JPH10223495A - Semiconductor device having flexible structure and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device having a flexible structure. SOLUTION: After hydrogen has been injected into an Si substrate 1 to a prescribed depth and a gate insulating film 2 and a gate 3 have been formed on the substrate 1, source and drain regions 4 are formed in the substrate. On the other hand, an SiO2 layer is formed on a second Si substrate. When heat treatment is performed, while the SiO2 layers on the substrate 1 and the second substrate are press-contacted with each other, the substrate 1 is divided into two parts from the hydrogen-injected region. The thinned substrate 1 is stuck to a flexible substrate 8, and the second Si substrate is removed by selectively etching the SiO2 layer on the second substrate. Since a semiconductor element, having a thickness of <=1μm, can be formed on the flexible substrate 8 in this way, a semiconductor device having a flexible structure can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor device, and more particularly to a semiconductor device having a flexible structure and a method of manufacturing the same.

[0002]

2. Description of the Related Art In the field of personal communication, the size and weight of communication devices have been remarkably reduced. Furthermore, flexibility is one of the characteristics that a human-friendly device should have. In other words, it will be important to develop equipment that does not break when bent. However, in a conventional semiconductor device such as a MOSFET, for example, the device itself has a thickness of about 1 μm. However, since this is formed on a semiconductor substrate having a thickness of about 500 μm, bending the semiconductor device may lead to destruction of the semiconductor device. .

Since a semiconductor device itself has a thickness of about 1 μm, a soft semiconductor device can be realized if the semiconductor device can be manufactured on a flexible material such as a plastic film. However, plastics generally have a problem with heat resistance. For this reason, development of plastics that can withstand high temperatures or lowering of the manufacturing process of the apparatus is an important issue. 10
There is a high temperature heat treatment exceeding 00 ° C., and there is a big wall in realizing plastics that can withstand high temperatures. In the latter case, for example, it is necessary to deposit polysilicon or SiO2 on a plastic substrate at a low temperature, but a high-quality interface between the SiO2 and the polysilicon formed at a low temperature cannot be obtained.

[0004]

As described above, the conventional semiconductor device structure and manufacturing method have a problem that a semiconductor device having a flexible structure cannot be realized. The present invention has been made to solve the above problems, and has as its object to realize a semiconductor device having a flexible structure and a method of manufacturing the same.

[0005]

According to the present invention, a semiconductor circuit comprising a fine semiconductor layer is formed on a flexible substrate. As described above, a semiconductor device having a flexible structure can be realized by forming a semiconductor circuit including a thin semiconductor layer over a flexible substrate having high flexibility. According to a second aspect of the present invention, a plurality of semiconductor circuits each formed of a thin semiconductor layer and stacked with a thin insulating layer interposed therebetween are formed on a flexible substrate. As described above, a semiconductor device having a flexible structure can be realized by forming a plurality of semiconductor circuits including thin semiconductor layers, which are stacked with a thin insulating layer interposed therebetween, over a flexible substrate. Further, as described in claim 3, the flexible substrate is a plastic substrate. The semiconductor layer is silicon.

According to another aspect of the present invention, a step of forming a semiconductor circuit composed of a fine semiconductor layer on a thin layer on the surface of a semiconductor substrate, and a step of removing a semiconductor substrate other than the thin layer including the semiconductor circuit. And a step of bonding a thin layer including a semiconductor circuit to a flexible substrate. As described above, a semiconductor device having a flexible structure can be realized by thinning a semiconductor substrate after the high-temperature manufacturing process of a semiconductor circuit is completed and bonding the thinned semiconductor substrate to a flexible substrate. According to a sixth aspect of the present invention, a step of forming a semiconductor circuit composed of a fine semiconductor layer on a thin layer on the surface of the first semiconductor substrate, and bonding the surface on which the semiconductor circuit is formed to a second semiconductor substrate A step of removing the first semiconductor substrate other than the thin layer including the semiconductor circuit; a step of bonding the thin layer including the semiconductor circuit to the flexible substrate;
Removing the semiconductor substrate. Thus, the surface on which the semiconductor circuit is formed is attached to the second semiconductor substrate, the first semiconductor substrate other than the thin layer including the semiconductor circuit is removed, and the thin layer including the semiconductor circuit and the flexible substrate are removed. By bonding and removing the second semiconductor substrate, a semiconductor device having a flexible structure can be realized.

