JPH06103732B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a functional element using a semiconductor thin film and a manufacturing technique thereof.

[Conventional technology]

A conventional technique relating to a functional element using a semiconductor thin film will be described below with reference to examples.

For example, FIG. 13 is a schematic cross-sectional view showing in sequence the structure of an example of a semiconductor device using a conventional semiconductor thin film in accordance with the structural steps. In the figure, 1 is a heat resistant substrate, 108 is a diffusion prevention layer, 2 is a semiconductor thin film, 5 is a cap layer, 11 is a pn junction layer provided on the surface of the semiconductor thin film 2, and 12 is a lattice electrode.

For the heat resistant substrate 1, for example, silicon, refractory metal, graphite, conductive ceramics or the like is used (FIG. 13 (a)). A diffusion prevention layer 108 made of a silicon oxide film is formed on this surface (FIG. 13B). Next, a part of the diffusion prevention layer 108 is removed by a method such as photoengraving to remove the opening 1
09 is provided (Fig. 13 (c)), on which semiconductor material gas,
For example, the semiconductor thin film 2 is formed by a method such as decomposition of silane, dichlorosilane, trichlorosilane, etc. (FIG. 13 (d)), and the capping layer 5 made of a silicon oxide film further covers it (FIG. 13 (e)). )). After the semiconductor thin film 2 is heated and melted and recrystallized from above the cap layer 5 (FIG. 13 (f)), the cap layer is removed by etching (see FIG.
Figure 13 (g)). After that, a bonding layer 11 is formed on the surface of the semiconductor thin film by growth of a microcrystalline film or impurity diffusion, a transparent conductive film (not shown) is provided if necessary, and a lattice electrode 12 is further provided to provide a semiconductor device. Is completed (Fig. 13 (h)).

The semiconductor device thus obtained is provided with an arrow 13 in FIG.
When the light is irradiated from the direction shown in (1), the light is absorbed inside the semiconductor device, an electromotive force is generated in the film thickness direction of the semiconductor thin film 2 by the pn junction provided in the semiconductor device, and a current can be taken out. it can. The current flows from the grid electrode 12 on the one hand,
The other is taken out from the heat resistant substrate 1 through the opening 109 provided in the diffusion prevention layer 108. Figure 14 shows 20th IEEE
In the structure of the semiconductor device announced at the PhotovoItaic Specialists Conference, in this case, the heat resistant substrate 1 is made of polycrystalline silicon, and the semiconductor thin film 2 is made of silicon. However, in the method of manufacturing a semiconductor device as described above, when forming the semiconductor thin film 2 on the diffusion prevention layer 108 and when melting and recrystallizing the semiconductor thin film 2, a process in a high temperature state is performed. Therefore, if the heat-resistant substrate 1 contains harmful impurities such as Fe, Ni, or Cr that deteriorate the characteristics of the semiconductor device, the heat-resistant substrate 1 passes through the opening 109 provided in the diffusion prevention layer 108. However, there is a problem that these impurities diffuse into the semiconductor thin film 2 and deteriorate the performance of the semiconductor device. Furthermore, in the semiconductor device having the above structure, the semiconductor thin film 2 and the heat-resistant substrate 1 are electrically contacted with each other through the opening 109 provided in the diffusion prevention layer 108. Since a conductive material is used as 1 and the whole is used as an electrode, the semiconductor thin film 2 provided thereon is divided into a plurality of regions and is electrically connected to each other, that is, integrated structure. It was difficult to realize the designed structure.

Further, FIG. 15 is a cross-sectional view showing the concept of the structure of another example of a conventionally proposed semiconductor device. In the figure, 101 is a silicon substrate, 118 is an integrated circuit region formed on the silicon substrate 101, 2 is a semiconductor thin film, 119 is an integrated circuit region provided on the semiconductor thin film 2, 120 is an interlayer insulating film, and 121 is mutual. Shows connection wiring.

