JPH09121039A - Semiconductor member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To specify the characteristic of a single crystal layer by selectively etching a semiconductor substrate wherein a non-porous semiconductor single crystal layer is left and is changed to a porous substrate. SOLUTION: A porous Si layer 21 is formed on a P-type Si substrate through an anode formation method, and a thin-film single crystal layer is formed on the surface thereof through epitaxial growth by using a crystal growth method by which a low-temperature growth can be realized. An oxide layer 24 is formed on the surface of another Si substrate 23, and it is adhered to the surface of the layer 22 on the porous Si substrate 21. Then, the substrate 21 is entirely etched for removal so as to form the layer 22 on the layer 24. Since the porous semiconductor layer is etched for removal without oxidizing the porous semiconductor layer, the porous semiconductor layer can be prevented from oxidization expansion, and the influence of deformation on the epitaxially grown single crystal layer can be prevented. In the non-porous single crystal layer 22 on an insulator 24, the time life of a carrier is 5.0×10<-4> sec or more, and the transition failure density is 2×10<4> /cm<2> or less.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a semiconductor member. More specifically, the present invention relates to a semiconductor member suitable for an electronic device or an integrated circuit, which is formed on a single crystal semiconductor layer on a dielectric or on an insulator.

[0002]

2. Description of the Related Art The formation of a single crystal Si semiconductor layer on an insulator is widely known as a silicon-on-insulator (SOI) technique and has many advantages that cannot be reached by a bulk Si substrate for producing a normal Si integrated circuit. Much research has been done because devices that use SOI technology have. That is, by using the SOI technology, Dielectric separation is easy and high integration is possible 1. Excellent radiation resistance 3. 3. Stray capacitance is reduced and high speed is possible. 4. The well process can be omitted. Latch-up can be prevented 6. Advantages such as the possibility of fully depleted field effect transistor by thinning the film can be obtained.

[0003] In order to realize many of the above advantages in device characteristics, researches have been made on a method of forming an SOI structure for several decades. The contents are summarized in, for example, the following documents.

Special Issue: "Sin
gle-crystal silicon on no
n-single-crystal insulator
rs ″; edited by GW Cullen,
Journal of Crystal Growth
h, volume 63, no 3, pp 429-5
90 (1983). Also, from the old days, SOS (silicon on sapphire) formed by heteroepitaxy Si on a single crystal sapphire substrate by CVD (chemical vapor deposition) is known. Although this was successful as the most mature SOI technology, a large amount of crystal defects due to lattice mismatch between the Si layer and the underlying sapphire substrate interface, mixing of aluminum from the sapphire substrate into the Si layer,
Above all, due to the high cost of the substrate and the delay in increasing the area, the spread of its application is hindered. In recent years, attempts have been made to realize an SOI structure without using a sapphire substrate. This attempt is roughly divided into the following three.

(1) After the surface of a Si single crystal substrate is oxidized, a window is opened to partially expose the Si substrate, and the portion is used as a seed for lateral epitaxial growth to form a Si single crystal layer on SiO _2. To do. (In this case, SiO ₂
With the deposition of a Si layer on top. (2) Using the Si single crystal substrate itself as the active layer,
SiO ₂ is formed thereunder. (This method does not involve deposition of a Si layer.) (3) Insulation separation is performed after Si is epitaxially grown on a Si single crystal substrate. (This method uses Si
With the deposition of layers. )

[0006]

As means for achieving the above (1), a method of directly laterally epitaxially growing a single crystal layer Si by CVD, a method of depositing amorphous Si, and performing a heat treatment to solid-phase lateral direction Epitaxial growth method, amorphous or polycrystalline Si layer focused and irradiated with electron beam, laser beam, or other energy beam to grow a single crystal layer on SiO ₂ by melting and recrystallization, and rod heater A method of scanning the melted region in a band shape by using the method (Zone melting recrystallization).
zation) is known. Each of these methods has advantages and disadvantages, but their controllability, productivity, uniformity,
There are still many problems in quality, and none have been industrially put to practical use. For example, the CVD method requires sacrificial oxidation to achieve a flat thin film, and the solid phase growth method has poor crystallinity. Further, the beam annealing method has a problem in controllability such as processing time by convergent beam scanning, beam overlap, focus adjustment, and the like. Of these, Zone Mel
Although the toning recrystallization method is the most mature, and relatively large-scale integrated circuits have been prototyped, many crystal defects such as point defects, line defects, and surface defects (subgrain boundaries) remain. And I haven't even made a minority carrier device.

The method (2) above, in which the Si substrate is not used as seeds for epitaxial growth, includes, for example, the following method.

[0008] 1. An oxide film is formed on a Si single crystal substrate in which V-shaped grooves are anisotropically etched on the surface, and a polycrystalline Si layer is deposited on the oxide film to be as thick as the Si substrate.
By polishing from the back surface of the i substrate, a Si single crystal region surrounded by the V groove and dielectrically separated is formed on the thick polycrystalline Si layer. In this method, although the crystallinity is good, the step of depositing polycrystalline Si to a thickness of several hundreds of microns, single crystal Si
There is a problem in terms of controllability and productivity in the step of polishing the substrate from the back surface and leaving only the separated Si active layer.

[0009] 2. SIMOX: Sepa
relation by ion-implanted o
xygen) is a method of forming a SiO ₂ layer by ion implantation of oxygen into a Si single crystal substrate, and is one of the most mature methods at present because it has good compatibility with the Si process. However, in order to form a SiO ₂ layer, it is necessary to implant oxygen ions at a dose of 10 ¹⁸ ions / cm ² or more, but the implantation time is long and the productivity cannot be said to be high. The cost is high. Furthermore,
Many crystal defects remain, and from an industrial viewpoint, the quality is not sufficient to produce a minority carrier device.

