JPH0779007A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing a semiconductor device which can properly divide and eliminate semiconductor films deposited across a plurality of regions without generating a residue and the like in its adjacent gap. CONSTITUTION:A semicoductor device comprises in such a way that a laser beam LB is irradiated in pulses from another main surface side of a substrate 10, on which semiconductor films are formed, to parts of the semiconductor films 12a, 12b, 12c... deposited across a plurality of regions, which are to be divided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device using a laser beam.

[0002]

2. Description of the Related Art Solar cells, one-dimensional photosensors, and the like exist as semiconductor devices having a semiconductor film as a photoactive layer.

FIG. 1 shows the basic structure of a solar cell, which is disclosed in US Pat. No. 4,281,208 and has already been put into practical use. (1) has an insulating property and a light-transmitting property such as glass and heat-resistant plastic. Substrate, (2a) (2b) (2c) ... is the substrate
(1) Transparent electrode film deposited on the upper surface at regular intervals, (3a) (3b)
(3c) ... Amorphous semiconductor film such as amorphous silicon superposed and deposited on each transparent electrode film, and (4a) (4b) (4c) ... superposed and deposited on each amorphous semiconductor film. The transparent electrode films (2a), (2b), (2c), ..., Or the back electrode film (4a) that are partially overlapped with the transparent electrode films (2b), (2c) ... ) (4
b) (4c) ... Each photoelectric conversion region (5a) (5b) (5
c) ... is configured.

Each of the amorphous semiconductor films (3a) (3b) (3c) ...
When a light is incident through the transparent substrate (1) and the transparent electrode films (2a) (2b) (2c) ... in sequence, for example, a PIN junction parallel to the film surface is included therein. Occur. Photoelectromotive force generated in each of the amorphous semiconductor films (3a) (3b) (3c) ... Is added in series by the connection with the back electrode films (4a) (4b) (4c).

In the solar cell having such a structure, a photographic etching technique which is excellent in fine workability is usually used. In the case of this technique, the step of depositing the transparent electrode film on the entire surface of the substrate (1) and the separation of the individual transparent electrode films (2a) (2b) (2c) ... A step of removing adjacent space portions of the electrode films (2a) (2b) (2c) ..., a step of depositing an amorphous semiconductor film on the entire surface of the substrate (1) including the respective transparent electrode films, and a photoresist. And individual amorphous semiconductor films (3a) (3b) (3c) by etching.
Of the amorphous semiconductor films (3a) (3b) (3c) ...

However, although the photo-etching technique is excellent in fine processing, it tends to cause defects in the amorphous semiconductor film due to peeling of the photoresist defining the etching pattern at the pinholes or at the peripheral edge.

The prior art disclosed in Japanese Patent Application Laid-Open No. 57-12568 is to provide the above-mentioned adjacent intervals by burning off the film by irradiating a laser beam. The technique, which does not use at all and is rich in fine workability, is extremely effective in solving the above problems.

However, as described above, the laser processing which does not use any wet process is extremely effective in terms of the fine workability, but as shown in the enlarged view of each of the photoelectric conversion regions in FIGS. (5a) (5b) ... Amorphous semiconductor film or backside electrode film continuously deposited on each region (5a) (5b)
... Adjacent spacing by laser beam irradiation to divide each
When the semiconductor film or the back electrode film located at (3 ′) or (4 ′) is removed, a melted material of the amorphous semiconductor film or the back electrode film or the like is formed in the adjacent space (3 ′) or (4 ′). Residue of
(6) or (7) remains in the vicinity of the removed portion or cannot be accurately removed in a predetermined pattern. The residues (6) and (7) due to the non-removal remain particularly on both side surfaces in the scanning direction of the laser beam. The residues (6) and (7) remaining on the both side surfaces have a normal distribution although the energy density distribution in the laser beam is small, so that the both side surfaces of the adjacent spacing portions (3 ′) (4 ′) are Is a low energy distribution, which is considered to be the result. Regardless of the cause, if the residues (6) and (7) are present in the adjacent gaps (3 ′) (4 ′) to be removed, the residue (6) of the amorphous semiconductor shown in FIG. The reason why the adhesion strength of the back surface electrode films (4a) (4b) deposited on the semiconductor films (3a) (3b) after the division is reduced, and finally the back surface electrode films (4a) (4b) are peeled off Also, in the case of the residue (7) on the back surface electrode film in FIG. 3, the transparent electrode film (2b) and the back surface electrode film (4b) in the same photoelectric conversion region (5b) are in direct contact with each other, resulting in a short circuit accident. Become.