According to another aspect of the present invention, a step of forming a semiconductor circuit comprising a fine semiconductor layer on a thin layer on the surface of the semiconductor substrate, and a step of bonding the surface on which the semiconductor circuit is formed to a flexible substrate And a step of removing a semiconductor substrate other than a thin layer including a semiconductor circuit. In this manner, a semiconductor device having a flexible structure can be realized by attaching a surface on which a semiconductor circuit is formed to a flexible substrate and removing a semiconductor substrate other than a thin layer including the semiconductor circuit. The step of removing the semiconductor substrate is a step of removing the semiconductor substrate by polishing or etching.

According to a ninth aspect of the present invention, in the step of forming a semiconductor circuit, ion implantation is performed on a semiconductor substrate.
This is a step of forming a semiconductor circuit in a thin layer between the region where the implanted ions enter and the substrate surface, and the step of removing the semiconductor substrate other than the thin layer including the semiconductor circuit is performed by performing a heat treatment in the region where the implanted ions enter. This is a step of dividing the semiconductor substrate. Further, as described in claim 10, the element used for the ion implantation is hydrogen or an inert gas. Further, as described in claim 11, the flexible substrate is a plastic substrate. Further, as described in claim 12, the semiconductor layer is silicon.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION

1. Embodiment 1. FIG. 1A is a sectional view of a semiconductor device according to a first embodiment of the present invention. This semiconductor device has a MOSF on a flexible substrate 8 made of plastic.
A semiconductor element having a thickness of 1 μm or less for ET is formed. The semiconductor element includes a silicon (Si) thin film 1, a gate insulating film 2, a gate 3 made of polysilicon, and source / drain regions to which impurities are added. 4. It comprises a source electrode and a drain electrode (not shown) formed on the source / drain region 4. Here, as one example of forming a semiconductor circuit on the flexible substrate 8, one MO
Although an SFET is shown, this is for ease of explanation.

As described above, since the semiconductor element having a thickness of 1 μm or less is formed on the flexible substrate 8 which is rich in flexibility, FIG.
As shown in (b), a semiconductor device having a flexible structure can be realized. For comparison, SOI (Silicon On I
FIG. 2 shows a cross section of a conventional semiconductor device using the substrate 31. The upper silicon layer 31a of the SOI substrate 31 is shown in FIG.
The semiconductor device shown in FIG. 1 is supported by a solid Si substrate 31c and an SiO2 layer 31b as an interlayer insulating film, in which a semiconductor element formed of a gate insulating film 32, a gate 33, and a source / drain region 34 is supported. different.

Embodiment 2 Next, as another embodiment of the present invention, a method 1 of manufacturing the semiconductor device shown in FIG.
An example will be described. 3 and 4 are cross-sectional views illustrating the steps of manufacturing the semiconductor device of FIG. First, as shown in FIG. 3A, hydrogen is implanted into the first Si substrate 1 at a predetermined depth (position indicated by a broken line in the figure) by ion implantation.

After a gate insulating film 2 and a gate 3 made of polysilicon are formed in a predetermined region on the Si substrate 1, ions of boron or the like are implanted by using the gate structure to form a source / drain region 4. Are formed in a self-aligned manner (FIG. 3B). Subsequently, the surface of such a structure has C
The SiO2 layer 5 is formed by the VD method or the like (FIG. 3)
(C)). Here, the SiO2 layer 5 may be lightly polished after deposition so that the surface becomes flat.

On the other hand, as shown in FIG.
An SiO2 layer 7 is formed on the surface of the i-substrate 6. And S
When the SiO2 layer 5 on the i-substrate 1 and the SiO2 layer 7 on the Si substrate 6 are brought into close contact and heat-treated at 400 to 600 DEG C. (FIGS. 3E and 3F), the SiO2 layer 5 SiO2
The layer 7 is integrated, and the Si substrate 1 is divided at the hydrogen injection region (the location indicated by the broken line in the figure) as a boundary (FIG. 4).
(A)).

A method of dividing the substrate in the hydrogen implanted region is a method known as SmartCut proposed by Bruel (for Smart Cut, see “Electronics Letters, Vo.
l. 31, No. 14, 1995, pp. 1201 ").