An integrated circuit region 118 is formed on the surface of the silicon substrate 101, and two semiconductor thin films 2 are provided on the surface of the silicon substrate 101 with an interlayer insulating film 120 interposed therebetween. The integrated circuit region 118 is formed on each semiconductor thin film 2. 119 is formed. Silicon substrate 101
The integrated circuit 118 above and the integrated circuit 119 on the semiconductor thin film 2 are
The integrated circuits are electrically connected to each other by the interconnection wiring 121, and each integrated circuit serves as a semiconductor device that performs one function as a whole. To configure the above structure,
First, an integrated circuit region 118 is formed on the silicon substrate 101,
An interlayer insulating layer 120 and a semiconductor thin film 2 are sequentially provided on it,
An integrated circuit is formed thereon, and the integrated circuit area 11 of the lower layer is formed.
8 and 119 and the interconnection wiring 121 are provided for the manufacturing method. As the semiconductor thin film 2 used in the semiconductor device having such a structure, generally, polycrystalline silicon or one obtained by melting and recrystallizing polycrystalline silicon is used.
Considering the electrical characteristics of the semiconductor thin film, it is preferable to use polycrystalline silicon as it is by melting and recrystallizing it and expanding the single crystal region, rather than using polycrystalline silicon as it is. However, in the semiconductor device having the above structure, when the manufacturing method of sequentially stacking the semiconductor thin films 2 on the silicon substrate on which the integrated circuit region 118 is formed as described above is adopted, the manufacturing process is In order to protect the function of the formed integrated circuit, it is necessary to avoid exposing the formed integrated circuit region to a temperature of 800 to 900 ° C. or higher. On the other hand, in order to melt and recrystallize the semiconductor thin film 2, in the case of silicon, the melting temperature is 1414 ° C. Therefore, it is necessary to expose the semiconductor thin film 2 to above this temperature, which is inconsistent with the above request. However, it has been difficult to realize such a semiconductor device.

In order to solve this, the semiconductor thin film 2 is irradiated with a laser beam or an electron beam, locally heated and melted and recrystallized to reduce the influence on the already formed integrated circuit region. There is an attempt to realize such a semiconductor device. For example, Figure 16 shows the IEDM Technical Digest.
(1981) is an example of a semiconductor device. In the figure, 101 is a p-type silicon substrate, 130 is an n-type diffusion region formed on the silicon substrate 101, 131 is a silicon oxide film, 132 is a first polycrystalline silicon layer, and 133 is a second polycrystalline silicon layer. . The second polycrystalline silicon layer 133 corresponds to the semiconductor thin film 2 in FIG. 15, and the silicon oxide film between the second polycrystalline silicon thin film 133, the first polycrystalline silicon thin film 132 and the silicon substrate 101. 131 corresponds to the interlayer insulating layer 120 in FIG. The contact portion between the second polycrystalline silicon layer 133 and the n-type diffusion region 130 corresponds to the interconnection wiring 121 in FIG. In this example, first polycrystalline silicon layer 132 and two n-type diffusion regions 130 and p
The type silicon substrate 101 constitutes one circuit element which is a constituent element of the integrated circuit, and the first polycrystalline silicon layer 132 and the second polycrystalline silicon layer 133 immediately thereabove form another circuit element. And are electrically connected to each other to form an integrated circuit. Laser beam irradiation is used for melt recrystallization of the semiconductor thin film, that is, the second polycrystalline silicon layer 133. Thus, for example, by adopting laser beam irradiation, a semiconductor device having a complicated structure as shown in FIG. 15 cannot be obtained, but it can be said to be a prototype thereof. Similar semiconductor devices with simpler structures are gradually being realized. However, in such a manufacturing method, it is difficult to obtain a single crystal region over a wide area in the semiconductor thin film 2 obtained by recrystallization by laser beam irradiation, and therefore, a large-scale complex film is formed on the semiconductor thin film 2. It is impossible to form an integrated circuit. Further, it takes a long time to perform laser beam irradiation on a large area, and there is a problem that productivity is poor.

[Problems to be Solved by the Invention]

Since the conventional semiconductor device and the manufacturing method thereof are configured as described above, it is difficult to suppress the mixing of impurities into the semiconductor thin film, it is difficult to realize an integrated structure, and it is difficult to increase the area. However, there were problems such as poor productivity.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a semiconductor device and a manufacturing method thereof capable of solving all the above problems.

