JP3676725B2 - Manufacturing method of semiconductor device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a semiconductor device such as a solar cell using a semiconductor film. To the law It is related.
In particular, a method of manufacturing a semiconductor device when the semiconductor film is separated from the substrate and applied to the semiconductor device. To the law It is concerned.
[0002]
[Prior art]
A conventional method of manufacturing a semiconductor device using a semiconductor film will be described with reference to FIGS. 13 and 14 are schematic views showing a conventional method for manufacturing a semiconductor device disclosed in, for example, US Pat. No. 4,727,047 and US Pat. No. 4,816,420.
[0003]
In FIGS. 13 and 14, 100 is a substrate, 101 is an insulating film covering the substrate 100, and 1 is a semiconductor film.
[0004]
The substrate 100 and the semiconductor film 1 are made of gallium arsenide, and first, the surface of the substrate 100 shown in FIG. Next, as shown in FIG. 13B, openings are provided in stripes in the insulating film 101 to expose the surface of the substrate 100. Next, as shown in FIGS. 13C, 14A, and 14B, the semiconductor film 1 is crystal-grown using the exposed substrate surface as a nucleus.
[0005]
In the structure shown in FIG. 14B, the semiconductor film 1 is connected to the substrate 100 only at the opening of the insulating film 101, and therefore, the material of the insulating film 101 is configured to have a weak bond with the semiconductor film 1. Thus, by applying mechanical stress to the semiconductor film 1, the connecting portion with the substrate 100 can be broken and the semiconductor film 1 can be peeled off from the substrate 100 as shown in FIG.
[0006]
However, in this method, since the connecting portion with the substrate 100 is broken and the semiconductor film 1 is forcibly peeled off, it is not always possible to separate the semiconductor film 1 without damaging it, and the yield is increased. There was a problem of being bad.
[0007]
Next, a conventional semiconductor device manufacturing apparatus will be described with reference to FIG. FIG. 15 is a perspective view showing a conventional semiconductor device manufacturing apparatus.
[0008]
In FIG. 15, reference numeral 600 denotes a semiconductor wafer, 500 denotes an apparatus, and 501 denotes a groove into which the semiconductor wafer 600 is inserted. The apparatus 500 is configured to insert one semiconductor wafer 600 into each groove 501 and handle a total of 25 semiconductor wafers 600 simultaneously. Then, wet processing such as cleaning and etching and transport are performed with the semiconductor wafer 600 loaded.
[0009]
However, when a semiconductor device is manufactured by processing the semiconductor wafer 600 as used in a conventional semiconductor device, the semiconductor wafer 600 has a high mechanical strength, so the device as shown in FIG. Although it can be handled simply by holding the peripheral edge at 500, when a semiconductor film having a thickness of 100 μm or less is handled, the mechanical strength of the semiconductor film is weak, so the semiconductor device as shown in FIG. In 500, there was a problem that the semiconductor film was easily destroyed and the yield was poor.
[0010]
Next, a method for loading the semiconductor wafer 600 into the apparatus 500 will be described with reference to FIG. FIG. 16 is a diagram showing a state in which a semiconductor wafer is loaded in a conventional semiconductor device manufacturing apparatus.
[0011]
In FIG. 16, reference numeral 502 denotes a belt for transporting the semiconductor wafer 600, and shows a state in which the semiconductor wafer 600 is transported while being on the belt 502 and is carried into the groove 501 of the apparatus 500. Reference numeral 503 denotes a stage for moving the apparatus 500 up and down.
[0012]
However, in handling the semiconductor wafer 600, it is assumed that the semiconductor wafer 600 has sufficient mechanical strength. Therefore, also in this case, when a semiconductor film having a thickness of 100 μm or less is handled, the mechanical strength of the semiconductor film is weak, so that the device 500 easily breaks the semiconductor film and has a poor yield. was there.
[0013]
Further, a method for manufacturing a semiconductor device using another conventional semiconductor film will be described with reference to FIGS. FIG. 17 shows a semiconductor device using a semiconductor film having a structure in which a diffusion layer is provided at least around the through hole on the semiconductor film surface, the inner wall of the through hole reaching the back surface from the front surface, and the back surface of the semiconductor film. It is a figure which shows the conventional manufacturing method.
[0014]
17A to 17C, 1 is a semiconductor film, 2 is a through-hole provided in the semiconductor film 1, 3 is a diffusion layer provided in the semiconductor film 1, and 5 is a resist.