Next, as shown in FIG.
The Si substrate 1 thinned in the step (a) is attached to the flexible substrate 8 with an adhesive. Then, the second Si substrate 6
Is for holding the semiconductor element in the process after the first Si substrate 1 is made thinner, and therefore becomes unnecessary after the semiconductor element is attached to the flexible substrate 8. Therefore, the Si substrate 6 is removed by selectively etching the SiO2 layer 5 and the SiO2 layer 7 using hydrofluoric acid (HF) (FIG. 4).
(C)). Finally, a source electrode and a drain electrode (not shown) are formed on the source / drain regions 4.

By a series of steps as described above, FIG.
The semiconductor device of (a) is manufactured. Note that, in the present embodiment, S
Although the i-substrate 1 is thinned, it may be thinned by polishing or etching. In addition, SiO by hydrofluoric acid
Although the Si substrate 6 is removed by selective etching of the two layers 5 and 7, the Si substrate 6 and the SiO2 layers 7 and 5 may be sequentially removed from the upper layer by polishing or etching.

Embodiment 3 In the second embodiment, the Si substrate 1 having the semiconductor element formed on its surface is thinned and attached to the flexible substrate 8. However, the semiconductor element is attached upside down to the flexible substrate 8. Is also good. FIG. 5 is a cross-sectional view showing a manufacturing process of such a semiconductor device as another embodiment of the present invention.

First, as shown in FIG. 5A, after a gate insulating film 2a and a gate 3a made of polysilicon are formed in a predetermined region on a Si substrate 1a, ions of boron or the like are formed by using this gate structure. Implantation is performed to form source / drain regions 4a. And, on such a structure,
An O2 layer 5a is formed and its surface is planarized by polishing or etching (FIG. 5B).

Subsequently, the flattened surface is attached to the flexible substrate 8a with an adhesive (FIG. 5C). Finally, the Si substrate 1a other than the thin layer on which the semiconductor element is formed is removed by polishing or etching (FIG. 5).
(D)). Thus, a semiconductor device in which the semiconductor element in FIG. 1 is turned upside down can be manufactured.

Embodiment 4 In the first to third embodiments, one semiconductor element is formed on a flexible substrate, but an element formed on a substrate may be formed by stacking a plurality of semiconductor elements. FIGS. 6, 7, and 8 are cross-sectional views showing a manufacturing process of such a semiconductor device as another embodiment of the present invention.

6 (a) to 6 (f) and FIG. 7 (a) are the same as the steps from FIG. 3 (a) to FIG. 3 (f) and FIG. 4 (a). That is, the Si substrate 1 is formed by ion implantation.
b is implanted at a predetermined depth (FIG. 6A),
After a gate insulating film 2b and a gate 3b made of polysilicon are formed on the gate electrode b, ions of boron or the like are implanted using the gate structure to form a source / drain region 4b (FIG. 6B). Then, S on the surface of such a structure
An iO2 layer 5b is formed (FIG. 6C).

On the other hand, as shown in FIG. 6D, an SiO2 layer 7b is formed on the surface of the Si substrate 6b. And Si
When the O2 layer 5b and the SiO2 layer 7b are brought into close contact with each other,
When heat treatment is performed at 600 ° C. (FIG. 6E, FIG.
(F)), the SiO2 layer 5b and the SiO2 layer 7b are integrated, and the Si substrate 1b is divided at the boundary of the hydrogen injection region (the location indicated by the broken line in the figure) (FIG. 7A).

Next, the Si thinned in the step of FIG.
The surface of the substrate 1b is thermally oxidized to form the SiO2 layer 9b (FIG. 7B). On the other hand, FIG. 6 (a) is used by using a Si substrate separated for thinning (hereinafter, this Si substrate is referred to as 1c in order to distinguish it from the thinned substrate 1b on which semiconductor elements are formed). 6) to 6 (c) are repeated.

That is, hydrogen is implanted at a predetermined depth in the Si substrate 1c, and the gate insulating film 2c and the gate 3 are formed on the substrate 1c.
After forming c, source / drain regions 4c are formed. Then, an SiO2 layer 5c is formed on the surface of such a structure (FIG. 7C). Subsequently, S on the Si substrate 1c
When the iO2 layer 5c and the SiO2 layer 9b on the Si substrate 6b are brought into close contact with each other and heat-treated at 400 to 600 DEG C. (FIG. 7).
(D), FIG. 7 (e)), SiO2 layer 5c and SiO2 layer 9
b are integrated, and the Si substrate 1c is divided at the boundary of the hydrogen implantation region (the location indicated by the broken line in the figure) (FIG. 8).
(A)).