Further, adjacent photoelectric conversion regions (5a) (5b) ...
In order to connect the two in series, the exposure length (D) of the transparent electrode film (2b) exposed from the adjacent amorphous semiconductor film (3b) as shown in FIG. It must be increased without reducing it.
Heretofore, in order to satisfy such a demand, the scanning speed of the laser beam is slowed down or the number of times of scanning is increased to deal with it.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its first object is to cause a peeling accident of a back electrode film in a solar cell. In a one-dimensional optical sensor in which a plurality of sensor areas are arranged one-dimensionally, an energy beam such as a laser beam that does not include a wet process despite suppressing the formation of a residue that causes a reduction in pattern accuracy. To enable the use of.

A second object of the solar cell is
It is intended to make the semiconductor film have a low processing power so as to have a wide working width and to appropriately increase the size of the serial connection portion.

[0012]

The method of manufacturing a semiconductor device according to the present invention is characterized in that a semiconductor film deposited over a plurality of regions on one main surface of a transparent substrate should be divided. A plurality of semiconductor films are formed by irradiating the adjacent spacing portion with a laser beam having a wavelength of about 0.53 μm from the other main surface side of the substrate in a pulsed manner to remove the semiconductor film located in the adjacent spacing portion. It is to divide into each area.

[0013]

According to the manufacturing method of the present invention, the semiconductor film deposited over a plurality of regions is irradiated with the laser beam from at least the other main surface side of the substrate. The semiconductor film can suppress the peeling accident of the back electrode film in the case of a solar cell, or the formation of a residue that causes a reduction in pattern accuracy in a one-dimensional optical sensor, and does not include a wet process. Enable the use of laser beams.

Further, by irradiating a laser beam having a wavelength of about 0.53 μm in a pulsed manner by reversing the conventional irradiation direction, the processing width of the semiconductor film can be widened with a low output. In the case of electrically connecting in series in the gap portion, the scanning speed of the laser beam can be increased or the number of times of scanning can be reduced, and the productivity can be improved.

[0015]

Embodiments FIGS. 4 to 9 show an embodiment of the manufacturing method of the present invention in the order of steps. In the process of FIG. 4, a substrate such as transparent glass having a thickness of 1 mm to 3 mm and an area of 10 cm × 10 cm to 40 cm × 40 cm.
(10) A transparent electrode film (11) made of tin oxide (SnO ₂ ) having a thickness of 2000Å to 5000Å is deposited on the entire upper surface.

In the process of FIG. 5, the adjacent gaps (11 ') are removed by the irradiation of the laser beam, and the individual transparent electrode films are removed.
(11a) (11b) (11c) ... Are separated and formed. The wavelength of the laser used is such that it is hardly absorbed by the substrate (10), and a pulse output type with a wavelength of 0.35 μm to 2.5 μm is preferable for the above glass. Such a preferred embodiment has a wavelength of about 1.06 μm, an energy density of 13 J / cm ² , and a pulse frequency of 3K.
It is a Nd: YAG laser of Hz, and the interval (L ₁ ) between the adjacent interval parts (11 ′) is set to about 100 μm.

In the process of FIG. 6, each transparent electrode film (11a) (11b)
(11c) ... The entire surface of the substrate (10) including the surface of the amorphous silicon (a) having a thickness of 5000 Å to 7000 Å that effectively contributes to photoelectric conversion.
An amorphous semiconductor film (12) such as -Si) is deposited. Such a semiconductor film (12) contains inside it a PIN junction parallel to the film plane, so more specifically, firstly P-type amorphous silicon carbide is deposited, then I-type and N-type non-crystalline silicon. Amorphous silicon is sequentially deposited.

