JP2003046199A - Method for manufacturing ii-vi group device using porous film and its structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a II-VI group semiconductor material that has high quality and no defect even if a substrate and a semiconductor material formed thereon have lattice constants different to each other, and to provide its structure. SOLUTION: This device is provided with a porous layer pinched by a semiconductor substrate and a first semiconductor film and a second semiconductor film formed on the first semiconductor film, and the second semiconductor film contains a II-VI group compound semiconductor.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a structure of a semiconductor device using a compound semiconductor material.

[0002]

2. Description of the Related Art Semiconductor lasers and light emitting diodes (L
The shortening of the wavelength of ED) has become an important factor for improving the recording density of optical disks and the resolution of laser printers. Especially blue and green lasers and LEDs
Is indispensable for realizing a self-luminous full-color display. Promising blue and green light emitting materials include II-VI group compounds represented by ZnSe. The II-VI system has an extremely high vapor pressure in the VI group system,
Bulk crystals are difficult to obtain. Therefore, GaAs having a close lattice constant is generally used as a ZnSe substrate.
However, there is a difference of about 0.27% in the lattice constant between this GaAs and ZnSe crystal, and defects generated at the interface between the GaAs substrate and ZnSe extend to the ZnSe film, resulting in deterioration of the film quality. In addition, since the difference in thermal expansion coefficient between GaAs and ZnSe is large, even if lattice matching is performed at the growth temperature, strain is generated between GaAs and ZnSe when the temperature is returned to room temperature. There is also a problem that defects occur inside. Due to such problems, Zn formed on the GaAs substrate
The Se-based laser does not reach the practical life. Similarly, in other II-VI groups such as ZnTe and CdTe, there is no substrate, and in order to obtain a good film, it is important to obtain a defect-free lattice-matched substrate.

Recently, a method of forming a compound semiconductor film with porous silicon sandwiched on a silicon substrate has been proposed as a method of forming a good film even in growth with different lattice constants. (JP-A-10-321535) In this method, a silicon substrate having a porous region is heat-treated in order to seal pores on the surface of the porous region, and a compound semiconductor layer is laminated on the substrate. ing. If the compound semiconductor layer is formed in this manner, lattice matching with the silicon substrate and lattice defects and strains caused by the difference in coefficient of thermal expansion generated when the temperature is lowered from the film forming temperature to room temperature are It is introduced only into the ultrathin silicon layer that seals the holes of the above, and not into the compound semiconductor layer. This is because the ultrathin silicon layer formed on the porous layer, which is weaker than that of bulk silicon, is much weaker than the grown compound semiconductor layer. In this manner, the layer into which defects are introduced is preferentially introduced not into the compound semiconductor layer but into the ultrathin silicon layer, so that the compound semiconductor layer with very few defects can be formed. Furthermore, this method does not use a production cost method such as bonding and selective etching of substrates unlike the conventional example,
The compound semiconductor substrate can be manufactured at a lower cost than the conventional example.

However, the above method is a method for forming a compound semiconductor on a silicon substrate. As a substrate for forming a compound semiconductor, it is possible to prevent the occurrence of anti-phase domains, as compared with a silicon substrate,
It is important to improve wettability and facilitate two-dimensional growth, and it is often better to use substrates made of the same compound semiconductor. Furthermore, in many compound semiconductors, the compound semiconductors represented by GaAs, InP, and GaP have closer differences in lattice constant and thermal expansion coefficient than silicon,
It is often suitable for growing compound semiconductors.

[0005]

According to the present invention, even if the lattice constants of the substrate and the semiconductor material formed thereon are different,
A method and structure for forming a high quality II-VI semiconductor material with few defects.

[0006]

The semiconductor structure of the present invention comprises:
In a structure having a porous layer sandwiched between a semiconductor substrate and a first semiconductor film and having a second semiconductor film on the semiconductor film, the second semiconductor film contains a II-VI group compound semiconductor. It is characterized by

Here, it is preferable that the first semiconductor film and the second semiconductor film have different lattice constants.
Further, it is preferable that the semiconductor substrate is GaP, GaAs, or InP.