3. A method of forming an SOI structure by dielectric isolation by oxidation of porous Si. This method uses P-type Si
Proton ion implantation of N-type Si layer on the surface of single crystal substrate,
(Imai et al., J. Crystal Growth, Vo
63, 547 (1983)) or by epitaxial growth and patterning to form islands, and only the P-type Si substrate is made porous from the surface by anodization in a HF solution so as to surround the Si islands. This is a method of dielectrically separating N-type Si islands by rapid oxidation. In this method,
The separated Si region is determined before the device process, which may limit the degree of freedom in device design.

As the method (3) described above, Japanese Patent Laid-Open No. 55-
No. 16464 discloses that an N-type single crystal Si layer is formed on a p-type Si wafer, and a glass layer containing an oxide of an N-type impurity is provided on the N-type single crystal Si layer.
It has a step of bonding a glass layer containing an oxide of N-type impurities provided on another silicon wafer by heat treatment. Then, after the bonding step, a P-type S
After the i-wafer is made porous, the porous layer is oxidized and the porous layer is removed by etching to form an SOI structure.

Further, in Japanese Patent Application Publication No. 53-45675, after a silicon single crystal wafer is made porous, the silicon single crystal wafer is oxidized to increase the resistance of the porous layer, and the porous layer is formed on the silicon layer. It is disclosed that a single crystal Si layer is formed, and a part of the single crystal Si layer is made porous so as to surround the single crystal Si region and the resistance is increased to separate the single crystal Si layer.

Each of the methods described in these publications includes a step of oxidizing the porous layer. Since the porous layer expands due to oxidation, the single crystal Si layer may be affected by strain. However, these methods have not always been able to constantly form a good quality single crystal Si layer on an insulator.

(Object of the Invention) An object of the present invention is to provide a semiconductor member which can meet the above problems and the above requirements.

Another object of the present invention is to provide a semiconductor member having a single crystal wafer with excellent crystallinity and an excellent single crystal layer on an insulator.

Still another object of the present invention is to use expensive SOS and SI even when manufacturing a large scale integrated circuit having an SOI structure.
It is an object of the present invention to provide a semiconductor member having excellent characteristics that can replace MOX.

The preferred semiconductor member of the present invention is as follows.

The semiconductor member of the present invention is a semiconductor member in which a non-porous silicon single crystal semiconductor region is arranged on a region made of an insulating material, and the dislocation defect density in the non-porous silicon single crystal semiconductor region is 2.0 × 10 ⁴ / cm ²
Below, the lifetime of the carrier is 5.0 × 10 ^-4 se
It is characterized by being c or more.

In addition, a non-porous silicon single crystal semiconductor region is disposed on a region made of an insulating material, and the dislocation defect density in the non-porous silicon single crystal semiconductor region is 2. 0 × 10 ⁴ / cm ² or less, the carrier lifetime is 5.0 × 10 ⁻⁴ sec or more, and the difference between the maximum value and the minimum value of the thickness of the silicon single crystal semiconductor region is 15 times the maximum value. % Or less.

(Function) The semiconductor member of the present invention has a single crystal semiconductor region having a large carrier lifetime and extremely few defects on an insulator with excellent uniformity of film thickness. Can be applied to. Further, the semiconductor member of the present invention is capable of high-speed response,
It can be applied to highly reliable semiconductor devices. or,
The semiconductor member of the present invention can be a substitute for expensive SOS and SIMOX.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below by taking silicon as an example of a semiconductor material, but the semiconductor material in the present invention is not limited to silicon.

According to observation with a transmission electron microscope, pores having an average diameter of about 600 Å are formed in the porous Si layer, and the density thereof is less than half that of single crystal Si. However, the single crystallinity is maintained. A single crystal is a crystalline solid whose orientation is the same in any part of the sample when attention is paid to any crystal axis, but the porous layer used in the present invention has pores. However, the crystal axis of the crystalline region is the same in every part, and is a single crystal. Then, it is possible to epitaxially grow a single crystal Si layer on the porous layer. However, at a temperature of 1000 ° C. or higher, rearrangement of atoms located around the inner hole may occur, and the characteristics of the enhanced etching may be impaired. Therefore, in the present invention, S
For the epitaxial growth of the i layer, a molecular beam epitaxial growth method, a plasma CVD method, a low pressure CVD method, a photo CVD method, a bias sputtering method, a liquid phase growth method, or another crystal growth method capable of low temperature growth is preferably used.

Since the porous layer has a large amount of voids formed therein, the density thereof can be reduced to less than half. as a result,
Since the surface area per unit volume (specific surface area) is drastically increased, the chemical etching rate thereof is significantly increased as compared with the etching rate of a normal non-porous single crystal layer. The present invention maintains the two characteristics of the above-described porous semiconductor, that is, single crystallinity, and allows epitaxial growth of a non-porous semiconductor single crystal on the porous semiconductor substrate, and a non-porous single crystal. It utilizes the fact that the etching rate is remarkably higher than that of, and a high quality non-porous semiconductor single crystal layer can be formed in a short time on a substrate having an insulating material surface.

The porous layer is made of N-type Si for the following reason.
Formed more easily on the P-type Si layer than on the layer. First, porous Si
Was discovered by Uhril et al. In the process of research on electropolishing of semiconductors in 1956 (A. Uhril, Be.
ll Syst. Tech. J. , Vol 35, p.
333 (1956)).

Unagami et al. Studied the dissolution reaction of Si in anodization, and reported that the anodic reaction of Si in an HF solution requires holes, and the reaction is as follows ( T. Unami: J. Electrochem. S
oc. , Vol. 127, p. 476 (1980)).

That is, Si + 2HF + (2-n) e ⁺ → SiF ₂ + 2H ⁺ + ne ^- SiF ₂ + 2HF → SiF ₄ + H ₂ SiF ₄ + 2HF → H ₂ SiF ₆ or Si + 4HF + (4-λ) e ⁺ → SiF ₄ + 4H ⁺ + Λe ^- SiF ₄ + 2HF → H ₂ SiF ₆

Here, e ⁺ and e ⁻ represent holes and electrons, respectively. N and λ are silicon 1
It is the number of holes necessary for the atoms to dissolve, and it is said that porous silicon is formed when the condition of n> 2 or λ> 4 is satisfied.