[Means for Solving the Problems]

In the method for manufacturing a semiconductor device according to the present invention, a semiconductor thin film is formed on a heat resistant substrate, a mother is formed on the semiconductor thin film, and then the heat resistant substrate is peeled from the semiconductor thin film.

Further, the semiconductor device according to the present invention is one in which a semiconductor thin film is formed on a base by the method for manufacturing a semiconductor device according to the present invention.

[Action]

In the method for manufacturing a semiconductor device according to the present invention, a semiconductor thin film is once formed on a heat resistant substrate, and then this semiconductor thin film is transferred onto a base.

Further, the semiconductor device according to the present invention is configured by transferring the semiconductor thin film once formed on the heat resistant substrate to the base of the semiconductor device.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. First
The drawings are schematic cross-sectional views for sequentially explaining the method of manufacturing a semiconductor device according to the first embodiment of the present invention in accordance with the manufacturing steps. In the figure, 1 is a heat resistant substrate, 2 is a semiconductor thin film, and 3 is a base of a semiconductor device.

The heat resistant substrate 1 (FIG. 1 (a)) must be such that its shape and composition do not change at the temperature required to form the semiconductor thin film 2. For example, when the semiconductor thin film 2 is polycrystalline silicon, in order to form it by decomposing the semiconductor material gas, the heat resistant substrate 1 needs to be heated from 600 ° C. to about 120 ° C.
It must have heat resistance to a temperature of 0 ° C. If the semiconductor thin film 2 is amorphous silicon, 300 ° C
Any material can be used as long as it can withstand a certain temperature. In the former case, for example, quartz, carbon, silicon, ceramics, refractory metal or the like is used as the material of the heat-resistant substrate 1 that satisfies this requirement, and in the latter case, glass, metal such as stainless steel, heat-resistant resin or the like is used. be able to.

A semiconductor thin film 2 is formed on the surface of the heat resistant substrate 1 by means such as decomposition of a semiconductor material gas (FIG. 1 (b)). If necessary, the semiconductor thin film 2 may be subjected to treatments necessary for applying it to a semiconductor device to be constructed, such as patterning, oxidation, impurity diffusion, annealing, recrystallization, epitaxial growth, and other thin film formation. Processing such as lamination formation and patterning thereof is performed. On the semiconductor thin film 2, the base 3 of the semiconductor device to be constructed using this is bonded (FIG. 1 (c)). For the bonding, the base 3 may be directly bonded to the semiconductor thin film 2, or a bonding agent may be used, or the bonding agent itself may be used as the base 3. The contact portion of the base 3 with the semiconductor thin film 2 is
When the adhesiveness to the semiconductor thin film 2 is sufficient, direct bonding is possible. For example, when the bonding agent itself is used as the matrix 3, or in the step of forming the semiconductor thin film 2, a material having high adhesiveness to the matrix is placed on the surface or the surface of the semiconductor thin film 2 by the treatment applied to the semiconductor thin film 2. This is the case where the surface shape has a high adhesiveness with the base material, for example, when an integrated circuit is formed on the surface of the semiconductor thin film 2 to form irregularities. The surface of the semiconductor thin film 2 may be intentionally treated in order to improve the adhesion to the base material 3.
As the bonding agent, for example, an organic material such as a polyimide resin, low melting point glass, a silicon oxide film to which phosphorus or boron is added, or the like can be used.

After that, the heat resistant substrate 1 is peeled from the semiconductor thin film 2 (FIG. 1 (d)). For example, when the heat-resistant substrate 1 is made of a porous material such as porous ceramics, a substance that dissolves the semiconductor thin film 2, that is, an etching solution or an etching gas is permeated into the heat-resistant substrate 1 so that the heat resistance of the semiconductor thin film is reduced. The heat-resistant substrate 1 can be separated from the semiconductor thin film 2 by partially melting the portion in contact with the heat-resistant substrate 1 and removing the bond between the heat-resistant substrate 1 and the semiconductor thin film 2.
For example, when the semiconductor thin film 2 is made of polycrystalline silicon, an etching solution such as a mixed solution of HF, HNO ₃ , and CH ₃ COOH can be used, and an etching gas such as CIF ₃ can be used. As a result, a semiconductor device having a structure in which the semiconductor thin film 2 is arranged on the base 3 is formed.