In the method for producing a semiconductor thin film of the present invention, a step of forming a porosity on a semiconductor substrate, a step of forming a thin film on the porosity, and a layer containing a II-VI group are formed on the thin film. It is characterized by

It is preferable that the thin film and the II-VI group formed on the thin film have different lattice constants. Also, the thin film and II-VI formed on the thin film.
It is preferable that the lattice constants of the groups are matched. further,
It is preferable to include a step of attaching the thin film to the second substrate and a step of separating the original substrate.

Also, a step of forming a multi-layered structure containing II-VI group on the thin film, and II- formed on the thin film.
It is preferable to include a step of attaching a multi-layered structure containing a VI group to the second substrate and a step of separating the original substrate. Further, it is preferable to include a step of attaching the thin film to the second substrate and a step of separating the original substrate. Further, the raw material for forming the film is preferably formed of a solid raw material, a hydride or an organic material.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION As a first mode of the present invention, a thin GaAs thin film is formed on the surface of a substrate having a porous GaAs region, and then a ZnSe film is grown.
The present invention provides a method for forming high quality films having different lattice constants.

In a second aspect of the present invention, porous Ga is used.
After forming a thin GaAs thin film on the surface of the substrate having the As region, a good quality ZnSeTe having different lattice constants is formed on the thin GaAs thin film.
The step of forming a film and the step of manufacturing a device on this ZnSeTe film provide a substrate for a green laser and a light emitting diode of good quality.

According to a third aspect of the present invention, porous In
After forming a thin InP thin film on the surface of a substrate having a P region, a step of forming a high-quality ZnSe film having different lattice constants thereon, a step of manufacturing a device on this ZnSe film, and a step of etching the device to form a substrate. This is a device manufacturing process including a process of separating and transferring.

According to a fourth aspect of the present invention, porous Ga is used.
After forming a thin GaP thin film on the surface of a substrate having a P region, a step of forming a high-quality ZnMgS film having different lattice constants thereon, a step of manufacturing a device on this ZnMgS film, and a device by etching the substrate. Separated from
This is a device manufacturing process including a transfer process.

[0015]

Example 1 Example 1 shows an example in which a good quality film can be obtained even when a film that is not lattice-matched with GaAs is formed using porous GaAs. Figure 1
This will be described with reference to (a), FIG. 1 (b) and FIG. 1 (c). Porous GaAs can be formed by anodizing n-type GaAs in HCl. P. Schmuki et al. (Journa
lofElectrochemicalSociety143, p.3316 (1996)) and Wada et al. (1998 Proceedings of Applied Physics 29a-PC-25). In FIG. 1A, 101 is a porous region 10.
It is a GaAs substrate having a (100) plane having 2 and a thickness of 450 μm. In order to manufacture such a substrate, an n-GaAs substrate is ultrasonically cleaned with isopropyl alcohol and methyl alcohol, and then an electrode that makes electrical contact with In on the back surface of the substrate is manufactured. After this, anodizing treatment in HCl solution,
A porous region can be formed on the surface of the GaAs substrate. The conditions for producing the porous GaAs are that the current is 5 mA / cm.
Anodization is carried out for 10 minutes with ^two flows, the thickness of the porous material is 10 μm, and the porosity is 20%.

Next, as shown in FIG. 1 (b), porous GaA
The surface layer 103 having the holes sealed on the surface of the s layer is formed. In order to form such a layer, a GaAs substrate 101 having a porous structure is formed on a molecular beam epitaxy apparatus (M
(BE method), the substrate temperature is heated to about 600 ° C. while irradiating with As, and held for 20 minutes. At this time G
The oxide film on the surface of the aAs substrate is removed, and Ga migration occurs on the outermost surface of the porous GaAs so as to smooth the irregularities and reduce the surface energy. As a result, the surface of the porous GaAs is flattened and buried as a thin GaAs single crystal film. At this time, a backscattered electron diffraction image (RHE
ED) changes from spot to streak.
At this time, it is possible to irradiate a small amount of Ga beam to further promote the sealing of the hole. G formed on the surface
The thickness of the single crystal layer of aAs is extremely thin, and is approximately the same as or smaller than the diameter of the hole, specifically 100 nm.
Or less, more preferably 30 nm or less. This thin G
The aAs single crystal layer plays an important role of transmitting the orientation information to the layer laminated on the aAs single crystal layer. On the other hand, this GaAs
If the single crystal is too thick, it becomes impossible for the porous layer to relax the strain due to the difference in lattice constant. That is, it is desirable that the thickness of the layer that fills the holes is sufficiently smaller than the thickness of the semiconductor layer formed thereabove, for example, 1/5.
It is desirable that it is less than or equal to 1/100, more preferably less than or equal to 1/100. More specifically, it is desirable to consider the film thickness of the compound semiconductor in the range of 1 nm to 100 nm.