[0015]
FIG. 17A shows a state in which the diffusion layer 3 is provided on the surface of the semiconductor film 1, the inner wall of the through hole 2, and the back surface of the semiconductor film 1. After that, as shown in FIG. 17B, a resist 5 is applied to the front surface of the semiconductor film 1, the inner wall of the through hole 2, and the peripheral portion of the through hole 2 on the back surface of the semiconductor film 1, such as photolithography or screen printing. To form. Next, as shown in FIG. 17C, the semiconductor film 1 is immersed in an etching solution, and the diffusion layer 3 in a region other than the peripheral portion of the through hole 2 on the back surface of the semiconductor film 1 is etched. Thereafter, the resist 5 is removed, and an electrode is provided on the back surface of the semiconductor film 1 as shown in FIG.
[0016]
However, in this method, since it is necessary to form the resist 5 on both surfaces of the semiconductor film 1, it is difficult to handle the semiconductor film 1 in a state where the resist 5 is formed, and the productivity is extremely poor. there were. Further, since it is necessary to etch the semiconductor film 1 itself, there is a drawback that only the surface that has been damaged by etching can be obtained from which the diffusion layer 3 is removed. Incidentally, when dry etching is used, the resist 5 may be formed only on the back surface, but there is a problem that etching damage is further increased.
[0017]
FIG. 18 is a diagram showing a conventional semiconductor device having a structure in which a diffusion layer is provided at least around the through hole on the front surface of the semiconductor film, the inner wall of the through hole reaching the back surface from the front surface, and the back surface of the semiconductor film. The figure (a) is the figure seen from the back surface, the figure (b) is sectional drawing seen from the AA 'line shown to (a), and the figure (c) is from the BB' line shown to (a). Each cross-sectional view is shown.
[0018]
Since the electrodes 4A and 4B connected to the diffusion layer 3 are provided on the back surface of the semiconductor film 1, the diffusion layer 3 is formed on the back surface according to the pattern of the electrodes 4A and 4B as well as the peripheral portion of the through hole 2. . For this reason, the area of the diffusion layer 3 is increased, which hinders improvement in performance as a semiconductor device.
[0019]
In addition, through holes 2 are formed at equal intervals in the semiconductor film 1. The current-voltage characteristic representing the performance of this semiconductor device depends greatly on the resistance of the surface of the semiconductor film 1 in the through hole 2 and the interval between the through holes 2, and sufficient characteristics can be obtained unless these parameters are appropriately controlled. It was difficult to obtain a semiconductor device.
[0020]
[Problems to be solved by the invention]
Manufacturing method of semiconductor device using conventional semiconductor film as described above Law is As described above, there are problems in that the yield is poor and the productivity is poor.
[0021]
The present invention has been made to solve the above-described problems. The semiconductor film can be easily separated from the substrate, the semiconductor film can be easily handled, the yield can be improved, and the productivity can be improved. Semiconductor device manufacturing method The law The purpose is to obtain.
[0022]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a method for manufacturing a semiconductor device including a step of separating a semiconductor film formed on a substrate from the substrate. A through hole provided in the semiconductor film, after introducing hydrofluoric acid from the through hole reaching the release layer formed between the substrate and the semiconductor film and removing the release layer by etching, During the separation of the semiconductor film, the semiconductor film and the substrate are filled with water or an aqueous solution, Holding the substrate, The semiconductor film is separated by sliding along the substrate surface.
[0025]
Of this invention Claim 2 In the method for manufacturing a semiconductor device according to the present invention, the separated semiconductor film has a thickness of 100 μm or less, and the semiconductor film is made of a tetrafluoroethylene resin mesh having a mesh pitch of 0.5 mm or more and 2.5 mm or less from the front and back sides. It further includes a step of performing wet processing such as cleaning and etching in a state of being sandwiched and held.
[0026]
Of this invention Claim 3 The method for manufacturing a semiconductor device according to the present invention further includes a step of holding and transporting the separated semiconductor film having a thickness of 100 μm or less and floating the semiconductor film on the surface of water.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
A method for manufacturing a semiconductor device according to an embodiment of the present invention will be described with reference to FIG. 1A to 1C are schematic views for explaining a method for manufacturing a semiconductor device according to an embodiment of the present invention.
[0035]
In FIGS. 1A to 1C, 100 is a substrate, 10 is a release layer, 11 is water, 1 is a semiconductor film, and 2 is a through hole provided in the semiconductor film 1.