From the above, P-type silicon in which holes are present is more likely to be made porous than N-type silicon having the opposite characteristic. Selectivity in this porosification has been demonstrated by Nagano et al. And Imai (Nagano, Nakajima, Anno, Ohnaka,
Kajiwara; Technical Report of IEICE, vol 79, SS
D 79-9549 (1979), (K. Imai; So
lid-State Electronics Vol
24, 159 (1981)). However, N-type silicon can be made porous depending on the setting of conditions.

The present invention will be specifically described below with reference to the drawings.

[Embodiment 1] A method for obtaining a semiconductor substrate by making all P-type substrates porous and epitaxially growing a single crystal layer will be described.

As shown in FIG. 1A, first, P-type Si is used.
A single crystal substrate is prepared and the whole is made porous. The thin film single crystal layer 22 is formed by performing epitaxial growth on the surface of the porous substrate by the crystal growth method capable of low temperature growth.
To form The P-type Si substrate is made porous by an anodization method using an HF solution. The porous Si layer 21 has a density of 1.1 to 0.6 g / cm ³ by changing the density of the single crystal Si from 2.33 g / cm ³ to an HF solution concentration of 50 to 20%. The range can be changed.

Next, as shown in FIG. 1B, another Si substrate 23 is prepared, an oxide layer 24 is formed on the surface thereof, and then the single crystal Si layer 22 on the porous Si substrate 21 is formed.
The Si substrate 23 having the oxide layer 24 on the surface is attached to the surface. After this, as shown in FIG.
The i substrate 21 is entirely removed by etching to form a thinned single crystal silicon layer 22 on the SiO ₂ layer 24. In the present invention, in order to etch away the porous semiconductor layer without subjecting the porous semiconductor layer to oxidation treatment,
Oxidative expansion of the porous semiconductor layer can be prevented, and influence of strain on the epitaxially grown single crystal layer can be prevented. According to this method, the single crystal Si layer 22 having the crystallinity equivalent to that of the silicon wafer is flattened and uniformly thinned on the oxide Si layer 24 which is an insulator, so that the whole area of the wafer becomes large. It is formed. The semiconductor substrate thus obtained can be suitably used also in the production of an electronic element which is insulated and separated.

The layer thickness of the non-porous semiconductor crystal layer formed on the porous semiconductor substrate is preferably 50 μm or less, more preferably 20 μm or less for forming the semiconductor single crystal layer in the thin film semiconductor device. Is desirable.

Further, the non-porous semiconductor single crystal and the substrate having an insulating material surface are stuck together in an atmosphere of nitrogen, an inert gas or a mixed gas thereof, or in an atmosphere containing an inert gas or nitrogen. It is preferable to carry out in the above, and it is more preferable to carry out in the heated state.

As an etchant for selectively etching the porous semiconductor substrate while leaving the non-porous semiconductor single crystal layer bonded on the substrate having the insulating material surface, for example, an aqueous solution of sodium hydroxide, Examples of the etchant include an aqueous solution of potassium hydroxide and a mixed solution of hydrofluoric acid-nitric acid-acetic acid.

Further, the base having an insulating material that can be used in the present invention means that at least the surface of the base is made of an insulating material, or the whole base is made of an insulating material. Good. Examples of the substrate whose surface is made of an insulating material include those obtained by oxidizing the surface of a single crystal or polycrystalline silicon substrate, and insulating a conductive or semiconductive substrate surface with oxides, nitrides, borides, etc. For example, a material layer is formed. Further, as a specific example of the base body in which the entire base body is made of an insulating material, a base body made of an insulating material such as quartz glass or sintered alumina can be cited.

In the first embodiment, an example in which a non-porous semiconductor single crystal layer is formed on a porous semiconductor substrate has been shown, but the present invention is limited to the mode of the first embodiment. Instead, the substrate having a single crystal layer made of a material that is difficult to be made porous (eg N-type silicon) and a layer made of a material that is easily made porous (eg P-type silicon) is subjected to a porosification treatment, A porous semiconductor substrate having a non-porous semiconductor single crystal layer may be formed.

In addition, in the step of removing the porous semiconductor substrate by etching, the non-porous semiconductor single crystal layer and the substrate having the surface of the insulating material are prevented from being adversely affected by the etchant during the etching treatment. It may be covered with an etching preventing material except for the semiconductor substrate.

The non-porous single crystal layer on the insulator thus formed has a carrier lifetime of 5.0 ×.
It can be 10 ⁻⁴ sec or more, and has significantly less crystal defects such as threading dislocations compared to the semiconductor single crystal layer obtained by SIMOX, and the layer thickness distribution of the semiconductor single crystal layer is extremely small. .

Specifically, the dislocation defect density is 2 × 10 ^4.
/ Cm ² or less, and regarding the layer thickness of the semiconductor single crystal layer, the area of the surface of the semiconductor single crystal layer is 20 cm ^{2 to} 500 cm ² (2
In the range of inch wafer to 10 inch wafer), the difference between the maximum thickness and the minimum thickness of the semiconductor single crystal layer can be suppressed to 10% or less with respect to the maximum thickness.

Hereinafter, other embodiments will be shown.

Embodiment 2 Embodiment 2 will be described below in detail with reference to FIG.

First, as shown in FIG. 2A, a low impurity concentration layer 122 is formed by epitaxial growth by various thin film growth methods. Alternatively, the P-type Si single crystal substrate 1
N-type single crystal layer 1 by implanting protons on the surface of 21
22 is formed.

Next, as shown in FIG. 2B, a P type S
The i single crystal substrate 121 is transformed from the back surface into a porous Si substrate 123 by an anodization method using an HF solution. This porous Si layer 123 has a density of single crystal Si of 2.33 g.
/ Cm ³ compared to the density of the HF solution concentration 50 to 2
Density 1.1 to 0.6 g / cm ³ by changing to 0%
The range can be changed. This porous layer is formed on the P-type substrate as described above.

As shown in FIG. 2 (c), another Si
After preparing the substrate 124 and forming the oxide layer 125 on the surface thereof, the single crystal Si layer 122 on the porous Si substrate 123 is formed.
A Si substrate 124 having the oxide layer 125 on the surface is attached to the surface.