In the step shown in FIG. 7, the adjacent spacing portions (12 ') are removed by laser beam irradiation from the other main surface side of the substrate (10) as shown by an arrow, and each individual amorphous semiconductor film ( 12a)
(12b), (12c) ... Are separated and formed. It is appropriate that the laser used has a wavelength band that is relatively absorbed by the amorphous semiconductor film (12). For example, the amorphous silicon (a) as in this embodiment is used.
As shown in Fig. 10, the absorption characteristics of the (Si) system are high in the ultraviolet region and the visible light region (α), and the optimum glass transmittance (T) as a material for the substrate (10) is about 0.35 µm or more. About 90%
From the above, a pulse output type laser having a wavelength of about 0.35 μm or more in the ultraviolet region and visible light region is suitable, and for example, a pulse output type laser having a wavelength of 0.53 μm included in the above wavelength region is used. Incidentally, the upper limit wavelength of the visible light region is the wavelength 1.06 disclosed in the prior art JP-A-57-12568.
The absorption coefficient is high with respect to μm, and its value is 10 ⁴ cm ^-1, which is about 0.
It is around 78 μm, and the transmittance (T) of glass is a characteristic of Pyrex (registered trademark) of Corning Incorporated, model number “7740”.

Therefore, in such a process, the wavelength is set to about 0.
It is preferable to irradiate the laser beam in the ultraviolet region and the visible light region of 35 μm to 0.78 μm in a pulsed manner.

The irradiation conditions of the pulse output type laser having the wavelength of 0.53 μm as described above are such that the pulse repetition frequency is 4 KHz, the energy density is 0.7 J / cm ² , and the distance (L ₂ ) between the adjacent interval portions (12 ′) to be removed is It is set to about 300 μm to 500 μm.

It should be noted that the irradiation direction of the laser beam should be noted in the irradiation of the laser beam.
2 ') ... Amorphous semiconductor not on the exposed surface side of the amorphous semiconductor film (12), but on the adhered interface side with the transparent electrode films (11a) (11b) (11c). Membrane (12) ... substrate as possible from the side
It is done from the other principal surface side of (10). That is,
Conventional laser beam irradiation is performed from the exposed surface side, and therefore the removal in the thickness direction is also gradually evaporated and removed from the exposed surface side.Therefore, if the laser beam has a normal type energy density distribution, The removed cross section of the part (12 ') also became a shape close to the normal type, and residues were generated on both sides due to unremoved as shown in Fig. 2. When irradiated from the other main surface side, the laser beam is emitted from the substrate (10) and the transparent electrode film (11a) (11a).
b) (11c) ... penetrates the transparent electrode film (11a) (11b) (11
It reaches the amorphous semiconductor film (12) deposited on the interface with (c), and tries to remove the film of the adjacent gap portion (12 ') to be removed from the deposition surface. At that time, the amorphous semiconductor film (12) melted by the laser beam irradiation is, of course, the substrate (10), the transparent electrode films (12a) (12b) (12c) ... and the amorphous material which has not yet been melted. Located in the adjacent space portion (12 ') surrounded by the semiconductor film (12). Therefore, the molten state of the amorphous semiconductor film melted from the interface progresses while expanding from the interface toward the exposed surface (surface), and when the film thickness becomes extremely thin, the melt becomes thin. The membrane breaks down and most of it dissipates into the atmosphere. As a result, little residue is present after processing. Above all, the wavelength is about 0.35
Irradiating the laser beam in the range of μm to 0.78 μm in a pulsed manner can sufficiently absorb the laser beam on the transparent electrode film side of the amorphous semiconductor film (12), which is the irradiation target, and Since the temperature difference between the laser beam irradiation side surface and the back surface of the high quality semiconductor film (12) can be increased, the temperature difference between the interface and the exposed surface becomes large, and the effective melting occurs.