FIGS. 2 and 3 show the second and third embodiments of the present invention in which the peeling layer 4 is provided in advance on the surface of the heat resistant substrate 1 before the semiconductor thin film 2 is formed. The peeling layer 4 is provided on at least a part of the surface of the heat resistant substrate 1 (FIG. 2 (a), FIG. 3 (a)). Forming the semiconductor thin film 2 on this (FIG. 2 (b), FIG. 3 (b)) and joining the mother body 3 thereto (FIG. 2 (c), FIG. 3 (c)) It is similar to that shown in FIG.

In the second embodiment shown in FIG. 2, the heat resistant substrate 1 is connected to the semiconductor thin film 2
In the step of peeling from the heat-resistant substrate 1, the peeling layer 4 provided between the heat-resistant substrate 1 and the semiconductor thin film 2 is chemically decomposed and removed by a solvent, and the heat-resistant substrate 1 is peeled from the semiconductor thin film 2. There is. When the solvent sufficiently penetrates into the gap between the semiconductor thin film 2 and the heat-resistant substrate 1, that is, the portion occupied by the release layer 4, the heat-resistant substrate 1 may be airtight.
When the semiconductor thin film 2 has a large area, a porous substrate is used as the heat resistant substrate 2. For example, when the semiconductor thin film 2 is made of polycrystalline silicon, the peeling layer 4 is a silicon oxide film,
Porous ceramics or the like can be used as the heat resistant substrate 1. For example, porous alumina is used as the porous ceramics. At this time, HF can be used as the solvent of the peeling layer 4. When a porous material is used for the heat-resistant substrate 1, a surface having sufficient flatness may not be obtained depending on the material, but by providing the release layer 4, the release layer 4 is provided.
By flattening the surface, a flat surface can be obtained. For example, when a silicon oxide film is used as the peeling layer 4, a flat surface can be obtained by using an oxide film to which phosphorus or boron is added and performing reflow.

In the third embodiment shown in FIG. 3, the heat-resistant substrate 1 is replaced by the semiconductor thin film 2
In the step of peeling the heat-resistant substrate 1 from the semiconductor thin film 2, the peeling layer 4 provided between the heat-resistant substrate 1 and the semiconductor thin film 2 is physically decomposed by mechanical stress to peel the heat-resistant substrate 1 from the semiconductor thin film 2. There is. As the peeling layer 4, for example, a layer formed by applying powder of silicon, silicon nitride, silicon oxide film, silicon carbide, boron nitride, or the like is used,
Since the bond between the semiconductor thin film 2 and the heat resistant substrate 1 is due to the weak bond between the particles of these powders, in this case,
By applying a mechanical stress for peeling the heat-resistant substrate 1 from the semiconductor thin film 2, the peeling layer 4 can be easily decomposed to separate the heat-resistant substrate 1 and the semiconductor thin film 2 (see FIG. 3 ( d)). Alternatively, the release layer 4 may be a layer formed by applying powder, for example, a layer coated with a silicon oxide film.

Further, FIG. 4 shows a fourth embodiment of the present invention in the case of zone melting and recrystallizing the once formed semiconductor thin film 2 in the step of forming the semiconductor thin film 2 on the heat resistant substrate 1. For example, a peeling layer 4 made of a silicon oxide film is provided on the surface of the heat resistant substrate 1 made of porous alumina or the like by a vapor phase method (FIG. 4 (a)). A polycrystalline silicon film is formed thereon as a semiconductor thin film 2 by a vapor phase method, and this is again covered with a cap layer 5 made of a silicon oxide film by the vapor phase method (FIG. 4 (b)). Further, a silicon nitride film may be provided on this. Next, the semiconductor thin film 2 is heated and melted, then fixed and recrystallized (FIG. 4 (c)),
The cap layer 5 is removed, the base 3 is bonded to the semiconductor thin film 2 (FIG. 4 (d)), HF is permeated into the heat resistant substrate 1,
The heat resistant substrate 1 is peeled off by dissolving the silicon oxide film of the peeling layer 4 (FIG. 4 (e)). For heating and melting the semiconductor thin film 2, an energy beam such as a laser or an electron beam may be used, or infrared irradiation or heating by a carbon heater or the like may be used. Zone melting and recrystallization is performed by linearly irradiating infrared rays, or by forming a band-shaped melted portion in the semiconductor thin film 2 with a linear carbon heater or the like and moving the melted portion.
Further, in the above example, the case where both the peeling layer 4 and the cap layer 5 are made of the silicon oxide film is shown, but when HF is used for removing the cap layer 5, the peeling layer 4 is not simultaneously removed at this time. As described above, the surface is covered with a protective material so that HF does not penetrate into the heat resistant substrate 1.