Thereafter, the porous Si substrate 123 is wholly etched to leave the thinned single crystal silicon layer 122 on the SiO ₂ layer 125 to form a semiconductor substrate.

According to this method, the oxide layer 1 which is an insulator
25, single crystal Si with crystallinity equivalent to that of silicon wafer
The layer 122 is flatly and uniformly thinned, and is formed in a large area over the entire area of the wafer.

The semiconductor substrate thus obtained can be suitably used also in the production of electronic elements which are insulated and separated.

Embodiment 2 above is an example of a method in which an N-type layer is formed on a P-type substrate before making it porous, and then only the P-type substrate is selectively made porous by anodization. is there.
Also in this embodiment, a semiconductor substrate having a semiconductor single crystal layer having the same performance as that of Embodiment 1 can be obtained.

[Embodiment 3] As shown in FIG. 3A, first, a P-type Si single crystal substrate is prepared, and the whole is made porous. Epitaxial growth is performed on the surface of the porous substrate by various growth methods to form the thin film single crystal layer 12.

As shown in FIG. 3B, another Si
After preparing the substrate 13 and forming the oxide layer 14 on the surface thereof, the Si substrate having the oxide layer 14 on its surface is bonded to the surface of the single crystal Si layer 12 on the porous Si substrate 11.

Next, as shown in FIG. 3B, a Si ₃ N ₄ layer 5 is deposited as an etching preventing film so as to cover the entire two bonded silicon wafers. Then, as shown in FIG. 3C, the Si ₃ N ₄ layer on the surface of the porous silicon substrate is removed. Apiezon wax may be used instead of Si ₃ N ₄ as another etching prevention film material. Thereafter, the porous Si substrate 11 is wholly etched to leave the thinned single crystal silicon layer 12 on the SiO ₂ layer 14 to form a semiconductor substrate.

FIG. 3C shows a semiconductor substrate obtained by the present invention. That is, by removing the Si ₃ N ₄ layer 15 as the etching prevention film in FIG. 3B, the Si substrate 13 via the SiO ₂ layer 14 which is an insulator is removed.
Single crystal Si layer 2 with crystallinity equivalent to that of a silicon wafer
However, it is formed into a flat and even thin layer and is formed in a large area over the entire wafer. The semiconductor substrate thus obtained can be suitably used from the viewpoint of producing an electronic element which is insulated and separated. Also in this embodiment example,
A semiconductor substrate having a semiconductor single crystal layer having the same performance as that of Embodiment 1 is obtained.

[Fourth Embodiment] The fourth embodiment of the present invention will be described in detail below with reference to FIG.

First, as shown in FIG. 4A, a low impurity concentration layer 112 is formed by epitaxial growth by various thin film growth methods. Alternatively, the P-type Si single crystal substrate 1
N-type single crystal layer 1 by ion-implanting protons on the surface of 11
12 is formed.

Next, as shown in FIG. 4B, a P type S
The i single crystal substrate 111 is transformed from the back surface into a porous Si substrate 113 by an anodization method using an HF solution. The porous Si layer 113 has a density of single crystal Si of 2.33 g.
/ Cm ³ compared to the density of the HF solution concentration 50 to 2
Density 1.1 to 0.6 g / cm ³ by changing to 0%
The range can be changed. This porous layer 113
Are formed on the P-type substrate as described above.

As shown in FIG. 4C, another Si
After preparing the base 114 and forming the oxide layer 115 on the surface thereof, the single crystal Si layer 112 on the porous Si base 113 is formed.
A Si substrate 114 having an oxide layer 115 on the surface is attached to the surface.

Here, as shown in FIG. 4C, a Si ₃ N ₄ layer 116 is deposited as an etching prevention film 116 so as to cover the entire bonded two silicon wafers. Then, as shown in FIG. 4C, the Si ₃ N ₄ layer on the surface of the porous silicon substrate is removed. Instead of Si ₃ N ₄ as the other etching prevention film 116, a material having excellent etching resistance such as apiezon wax may be used. Thereafter, the porous Si substrate 113 is wholly etched to leave the thinned single crystal silicon layer 112 on the SiO ₂ layer 115 to form a semiconductor substrate. FIG. 4D shows a substrate having a semiconductor layer obtained by the present invention.
That is, the etching prevention film 116 shown in FIG.
By removing the Si ₃ N ₄ layer 116 as a layer, a single crystal Si layer 112 having a crystallinity equivalent to that of a silicon wafer is flattened and uniformly thinned on the SiO ₂ layer 115 which is an insulator. , Is formed in a large area over the entire wafer.

The semiconductor substrate thus obtained can be suitably used also in the production of electronic elements which are insulated and separated without being adversely affected by the etchant. The semiconductor substrate obtained in this example of the embodiment has the same performance as that of the example 1 of the embodiment.

[Embodiment 5] As shown in FIG. 5A, first, a P-type Si single crystal substrate is prepared, and the whole is made porous. Epitaxial growth is performed on the surface of the porous substrate by various growth methods to form the thin film single crystal layer 32.

As shown in FIG. 5B, another Si
After the base 33 is prepared and the oxide layer 34 is formed on the surface thereof, the Si having the oxide layer 34 on the surface is formed on the surface of the oxide layer 36 formed on the single crystal Si layer 32 on the porous Si base 31.
The base 33 is attached. This bonding step is performed by bringing the cleaned surfaces into close contact with each other and then heating them in an inert gas atmosphere or a nitrogen atmosphere. The oxide layer 34 is formed in order to reduce the interface state of the non-porous single crystal layer 32 which is the final active layer.
As shown in FIG. 5B, as the etching prevention film, S
An i ₃ N ₄ layer 35 is deposited to cover the entire two bonded silicon wafers. Next, as shown in FIG. 5C, the Si ₃ N ₄ layer 3 on the surface of the porous silicon substrate 31.
5 is removed. Si ₃ as another etch stop material
Apiezon wax or the like may be used instead of N ₄ . After that, the porous Si substrate 31 is entirely etched to leave the thinned single crystal silicon layer 32 on the SiO ₂ layer to form a semiconductor substrate.