Another method for promoting hole sealing is migration enhanced epitaxy (ME).
There is a method using E). It is effective to promote migration of group III atoms by using this method.
In the case of GaAs, this method supplies only Group III to promote migration of Group III atoms,
This is a method of limiting the supply amount of the V group until the II group settles at an appropriate site.

In the above example, the MBE method is used as a method for filling the porous surface.
It is not limited to this method, but the chemical beam method (CB
E method) or MOCVD method may be used. The same effect can be obtained by using not only a solid source but also an organic compound such as trimethylgallium or arsine as the form of the supply material.

Next, as shown in FIG. 1C, a II-VI group compound semiconductor layer 104 is continuously formed on the surface portion 103. At this time, the thickness of the compound semiconductor layer 104 to be formed is sufficiently thicker than the thickness of the surface portion 103 as described above. Here, ZnSe, which is the substrate of the blue semiconductor laser, is epitaxially grown to a thickness of 1 μm. The growth conditions at this time are a substrate temperature of 300 ° C.
The VI / II ratio is ~ 2. When the dislocations of this ZnSe film were confirmed by an electron microscope, almost no defect density was observed,
It is confirmed to be a good film. When the etch pitch density of this wafer is measured by defect revealing etching, a defect density of 10 ⁴ cm ⁻² or less can be obtained.
This defect density is sufficiently low as a substrate for producing a laser wafer.

As described above, the compound semiconductor 104
Form a lattice defect caused by a difference in lattice constant with GaAs and a difference in coefficient of thermal expansion, a fragile porous GaAs film 1 is formed.
02 is mainly introduced into the GaAs surface layer formed on
It is hardly introduced into ZnSe of the grown compound semiconductor layer 104. Therefore, the compound semiconductor single crystal layer 104 having very few defects can be obtained.

As a substrate for forming the porous layer, In
P substrate, GaP, Si anodized by H ₂ SO ₄
The substrate etc. can be raised. Basically, the substrate is not limited to the binary compound semiconductor as long as the porous layer can be formed.

(Embodiment 2) A second embodiment of the present invention is shown in FIG.
A description will be given using (a) to (h). In this example, Ga
An example using an As substrate and a specific laser configuration are described. It also describes a process of peeling the porous portion of the produced semiconductor laser.

In FIG. 2A, reference numeral 211 denotes the porous region 2.
12 is a GaAs substrate having 12. In order to manufacture such a substrate, an n-GaAs substrate is ultrasonically cleaned with isopropyl alcohol and methyl alcohol, and then an electrode that makes electrical contact with Ga on the back surface of the substrate is manufactured. After that, anodization treatment is performed in an HCl solution to form the porous region 212 on the GaAs substrate surface.

Next, as shown in FIG. 2 (b), porous GaA
A surface layer 213 in which the holes are sealed is formed on the surface of the s layer. In order to form such a layer, the GaAs substrate 211 having a porous structure is loaded into a molecular beam epitaxy apparatus and the substrate temperature is heated to about 600 ° C. while irradiating As. By this process, the oxide film on the surface of the GaAs substrate is removed, and Ga migration occurs in the direction of smoothing the unevenness and lowering the surface energy on the surface of the porous GaAs from which the oxide film has been removed. As a result, porous GaAs
Surface is flattened and buried as a thin GaAs single crystal film. At this time, it is possible to irradiate a small amount of Ga beam to further promote the sealing of the hole. In this example,
Although the element to be supplied is supplied in the solid state, it is not necessarily limited to the solid element. Organometallic materials such as trimethylindium and hydride phosphines were used.
Chemical beam epitaxy or MOCVD method may be used.

Next, as shown in FIG. 2C, the surface portion 21
The II-VI group compound semiconductor layer 214 is continuously formed on the third layer 3. At this time, the thickness of the compound semiconductor layer 214 to be formed is sufficiently thicker than the thickness of the surface portion 213.