FIG. 5 shows a fifth embodiment of the invention, which shows an embodiment similar to the fourth embodiment of FIG.
In the step of forming the semiconductor thin film 2, the heat-resistant substrate 1 and the semiconductor crystal 6 are arranged adjacent to each other so that their surfaces are flush with each other (FIG. 5 (a)), and the heat-resistant substrate 1 and the semiconductor crystal 6 are formed. The semiconductor thin film 2 is formed on both of them (FIG. 5 (b)). The semiconductor crystal 6 is made of the same material as the semiconductor thin film 2. For example, when the semiconductor thin film 2 is polycrystalline silicon, the semiconductor crystal 6 is a silicon single crystal. Next, when performing zone melting recrystallization on the semiconductor thin film 2,
First, the semiconductor thin film 2 on the semiconductor crystal 6 is heated and melted, the heated portion is moved, the semiconductor thin film 2 on the heat resistant substrate 1 is sequentially melted from the end, and the portion above the semiconductor crystal 6 is moved by moving the melting portion. To the upper portion of the heat resistant substrate 1 are solidified in order. By this operation, the semiconductor thin film 2 on the semiconductor crystal 6 is drawn into the crystal orientation of the semiconductor crystal 6 and tries to solidify with the same crystal orientation, and the semiconductor thin film 2 on the heat resistant substrate 1 has already been The semiconductor thin film 2 is drawn into the portion of the semiconductor thin film 2 that has solidified in the same crystal orientation as the semiconductor crystal 6 and tries to solidify in the same crystal orientation. As a result, most of the recrystallized semiconductor thin film 2 is solidified in the same crystal orientation as the semiconductor crystal 6, and the semiconductor thin film 2 having a single crystal region over a wide area is obtained. Further, the advantage of performing the zone melting recrystallization is that when the semiconductor thin film 2 contains impurities, the impurities having a small segregation coefficient are swept away by the movement of the melted portion and purified at the same time as the recrystallization. Is the point where In the subsequent steps, as in the case shown in FIG. 4, the semiconductor thin film 2 is joined to the base 3 (FIG. 5 (d)), the peeling layer 4 is decomposed to separate the heat resistant substrate 1 (FIG. 5). (E)) Further, the semiconductor crystal 6 is separated (FIG. 5 (e)).