FIG. 11 is a conceptual diagram showing the principle of the method of the present invention. In FIG. 11, (LA) is a laser device, and the laser beam (LB) leaving the laser device (LA) is a reflecting mirror. (R
M), objective lens (OL), substrate (10) and transparent electrode film (11)
It reaches the amorphous semiconductor film (12) which is the film to be processed through. On the other hand, in the conventional method, as shown in FIG.
Laser beam (LB) whose beam diameter is adjusted by (OL)
Irradiates the surface of the amorphous semiconductor film (3) as the film to be processed directly without penetrating the substrate (1) and the transparent electrode film (2).

The difference in the processing characteristics of the laser beam (LB) will be described below based on theoretical calculation and experimental results.

13, 14 and 15 show a laser beam (LB) from the other main surface side of the substrate (10) on which the method of the present invention is applied to the amorphous silicon-based amorphous semiconductor film (12). Absorption rate (A), reflectance (R), and transmittance (T) intensities upon irradiation are optically analyzed using the film thickness of the transparent electrode film (11) as a parameter and plotted. The horizontal axis represents the film thickness of the amorphous semiconductor film (12), and the vertical axis represents each intensity. That is, the film thickness (Ttco) of the transparent electrode film (11) of FIG. 13 is about 2100Å, and
Those of 15 are about 2800Å and about 3300Å, respectively, and the above-mentioned film thickness is in a range used as a transparent electrode film (11) of a usual photovoltaic device. As a result of such theoretical calculation, the amorphous semiconductor film (1
Although the absorption characteristics of the laser beam in 2) vary depending on the film thickness of the transparent electrode film (11) provided on the irradiation surface side, the amorphous semiconductor film (12) has the lowest absorption rate (A) in FIG. ) For practical use as a photoactive layer is about 5000Å or about 4000
Absorption characteristics of about 64% above Å, and 99% at the highest in Fig. 13.

On the other hand, FIG. 16 shows the absorptance (A), reflectance (R) and transmittance (a) when the amorphous semiconductor film (3) according to the conventional method is irradiated with a laser beam (LB) from its exposed surface. The relationship between each intensity of T) and the film thickness of the transparent electrode film (2) is shown. That is, when the film thickness of the amorphous semiconductor film (3) is set to 5000 Å which can be practically used as a photoactive layer, the strength of any of A, R, and T is the film thickness of the lower transparent electrode film (2). It turns out that it doesn't depend on.

FIG. 17 shows that, in the conventional method from FIG. 16, in the irradiation of the laser beam (LB) of the amorphous semiconductor film (3), any intensity of A, R, and T is applied to the transparent electrode. As a result of clarification that the film thickness does not depend on the film thickness of the film (2), the film thickness dependence of the amorphous semiconductor film (3) when the film thickness (Ttco) of the transparent electrode film (2) is fixed to 2000Å Is a theoretical calculation.

FIG. 18 shows the substrate (10), the transparent electrode film (11) and the amorphous semiconductor film (12) to be processed, that is, the amorphous semiconductor film (12), which have the same structure as FIG. 13 is a comparative example when a laser beam (LB) is irradiated based on the principle of the method of the present invention in FIG. The laser used and the other laser conditions are the same for both, and only the irradiation direction of the laser beam (LB) is different. Thus, in the method of the present invention, the absorption rate (A) in the amorphous semiconductor film (12) is 90% in the practical film thickness.
Therefore, it is possible to process at a lower output than the conventional method.

19 and 20 are simulations of the temperature distribution when the laser beam (LB) is irradiated with the energy density based on the reflectance and the absorptance obtained in FIGS. 18 and 17. . In the斯Ru simulation, energy density of at laser beam to the present invention the method of FIG. 19 is set to 0.351J / cm ^2, also that of the conventional method of FIG. 20 is a 0.559J / cm ^2, the present invention Although the method has a lower energy density, the temperature rises after the elapse of the same time from the start of laser beam (LB) irradiation are almost the same in both cases.