[0036]
For example, the substrate 100 is made of a single crystal silicon wafer, and the release layer 10 is made of a silicon oxide film formed by thermally oxidizing the substrate 100. Alternatively, the release layer 10 may be a silicon oxide film deposited by a technique such as CVD. The thickness of the single crystal silicon wafer is usually 625 μm when the diameter is 6 inches. The thickness of the release layer 10 is 1 μm, for example. The semiconductor film 1 is a polycrystalline silicon film deposited on the release layer 10 by a technique such as CVD. Furthermore, the electrical characteristics may be improved by enlarging the crystal grain size by means such as zone melting recrystallization or solid phase growth. When the semiconductor film 1 is used to form a solar cell, for example, the thickness of the semiconductor film 1 is preferably about 30 to 50 μm.
[0037]
FIG. 1A shows a state in which a through hole 2 reaching the peeling layer 10 is provided in the semiconductor film 1. In this state, this is immersed in hydrofluoric acid (not shown), hydrofluoric acid is introduced from the through-hole 2 to remove the peeling layer 10 by etching, and then washed with water, as shown in FIG. The space between the semiconductor film 1 and the substrate 100 is replaced with water 11. In this state, the water 11 acts like an adhesive between the semiconductor film 1 and the substrate 100, and the semiconductor film 1 cannot be easily peeled off from the substrate 100. Incidentally, even if it is left in this state or heated and dried to eliminate the water 11 between the semiconductor film 1 and the substrate 100, a bond is formed between them, and the semiconductor film 1 is naturally There will be no peeling.
[0038]
1B, when the substrate 100 is held and a lateral force is applied to the semiconductor film 1 along the surface of the substrate 100 as indicated by an arrow in the figure, The water 11 between the substrates 100 serves as a lubricant, and the semiconductor film 1 can be easily slid on the substrate 100. In this way, as shown in FIG. 1C, the semiconductor film 1 is pulled out from above the substrate 100 and separated from the substrate 100. According to this method, when the semiconductor film 1 is made of silicon, it can be easily separated to a thickness of 10 μm and a size of 10 cm square.
[0039]
In the first embodiment, when the semiconductor film 1 is separated, the semiconductor film 1 and the substrate 100 are filled with water 11 or an aqueous solution, and the semiconductor film 1 is slid along the substrate surface to be separated. is there. Therefore, the semiconductor film 1 can be separated without damage, the yield can be improved, and the productivity can be improved.
[0040]
Embodiment 2. FIG.
A semiconductor device manufacturing apparatus according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view showing an apparatus for realizing the method for manufacturing the semiconductor device shown in FIG.
[0041]
In FIG. 2, 21 is a first region, 22 is a second region, 23 is a step between the first region 21 and the second region 22, and 24 is a frame.
[0042]
A flat first region 21 and a second region 22 are formed as shown in FIG. 2 by spotting a flat Teflon (registered trademark) plate having a thickness of about 1 cm. . The first region 21 is uniformly spotted to a depth of about 2 to 3 times the thickness of the substrate 100, and the second region 22 is spotted slightly shallower than that. The first region 21 and the second region 22 are formed in areas that can accommodate the substrate 100 and the semiconductor film 1, respectively. The step 23 between the first region 21 and the second region 22 is set to be smaller than the thickness of the substrate 100 and larger than half the thickness of the substrate 100. Around the first area 21 and the second area 22, a part having no spot facing is left to be a frame 24.
[0043]
Next, a method for manufacturing a semiconductor device using the apparatus of FIG. 2 will be described. With the semiconductor film 1 as shown in FIG. 1B on the substrate 100, the substrate 100 is placed in the first region. In this state, the whole is immersed in water or wetted with water, and a force is applied to the semiconductor film 1 in the lateral direction to move to the second region 22. At this time, the substrate 100 is caught by the step 23 and cannot move to the second region 22, but since the step 23 is set smaller than the thickness of the substrate 100, the semiconductor film 1 on the substrate 100 is caught by the step 23. It can move smoothly without hindrance. When the semiconductor film 1 is completely moved to the second region 22, the separation of the semiconductor film 1 and the substrate 100 is completed. Therefore, the semiconductor film 1 can be separated without damage, the yield can be improved, and the productivity can be improved.
[0044]
At this time, the lateral force applied to the semiconductor film 1 may be applied, for example, by pressing the end of the semiconductor film 1 with a jig, or the entire surface of the semiconductor film 1 is softly pressed and applied by friction. May be. Alternatively, the semiconductor film 1 may be moved by gravity with the whole tilted. In this case, the movement of the semiconductor film 1 becomes smoother by applying vibration such as application of ultrasonic waves. Alternatively, the semiconductor film 1 may be moved from above the semiconductor film 1 toward the second region 22 by friction with water.