FIG. 5C shows a substrate having a semiconductor layer obtained by the present invention. That is, by removing the Si ₃ N ₄ layer 35 as the etching prevention film shown in FIG. 5B, the crystallinity on the Si substrate 33 is equivalent to that of a silicon wafer through the SiO ₂ layers 34 and 36. Crystal Si
The layer 32 is flatly and uniformly thinned to be formed in a large area over the entire area of the wafer. The semiconductor substrate obtained in this way can also be used favorably in terms of producing an electrically isolated electronic element. The semiconductor substrate obtained in this example of the embodiment has the same performance as that of the example 1 of the embodiment.

[Sixth Embodiment] A sixth embodiment of the present invention will be described in detail below with reference to FIG.

First, as shown in FIG. 6A, a low impurity concentration layer 132 is formed by epitaxial growth by various thin film growth methods. Alternatively, the P-type Si single crystal substrate 1
N-type single crystal layer 1 by ion-implanting protons on the surface of 31
32 are formed.

Next, as shown in FIG. 6B, a P type S
The i single crystal substrate 131 is transformed from the back surface into a porous Si substrate 133 by an anodization method using an HF solution. This porous Si layer 133 has a density of single crystal Si of 2.33 g /
Compared with cm ³ , the density of HF solution is 50 to 20
The density can be changed in the range of 1.1 to 0.6 g / cm ³ by changing the density to%. This porous layer is formed on the P-type substrate as described above.

As shown in FIG. 6C, another Si
After preparing the substrate 134 and forming the oxide layer 135 on the surface thereof, the single crystal Si layer 132 on the porous Si substrate 133 is formed.
The Si substrate 134 having the oxide layer 135 is attached to the surface of the oxide layer 137 formed above.

Next, as an etching prevention film 136,
A Si ₃ N ₄ layer 136 is coated and deposited on the entire two bonded silicon wafers. Thereafter, as shown in FIG. 6D, Si on the surface of the porous silicon substrate 133 is
_{The 3} N ₄ layer 136 is removed. After this, the porous Si substrate 1
31 is chemically etched to form a SiO ₂ layer 135,
A thin film single crystal silicon layer is left on 137 to form a semiconductor substrate.

The semiconductor substrate thus obtained is excellent in the adhesiveness between the layers and can be suitably used from the viewpoint of producing an electronic element which is insulated and separated. The semiconductor substrate obtained in this example of the embodiment has the same performance as that of the example 1 of the embodiment.

[Embodiment 7] As shown in FIG. 7A, first, a P-type Si single crystal substrate is prepared, and the whole is made porous. Epitaxial growth is performed on the surface of the porous substrate by various growth methods to form the thin film single crystal layer 42. As shown in FIG. 7B, another Si substrate 43 is prepared, an oxide layer 44 is formed on the surface thereof, and then an oxide layer formed on the single crystal Si layer 42 on the porous Si substrate 41. 45, S having the oxide layer 44 on the surface
The i base 43 is attached. This bonding step is performed by bringing the cleaned surfaces into close contact with each other and then heating them in an inert gas atmosphere or a nitrogen atmosphere. The oxide layer 44 is formed in order to reduce the interface state of the single crystal layer 42 which is the final active layer as a semiconductor. As shown in FIG. 7C, the porous Si substrate 41 is wholly etched to leave the thinned single crystal silicon layer on the SiO ₂ layers 44 and 45 to form a semiconductor substrate. FIG. 7C shows the semiconductor substrate obtained by the present invention.

Si substrate 4 via SiO ₂ layers 44 and 45
A single crystal Si layer 42 having the same crystallinity as that of a silicon wafer is flattened and uniformly thinned on 3 to form a large area over the entire wafer. The semiconductor substrate thus obtained can be suitably used from the viewpoint of producing an electronic element which is insulated and separated. The semiconductor substrate obtained in this example of the embodiment has the same performance as that of the example 1 of the embodiment.

[Embodiment 8] Hereinafter, Embodiment 8 of the present invention will be described in detail with reference to FIG.

First, as shown in FIG. 8A, a low impurity concentration layer 142 is formed by epitaxial growth by various thin film growth methods. Alternatively, the P-type Si single crystal substrate 1
N-type single crystal layer 1 by ion-implanting protons on the surface of 41
42 is formed.

Next, as shown in FIG. 8B, a P type S
The i single crystal substrate 141 is transformed from the back surface into a porous Si substrate 143 by an anodization method using an HF solution. The porous Si layer 143 has a single crystal Si density of 2.33 g /
Compared with cm ³ , the density of HF solution is 50 to 20
The density can be changed in the range of 1.1 to 0.6 g / cm ³ by changing the density to%. This porous layer is formed on the P-type substrate 141 as described above.

As shown in FIG. 8C, another Si
After preparing the substrate 144 and forming the oxide layer 145 on the surface thereof, the single crystal Si layer 142 on the porous Si substrate 143 is formed.
The oxide layer 145 is formed on the surface of the oxide layer 146 formed above.
The Si base 144 having the is bonded.

After that, the porous silicon substrate is entirely chemically etched to leave a thinned single crystal silicon layer on the SiO ₂ layers 145 and 146 to form a semiconductor substrate.

FIG. 8D shows a semiconductor substrate obtained by the present invention. Si through the SiO ₂ layers 145 and 146
A single crystal Si layer 142 having crystallinity equivalent to that of a silicon wafer is flatly and uniformly thinned on the substrate 144, and is formed in a large area over the entire wafer.

The semiconductor substrate thus obtained can be preferably used also from the viewpoint of manufacturing an electronic element which is insulated and separated. The semiconductor substrate obtained in this example of the embodiment has the same performance as that of the example 1 of the embodiment.