When the laser beam (LB) is actually irradiated on the basis of the above theoretical calculation, the energy density and the processing width (removal width) of the amorphous semiconductor film (12) are compared with the method of the present invention and the conventional method. 21 and 22 show comparative examples. That is, FIG. 21 shows an amorphous silicon-based amorphous semiconductor film (12) with a film thickness of about 6000 Å.
Shows the relationship between the threshold energy density of the laser beam and the scanning speed necessary to remove the already formed transparent electrode film (11) without causing thermal damage, and as shown in the figure, the substrate ( The method of the present invention in which the laser beam is irradiated from the other main surface side of 10) requires an energy density of about 1/2. Further, FIG. 22 shows how much the semiconductor film (12) can be processed (removed) with respect to the amorphous semiconductor film (12) by one scanning of the laser beam (LB), and under the same conditions. Therefore, it can be seen that the method of the present invention can perform wide processing. That is, such wide processing is performed by setting the exposure length of the transparent electrode (2b) (or (11b) in the embodiment of the present invention) indicated by the symbol D in FIG. 2 to the scanning speed of the laser beam (LB). This means that a product having a sufficient length can be obtained without delaying the scanning or stopping the scanning a few times, and the productivity can be improved.

The laser commonly used in such experiments is a pulse output type laser having a repetition frequency of 4 KHz and a wavelength of 0.53 μm.

FIG. 23 and FIG. 24 are schematic views of micrographs obtained by scanning the amorphous semiconductor film (12) once with a pulsed laser beam by the method of the present invention and the conventional method, Amorphous semiconductor film where both are in the same direction (12)
From the exposed surface side of. In both figures, the laser used is a pulse output type laser with a wavelength of 0.53 μm as described above, the conditions such as laser output and scanning speed are the same, and only the irradiation direction of the laser beam (LB) is 23 according to the method of the present invention is different only in that it is the other main surface side of the substrate (10) as shown in FIG.

In this way, despite the fact that the laser processing was performed under the same conditions except for the irradiation direction, a clear processing interface without residue was obtained and the processing (removal) width was also obtained in the method of the present invention. It can be understood that a wide range can be obtained. Furthermore, the generation of the heat-affected layer, which has been conventionally seen at the processing interface, is suppressed.

Thus, as described above, the amorphous semiconductor film (12a)
(12b), (12c), etc. are individually and clearly separated by irradiation with a laser beam (LB) from the other main surface side of the substrate (10) as shown in FIG. ) (12b) (12c) ... and transparent electrode films (11a) (11b) (11c) ...
(10) An aluminum single-layer structure having a thickness of about 4000 Å to 2 μm on the entire upper surface, a double-layer structure of titanium or titanium silver on the aluminum, and a double-layered back electrode film (13). ) Is deposited. (FIG. 8) In the final step of FIG. 9, the adjacent gap portion (13 ′) is removed by irradiation with the laser beam (LB), and the individual back electrode films (13a) (13b) (13c) ...
Is formed. As a result, each photoelectric conversion area (14a) (14b) (1
4c) ... are electrically connected in series. The laser beam (L
Adjacent interval (13 ') to be removed by irradiation of B) is a transparent electrode film
When located on the exposed portions of (11a), (11b), (11c), ..., It is applied from the other main surface side of the substrate (10) in the same direction as the irradiation direction of the amorphous semiconductor film (12). The laser used has a wavelength of 1.06μ
It is a pulse output laser of m, and the energy density at that time is about 3 J / cm ² . The space (L) between the adjacent space portions (13 ')
3) is set to, for example, about 20 μm to 100 μm.

FIG. 25 shows a transparent electrode film (irradiation of a laser beam (LB) from the other main surface side of the substrate (10) to the back electrode film (13) made of aluminum having a thickness of 5000 Å. The film thickness dependence of 11) is optically analyzed with respect to the absorptance (A), reflectance (R) and transmittance (T). It has not been. According to this optical analysis, although the absorptance (A) of the back electrode film (13) changes periodically depending on the film thickness of the transparent electrode film (11), the back electrode film (13)
Compared with FIG. 26 showing the analysis result when the laser beam (LB) is irradiated from the exposed surface side, an increase of about 1.6 to 2.25 times is seen. That is, such an increase in the absorptance means that the laser beam (LB) can be applied from the other main surface side of the substrate (10) to perform processing with low output, and effective use of the laser beam can be achieved. .