[0045]
In the second embodiment, the step 23 is set to be larger than half the thickness of the substrate 100 for the following reason. That is, the peripheral edge of the substrate 100 is usually chamfered, and the cross section has a slightly rounded shape. Therefore, if the step 23 is smaller than half of the thickness of the substrate 100, the substrate 100 rides on the step 23 when a force to move the semiconductor film 1 to the second region 22 is applied. This is because the semiconductor film 1 and the substrate 100 may not be separated from each other.
[0046]
Embodiment 3 FIG.
A semiconductor device manufacturing apparatus according to Embodiment 3 of the present invention will be described with reference to FIG. 3 is a schematic cross-sectional view showing a semiconductor device manufacturing apparatus according to Embodiment 3 of the present invention.
[0047]
In FIG. 3, 31 is a first space and 32 is a second space.
[0048]
The first space 31 and the second space 32 are configured by combining a plate material of tetrafluoroethylene resin or the like. The first space 31 is configured to be accommodated with the semiconductor film 1 attached to the substrate 100, and the second space 32 is configured to accommodate only the semiconductor film 1. The first space 31 is larger than the thickness of the substrate 100 and the semiconductor film 1, and the second space 32 is smaller than the thickness of the substrate 100 and larger than the thickness of the semiconductor film 1.
[0049]
In this state, when the peeling layer 10 is removed by etching by immersion in hydrofluoric acid, the force for fixing the semiconductor film 1 to the substrate 100 is lost, so that the semiconductor film 1 is second along the surface of the substrate 100 by gravity. It moves toward the space 32. Since the substrate 100 has a size that cannot move into the second space 32, only the semiconductor film 1 moves into the second space 32, and the semiconductor film 1 and the substrate 100 are separated. Therefore, the semiconductor film 1 can be separated without damage, the yield can be improved, and the productivity can be improved.
[0050]
Embodiment 4 FIG.
A semiconductor device manufacturing apparatus according to Embodiment 4 of the present invention will be described with reference to FIG. 4 is a schematic front view showing a semiconductor device manufacturing apparatus according to Embodiment 4 of the present invention.
[0051]
In FIG. 4, 31A is a first space, and 32A is a second space.
[0052]
In the third embodiment, the thickness of the first space 31 and the second space 32 is changed. In the fourth embodiment, as shown in FIG. In combination, when the semiconductor film 1 is smaller than the size of the substrate 100, the width of the second space 32A is configured to be smaller than the width of the first space 31A so that the semiconductor film 1 enters but the substrate 100 does not enter. Is.
[0053]
In this case as well, when the peeling layer 10 is etched and removed by immersion in hydrofluoric acid, the force for fixing the semiconductor film 1 to the substrate 100 is lost. And move toward the second space 32A. Since the substrate 100 has a size that cannot move into the second space 32A, only the semiconductor film 1 moves into the second space 32A, and the semiconductor film 1 and the substrate 100 are separated. Therefore, the semiconductor film 1 can be separated without damage, the yield can be improved, and the productivity can be improved.
[0054]
Embodiment 5 FIG.
A method for manufacturing a semiconductor device according to Embodiment 5 of the present invention will be described.
[0055]
In FIG. 1 showing the first embodiment, by removing hydrofluoric acid from the through hole 2 provided in the semiconductor film 1 and reaching the release layer 10 and removing the release layer 10 by etching, the semiconductor film 1 and The process of removing the bond with the substrate 100 has been described. At this time, it is generally known that the etching rate of hydrofluoric acid on the silicon oxide film depends on the temperature of hydrofluoric acid.
[0056]
By the way, since the narrow gap between the semiconductor film 1 and the substrate 100 must be etched through the narrow hole of the through hole 2, it takes a very long time until the etching is completely completed at room temperature. When the interval between the through holes 2 was 1 mm, it took about 1 day and night. The required time did not change greatly even when the size of the through hole 2 and the thickness of the release layer 10 were changed.
[0057]
On the other hand, increasing the temperature of hydrofluoric acid greatly shortened the time required to complete the etching. It has been found effective to raise the temperature to 50 ° C. or higher. Thereby, the etching was completed in 2 to 3 hours when the interval between the through holes 2 was 1 mm. Therefore, the semiconductor film 1 can be separated without damage, the yield can be improved, and the productivity can be improved.