Then, as shown in FIG. 8B, the thinned Si substrate 1c is attached to the flexible substrate 8b with an adhesive. Finally, the SiO2 layers 5b and 7 are formed using hydrofluoric acid.
b is selectively etched to remove the Si substrate 6b (FIG. 8C). Further, by polishing or etching, the Si substrate 6b and the SiO2 layers 7b, 5b
It is needless to say that may be removed.

Through a series of steps as described above, a semiconductor device in which a plurality of semiconductor elements are stacked can be realized. Note that, in this embodiment, an example in which two semiconductor elements are stacked is described, but the thickness of the element after stacking is 1 μm.
Three or more layers may be stacked as long as they are thin and flexible, and in this case, FIGS. 7B to 7E
Needless to say, it is only necessary to repeat the step as many times as necessary.

Embodiment 5 FIG. 9 is a sectional view of a semiconductor device showing another embodiment of the present invention. This semiconductor device has an MO on a flexible substrate 21 made of plastic.
A semiconductor element having a thickness of 1 μm or less to be an SFET is formed, and the semiconductor element is a silicon (Si) thin film 1
1, 14; SiO2 layers 12 and 15, source / drain regions 13, SiO2 layers 16 and 20 serving as gate insulating films, polysilicon layer 19 serving as gates, and source and drain electrodes formed on source / drain regions 13. (Not shown).

Embodiment 6 Next, a method of manufacturing the semiconductor device of FIG. 9 will be described as another embodiment of the present invention. 10 and 11 are cross-sectional views illustrating the steps of manufacturing the semiconductor device of FIG. First, as shown in FIG.
The i-substrate 11 is thermally oxidized to form a SiO2 layer 12, and impurity ions are implanted through the SiO2 layer 12 to form source / drain regions 13. Further, hydrogen is implanted into the Si substrate 11 at a predetermined depth (position indicated by a broken line in the figure) by ion implantation.

Subsequently, after forming the SiO 2 layer 15 on the surface of the Si substrate 14, the SiO 2 layer 12 on the Si substrate 11 is formed.
And the SiO2 layer 15 on the Si substrate
When heat treatment is performed at 00 to 600 ° C. (FIG. 10B), S
The SiO 2 layer 12 and the SiO 2 layer 15 are integrated, and the Si substrate 1 is bounded by a hydrogen injection region (a location indicated by a broken line in the drawing).
1 is divided. Then, the temperature is raised as it is to activate the ion-implanted impurities.

Next, the surface of the Si substrate 11 thinned in the step of FIG. 10B is thermally oxidized to form an SiO2 layer 16 (FIG. 10C). Then, hydrogen ions are implanted from the surface of the SiO2 layer 16 to a predetermined depth of the Si substrate 14 (FIG. 10D). On the other hand, as shown in FIG.
SiO2 layer 18 and polysilicon layer 1 on Si substrate 17
9. An SiO2 layer 20 is sequentially formed.

The SiO 2 layer 16 on the Si substrate 14 and the SiO 2 layer 20 on the Si substrate 17 are brought into close contact with each other,
When heat treatment is performed at 00 ° C. (FIG. 11B), the SiO 2 layer 16 and the SiO 2 layer 20 are integrated, and the Si substrate 14 is divided at the hydrogen injection region (the location indicated by the broken line in the figure). Next, the thinned Si substrate 14 is attached to the flexible substrate 21 with an adhesive (FIG. 11C).

Finally, by etching using hydrofluoric acid, the SiO 2 layer 18 is selectively etched to separate the Si substrate 17, and the SiO 2 layers 16 and 20 on the source / drain regions 13, the polysilicon layer By removing 19 and forming a source electrode and a drain electrode (not shown) on the source / drain region 13, the semiconductor device of FIG. 9 can be manufactured.