[Embodiment 9] As shown in FIG. 9A, first, a P-type Si single crystal substrate is prepared, and the whole is made porous. By various growth methods, epitaxial growth is performed on the surface of the porous substrate 51, and the thin film single crystal layer 5 is formed.
Form 2

As shown in FIG. 9B, a light transmissive substrate 53 typified by glass is prepared and a porous Si substrate 51 is prepared.
The light transmissive substrate 53 is attached to the surface of the upper single crystal Si layer 52.

Here, as shown in FIG. 9B, a Si ₃ N ₄ layer 54 is deposited as an etching prevention film 54 so as to cover the entire two bonded substrates. Next in FIG.
As shown in (c), S on the surface of the porous silicon substrate is
The i ₃ N ₄ layer 54 is removed. After this, the porous Si substrate 5
1 is completely removed by etching, and the thinned single crystal silicon layer 52 is left on the light transmissive substrate 53 to form a semiconductor substrate. FIG. 9C shows a semiconductor substrate obtained by the present invention. The semiconductor substrate thus obtained can be preferably used from the viewpoint of producing an electronic element that is insulated and separated by a light-transmitting insulating material. The semiconductor substrate obtained in this example of the embodiment has the same performance as that of the example 1 of the embodiment.

[Embodiment 10] Hereinafter, Embodiment 10 of the present invention will be described in detail with reference to FIG.

First, as shown in FIG. 10A, a low impurity concentration layer 152 is formed by epitaxial growth by various thin film growth methods. Alternatively, the surface of the P-type Si single crystal substrate 151 is ion-implanted with protons to form the N-type single crystal layer 152.

Next, as shown in FIG. 10B, the P type
Anode using Si single crystal substrate 151 with HF solution from the back side
The porous Si substrate 153 is transformed by the chemical conversion method.
This porous Si layer 153 has a single crystal Si density of 2.33 g.
/ Cm^ThreeThe density of HF solution is 50 to 2
Density 1.1-0.6g / cm by changing to 0% ^Three
The range can be changed. This porous layer 153
Are formed on the P-type substrate 151 as described above.

As shown in FIG. 10C, a light transmissive substrate 154 is prepared, and the single crystal S on the porous Si substrate 153 is prepared.
The light transmissive substrate 154 is attached to the surface of the i layer 152. Then, as shown in FIG. 10C, a Si ₃ N ₄ layer or the like is bonded as the etching prevention film 155 to form a 2
The entire substrate is coated and deposited. Continuing with FIG.
As shown in (d), the Si ₃ N ₄ layer 155 on the surface of the porous silicon substrate 153 is removed. After this, the porous S
The i-base 153 is completely removed by etching to remove the light-transmitting base 1.
The thinned single crystal silicon layer 152 is left on 54 to form a semiconductor substrate.

FIG. 10D shows a semiconductor substrate obtained by the present invention. That is, a single crystal Si layer 152 whose crystallinity is equivalent to that of a silicon wafer is formed on a light transmissive substrate 154.
Flat and evenly thinned over the entire wafer,
It is formed in a large area.

The semiconductor substrate thus obtained can be preferably used also from the viewpoint of producing an electronic element which is insulated and separated by a light-transmitting insulating material. The semiconductor substrate obtained in this example of the embodiment has the same performance as that of the example 1 of the embodiment.

[Embodiment Example 11] As shown in FIG. 11A, first, a P-type Si single crystal substrate is prepared, and all of it is made porous. The thin film single crystal layer 62 is formed by performing epitaxial growth on the surface of the porous substrate 61 by various growth methods.

As shown in FIG. 11B, a light-transmissive substrate 63 typified by glass is prepared and a porous Si substrate 6 is prepared.
The light transmissive substrate 63 is attached to the surface of the single crystal Si layer 62 on 1.

After this, the porous Si substrate 61 is wholly etched to leave the thinned single crystal silicon layer 62 on the light transmissive substrate 63 to form a semiconductor substrate.

FIG. 11C shows a semiconductor substrate obtained by the present invention. The single crystal Si layer 62 having crystallinity equivalent to that of a silicon wafer is flatly and uniformly thinned on the light transmissive substrate 63 to have a large area over the entire wafer. The semiconductor substrate thus obtained can be preferably used from the viewpoint of producing an electronic element that is insulated and separated by a light-transmitting insulating material.

Embodiment 12! Embodiment 12 of the present invention will be described in detail below with reference to FIG.

First, as shown in FIG. 12A, a low impurity concentration layer 162 is formed by epitaxial growth by various thin film growth methods. Alternatively, protons are ion-implanted into the surface of the P-type Si single crystal substrate 161 to form the N-type single crystal layer 162.

Next, as shown in FIG. 12B, the P type Si single crystal substrate 161 is transformed from the back surface into a porous Si substrate 163 by an anodization method using an HF solution.
This porous Si layer 163 has a single crystal Si density of 2.33 g.
/ Cm ³ compared to the density of the HF solution concentration 50 to 2
Density 1.1 to 0.6 g / cm ³ by changing to 0%
The range can be changed. This porous layer 163
Are formed on the P-type substrate 163 as described above.

As shown in FIG. 12C, a light transmissive substrate 164 is prepared, and the single crystal S on the porous Si substrate 163 is prepared.
The light transmissive substrate 164 is attached to the surface of the i layer 162. As shown in FIG. 12C, a porous Si substrate 163
Are completely removed by etching to leave the thin-film single crystal silicon layer 162 on the light transmissive substrate 164 to form a semiconductor substrate.

FIG. 12D shows a semiconductor substrate obtained by the present invention. That is, a single crystal Si layer 162 having a crystallinity equivalent to that of a silicon wafer is formed on a light transmissive substrate 164.
Flat and evenly thinned over the entire wafer,
It is formed in a large area.

The semiconductor substrate thus obtained can be preferably used also from the viewpoint of producing an electronic element which is insulated and separated by a light-transmitting insulating material. The semiconductor substrate obtained in this example of the embodiment has the same performance as that of the example 1 of the embodiment.

[Embodiment 13] Description will be given with reference to FIG. As shown in FIG. 13A, first, a porous region 1301 is formed in a part of the Si single crystal substrate 1300. Then, a thin film Si single crystal layer 1302 is formed on the porous region 1301 by various crystal growth methods (FIG. 13B).

