element, and such a solar cell element tends to cause a decrease in output.

  The present invention has been made in view of such problems, and is a substrate cleaning apparatus capable of performing sufficient cleaning with the substrate fixed to the base, a method for manufacturing the substrate, and a solar cell with improved yield and excellent characteristics. An object is to provide an element.

  The cleaning apparatus according to the present invention includes a tank for storing a liquid for cleaning a substrate row composed of a plurality of substrates having one side bonded to a base, and an end portion on the side of the substrate row not bonded to the base. And an opening for ejecting the liquid, and a nozzle provided in the tank.

  The substrate manufacturing method of the present invention includes a step of preparing a block bonded to a base and a nozzle having an opening for ejecting a cleaning liquid, slicing the block bonded to the base, and bonding the block to the base. A substrate row, a step of arranging the opening of the nozzle in the vicinity of an end of the substrate row not bonded to the base, and the cleaning liquid is ejected from the opening of the nozzle, Cleaning the rows and peeling the substrate row from the base to form a plurality of substrates.

  The solar cell element of this invention has the board | substrate which consists of a silicon | silicone manufactured by one of the above-mentioned manufacturing methods, and the semiconductor junction area | region and electrode which were formed in the said board | substrate.

  Since the present invention has the above-described configuration or process, the interval between the substrates located in the vicinity of the nozzle opening is widened during cleaning, and the cleaning liquid is sufficiently circulated between the substrates to sufficiently clean the substrates. Can do. For this reason, the yield of a board | substrate preparation process can be improved. In particular, when the substrate is made of silicon, the yield of an element process of a solar cell element manufactured using the silicon substrate is improved, and a solar cell element having excellent characteristics can be obtained.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Cleaning device)
FIG. 1 is a diagram showing a first embodiment of a step of cleaning a cut block in the substrate manufacturing process of the present invention, and FIG. 2 (a) is cut into the cleaning tank 5 shown in FIG. FIG. 2B is a schematic diagram showing a state in which the block 1 is arranged, and FIG. 2B is an enlarged view showing the sliced block and the nozzle 8 in FIG. 3 is a sectional view showing a block to be cut, FIG. 4A is a perspective view showing the cut block, and FIG. 4B is a sliced block of FIG. 4A. It is an enlarged view which shows the part fixed to the base.

  The cleaning apparatus of this embodiment cleans the cut block 1 as shown in FIG.

  The block 1 is obtained by cutting the end of an ingot made of a semiconductor material, a magnetic material, ceramics or the like so as to have a desired size. One side of the block 1 is fixed to the base 2 with an adhesive 3. By cutting such a block 1 with a wire saw or the like, as shown in FIG. 4 (a), the block 1 is divided into a plurality of substrates, and one side surface is bonded to the base 2. The substrate row is peeled from the base 2 to become a plurality of substrates 1a. In particular, when the block 1 is a silicon ingot, the end portion of a single crystal silicon ingot or a polycrystalline silicon ingot (semiconductor ingot) produced by a pulling method, a casting method, or the like is cut into the silicon ingot 1. Then, the silicon ingot 1 is fixed to the base 2 with the adhesive 3. Then, the silicon ingot 1 is divided into a thickness of 250 μm or less, more preferably 200 μm or less, thereby forming a substrate row bonded to the base 2. The silicon substrate row is peeled off from the base 2 to become a silicon substrate 1a used for the solar cell element.

  The base 2 has a role of fixing the block 1 and is made of a material such as a carbon material, glass, or resin. When the block 1 is sliced, a part of the base 2 is cut as shown in FIG.

  As the adhesive 3, an adhesive whose adhesive strength is lowered by raising the temperature is used in order to easily peel the substrate row from the base 2. Such an adhesive 3 is made of, for example, a thermosetting two-component epoxy type, an acrylic type, a reacrate type, or a wax. For example, when an epoxy system is used as the adhesive 3, it can be easily peeled off from the base 2 by heating the adhesive 3 to 80 ° C. or higher.