In the removal process by irradiation with the laser beam (LB), the melted state of the back electrode film (13) located in the adjacent interval portion (13 ') to be removed is the amorphous semiconductor film (12). The transparent electrode film on the laser beam (LB) side
The film progresses while expanding from the interface with (11) toward the exposed surface (surface), and when the back electrode film (13) becomes thin, the film (13)
Since it breaks down and dissipates into the atmosphere, the processed interface becomes clear without any residue (7). Therefore, the short circuit accident of one photoelectric conversion region (14a) (14b) (14c) ... Using the residue (7) of the back electrode film (13) as a medium as shown in FIG. 3 does not occur. That is, from the exposed surface side of the back surface electrode film (13) to the adjacent spacing portion (13 ')
When removing the back electrode film, the transparent electrode film (11) exists under the back electrode film (13), and the back electrode film (13) is removed by a high energy density laser beam (LB). For example, since the lower transparent electrode film (11) is thermally damaged or the laser beam (LB) is irradiated from the exposed surface side, the residue (7) remains at the processing interface as shown in FIG. It was.

FIGS. 27 to 31 show the steps included in the manufacturing method of the present invention, and FIGS. 5 to 9 show the steps of the first and second embodiments of the present invention. Substantially corresponds to the process.

That is, in the process of FIG. 27, the laser beam has already been
(LB) is applied to the photoelectric conversion regions (14a) (14b) ... Divided into transparent electrode films (11a) (11b).
A transparent insulating heat insulating layer (15) such as O ₂ or Si ₃ N ₄ is selectively formed. Such an insulating and heat-insulating layer (15) is, for example, 15 April 1982.
Appl. Phys. Lett. 40 (8) pp. 716-718 “La
ser-induced chemical vapor deposition of SiO
₂ "and silane (SiH ₄ ) and nitrous oxide.
(N ₂ O) was introduced into the reaction chamber, and the wavelength was 193 nm ArF.
The plasma photo-excited by the laser decomposes the reaction gas, and it can be selectively formed only at the portion irradiated with the laser beam.

In the process of FIG. 28, the substrate (10) including the transparent electrode films (11a) (11b) ... And the insulating and heat insulating layer (15) is included as in the process of FIG.
An amorphous semiconductor film (12) is deposited on the entire surface of the substrate, and the laser beam (LB) is irradiated from the other main surface side of the substrate (10) in the process of FIG. The adjacent spacing part (12 ′) of () is removed, and each photoelectric conversion region (14a) (14b) ... Is divided. In such a step, the amorphous semiconductor film is electrically coupled to the extended portion of the back surface electrode film (13a) extending from the photoelectric conversion region (14a) on the left from the adjacent spacing portion (12 '). The left end of the lower transparent electrode film (11b) is exposed from (12b), and the exposed interface is covered with the insulating heat insulating layer (15).

In the process of FIG. 30, the exposed portions of the amorphous semiconductor films (12a) (12b) ... And the transparent electrode film (11b), which are individually divided,
Further, a back electrode film (13) made of aluminum (Al) or the like is deposited on the entire surface of the substrate (10) including the insulating heat insulating layer (15). After the deposition, the laser beam (LB) is irradiated from the exposed surface (front surface) side of the back electrode film (13) to the adjacent spacing portion (13 ') defined by the dashed line in the figure.

FIG. 32 shows the structure in which the insulating heat insulating layer (15) made of SiO ₂ having a film thickness of 5000 Å is arranged on SnO ₂ having a film thickness of 5000 Å as described above. FIG. 33 shows the temperature distribution in the region (131) where the amorphous semiconductor film (12b) does not exist, and FIG. 33 shows the temperature distribution in the region (132) where the amorphous semiconductor film (12b) exists. Shows. The substrate
(10) is made of glass.

On the other hand, FIG. 34 shows the temperature distribution when the insulating heat insulating layer (15) is not present in the region (131), and FIG. 35 is the insulating heat insulating layer (15) is not present in the region (132). This is the temperature distribution when.