An oxide film 13 is formed on the thin film Si single crystal layer 1302.
03 are formed (FIG. 13C).

An oxide film 1305 formed on the surface of another Si substrate 1304 and the oxide film 1303 are bonded together (FIG. 13D).

Next, the Si single crystal gas 1300 remaining without being made porous is removed by mechanical polishing such as grinding or etching to expose the porous region 1301 (FIG. 1).
3 (e)).

The porous region 1301 is removed by etching,
A semiconductor substrate having a thin film Si single crystal layer is formed on the insulator (FIG. 13 (f)).

When such a process is adopted, the time required for making the substrate porous can be shortened, and the time for removing the porous Si substrate by etching can also be shortened, so that the efficiency of substrate formation can be improved.

It is also possible to directly bond the thin film Si single crystal layer 1302 and the oxide film 1305 without forming the oxide film 1303 shown in FIG.
Instead of the oxide film 1305 formed above, an insulating substrate such as glass can be attached.

It is also possible to incorporate the steps in Embodiments 1 to 12 into this embodiment.

The semiconductor substrate thus obtained has the same excellent performance as the semiconductor substrates obtained in the first to twelfth embodiments.

The present invention will be described below with reference to specific examples.

[0107]

【Example】

(Example 1) P-type (100) single crystal Si substrate (Si wafer) having a diameter of 3 inches and a thickness of 200 microns
Was subjected to anodization in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And 200
The entire P-type (100) Si substrate with a micron thickness was made porous in 24 minutes.

M on the P-type (100) porous Si substrate 21
BE (Molecular Beam Epitaxy: Molecular Be)
The Si epitaxial layer was grown to a thickness of 0.5 μm by the am epitaxy method. The deposition conditions are
It is as follows. Temperature: 700 ° C. Pressure: 1 × 10 ⁻⁹ Torr Growth rate: 0.1 nm / sec

Next, on the surface of the epitaxial layer 21, the other Si substrate 23 having a 5000 Å oxide layer 24 formed thereon is superposed, and the surface of the Si substrate 23 is set to 800 in a nitrogen atmosphere.
The two Si substrates were firmly bonded together by heating at 0.5 ° C. for 0.5 hour. Then, the porous Si substrate 21 was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8).

As described above, the etching rate for a normal Si single crystal hydrofluoric acid / nitric acid solution is about 1 micron per minute (hydrofluoric / nitric acid / acetic acid solution 1: 3: 8).
The etching rate of the porous layer is increased by about 100 times. That is, the porous Si substrate 21 having a thickness of 200 μm was removed in 2 minutes.

Thus, 0.5 μm is formed on the SiO ₂ layer 24.
The single-crystal Si layer 22 having a thickness of 1 can be formed.

The thickness of the obtained single crystal Si layer was examined by using scanning ellipsometry. Specifically, 3 in
The entire surface of the ch wafer was scanned and measured. Result 3
The difference between the maximum value and the minimum value of the thickness of the single crystal Si layer within the plane of the inch wafer was suppressed to 5% or less with respect to the maximum value of the thickness.

Further, as a result of the plane observation of the single crystal Si layer by a transmission electron microscope, the dislocation defect density was suppressed to 1 × 10 ³ / cm ² or less, and a new crystal defect was found in the single crystal Si layer forming step. It was not introduced, and it was confirmed that good crystallinity was maintained.

Further, for the single crystal Si layer, MOS ct
When the minority carrier lifetime was measured using the method, a high value of 2.0 × 10 ⁻³ sec was shown.

Example 2 A P-type (100) single crystal Si substrate having a diameter of 4 inches and a thickness of 500 μm
Anodization was performed in a 0% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the total P-type (100) Si substrate with a thickness of 500 microns is 6
It was made porous at 0 minutes.

On the P-type (100) porous Si substrate 21, the Si epitaxial layer 22 was grown at a low temperature of 0.5 micron by the plasma CVD method. The deposition conditions are as follows. Gas: SiH ₄ High frequency power: 100 W Temperature: 800 ° C. Pressure: 1 × 10 ^-2 Torr Growth rate: 2.5 nm / sec

Next, on the surface of this epitaxial layer 22, another Si having a 5000 Å oxide layer 24 formed on the surface was formed.
The bases 23 are superposed and placed in a nitrogen atmosphere at 700.degree.
The two Si substrates were firmly bonded together by heating for 5 hours. Then, a hydrofluoric nitric acid acetic acid solution (1: 3:
8) was used to remove the porous Si substrate 21 by etching.

As described above, the etching rate of a normal Si single crystal hydrofluoric acid / nitric acid solution is about 1 micron per minute (fluorine / nitric acid / acetic acid solution 1: 3: 8).
The etching rate of the porous layer is increased by about 100 times. That is, the porous Si substrate 21 having a thickness of 500 microns was removed in 5 minutes.

A single crystal Si layer having a thickness of 0.5 μm could be formed on the SiO ₂ layer 24.

The thickness of the obtained single crystal Si layer was examined by using scanning ellipsometry. Specifically, 4in
The entire surface of the ch wafer was scanned and measured. As a result 4
The difference between the maximum value and the minimum value of the thickness of the single crystal Si layer in the plane of the inch wafer was suppressed to 7% or less with respect to the maximum value of the thickness.

Further, as a result of the plane observation of the single crystal Si layer by a transmission electron microscope, the dislocation defect density was suppressed to 1 × 10 ³ / cm ² or less, and new crystal defects were found in the single crystal Si layer forming step. It was not introduced, and it was confirmed that good crystallinity was maintained.

In addition, for the single crystal Si layer, MOS ct
When the minority carrier lifetime was measured using the method, a high value of 2.0 × 10 ⁻³ sec was shown.

Example 3 A P-type (100) single crystal Si substrate (S having a diameter of 3 inches and a thickness of 200 microns) (S
The i-wafer) was anodized in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min.
And P-type (100) S with a thickness of 200 microns
The entire i-substrate became porous in 24 minutes.