When forming the source and drain structures in the step of FIG. 10A, the order of thermal oxidation and impurity ion implantation may be reversed. Also, impurity diffusion may be used instead of ion implantation. The polysilicon layer 19 is made of crystalline Si.
It may be a layer. Further, the Si substrate 14 may be removed in the step of FIG. In this case, FIG.
The depth at which hydrogen ions are implanted in the step
The substrate 14 is removed by making it coincide with the interface of the layer 15, and the SiO2 layer 15 is attached to the flexible substrate 21 in the step of FIG. The hydrogen implanted in the step of FIG. 10D may be implanted in the Si substrate 14 in advance. In this case, the injection amount is controlled so as not to be cracked by the heat treatment in the step of FIG.

In the above embodiment, the MOSFET has been described as an example of the semiconductor element. However, a planar type bipolar transistor or another element structure may be used. Also,
Needless to say, instead of one semiconductor element, an integrated circuit including a plurality of semiconductor elements may be two-dimensionally arranged on the flexible substrate. Further, in the present embodiment, hydrogen is used as an element used in the smart cut method for thinning the Si substrate, but an inert gas may be used.

[0035]

According to the present invention, as described in the first aspect, a semiconductor circuit comprising a fine semiconductor layer is formed on a flexible substrate having a high flexibility, so that a semiconductor device having a flexible structure is provided. Can be realized. Since the semiconductor circuit can be manufactured at a high temperature, the characteristics of the semiconductor circuit do not deteriorate due to the formation at a low temperature, and there is no need to use a flexible substrate that can withstand a high temperature. Further, if a transparent material is used for the flexible substrate, light can be introduced from the back surface of the element, and a structure convenient for a semiconductor device performing photoelectron fusion can be realized.

Further, since a plurality of semiconductor circuits composed of fine semiconductor layers, which are stacked with a fine insulating layer interposed therebetween, are formed on a flexible substrate, a plurality of semiconductor circuits are formed. A stacked semiconductor device having a flexible structure can be realized. Since the semiconductor circuit can be manufactured at a high temperature, the characteristics of the semiconductor circuit do not deteriorate due to the formation at a low temperature, and there is no need to use a flexible substrate that can withstand a high temperature. Further, if a transparent material is used for the flexible substrate, light can be introduced from the back surface of the element, and a structure convenient for a semiconductor device performing photoelectron fusion can be realized.

According to a fifth aspect of the present invention, after the high-temperature manufacturing step of the semiconductor circuit is completed, the semiconductor substrate other than the thin layer including the semiconductor circuit is removed, and the thin layer including the semiconductor circuit and the flexible substrate are removed. By bonding the semiconductor devices, a semiconductor device having a flexible structure can be realized. In addition, since the semiconductor circuit can be manufactured at a high temperature, the characteristics of the semiconductor circuit do not deteriorate due to the formation at a low temperature, and there is no need to use a flexible substrate that can withstand a high temperature.

Further, the surface on which the semiconductor circuit is formed is bonded to the second semiconductor substrate, and the first semiconductor substrate other than the thin layer including the semiconductor circuit is removed,
A thin layer including a semiconductor circuit is bonded to a flexible substrate to form a second layer.
By removing the semiconductor substrate, a semiconductor device having a flexible structure can be realized. In addition, since the semiconductor circuit can be manufactured at a high temperature, the characteristics of the semiconductor circuit do not deteriorate due to the formation at a low temperature, and there is no need to use a flexible substrate that can withstand a high temperature.

According to the present invention, the surface on which the semiconductor circuit is formed is attached to a flexible substrate, and the semiconductor substrate other than the thin layer including the semiconductor circuit is removed.
A semiconductor device having a flexible structure can be realized. In addition, since the semiconductor circuit can be manufactured at a high temperature, the characteristics of the semiconductor circuit do not deteriorate due to the formation at a low temperature, and there is no need to use a flexible substrate that can withstand high temperatures.

In addition, as described in claim 8, the semiconductor substrate according to claim 5, the first and second semiconductor substrates according to claim 6, and the semiconductor substrate according to claim 7 can be easily polished or selectively etched. The semiconductor circuit can be easily thinned.

According to a ninth aspect of the present invention, in the step of forming a semiconductor circuit, a step of introducing a defect into the semiconductor substrate by performing ion implantation on the semiconductor substrate and removing the semiconductor substrate is performed by a heat treatment. , The semiconductor substrate according to claim 5, the first semiconductor substrate according to claim 6, and the semiconductor substrate according to claim 7 can be easily removed, and the thickness of the semiconductor circuit can be easily reduced. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a conventional semiconductor device using an SOI substrate.