FIG. 6 is a schematic cross-sectional view for sequentially explaining the sixth embodiment of the present invention when the method for manufacturing a semiconductor device according to the present invention described above is applied to an actual semiconductor device according to the manufacturing process. It is a figure. Heat resistant substrate 1 (Fig. 6 (a))
A peeling layer 4 is provided on the upper surface (FIG. 6 (b)), a p-type polycrystalline silicon thin film, for example, is formed thereon as the semiconductor thin film 2 (FIG. 6 (c)), and this is covered with a cap layer 5. (FIG. 6 (d)). After the zone-melting recrystallization of the semiconductor thin film 2 (FIG. 6 (e)), the cap layer 5 is removed (FIG. 6 (f)), and the p ⁺ diffusion layer 7 and the oxide film 8 are formed on the surface of the semiconductor thin film 2. It is formed (FIG. 6 (g)). Next, the oxide film 8 is patterned to provide an opening 9 in a part thereof (FIG. 6 (h)),
A metal layer 10 is formed thereon by sputtering of aluminum, silver or the like, vacuum vapor deposition or the like (FIG. 6 (i)), and the mother body 3 is bonded thereon (FIG. 6 (j)). Then, the release layer 4
Is disassembled to separate the heat resistant substrate 1 (FIG. 6 (k)),
A junction layer 11 is provided on the surface of the semiconductor thin film 2 by n ⁺ diffusion or an n-type microcrystalline film, and a pn junction is formed.
A lattice electrode 12 is provided on the surface (Fig. 6 (l)), and when the semiconductor device thus obtained is irradiated with light from the direction shown by arrow 13 in Fig. 6 (l), the light is absorbed inside the semiconductor device. Then, an electromotive force is generated in the film thickness direction of the semiconductor thin film 2 by the pn junction provided in the semiconductor device, and an electric current can be taken out. The current is taken out from the grid electrode 12 on the one hand and from the metal layer 10 on the other hand through the opening 9 provided in the oxide film 8. Further, the metal layer 10 has a function of reflecting the incident light and making it incident on the semiconductor thin film 2 again when the incident light is not sufficiently absorbed by passing through the semiconductor thin film 2 only once. According to this method, since the semiconductor thin film 2 is melted and recrystallized while the entire surface is covered with the peeling layer 4 and the cap layer 5, contamination by impurities when heated and melted can be prevented. it can.

Further, FIG. 7 shows a semiconductor device according to a seventh embodiment of the present invention similar to that shown in FIG. 6 in order of the manufacturing steps thereof, and the steps of FIGS. 7 (a) to 7 (f) are shown. Is similar to FIGS. 6 (a) to 6 (f). In FIG. 7, the bonding layer 11 is first formed on the surface of the semiconductor thin film 2 to provide the grid electrode 12 (FIG. 7 (g)), and the transparent base 3
(FIG. 7 (h), then the peeling layer 4 is decomposed to separate the heat-resistant substrate 1 (FIG. 7 (i)), and the metal layer 10 is provided to form the back electrode (FIG. 7 ( j)). In this case, the light is emitted from the side of the translucent base 3 as shown by the arrow 13.

Although the semiconductor device in which the semiconductor thin film 2 is used without patterning has been shown in the above-described embodiments, the semiconductor thin film 2 may be divided into regions of an appropriate size to be used, and FIG. The eighth embodiment of the present invention thus configured is shown. The steps of FIGS. 8 (a) to 8 (f) are the same as those of FIGS. 6 (a) to 6 (f). In FIG. 8 (g), a p ⁺ diffusion layer 7 is formed on the semiconductor thin film 2,
Similar to FIG. 6, the oxide film 8 may be provided, but for simplicity, the figure shows the case where the oxide film 8 is not provided. A metal layer 10 is provided on this (FIG. 8 (h)), this is patterned (FIG. 8 (i)), then the mother body 3 is bonded (FIG. 8 (j)), and the peeling film 4 is decomposed. Then, the heat resistant substrate 1 is separated (FIG. 8 (k)). Further, the semiconductor thin film 2 is divided in conformity with the pattern of the metal layer 10 and patterned (FIG. 8 (l)). At this time, for example, as shown in the figure, a part of the metal layer 10 is exposed in a gap formed by dividing the semiconductor thin film 2. After that, pn is formed on the semiconductor thin film 2.
A bonding layer (not shown) is formed, and the grid electrode 12 is formed so that a part thereof contacts the metal layer 10 exposed in the gap of the semiconductor thin film 2 (FIG. 8 (m)). Accordingly, when the semiconductor device is a semiconductor element for generating power by irradiation of light as shown in FIG. 6 and FIG. 7, for example, a power generation region by a plurality of semiconductor thin films 2 on one base body 3. And a semiconductor device having a structure in which they are connected in series is obtained.