All the lasers used are pulse output type lasers having a wavelength of 1.06 μm, and the energy density Eo of such a laser beam is as shown in the figure, the surface temperature of the aluminum back electrode film (13) to be removed. Was the output required to reach the melting point.

In this way, by arranging the insulating heat insulating layer (15) on the transparent electrode film (12b) ... In the adjacent space portion (13 ') to be removed, the insulating heat insulating layer (15) acts as a heat insulator, and the transparent electrode film (12b). ) ... give no thermal damage. Further, as a result of blocking the heat conduction to the transparent electrode films (12b) ..., the dissipation of heat is suppressed and it becomes possible to process with low output.

FIG. 31 shows the photoelectric conversion regions which are adjacent to each other in a state where the adjacent gap portions (13 ') of the back surface electrode films (13a) (13b) ... Are removed.
(14a) (14b) ... are electrically connected in series. On the other hand, 1
In one photoelectric conversion region (14b), the laser beam (LB) is irradiated from the exposed surface (front surface) side of the back electrode film (13), not from the other main surface side of the substrate (10) as shown in FIG. Because I did
A residue (7) of the back electrode film (13) is generated at the processing interface. This residue (7) was a factor that short-circuited the photoelectric conversion region (5b) in the conventional example shown in FIG. 3, but as is clear from the figure, the exposed interface of the transparent electrode film (11b) ... Since (11b ') is covered by the insulating heat insulating layer (15), a short circuit does not occur. That is, when the laser beam (LB) is irradiated, the insulating heat insulating layer (15) acts as a heat insulator that blocks heat conduction to the lower layer and contributes to avoiding thermal damage and reducing the output of processing. Is the residue of the back electrode film (13b)
Acts as an insulator to prevent short circuit accidents using (7) as a medium. The irradiation direction of the laser beam (LB) on the transparent electrode film (11) may be either, but scattered matter scattered by the irradiation of the laser beam (LB) is a laser device.
Substrate from the point of not scratching the objective lens (OL) on the (LA) side
It is good to apply from the other main surface side of (10).

[0045]

As is apparent from the above description, the present invention is as follows.
Since the semiconductor film deposited over the plurality of regions on the one main surface of the translucent substrate is irradiated with the laser beam from at least the other main surface side of the substrate, the semiconductor film in the irradiated adjacent gap portion is In the case of solar cells, it causes the back electrode film peeling accident, and in the case of a one-dimensional optical sensor in which multiple sensor areas are arranged one-dimensionally, it suppresses the formation of residues that lowers the pattern accuracy. Nevertheless, it can be removed and a laser beam without a wet process can be used. Also, about 0.35 μm to 0.78
By irradiating the laser beam in the wavelength region of μm in a pulsed manner by reversing the irradiation direction, it is possible to widen the processing width of the semiconductor film with a low output, and to increase the electrical width in the adjacent space. When applied to the production of solar cells connected in series, the scanning speed of the laser beam can be increased or the number of times of scanning can be decreased, resulting in improvement in productivity.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an element structure showing a typical example of a solar cell.

FIG. 2 is an enlarged cross-sectional view for explaining a conventional solar cell.

FIG. 3 is an enlarged cross-sectional view for explaining a conventional solar cell.

FIG. 4 is a sectional view of an element structure for explaining the manufacturing method of the present invention.

FIG. 5 is a sectional view of an element structure for explaining the manufacturing method of the present invention.

FIG. 6 is a cross-sectional view of an element structure for explaining the manufacturing method of the present invention.

FIG. 7 is a cross-sectional view of an element structure for explaining the manufacturing method of the present invention.

FIG. 8 is a sectional view of an element structure for explaining the manufacturing method of the present invention.

FIG. 9 is a sectional view of an element structure for explaining the manufacturing method of the present invention.

FIG. 10 is a curve diagram showing the relationship between the absorption coefficient of an amorphous silicon-based semiconductor film and the transmittance of glass and the wavelength.

FIG. 11 is a conceptual diagram for explaining the principle of the manufacturing method of the present invention.

FIG. 12 is a conceptual diagram for explaining the principle of a conventional manufacturing method.