As described above, the compound semiconductor 214
Form a lattice defect caused by a difference in lattice constant with GaAs and a difference in coefficient of thermal expansion, a fragile porous GaAs film 2 is formed.
It is mainly introduced into the GaAs surface layer 213 formed on 12 and is hardly introduced into the grown compound semiconductor layer 214. Therefore, the compound semiconductor single crystal layer 214 having very few defects can be obtained.

On this substrate, a semiconductor layer having a semiconductor film having the same lattice constant as 214 is laminated.

In FIG. 2D, 216 has the same structure as that of FIG. 221 has the same composition as the 214 layer, and n−
It is ZnSe. On top of that, n-ZnMgSSe, which is the cladding layer 222, is formed. The lattice constant is 0.5668 nm. An optical confinement layer n-ZnSe shown at 223 is formed thereon. 228 is an active layer of Zn
CdSe has a thickness of 9 nm. After forming p-ZnSe which is the upper optical confinement layer 226 thereon,
P-ZnMgSSe which is the upper cladding layer shown in 227.
To form. Finally, p-ZnSSe shown at 229 is formed. As the growth method, here, the molecular beam epitaxy method (MBE) is used. Zn, M
g, S, and Se are supplied as solid sources, and Ga (n-type) is used as a dopant and nitrogen (N-type) doping by plasma is used. 2 (f), (g), and (h) describe a step of peeling only the semiconductor laser structure from the porous substrate. Reference numeral 211 in FIG. 2 (f) is GaAs which is a substrate. Reference numeral 212 represents porous GaAs, and reference numeral 219 represents a laser structure formed on the porous material.
As shown in FIG. 2G, this structure is bonded to the Si substrate 230 with the P side as the bonding surface. In this example, there is only one device, but a plurality of devices may be arranged side by side, that is, arrayed. After joining, as shown in FIG. 2 (h), the porous GaAs portion 212 was thinned with H ₂ SO ₄
Etching with a system etchant. The porous GaAs region has an etching difference of 1000 times or more as compared with single crystal GaAs, and only 212 can be easily etched. As shown in FIG. 2H, it is possible to manufacture a laser by taking out only the laser portion.

As explained above, the porous compound semiconductor,
This time, by using porous GaAs, it is possible to realize a ZnSe laser having a lattice constant that is not matched with the GaAs substrate.

In this example, ZnSe is shown, but
Other materials include ZnTe, CdTe, MgT
It is also possible to form a good film for the II-VI group containing e, CdSe, etc., and it is possible to manufacture a device using a good film as in this example. Further, although the semiconductor laser is taken as a device in this embodiment, the device is not limited to the semiconductor laser. Besides a laser, a field effect transistor (FET), a photoelectric conversion element, etc. can be realized.

Although a molecular beam epitaxy (MBE) method is mainly described here as a method for manufacturing a semiconductor device, the method is not necessarily limited to this, and a gas source may be used. H ₂ S, H ₂ Se, DMS (dim
ethylsulfide) or DMSe (dimethylselenide), I
DMZn (dimethylzinc), ZMC as a group I source
There is d (dimethylcadmium) etc. and it can grow. These organic substances are used after being cracked.

(Embodiment 3) Embodiment 3 of the present invention is an example of producing a substrate for realizing a green laser, which is as highly demanded as a blue laser.

The third embodiment of the present invention is an example of growing a ZnSeTe layer which is not lattice-matched with InP using an InP porous layer as a substrate for a green laser.

This will be described with reference to FIGS. 3 (a), 3 (b) and 3 (c). In FIG. 3A, 301 is an InP substrate having a porous region 302 and has a thickness of 500 μm.
In order to manufacture such a substrate, an n-InP substrate is organically cleaned, and then an electrode is formed on the back surface of the substrate to make electrical contact with In. After that, anodization treatment can be performed in an HCl solution to form a porous region on the surface of the InP substrate. The production conditions of the porous InP are as follows: an electric current of 5 mA / cm ² is applied to perform anodization for 20 minutes.
The thickness of the porous material is 15 μm and the porosity is 25%.

Next, as shown in FIG. 3B, porous InP
A surface layer layer 303 is formed in which the holes are sealed on the surface of the layer. The method for producing this layer is the same as that described in Example 1.