[0058]
The reason why it is effective to raise the temperature to 50 ° C. or higher is considered as follows. That is, for one thing, the reaction becomes active and the etching speed itself increases. Secondly, the gas component generated by the etching is easily vaporized, becomes a bubble, pushes up the semiconductor film 1, widens the gap between the semiconductor film 1 and the substrate 100, and improves the flow of hydrofluoric acid. is there. This effect is more remarkable when the thickness of the semiconductor film 1 is smaller. Third, the viscosity of hydrofluoric acid is lowered, and the wraparound between the semiconductor film 1 and the substrate 100 is improved.
[0059]
Embodiment 6 FIG.
A semiconductor device manufacturing apparatus according to Embodiment 6 of the present invention will be described with reference to FIG. FIG. 5 is a schematic cross-sectional view showing an apparatus for realizing the semiconductor device manufacturing method according to the fifth embodiment.
[0060]
In FIG. 5, 51 is a first container filled with hydrofluoric acid 33, 52 is a second container filled with water 11, 53 is a heating device provided at the bottom of the second container 52, 54 Is a temperature control device that is connected to a heating device 53 and a temperature sensor (not shown) provided in the water, and includes a CPU, a ROM, a RAM, and the like. Reference numeral 510 denotes a lid of the first container 51, and 520 denotes a lid of the second container 52.
[0061]
The first container 51 and the second container are made of tetrafluoroethylene resin. Each is a seamless integrated product made by cutting from a tetrafluoroethylene resin block. The apparatus of Embodiments 2 to 4 is placed in the first container 51 and the required amount of hydrofluoric acid 33 is filled. The first container 51 is placed in the second container 52, and the required amount of water 11 is filled in the gap. The first container 51 has a lid 510, and the second container has a lid 520, which is hermetically sealed. In addition, the peripheral part of the lid | cover 510 is made to cover the 1st container 51 main body from the outer side. This is because when the water evaporated by heating falls as water droplets on the inner surface of the lid 510, it is mixed into the first container 51 through the gap between the lids 510, thereby reducing the concentration of hydrofluoric acid 33 inside. This is to prevent this.
[0062]
In this state, the water 11 in the container is heated by the heating device 53 in the second container 52, and the temperature is controlled by the temperature control device 54 so that the temperature becomes a constant value of 50 ° C. or more. As a result, the first container 51 is heated, and the hydrofluoric acid 33 in the first container 51 is indirectly heated. With this configuration, it is possible to prevent the hydrofluoric acid 33 that is the strongest acid from coming into direct contact with the heating device 53, enabling stable heating and reducing the amount of hydrofluoric acid 33 to the minimum necessary. It is possible to save the usage amount and use it effectively.
[0063]
Embodiment 7 FIG.
A semiconductor device manufacturing apparatus according to Embodiment 7 of the present invention will be described with reference to FIG. FIG. 6 is a schematic view showing a semiconductor device manufacturing apparatus according to the present invention.
[0064]
In FIG. 6, 61 is a tetrafluoroethylene resin mesh. Reference numeral 1 denotes a semiconductor film.
[0065]
The semiconductor film 1 is held in a gap surrounded by two sheets of a tetrafluoroethylene resin mesh 61. In this state, wet processing such as cleaning and etching is performed. The mesh pitch of the tetrafluoroethylene resin mesh 61 is 0.5 mm or more and 2.5 mm or less. The reason why the mesh pitch is 0.5 mm or more is that when the mesh pitch is smaller than this, water or the etching solution may not permeate due to surface tension.
[0066]
However, if the mesh pitch is too large, the stress applied to the semiconductor film 1 during processing increases. Considering a case where a 6-inch (150 mm) wafer is supported only by its peripheral edge as in a conventional manufacturing apparatus (see FIG. 15), the thickness of the 6-inch wafer is 0.625 mm, so the aspect ratio is 250. is there. When the same aspect ratio is considered for the semiconductor film 1 having a thickness of 100 μm, the mesh pitch is 25 mm. Considering the case where the safety factor is 10 times and the thickness of the semiconductor film 1 is 10 μm, the mesh pitch is 2.5 mm.
[0067]
Embodiment 8 FIG.
A method for manufacturing a semiconductor device according to the eighth embodiment of the present invention will be described with reference to FIG. FIG. 7 is a schematic diagram showing a method for manufacturing a semiconductor device according to the eighth embodiment of the present invention.