  The cleaning liquid 4 has a role of cleaning the substrate row stored in the cleaning tank 5 and bonded to the base 2. In FIG. 1, the substrate row bonded to the base 2 is continuously immersed and cleaned in a plurality of cleaning liquids 4 (4a, 4b). Here, for the plurality of types of cleaning liquids 4, the cleaning liquid 4 a that cleans the substrate row first removes rough dirt, and the cleaning solution 4 b that cleans the substrate row later cleans the previously cleaned substrate row. To do. For example, kerosene, neutral liquid, water, or alkaline liquid is used as the plurality of cleaning liquids 4. Further, any of nonionic, anionic and cationic surfactants may be contained. The alkaline solution has a pH of 9 to 14, and the neutral solution has a pH of 5 to 9. For example, when the ingot 1 is sliced with an oil-based cutting liquid used in a loose abrasive type wire saw apparatus, kerosene is used as the cleaning liquid 4 for cleaning the substrate row first, and the cleaning solution 4 for cleaning the substrate row later. An alkali solution can be used. Thereby, after removing the wrapping oil and silicon waste adhering to the substrate row with kerosene, the oil and dirt can be washed with the alkaline liquid. Further, when an alkaline liquid is used as the cleaning liquid 4 for cleaning the substrate row first, and hot water is used as the cleaning solution 4 for cleaning the substrate row later, the detergent and dirt can be removed with the hot water. Further, for example, when the ingot 1 is sliced with a water-soluble coolant used in an abrasive-fixed wire saw device, an aqueous solution or a neutral solution is used as the cleaning solution 4, and the water-soluble coolant attached to the substrate 1a. And dirt is washed.

  Among such cleaning liquids 4, the alkaline liquid is preferably managed with a Brix value. Here, the Brix value refers to the% concentration of the soluble solid contained in the aqueous solution. The Brix value can be measured by a digital refractometer, for example, measured by an Atago process (in-line) refractometer PRM-85. Since the alkaline liquid for cleaning the substrate row is managed by the Brix value, the sliced block 1 is difficult to peel from the base 2 in the cleaning process and the drying process.

  Here, the plurality of cleaning liquids 4 may be stored in one tank 5 for each liquid type. In this case, since each cleaning liquid is stored in one tank, the labor for carrying the cleaning object to the next processing step is reduced, and the manufacturing efficiency is improved.

  Moreover, the temperature of each of the plurality of cleaning liquids 4 may gradually increase. Moreover, in the process of being continuously immersed in the plurality of cleaning liquids 4 (4a, 4b), when the temperature of the cleaning liquid 4b used later is lower than the maximum temperature of the cleaning liquid 4a used earlier, the adhesive strength is increased by high-temperature cleaning. The lowered adhesive strength of the adhesive can be temporarily recovered, the fall of the substrate 1a from the base 2 can be suppressed, and the cleanliness of the substrate 1a can be increased.

  As shown in FIGS. 2A and 2B, the cleaning tank 5 includes a nozzle 8 having a plurality of openings 9 provided in the lower part of the tank 5. The nozzle 8 is provided in the vicinity of the surface of the substrate row opposite to the surface to which the slice base 2 is bonded. The opening 9 of the nozzle 8 ejects the cleaning liquid 4 to the substrate row. As a result, pressure is applied to the substrate 1a in the vicinity of the opening 9, the interval between the substrates 1a is widened, and the cleaning liquid 4 can easily enter between the substrates 1a. For this reason, the substrate 1a can be sufficiently cleaned.

  The length of one side of the substrate 1a is a, and when viewed from above the cleaning tank 5, the nozzle 8 is preferably located 1 / 3a or less from the side end 1b of the substrate 1a, and the center of the substrate 1a Compared with the case where the nozzle 8 is located in the portion, the interval between the substrates 1a can be sufficiently opened. Accordingly, sufficient cleaning can be performed and the cleaning time can be shortened.

  The diameter of the opening 9 of the nozzle 8 may be, for example, 1 mm or more and 2 mm or less, and the distance between the openings 9 may be 5 mm or more and 20 mm or less. Further, the pressure of the cleaning liquid 4 supplied into the nozzle 8 may be 0.04 MPa or more and 0.1 MPa or less.

  Further, when the side surface of the cleaning tank 5 is viewed from the side, the position where the nozzle 8 is arranged is a position that is separated from the lower end 1c of the substrate 1a by 5 mm or more and 30 mm or less, so that the substrates 1a more effectively. Can be opened, and the substrate 1a can be sufficiently cleaned.