Next, as shown in FIG. 3C, the surface portion 30
The II-VI group compound semiconductor layer 304 is continuously formed on the film 3. 304 is a ZnSeTe layer having a lattice constant of 0.
It is 588 nm. ZnSeTe of 304 becomes a film with few defects due to the effect of the porous layer.

Subsequently, in the laser structure using this film as the substrate, the active layer is ZnSeTe.
Further, the clad has a structure of ZnMgSeTe. No defects are introduced into the laser film due to the effect of the porous InP of the InP film used as the substrate.

According to the essence of the present invention, a substrate having a porous layer can form a film with few defects even in a film not lattice-matched with the substrate, and a substrate having a good II-VI film aligned with this film is produced. There is something that can be done. Therefore, it is not limited to ZnSeTe shown in Example 3. As some examples, ZnS, ZnTe, CdS, CdSe,
CdTe, ZnSSe, ZnMgSSe, ZnC
dS, CMgTe, ZnCdTe, ZnMgCdTe
A II-VI group compound represented by, for example, can be supplied in a state with few defects. When this is used as a substrate, a good II-VI group device can be manufactured.

(Embodiment 4) A second embodiment of the present invention is shown in FIG.
A description will be given using (a) to (e). This embodiment is an example using a GaP substrate and describes a specific laser configuration. It also describes a process of peeling the porous portion of the produced semiconductor laser.

In FIG. 4A, 401 is the porous region 4.
GaP substrate having 02. In order to manufacture such a substrate, an n-GaP substrate is ultrasonically cleaned with isopropyl alcohol and methyl alcohol, and then an electrode that makes electrical contact with Ga on the back surface of the substrate is manufactured. After that, anodization treatment can be performed in an HCl solution to form a porous region on the surface of the GaP substrate.

Next, as shown in FIG. 4B, porous GaP
On the surface of the layer, a surface layer 403 having the holes sealed is formed. In order to form such a layer, the porous GaP substrate 401 is loaded into a molecular beam epitaxy apparatus, and the substrate temperature is heated to about 600 ° C. while irradiating P. By this process, the oxide film on the surface of the GaP substrate is removed, and on the surface of the porous GaP from which the oxide film is removed, Ga migration occurs in the direction of smoothing the unevenness and lowering the surface energy. As a result, the surface of the porous GaP is flattened and buried as a thin GaP single crystal film. Next, as shown in FIG. 4C, a ZnSSe compound semiconductor layer 404 having a lattice constant of 0.55 nm is continuously formed on the surface portion 403. At this time, the thickness of the compound semiconductor layer 404 to be formed is made sufficiently thicker than the thickness of the surface portion 403.

As described above, the compound semiconductor 404
Of the porous GaP film 402, the lattice defects caused by the difference in the lattice constant with GaP and the difference in the coefficient of thermal expansion are fragile.
Is mainly introduced into the GaP surface layer 403 formed on
It is hardly introduced into the grown compound semiconductor layer 404. Therefore, the compound semiconductor single crystal layer 404 with very few defects can be obtained.

On this substrate, a semiconductor layer having a semiconductor film having the same lattice constant as 404 is laminated.

In FIG. 4D, 406 has the same structure as that of FIG. 411 has the same composition as the 404 layer, and n−
It is ZnMgS. On top of that, n-ZnMgS which is a clad layer 412 is formed. The lattice constant is 0.
55 nm. An optical confinement layer n indicated by 413 is formed on this.
-ZnMgSSe is formed. Reference numeral 418 is an active region. This structure will be described with reference to FIG. Reference numeral 414 denotes an active layer, which is ZnSSe having a lattice constant of 0.55 nm.
It is 6 nm. 415 is ZnMgS having the same composition as 413
Se is 10 nm. After forming p-ZnMgSSe, which is the upper optical confinement layer 416, on this, 41
P-ZnMgS, which is the upper clad layer shown in FIG. 7, is formed. Finally, p-ZnSSe shown in 419 is formed. The above is the laser configuration. As shown in Example 2, this laser portion may be peeled off from the porous GaP substrate and transferred to another substrate. Finally, the electrodes are formed and the fabrication of the semiconductor laser structure is completed.

As described above, by using a compound semiconductor having a porous film, this time porous GaP, a green ZnS laser having a lattice constant that is not matched with the substrate can be realized. It was Although the active layer and the barrier layer are not strained in this embodiment, they may be strained.