In the above-described embodiment, the case where the grid electrode 12 is used to electrically connect the divided semiconductor thin films 2 has been described, but a transparent conductive film or the like may be used, for example. Further, a power generation element formed by the second semiconductor thin film may be further laminated in the power generation region formed by the semiconductor thin film 2. For example, in the ninth embodiment shown in FIG. The machining process is shown step by step. The semiconductor thin film 2 made of, for example, polycrystalline silicon or the like, on which the pn junction layer (not shown) is divided, is covered with a power generation element made of a second semiconductor thin film 14, for example, amorphous silicon (9th embodiment). Figure (a)).
Part of the second semiconductor thin film 14 is melted and removed by, for example, a laser beam (FIG. 9 (b)), and then covered with a transparent conductive film 15 (FIG. 9 (c)). Further, the second semiconductor thin film 14 and a part of the transparent conductive film 15 are simultaneously cut and removed by a laser beam or the like (FIG. 9 (d)).

Further, as shown in the tenth embodiment in FIG. 10, after the second semiconductor thin film 14 and the transparent conductive film 15 are formed on the entire surface (FIG. 10 (a)), the second semiconductor thin film 14 and the transparent conductive film 15 are formed by a laser beam or the like. The transparent conductive film 15 is removed by cutting and removing (FIG. 10 (b)), and then filling one cut portion with, for example, a conductive paste.
And the metal film 10 are electrically connected (FIG. 10 (c)). As a result, a semiconductor device having a structure in which a power generating element having a laminated structure of the semiconductor thin film 2 and the second semiconductor thin film 14 is provided in a plurality of regions on the same base 3 and these are connected in series is obtained.

FIG. 11 and FIG. 12 describe, in order, the eleventh and twelfth embodiments of the present invention when the method for manufacturing a semiconductor device according to the present invention is applied to another semiconductor device, in accordance with the manufacturing steps thereof. FIG. The embodiments shown here relate to a semiconductor integrated circuit using a semiconductor thin film, and more particularly to a semiconductor device having a structure in which semiconductor thin films forming the integrated circuit are laminated in multiple layers. 11 (a) to 11 (f)
The steps of FIGS. 12 (a) to 12 (f) are similar to those of FIGS. 6 (a) to 6 (f). As shown in FIG. 11, for example, a base 3 is formed on a semiconductor thin film 2 formed on a heat-resistant substrate 1 via a release layer 4, and an electrically insulating bonding agent such as polyimide resin or low-melting glass is used. Bonding is performed using 17 (Fig. 11 (g)). After the release layer 4 is decomposed to separate the heat resistant substrate 1 (FIG. 11 (h)), the semiconductor thin film 2 is processed to form the integrated circuit region 18 (FIG. 11 (i)). Any material can be used as the base material 3 and the bonding agent 17 as long as it can withstand the process for forming the integrated circuit region 18. For example, if a semiconductor substrate on which an integrated circuit is already formed is used as the base material 3, the integrated circuit can be sandwiched between insulators. A semiconductor device having a laminated structure can be obtained. If the semiconductor device according to this embodiment is used as the base 3 and the semiconductor thin films 2 are repeatedly stacked, a semiconductor device having a structure in which semiconductor thin films provided with integrated circuits are stacked in multiple layers can be obtained.

Further, as shown in FIG. 12, an integrated circuit region 18 is formed on the surface of the heat-resistant substrate 1 before separating the semiconductor thin film 2 therefrom (FIG. 12 (g)), and then the base 3 is formed.
May be joined (FIG. 12 (h)) and the heat resistant substrate 1 may be separated (FIG. 12 (i)). In this case, the mother body 3 and the bonding agent 17 do not have to withstand the process for forming the integrated circuit, so that the mother body 3 may be any one as long as it can mechanically support the semiconductor thin film 2, and its material can be selected. Greater freedom.

As described above, according to the method of manufacturing a semiconductor device of the present invention, the melting and recrystallization of the semiconductor thin film 2 is performed on the heat resistant substrate 1. Therefore, the temperature rise during recrystallization causes the already formed integrated circuit to be formed. It is possible to configure a semiconductor integrated circuit having a multi-layer structure without affecting the operation of. Further, since heating by an infrared heater or a carbon heater can be used as a means for melting and recrystallizing the semiconductor thin film 2, a large area of the semiconductor thin film 2 can be processed at one time, and productivity is improved. .