[0068]
In FIG. 7, 71 is water (water flow). In addition, 1 is a semiconductor film and 2 is a through hole.
[0069]
The semiconductor film 1 floats on the surface due to the surface tension of the water 71. At this time, the force that supports the semiconductor film 1 is applied to the entire contact surface between the semiconductor film 1 and the water 71, and the semiconductor film 1 is not broken by a local stress load. Therefore, the process yield is improved. In addition, since only the water 71 is in contact with the semiconductor film 1, there is an advantage that not only it can be easily moved to another place but also there is no contamination with impurities.
[0070]
Embodiment 9 FIG.
A semiconductor device manufacturing apparatus according to Embodiment 9 of the present invention will be described with reference to FIG. FIG. 8 is a schematic diagram showing a semiconductor device manufacturing apparatus according to Embodiment 9 of the present invention.
[0071]
In FIG. 8, 81 is a cassette and 82 is a stage. In addition, 1 is a semiconductor film, 2 is a through-hole, 61 is a tetrafluoroethylene resin mesh, and 71 is water.
[0072]
The semiconductor film 1 floats and is supported on the water 71 and is moved and conveyed according to the flow of the water 71. When the semiconductor film 1 moves to the position of the cassette 81, the stage 82 rises and is scooped up by the tetrafluoroethylene resin mesh 61 set in the cassette 81 and moves from the surface of the water 71 into the cassette 81. At this time, the force for supporting the semiconductor film 1 is always applied evenly to the entire surface of the semiconductor film 1, and the semiconductor film 1 is not destroyed by the local load stress applied to the semiconductor film 1. Therefore, the yield is improved and the productivity is improved.
[0073]
Embodiment 10 FIG.
A method for manufacturing a semiconductor device according to Embodiment 10 of the present invention will be described with reference to FIG. FIG. 9 is a schematic diagram for illustrating a method of manufacturing a semiconductor device according to the tenth embodiment of the present invention. It demonstrates below in order of a process according to a figure.
[0074]
As shown in FIG. 9A, the diffusion layer 3 is formed on the front and back surfaces of the semiconductor film 1 and the inner wall of the through hole 2. An insulating film 12 made of, for example, a silicon nitride film, a silicon oxide film, or a laminate of these is formed on the front and back surfaces of the semiconductor film 1 and the inner wall of the through hole 2.
[0075]
As shown in FIG. 9B, a resist (not shown) is provided on the opening peripheral edge of the back surface of the through hole 2, and the insulating film 12 is patterned by dry etching from the back surface side. As a result, the insulating film 12 remains on the peripheral edge of the opening on the back surface of the through hole 2 in accordance with the resist pattern.
[0076]
Thereafter, as shown in FIG. 9C, using this insulating film 12 as a mask, the diffusion layer 3 on the surface of the semiconductor film 1 is etched with, for example, an alkali solution such as sodium hydroxide or a mixed acid of hydrofluoric acid and nitric acid. And patterning.
[0077]
According to this method, the resist only needs to be formed on the back surface side of the semiconductor film 1, and the productivity and the yield are greatly improved.
[0078]
In addition, when this method is applied to a process of manufacturing a solar cell using the semiconductor film 1, for example, an antireflection film formed to reduce the reflection loss on the light incident surface of the solar cell is used as the insulating film 12. As a result, the number of steps in the process is simplified, and the productivity and yield are greatly improved. For example, a silicon nitride film can be used as the antireflection film. In many cases, before the antireflection film is provided, the surface of the semiconductor film 1 is thinly oxidized to form a silicon oxide film so that the surface is inactivated. It may be said that it is a laminated film.
[0079]
Embodiment 11 FIG.
A semiconductor device according to Embodiment 11 of the present invention will be described with reference to FIG. 10A and 10B are diagrams showing a semiconductor device according to an eleventh embodiment of the present invention, in which FIG. 10A is a diagram viewed from the back surface, FIG. 10B is a cross section viewed from the line AA ′ in FIG. These respectively show the cross section seen from the BB 'line of (a).
[0080]
Thus, when the insulating film 12 serves to inactivate the surface of the semiconductor film 1, the surface of the semiconductor film 1 is covered with the insulating film 12 as much as possible in terms of performance as a semiconductor device. desirable. By the way, considering a semiconductor film having a structure in which the electrode 4A on the diffusion layer 3 side is provided on the back side of the semiconductor film 1, in the conventional semiconductor device, the electrode 4A on the diffusion layer 3 side contacts the other region as described above. Therefore, it is necessary to form the diffusion layer 3 on the back surface of the semiconductor film 1 in accordance with the electrode pattern on the diffusion layer 3 side as well as the periphery of the opening of the through hole 2.