FIG. 13 is a curve diagram obtained by optically analyzing the respective intensities of absorptance (A), reflectance (R) and transmittance (T) of the transparent electrode film in the production method of the present invention.

FIG. 14 is a curve diagram obtained by optically analyzing the respective intensities of absorptance (A), reflectance (R) and transmittance (T) of the transparent electrode film in the production method of the present invention.

FIG. 15 is a curve diagram obtained by optically analyzing the respective intensities of absorptance (A), reflectance (R) and transmittance (T) of the transparent electrode film in the production method of the present invention.

FIG. 16 is a graph showing the dependence of the respective absorptances (A), reflectances (R) and transmittances (T) of the amorphous semiconductor film on the thickness of the transparent electrode film in the conventional manufacturing method. It is the curve figure analyzed in FIG.

FIG. 17 is an absorption rate (A) for a workpiece having the same structure,
It is a curve figure for comparing a reflectance (R) and a transmittance (T).

FIG. 18 is an optical analysis characteristic diagram of absorptance (A), reflectance (R) and transmittance (T) in the manufacturing method of the present invention.

FIG. 19 is a curve diagram showing a temperature distribution in the depth direction according to the manufacturing method of the present invention.

FIG. 20 is a curve diagram showing the temperature distribution in the depth direction in the conventional manufacturing method.

FIG. 21 is a curve diagram showing the relationship between the laser beam scanning speed and the threshold energy density.

FIG. 22 is a diagram showing a manufacturing method of the present invention and a manufacturing method of a conventional example,
It is a curve figure which shows the processing width of an amorphous semiconductor film.

FIG. 23 is a schematic diagram of a micrograph of an adjacent gap portion when an amorphous semiconductor film is removed by the manufacturing method of the present invention.

FIG. 24 is a schematic diagram of a micrograph of an adjacent gap portion when an amorphous semiconductor film is removed by a conventional method.

FIG. 25 is an optical analysis characteristic diagram for the back electrode film.

FIG. 26 is an optical analysis characteristic diagram for the back electrode film.

FIG. 27 is a sectional view of an element structure for explaining the manufacturing method of the present invention.

FIG. 28 is a sectional view of the element structure for explaining the manufacturing method of the present invention.

FIG. 29 is a sectional view of the element structure for explaining the manufacturing method of the present invention.

FIG. 30 is a sectional view of the element structure for explaining the manufacturing method of the present invention.

FIG. 31 is a sectional view of an element structure for explaining the manufacturing method of the present invention.

FIG. 32 is a curve diagram showing a temperature distribution in the manufacturing method of the present invention.

FIG. 33 is a curve diagram showing a temperature distribution in the manufacturing method of the present invention.

FIG. 34 is a curve diagram showing a temperature distribution in the conventional manufacturing method.

FIG. 35 is a curve diagram showing a temperature distribution in a conventional manufacturing method.

[Explanation of symbols]

(10) ... Substrate (12) (12a) (12
b) (12c) ... Amorphous substrate (13) (13a) (13b) (13c) ... Back electrode film (15) ... Insulation heat insulation layer

[Procedure amendment]

[Submission date] September 30, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

[0012]

The method of manufacturing a semiconductor device according to the present invention is characterized in that a semiconductor film deposited over a plurality of regions on one main surface of a transparent substrate should be divided. A laser beam having a wavelength of about 0.53 μm and a pulse width of 244 nsec or less is radiated from the other main surface side of the substrate in a pulsed manner to the adjacent spacing portion. Is to remove the semiconductor film located at the position to divide the semiconductor film into a plurality of regions, and the thickness of the semiconductor film is 4000.
Å More than that.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication 7210-4M H01L 27/14 C

Claims (1)

[Claims] 1. A wavelength is applied from the other main surface side of the substrate to an adjacent space to be divided of a semiconductor film which is deposited over a plurality of regions on one main surface of the transparent substrate. About 0.53 μm
A method of manufacturing a semiconductor device, comprising: irradiating a laser beam in a pulse manner to remove the semiconductor film located in the adjacent space portion and dividing the semiconductor film into a plurality of regions.