(Substrate manufacturing method)
The substrate manufacturing method of the present embodiment includes a step of preparing a block 1 bonded to the base 2 and a nozzle 8 having an opening for ejecting a cleaning liquid, slicing the block 1 bonded to the base 2, and a base 2, a step of forming a substrate row bonded to the substrate 2, a step of disposing the opening 9 of the nozzle 8 in the vicinity of the end of the substrate row not bonded to the base 2, and ejecting a cleaning liquid from the opening 9 of the nozzle 8, A step of cleaning the substrate row, and a step of peeling the substrate row from the base 2 to form a plurality of substrates 1a.

≪Slicing process≫
First, the block 1 bonded to the base 2 with the adhesive 3 or the like is prepared. Next, one or a plurality of blocks 1 are arranged in the wire saw device. Here, the wire saw device can be roughly divided into two types of wire saw devices. For example, a loose abrasive type wire saw device that cuts the block 1 by the lapping action of the wire by supplying a cutting fluid containing abrasive grains, and an abrasive fixed type that cuts the block 1 by fixing the abrasive grains to the wire itself There is a wire saw device.

  The wire used in the loose abrasive type wire saw device may be, for example, a piano wire mainly composed of iron or an iron alloy, and the cutting fluid is, for example, abrasive grains such as silicon carbide, alumina, diamond, mineral oil, etc. The wrapping oil composed of a surfactant and a dispersing agent is mixed, and the cutting liquid is supplied evenly and evenly to a plurality of wires stretched from the supply nozzle. The wire diameter is 100 μm to 180 μm, more preferably 140 μm or less.

  The wire used in the fixed wire type wire saw device is, for example, a diamond wire made of diamond or silicon carbide is fixed to a piano wire mainly composed of iron or an iron alloy by plating with nickel, copper or chromium. Alternatively, an abrasive fixed wire fixed with a resin adhesive such as resin is used, and a water-soluble coolant made of glycol is supplied to the wire and block 1 for the purpose of temperature control during slicing and removal of silicon debris. Is done. The wire diameter is 100 μm to 180 μm, more preferably 140 μm or less.

≪Cleaning process≫
Next, the substrate row after slicing is cleaned with the cleaning liquid 4. In the cleaning process of the present embodiment, the sliced ingot 1 is set on the cleaning jig 6 so that the base 2 comes to the side, and is immersed in the cleaning liquid 4 and cleaned. When the cleaning liquid 4 is composed of a plurality of liquids, the cleaning liquid 4 is transported onto the adjacent tanks 5 by the transport device 7 and immersed in the cleaning liquid 4 for cleaning.

  For example, when slicing with an oil-based cutting liquid, after removing wrapping oil and silicon debris adhering to the substrate 1a with kerosene at room temperature to about 30 ° C., oil or dirt adhering to the substrate 1a is further removed with an alkaline solution. Finally, the alkaline liquid and dirt adhering to the substrate 1a are washed with warm water. Further, even when slicing is performed with an abrasive fixed wire saw device, the water-soluble coolant and dirt adhering to the substrate 1a are washed with an alkaline solution or a neutral solution. At this time, the substrate 1 a may be moved in the cleaning tank 5, put into and out of the cleaning liquid 4, the cleaning liquid may overflow, or ultrasonic cleaning may be performed. In addition, a plurality of cleaning tanks 5 having the same cleaning liquid 4 are prepared, and are sequentially transported and immersed in the transport device 7 to remove rough dirt in the first cleaning tank 5 and proceed to the next cleaning tank 5. As a result, the cleanliness of the substrate 1a can be increased, and the time of immersion in one cleaning tank 5 can be shortened to clean more substrates 1a. Further, shower cleaning may be performed before the substrate 1 a is put into the cleaning tank 5.

  In the substrate manufacturing method of the present embodiment, as shown in FIGS. 2A and 2B, the slice base of the substrate 1a is formed from the nozzle 8 having a plurality of openings 9 provided in the lower portion of the cleaning tank 5. The cleaning liquid 4 is jetted into the tank against the side surface opposite to the side surface to which 2 is bonded. Thereby, the substrate 1a can be sufficiently cleaned.

  Further, when the plurality of substrates 1a are moved in the longitudinal direction of the nozzle, a portion of the substrates 1a having a narrow interval can be positioned on the vicinity of the opening 9 to increase the interval between the substrates. Easy to wash sufficiently.