[0081]
On the other hand, in the embodiment shown in FIG. 10, the contact portion of the electrode 4A connected to the diffusion layer 3 to the diffusion layer 3 and the contact portion of the other electrode 4B to the semiconductor film 1 are excluded. The semiconductor film 1 is covered with an insulating film 12. Therefore, the formation of the diffusion layer 3 on the back surface of the semiconductor film 1 may be performed only at the peripheral edge of the opening of the through hole 2, and the area of the diffusion layer 3 can be reduced, thereby improving the performance of the semiconductor device. Further, when an antireflection film in the case of a solar cell is used as the insulating film 12 at this time, the number of processes is reduced and productivity and yield are improved.
[0082]
Embodiment 12 FIG.
A method for manufacturing a semiconductor device according to Embodiment 12 of the present invention will be described with reference to FIG. FIG. 11 is a schematic cross-sectional view for illustrating the method for manufacturing a semiconductor device according to the twelfth embodiment of the present invention. It demonstrates below in order of a process according to a figure.
[0083]
As shown in FIG. 11A, a second insulating film 112 made of, for example, a silicon oxide film is formed on the front and back surfaces of the semiconductor film 1 and the inner wall of the through hole 2.
[0084]
As shown in FIG. 11B, the second insulating film 112 is patterned according to the formation pattern of the diffusion layer 3. That is, the second insulating film 112 is etched by covering a portion other than the region where the diffusion layer 3 is formed with a resist (not shown).
[0085]
As shown in FIG. 11C, in this state, the diffusion layer 3 is formed by diffusion of impurities such as phosphorus.
[0086]
According to this method, it is not necessary to etch the semiconductor film 1 itself for patterning the diffusion layer 3, and the diffusion layer 3 is formed only at the peripheral edge of the opening of the through hole 2 on the back surface without damaging the surface. Can do it. The second insulating film 112 uses a silicon oxide film formed by CVD, which is convenient in terms of ease of formation and etching and consistency with other processes. In this case, light etching is usually performed with hydrofluoric acid diluted before impurity diffusion, but the silicon oxide film is also etched at that time. Therefore, it is desirable that the thickness formed as the second insulating film 112 be 1000 angstroms or more.
[0087]
In order to obtain the structure shown in FIG. 10, thereafter, the insulating film 12 is provided on the front and back surfaces of the semiconductor film 1 and the inner wall of the through hole 2, and the electrode 4 A connected to the diffusion layer 3 contacts the diffusion layer 3. The electrode 4B and the other electrode 4B connected to the diffusion layer 3 are covered with a resist, covering the portion other than the contact portion of the electrode 4B of the other electrode and the electrode 4B with the resist and etching the insulating film 12. It forms. As described above, the insulating film 12 at this time may be an antireflection film in the case of a solar cell.
[0088]
Embodiment 13 FIG.
As described above, the diffusion layer 3 is provided on the front surface of the semiconductor film 1, the inner wall of the through hole 2 reaching from the front surface to the back surface, and the peripheral portion of the opening of the through hole 2 of the semiconductor film 1, and the electrode connected to the diffusion layer 3 A semiconductor device having a structure in which both the electrode 4 and the other electrode 4 are provided on the back side of the semiconductor film 1 is fabricated. A current-voltage curve representing the performance when a solar cell is fabricated using this structure. FIG. 12 shows these curve factors.
[0089]
12A shows the arrangement pattern of the through-holes 2 in the case of a lattice pattern having a square as a minimum unit, and FIG. 12B shows the case of a pattern having an equilateral triangle as a minimum unit. In order to obtain sufficiently excellent performance as a solar cell, a value of about 0.78 or more is required as a fill factor. From this figure, in this case, the arrangement pitch of the through holes 2 is used in any case. Is 1.5 mm or less, and the resistance value between the front and back of the semiconductor film 1 of the through hole 2 is required to be 10Ω or less.
[0090]
In each of the above embodiments, the case where silicon is mainly used as the material of the substrate 100 and the semiconductor film 1 has been described. However, other materials may be used, and the same effect can be obtained.