Further, when a semiconductor device having a structure in which the semiconductor thin films 2 on which integrated circuits are formed is stacked in this way, the thickness of the semiconductor thin films 2 is as thin as possible within the range that does not hinder the operation as an integrated circuit. For example, in the case of FIG. 11, before forming the integrated circuit in FIG. 11 (i), in the case of FIG. 12, before forming the integrated circuit in FIG. 2 may be etched or polished to reduce the thickness.

In each of the above embodiments, the case where the polycrystalline silicon thin film is mainly used as the semiconductor thin film 2 and the silicon oxide film is mainly used as the peeling layer 4 has been described, but the material of each part is not limited to these. is not.

〔The invention's effect〕

As described above, in the semiconductor device and the manufacturing method thereof according to the present invention, the semiconductor thin film is formed on the heat resistant substrate, the mother body is formed on the semiconductor thin film, and then the heat resistant substrate is separated from the semiconductor thin film. Since it is configured as described above, it is possible to prevent impurities from being mixed into the semiconductor thin film, which makes it possible to increase the area and improve the productivity. There is an effect that an electrically connected integrated structure can be realized, a degree of freedom in selecting a material of the base body is large, and a semiconductor device in which many functions are integrated can be realized.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view for sequentially explaining a method of manufacturing a semiconductor device according to a first embodiment of the present invention in accordance with the manufacturing steps thereof, and FIGS. 2 to 5 are second to third embodiments of the present invention. 6 is a schematic cross-sectional view for sequentially explaining the method for manufacturing a semiconductor device according to the fifth embodiment of the present invention in accordance with the manufacturing steps.
FIGS. 7A to 12 are schematic cross-sectional views for sequentially explaining a sixth embodiment in which the method for manufacturing a semiconductor device according to the present invention is applied to an actual semiconductor device according to the manufacturing process. FIGS. 13A to 13C are schematic cross-sectional views for sequentially explaining the seventh to twelfth embodiments when the method for manufacturing a semiconductor device according to the present invention is applied to another actual semiconductor device and the manufacturing steps thereof, and FIG. FIG. 14 is a schematic cross-sectional view for explaining a conventional method for manufacturing a semiconductor device according to the manufacturing process, and FIGS. 14 to 16 are schematic cross-sectional views showing the structure of a conventional semiconductor device. In the figure, 1 is a heat resistant substrate, 2 is a semiconductor thin film, 3 is a matrix, and 4 is a release layer. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (5)

[Claims] 1. A zone melting recrystallization by providing the semiconductor thin film on a heat-resistant substrate having a mechanical strength necessary for holding the semiconductor thin film at a temperature required for zone melting recrystallization of the semiconductor thin film. By including, a step of forming the semiconductor thin film on the heat-resistant substrate, a step of bonding a mother body on the semiconductor thin film, and a step of peeling the heat-resistant substrate from the semiconductor thin film, Of manufacturing a semiconductor device. 2. A step of coating at least a part of the surface of the heat-resistant substrate with a release layer in advance and peeling the heat-resistant substrate from the semiconductor thin film before forming the semiconductor thin film on the heat-resistant substrate. The method for manufacturing a semiconductor device according to claim 1, wherein the heat-resistant substrate and the semiconductor thin film are separated by decomposing the peeling layer in. 3. The heat resistant substrate is made of a porous material, and in the step of peeling the heat resistant substrate from the semiconductor thin film, a substance that decomposes the semiconductor thin film or the peeling layer is placed in the heat resistant substrate. By permeating,
The method for manufacturing a semiconductor device according to claim 1, wherein the heat-resistant substrate and the semiconductor thin film are separated from each other. 4. It is necessary to hold the semiconductor thin film on the semiconductor thin film formed on a heat-resistant substrate having a mechanical strength necessary to hold the semiconductor thin film at a temperature necessary to form the semiconductor thin film. A semiconductor device comprising the semiconductor thin film and the matrix by joining a matrix having excellent mechanical strength and peeling the heat resistant substrate from the semiconductor thin film. 5. A semiconductor device having a semiconductor thin film on a base according to claim 4 is used as a second base, and a second semiconductor thin film is formed on the second base through an insulator. A semiconductor device characterized by the above.