  As another embodiment, as shown in FIGS. 5A and 5B, a plurality of nozzles 8 including a first nozzle 8 a and a second nozzle 8 b can be provided in one cleaning tank 5. . The first nozzle 8a and the second nozzle 8b are each provided with an opening 9a and an opening 9b, and the opening 9a and the opening 9b are arranged so as not to be adjacent to each other in plan view. In the cleaning, the cleaning liquid 4 is not supplied to the second nozzle 8b, the cleaning liquid 4 is ejected from the first nozzle 8a, and then the supply of the cleaning liquid 4 to the first nozzle 8a is stopped, and the cleaning liquid 4 is supplied from the second nozzle 8b. This can be done by ejecting. As a result, sufficient cleaning can be performed by widening the interval between the substrates 1a located in the vicinity of the opening 9a of the first nozzle 8a, and then the interval between the substrates 1a located in the vicinity of the opening 9b of the second nozzle 8b is opened sufficiently. Therefore, the substrate row can be sufficiently cleaned.

  The number of nozzles 8 is not limited to two, but may be three or more in one cleaning tank 5, and the position of the opening 9 of the nozzle 8 is different as described above, and the timing of supplying the cleaning liquid 4 from the nozzle 8 is different. The same effect can be obtained by being different.

  Further, as another embodiment, as shown in FIGS. 6A and 6B, in the plurality of cleaning tanks 5 (first cleaning tank 5a and second cleaning tank 5b) having the same cleaning liquid 4, respectively. A first nozzle 8a and a second nozzle 8b can be provided. The first nozzle 8a and the second nozzle 8b are each provided with an opening 9a and an opening 9b, and the opening 9a and the opening 9b are arranged so as not to be adjacent to each other in plan view. The cleaning is performed in the first cleaning tank 5a with sufficient space between the substrates 1a located near the opening 9a of the first nozzle 8a, and then the second nozzle 8b is cleaned in the second cleaning tank 5b. Since sufficient cleaning is performed with an interval between the substrates 1a located in the vicinity of the opening 9b, the substrate 1a can be sufficiently cleaned. Note that the number of cleaning tanks having the same cleaning liquid is not limited to two tanks, and there may be three or more tanks, and the same effect can be obtained by changing the positions of the openings 9 of the nozzles 8 in the respective cleaning tanks 5 as described above. Can do. Further, the temperature of the cleaning liquid 4 may be increased every time the next cleaning tank 5 is reached, or the temperature of the last cleaning tank 5 is higher than the temperature of the first cleaning tank 5 by continuing the cleaning tank 5 at the same temperature. Thus, the temperature of the cleaning liquid 4 may be changed for each cleaning tank 5.

  Furthermore, when all the substrates 1a located in the openings 9a of the first nozzle 8a are different from all the substrates 1a located in the openings 9b of the second nozzle 8b, the openings 9 can be formed in a more dispersed manner. Therefore, the substrate 1a can be sufficiently cleaned.

  As the immersion time, the substrate 1a is immersed in one cleaning solution for 20 to 60 minutes.

≪Drying process and peeling process≫
Next, the substrate row cleaned in the above process is dried. Although vacuum drying or electromagnetic wave drying may be used, the substrate 1a can be peeled from the base by heating and drying to increase the temperature of the adhesive 3 as the substrate 1a is dried.

  As shown in FIG. 7, the substrate 1a is placed on the installation table 13 with the base 2 as a side surface, and the atmosphere is heated as shown in FIG. Blow toward the substrate 1a. The installation table 13 has a mesh shape. And heating temperature heats the temperature in atmosphere to 100 to 150 degreeC, for example, and heats air to 80 to 110 degreeC. The pressure of the air nozzle is 0.01 to 0.5 MPa, and the flow rate is 100 to 200 L / min. The drying time is 20 to 60 minutes.

  You may raise the temperature of the board | substrate 1a in heat drying. Further, by adjusting the time for blowing the substrate 1a in order by air, the temperature of the substrate 1a may be raised and then lowered or raised. The substrate 1a can be sufficiently dried by gradually raising the temperature of the substrate 1a while repeating this. Further, since the viscosity of the adhesive 3 is lowered when the substrate 1a is peeled from the base 2, it is possible to prevent the adhesive 3 from remaining on the substrate 1a side. Simply, when the temperature is raised, the viscosity of the adhesive 3 increases and the adhesive 3 remains on the substrate 1a.