FIG. 3 is a cross-sectional view showing a step of manufacturing the semiconductor device of FIG. 1 as another embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a manufacturing process of the semiconductor device of FIG. 1 as another embodiment of the present invention;

FIG. 5 is a cross-sectional view showing a step of manufacturing a semiconductor device as another embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a step of manufacturing a semiconductor device as another embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a step of manufacturing a semiconductor device as another embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a step of manufacturing a semiconductor device as another embodiment of the present invention.

FIG. 9 is a cross-sectional view of a semiconductor device according to another embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a step of manufacturing the semiconductor device of FIG. 9 as another embodiment of the present invention;

FIG. 11 is a cross-sectional view showing a step of manufacturing the semiconductor device of FIG. 9 as another embodiment of the present invention;

[Explanation of symbols]

1, 6, 1a, 1b, 1c, 11, 14, 17 ... Si substrate, 2, 2a, 2b, 2c ... Gate insulating film, 3, 3a,
3b, 3c: gate, 4, 4a, 4b, 4c, 13 ... source / drain regions, 5, 7, 5a, 5b, 7b, 9
b, 5c, 12, 15, 16, 18, 20 ... SiO2
Layers 8, 8a, 8b, 21: flexible substrate, 19: polysilicon layer.

Claims (12)

[Claims] 1. A semiconductor device having a flexible structure, wherein a semiconductor circuit including a fine semiconductor layer is formed on a flexible substrate. 2. A semiconductor device having a flexible structure, wherein a plurality of semiconductor circuits each including a thin semiconductor layer, which are stacked with a thin insulating layer interposed therebetween, are formed on a flexible substrate. 3. The semiconductor device having a flexible structure according to claim 1, wherein the flexible substrate is a plastic substrate. 4. The semiconductor device having a flexible structure according to claim 1, wherein said semiconductor layer is made of silicon. 5. A step of forming a semiconductor circuit comprising a fine semiconductor layer on a thin layer on the surface of a semiconductor substrate; a step of removing a semiconductor substrate other than the thin layer including the semiconductor circuit; And a step of bonding a flexible substrate to the semiconductor device. 6. A step of forming a semiconductor circuit comprising a fine semiconductor layer on a thin layer on the surface of a first semiconductor substrate, a step of bonding the surface on which the semiconductor circuit is formed to a second semiconductor substrate, A step of removing a first semiconductor substrate other than a thin layer including: a step of bonding a thin layer including the semiconductor circuit to a flexible substrate; and a step of removing a second semiconductor substrate. Of manufacturing a semiconductor device having a flexible structure. 7. A step of forming a semiconductor circuit composed of a fine semiconductor layer on a thin layer on a surface of a semiconductor substrate, a step of bonding the surface on which the semiconductor circuit is formed to a flexible substrate, and a thin layer including the semiconductor circuit. And a step of removing a semiconductor substrate other than the above. 8. The method for manufacturing a semiconductor device having a flexible structure according to claim 5, wherein the step of removing the semiconductor substrate is a step of removing the semiconductor substrate by polishing or etching. A method for manufacturing a semiconductor device having a flexible structure. 9. The method for manufacturing a semiconductor device having a flexible structure according to claim 5, wherein, in the step of forming the semiconductor circuit, ion implantation is performed on a semiconductor substrate, and a region where the implanted ions enter and a substrate surface are formed. Forming a semiconductor circuit in a thin layer between the two.The step of removing the semiconductor substrate other than the thin layer including the semiconductor circuit is a step of performing a heat treatment to divide the semiconductor substrate in the intrusion region of the implanted ions. A method for manufacturing a semiconductor device having a flexible structure. 10. The method for manufacturing a semiconductor device having a flexible structure according to claim 9, wherein the element used for the ion implantation is hydrogen or an inert gas. Production method. 11. The method for manufacturing a semiconductor device having a flexible structure according to claim 5, 6 or 7, wherein the flexible substrate is a plastic substrate. Production method. 12. The method for manufacturing a semiconductor device having a flexible structure according to claim 5, 6 or 7, wherein the semiconductor layer is silicon.