[0091]
【The invention's effect】
As described above, the method for manufacturing a semiconductor device according to claim 1 of the present invention includes a step of separating a semiconductor film formed on a substrate from the substrate. A through hole provided in the semiconductor film, after introducing hydrofluoric acid from the through hole reaching the release layer formed between the substrate and the semiconductor film and removing the release layer by etching, During the separation of the semiconductor film, the semiconductor film and the substrate are filled with water or an aqueous solution, Holding the substrate, Since the semiconductor film is separated by sliding along the substrate surface, the semiconductor film can be easily separated without breaking, and the yield and productivity can be improved.
[0094]
Of this invention Claim 2 As described above, in the method of manufacturing a semiconductor device according to the present invention, the separated semiconductor film has a thickness of 100 μm or less, and the semiconductor film is made of a tetrafluoroethylene resin having a mesh pitch of 0.5 mm or more and 2.5 mm or less. Since it further includes a step of performing wet processing such as cleaning and etching while being held between the front and back with a mesh, the semiconductor film can be handled without being destroyed, and the yield and productivity can be improved. .
[0095]
Of this invention Claim 3 As described above, the method for manufacturing a semiconductor device according to the present invention has a thickness of the separated semiconductor film of 100 μm or less, and further includes a step of holding and transporting the semiconductor film floating on the surface of water. The semiconductor film can be handled without being destroyed, yield and productivity can be improved, and impurities are not contaminated.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a method for manufacturing a semiconductor device according to a first embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view showing a semiconductor device manufacturing apparatus according to a second embodiment of the present invention.
FIG. 3 is a schematic sectional view showing a semiconductor device manufacturing apparatus according to a third embodiment of the present invention.
FIG. 4 is a schematic front view showing a semiconductor device manufacturing apparatus according to a fourth embodiment of the present invention.
FIG. 5 is a schematic cross sectional view showing a semiconductor device manufacturing apparatus according to a sixth embodiment of the present invention.
FIG. 6 is a schematic view showing a semiconductor device manufacturing apparatus according to a seventh embodiment of the present invention.
FIG. 7 is a schematic view showing a method for manufacturing a semiconductor device according to an eighth embodiment of the present invention.
FIG. 8 is a schematic diagram showing a semiconductor device manufacturing apparatus according to a ninth embodiment of the present invention.
FIG. 9 is a schematic cross sectional view showing the method for manufacturing the semiconductor device according to the tenth embodiment of the present invention.
FIG. 10 is a diagram showing a semiconductor device according to an eleventh embodiment of the present invention.
FIG. 11 is a schematic cross sectional view showing the method for manufacturing the semiconductor device according to the twelfth embodiment of the present invention.
FIG. 12 is a diagram showing a current-voltage characteristic curve of a semiconductor device according to Embodiment 13 of the present invention.
FIG. 13 is a schematic view showing a conventional method for manufacturing a semiconductor device.
FIG. 14 is a schematic view showing a conventional method for manufacturing a semiconductor device.
FIG. 15 is a diagram showing a conventional semiconductor device manufacturing apparatus;
FIG. 16 is a diagram showing a conventional semiconductor device manufacturing apparatus;
FIG. 17 is a diagram showing a conventional method for manufacturing a semiconductor device.
FIG. 18 is a diagram showing a conventional semiconductor device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Semiconductor film, 2 Through-hole, 3 Diffusion layer, 4A, 4B electrode, 10 Release layer, 11 Water, 12 Insulating film, 21 1st area | region, 22 2nd area | region, 31, 31 A 1st space, 32, 32A second space, 61 4 mesh made of ethylene fluoride resin, 100 substrate, 112 second insulating film.

Claims (3)

In a method for manufacturing a semiconductor device including a step of separating a semiconductor film formed on a substrate from the substrate,
A through hole provided in the semiconductor film, after introducing hydrofluoric acid from the through hole reaching the release layer formed between the substrate and the semiconductor film and removing the release layer by etching, When separating the semiconductor film, water or an aqueous solution is filled between the semiconductor film and the substrate, the substrate is held, and the semiconductor film is slid along the substrate surface to be separated. A method for manufacturing a semiconductor device. The separated semiconductor film has a thickness of 100 μm or less, and the semiconductor film is washed with a tetrafluoroethylene resin mesh having a mesh pitch of 0.5 mm or more and 2.5 mm or less and held between the front and back sides, The process of wet processing such as etching
The method of manufacturing a semiconductor device according to claim 1 , further comprising : The separated semiconductor film has a thickness of 100 μm or less, and the semiconductor film is held on a surface of water and transported.
The method of manufacturing a semiconductor device according to claim 1 , further comprising :

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