  Finally, the substrate 1a can be peeled from the base 2 by heating to a temperature at which the adhesive 3 can be peeled, for example, 100 ° C. or higher. In addition, as a peeling direction, it can peel easily by applying a stress to the plane direction of the base 2.

  When the ingot 1 is made of silicon, the substrate 1a obtained by the above method is used as a solar cell element. The cleaned substrate 1a is formed as a solar cell element by etching a damaged layer on the surface of the substrate 1a generated by the slicing process with an alkaline aqueous solution (for example, NaOH aqueous solution) to form a semiconductor junction region and an electrode on the substrate 1a. .

  In addition, this invention is not limited to the said embodiment, Many corrections and changes can be added within the scope of the present invention.

  For example, the slicing process may be performed as it is without cutting the semiconductor ingot.

  Further, as a peeling method, the film may be peeled by dipping in an organic solvent such as hot water or methylene chloride.

Example 1
Embodiment 1 of the present invention will be described below.

≪Slicing process≫
First, an epoxy adhesive was applied to a slice base made of a glass plate, and a rectangular parallelepiped polycrystalline silicon block of 156 mm × 156 mm × 300 mm was placed on the slice base to cure the adhesive. Supplying lapping oil consisting of silicon carbide abrasive grains (# 1200), mineral oil, surfactant and dispersant to the wire (wire diameter: 120 μm), and slicing the block bonded to the slice base to produce a silicon substrate did. The thickness of the silicon substrate was 180 μm.

≪Cleaning process≫
Next, the silicon substrate manufactured in the above process was washed. The cleaning was performed in the following steps.

  First, two cleaning tanks having a cleaning liquid made of kerosene were provided, and a silicon substrate to which a slice base was bonded was immersed and ultrasonically cleaned. The temperature of kerosene was 30 ° C. in both tanks, and the total immersion time was 25 minutes.

  Next, five cleaning tanks having a cleaning liquid composed of an alkaline liquid containing a nonionic surfactant were provided, and the silicon substrate adhered to the slice base was immersed and ultrasonically cleaned. The temperature of the alkaline liquid was 60 ° C. for all 5 tanks, and the total immersion time was 40 minutes.

  Finally, four cleaning tanks having a cleaning liquid made of warm water were provided, and the silicon substrate to which the slice base was bonded was immersed and ultrasonically cleaned. The temperature of the hot water was 55 ° C. for all 4 tanks, and the total immersion time was 40 minutes.

  As an example of the present invention, a nozzle for ejecting a cleaning liquid was installed in each cleaning tank on the side surface opposite to the side surface to which the slice base of the substrate was bonded. In addition, cleaning was performed under the conditions (Examples 1 to 6) in which the distance from the lower end of the substrate was 3 mm, 5 mm, 10 mm, 20 mm, 30 mm, and 35 mm at the height of the nozzle. The nozzles provided in the cleaning tank having the same cleaning liquid are formed so that the positions of the openings are different. Further, as a comparative example, cleaning was performed in the case where the nozzle was not installed (Comparative Example 1) and in the case where the nozzle was installed in each cleaning tank at the center of the substrate (Comparative Example 2).

≪Drying process and peeling process≫
Finally, the silicon substrate cleaned in the above process was dried by heating. The temperature in the heating apparatus was 140 ° C., and the temperature of air blow was 90 ° C. Then, instead of measuring the temperature of the adhesive, the temperature of the slice base was measured and heated to 100 ° C., and the silicon substrate was peeled from the slice base.

  Under each condition, 10 silicon blocks were used, and the cleanliness of the silicon substrate in the cleaning process was confirmed. The cleanliness is an average value obtained by evaluating image processing for dirt, chips, abrasive residue, and the like attached when 10 silicon substrates are extracted from each silicon block, and a cellophane tape is attached to each silicon substrate and peeled off. . In addition, the cleanliness of all the cellophane tapes was set to 0, and the cleanliness of the cellophane tape was set to 1 if it was not dirty at all.

  The results are shown in Table 1.