[0046]

According to the first aspect of the present invention, the porous G
By forming a thin GaAs thin film on the surface of a substrate having an aAs region and then growing a ZnSe film, a good quality film having different lattice constants can be obtained.

According to the second aspect of the present invention, porous Ga is used.
After forming a thin GaAs thin film on the surface of a substrate having an As region, a step of forming a high-quality ZnSe film having different lattice constants thereon, a step of manufacturing a device on this ZnSe film, and a step of etching the device to form a substrate. Separated from
A good blue laser device can be manufactured by a process including a transfer process.

According to the third aspect of the present invention, porous In
After the thin InP thin film is formed on the surface of the substrate having the P region, a good quality ZnSeTe film having different lattice constants can be obtained, and a good film can be formed.

According to the fourth aspect of the present invention, porous Ga is used.
A thin GaP thin film is formed on the surface of a substrate having a P region, and then a high-quality ZnMgS film having different lattice constants is formed on the thin GaP thin film to manufacture a good semiconductor laser device lattice-matched on the ZnMgS film. You can

[Brief description of drawings]

FIG. 1 is a diagram for explaining a first embodiment.

FIG. 2 is a diagram for explaining a second embodiment.

FIG. 3 is a diagram for explaining a third embodiment.

FIG. 4 is a diagram for explaining a fourth embodiment.

[Explanation of symbols]

101 GaAs substrate, 102 porous region, 103 Surface layer 104 compound semiconductor layer, 211 GaAs substrate, 212 porous region 213 surface layer, 214 a compound semiconductor layer, 222 clad layer, 223 optical confinement layer, 228 active layer, 226 upper optical confinement layer, 227 upper cladding layer, 301 InP substrate, 302 porous region, 303 surface layer, 304 compound semiconductor layer, 401 GaP substrate, 402 porous region, 403 surface layer, 404 compound semiconductor layer, 412 clad layer, 413 optical confinement layer, 414 active layer, 415 upper optical confinement layer, 416 Upper cladding layer.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Taku Ezaki             Kyano, 3-30-2 Shimomaruko, Ota-ku, Tokyo             Within the corporation F-term (reference) 5F041 AA40 CA05 CA34 CA35 CA37                       CA41 CA43 CA66 CA77                 5F045 AA05 AB22 AF04 BB16 CA12                       HA04                 5F073 AA45 AA73 AA74 CA22 CB02                       DA06 DA28

Claims (11)

[Claims] 1. A structure having a porous layer sandwiched between a semiconductor substrate and a first semiconductor film, and having a second semiconductor film on the semiconductor film, wherein the second semiconductor film has a II-VI group structure. A semiconductor structure comprising a compound semiconductor. 2. The semiconductor structure according to claim 1, wherein the first semiconductor film and the second semiconductor film have different lattice constants. 3. The semiconductor substrate is GaP, GaAs,
The semiconductor structure according to claim 1, wherein the semiconductor structure is InP. 4. A semiconductor device structure having a part of the structure according to any one of claims 1 to 3. 5. A semiconductor thin film fabrication, comprising: forming a porous layer on a semiconductor substrate; forming a thin film on the porous layer; and forming a layer containing a II-VI group on the thin film. Law. 6. The thin film and II- formed on the thin film
The method for producing a semiconductor thin film according to claim 5, wherein the group VI has different lattice constants. 7. The thin film and II- formed on the thin film
7. The method for producing a semiconductor thin film according to claim 5, wherein the group VI group lattice constants are the same. 8. The method for producing a semiconductor thin film according to claim 5, further comprising a step of attaching the thin film to a second substrate and a step of separating the original substrate. 9. A step of forming a multi-layered structure containing a II-VI group on the thin film, and II-VI formed on the thin film.
8. The method for manufacturing a semiconductor thin film according to claim 5, further comprising a step of attaching a multi-layered structure containing a group to a second substrate and a step of separating the original substrate. 10. The method for producing a semiconductor thin film according to claim 5, further comprising a step of attaching the thin film to a second substrate and a step of separating the original substrate. 11. The method for producing a semiconductor thin film according to claim 5, wherein the raw material for forming the film is a solid raw material, a hydride or an organic material.