  From Table 1, it was confirmed that the cleaning methods according to Examples 1 to 6 had higher cleanliness than the cleaning methods of Comparative Examples 1 and 2. Furthermore, by setting the height of the nozzle to 5 mm or more and 30 mm or less from the lower end portion of the substrate, the interval between the substrates can be further easily opened, and the cleanliness can be further increased.

It is a figure which shows one Embodiment of the washing | cleaning process of this invention. (A) is the schematic which shows a mode that the block 1 cut | disconnected in the washing tank 5 shown in FIG. 1 is arrange | positioned, (b) is an enlarged view which shows the sliced block 1 and the nozzle 8 of (a). It is. It is sectional drawing which shows the block which is a to-be-cut object. (A) is a perspective view which shows the cut | disconnected block, (b) is an enlarged view which shows the part fixed to the base among the sliced blocks of (a). (A) is the schematic which shows other embodiment of the washing | cleaning apparatus of this invention, (b) is the enlarged view seen from the top. (A) is other embodiment schematic of the washing | cleaning apparatus of this invention, (b) is the enlarged view seen from the top. It is a figure which shows one Embodiment of the drying process of this invention.

Explanation of symbols

1: Block 1a: Substrate 2: Slice base 4: Cleaning liquid 5: Cleaning tank 8: Nozzle 9: Opening

Claims (13)

A tank for storing a liquid for cleaning a substrate row composed of a plurality of substrates having one side bonded to the base;
A cleaning apparatus, comprising: an opening that is disposed near an end of the substrate row that is not bonded to the base and that ejects the liquid, and is provided in the tank.     The length of one side of the substrate is a, and the nozzle is arranged at a distance of 1 / 3a or less from the end of the substrate row when the tank is viewed in plan. The cleaning apparatus according to 1. The cleaning apparatus according to claim 1, wherein the nozzle is disposed 5 mm or more and 30 mm or less away from a lower end portion of the substrate when the tank is viewed from the side.
  The tank has a plurality of nozzles including a first nozzle and a second nozzle. When the tank is viewed in plan, the substrate closest to the opening of the first nozzle and the opening of the second nozzle The cleaning apparatus according to claim 1, wherein the closest substrate is different. The tank includes a first tank including a first nozzle and a second tank including a second nozzle,
The substrate closest to the opening of the first nozzle and the substrate closest to the opening of the second nozzle are different from each other when the tank is viewed in plan. A cleaning apparatus according to claim 1. A step of preparing a block bonded to the base and a nozzle having an opening for ejecting a cleaning liquid;
Slicing the block bonded to the base into a substrate row bonded to the base;
Disposing the opening of the nozzle in the vicinity of the end of the substrate row not bonded to the base;
Ejecting the cleaning liquid from the opening of the nozzle to clean the substrate row;
Separating the substrate row from the base to form a plurality of substrates.   7. The substrate row is cleaned by spraying the cleaning liquid from the opening of the nozzle after the substrate row bonded to the base is immersed in a tank in which a cleaning solution is stored. Substrate manufacturing method. 8. The method for manufacturing a substrate according to claim 6, wherein in the step of cleaning the substrate row, the space between the substrates is widened by the cleaning liquid.   The tank has a plurality of nozzles including a first nozzle and a second nozzle, and in the step of cleaning the substrate row, the first nozzle and the second nozzle respectively clean different substrates. The manufacturing method of the board | substrate in any one of Claims 6-8.   The tank has a plurality of nozzles including a first nozzle and a second nozzle, and in the step of cleaning the substrate row, the cleaning liquid is not ejected from the second nozzle while the cleaning liquid is ejected from the first nozzle. A method for manufacturing a substrate according to any one of claims 6 to 9.   The tank includes a first tank including a first nozzle and a second tank including a second nozzle, and in the step of cleaning the substrate row, the first nozzle and the second nozzle are respectively The substrate manufacturing method according to claim 6, wherein different substrates are cleaned.   The substrate manufacturing method according to claim 9, wherein a substrate located in the vicinity of the opening of the first nozzle is different from a substrate located in the vicinity of the opening of the second nozzle. A substrate made of silicon manufactured by the manufacturing method according to claim 6,
A solar cell element comprising a semiconductor junction region and an electrode formed on the substrate.

Images