The Si epitaxial layer 22 is formed on the P-type (100) porous Si substrate 21 by the bias sputtering method.
Were grown to a thickness of 0.5 micron. The deposition conditions are as follows. RF frequency: 100 MHz High frequency power: 600 W Temperature: 300 ° C. Ar gas pressure: 8 × 10 ⁻³ Torr Growth time: 60 minutes Target DC bias: −200 V Substrate DC bias: +5 V

Next, on the surface of this epitaxial layer 22, another Si having a 5000 Å oxide layer 24 formed on the surface was formed.
The bases 23 are overlapped and placed in a nitrogen atmosphere at 800.degree.
The two Si substrates were firmly bonded together by heating for 5 hours. Then, a hydrofluoric nitric acid acetic acid solution (1: 3:
8) was used to remove the porous Si substrate 21 by etching.

As described above, the etching rate for a normal Si single crystal hydrofluoric acid / nitric acid solution is about 1 micron per minute (fluorine / nitric acid / acetic acid solution 1: 3: 8).
The etching rate of the porous layer is increased by about 100 times. That is, the porous Si substrate 21 having a thickness of 200 μm was removed in 2 minutes.

Thus, 0.5 μm is formed on the SiO ₂ layer 24.
It was possible to form a single crystal Si layer having a thickness of.

Example 4 A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm
Anodization was performed in a 0% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the total P-type (100) Si substrate with a thickness of 200 microns is 2
It became porous in 4 minutes.

The Si epitaxial layer 22 was grown on the P-type (100) porous Si substrate 21 by the liquid phase growth method to a thickness of 0.5 μm. The growth conditions are as follows. Solvent: Sn Growth temperature: 900 ° C. Growth atmosphere: H ₂ Growth time: 10 minutes

Next, on the surface of the epitaxial layer 22, another Si substrate 23 having a 5000 Å oxide layer 24 formed thereon is placed, and the surface of the Si substrate 23 is set to 800 in a nitrogen atmosphere.
The two Si substrates were firmly bonded together by heating at 0.5 ° C. for 0.5 hour. Then, the porous Si substrate 21 was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then, the porous Si substrate 21 having a thickness of 200 μm was removed in 2 minutes.

Thus, 0.5 μm is formed on the SiO ₂ layer 24.
The single-crystal Si layer 22 having a thickness of 1 can be formed.

(Embodiment 5) A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm was used.
Anodization was performed in a 0% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the total P-type (100) Si substrate with a thickness of 200 microns is 2
It became porous in 4 minutes.

On the P-type (100) porous Si substrate 21, the Si epitaxial layer 21 was formed to 0.5 by the low pressure CVD method.
It was grown to a micron thickness. The deposition conditions are as follows. Source gas: SiH ₄ Carrier gas: H ₂ Temperature: 850 ° C. Pressure: 1 × 10 ^-2 Torr Growth rate: 3.3 nm / sec

Next, on the surface of the epitaxial layer 22, another Si having a 5000 Å oxide layer 24 formed on the surface was formed.
The two Si substrates 23 were firmly bonded together by stacking the substrates and heating them in a nitrogen atmosphere at 800 ° C. for 0.5 hours. Then, a hydrofluoric nitric acid acetic acid solution (1: 3:
8) was used to remove the porous Si substrate 21 by etching. Then, the porous Si substrate 21 having a thickness of 200 μm was removed in 2 minutes.

Thus, 0.5 μm is formed on the SiO ₂ layer 24.
It was possible to form a single crystal Si layer having a thickness of. When SiH ₂ Cl ₂ was used as the source gas, it was necessary to raise the growth temperature by several tens of degrees, but the enhanced etching characteristic peculiar to the porous substrate was maintained.

Example 6 A Si epitaxial layer 122 having a thickness of 1 micron was grown on a P-type (100) Si substrate 121 having a diameter of 3 inches and a thickness of 200 microns by the CVD method. The deposition conditions are as follows. Reaction gas flow rate: SiH ₄ Cl ₂ 1000 SCCM H ₂ 230 l / min. Temperature: 1080 ° C. Pressure: 80 Torr Time: 2 min.

This substrate 121 was anodized in a 50% HF solution. Current density at this time is 100m
It was A / cm ² . The rate of porosification at this time is
8.4 μm / min. The entire P-type (100) Si substrate 121 having a thickness of 200 microns was made porous in 24 minutes. In this anodization, P-type (100) Si
Only the base 121 was made porous, and the Si epitaxial layer 122 remained unchanged. Next, another Si substrate 124 having a 5000 Å oxide layer 125 formed on the surface thereof is superposed on the surface of the epitaxial layer 122, and the two Si substrates are heated at 800 ° C. for 0.5 hour in a nitrogen atmosphere. Were firmly bonded together. Then, the porous Si substrate 123 was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then, the porous Si substrate 123 having a thickness of 200 μm was removed in 2 minutes.

When the thickness of the obtained single crystal Si layer was examined by using scanning ellipsometry, the difference between the maximum value and the minimum value of the thickness of the single crystal Si layer in the plane of the 3-inch wafer was found to be It was suppressed to 5% or less with respect to the maximum value.

Further, as a result of the plane observation of the single crystal Si layer by a transmission electron microscope, the dislocation defect density was suppressed to 1 × 10 ³ / cm ² or less, and new crystal defects were not formed in the single crystal Si layer forming step. It was not introduced, and it was confirmed that good crystallinity was maintained.

When the lifetime of the minority carrier in the single crystal Si layer was measured by the microwave reflection method, a high value of 2.0 × 10 ⁻³ sec was shown.

(Embodiment 7) CVD is performed on a P-type (100) Si substrate having a diameter of 3 inches and a thickness of 200 microns.
Method, the Si epitaxial layer 122 was made to have a thickness of 0.5 micron. The deposition conditions are as follows. Reaction gas flow rate: SiH ₄ Cl ₂ 1000 SCCM H ₂ 230 l / min. Temperature: 1080 ° C. Pressure: 80 Torr Time: 1 min.

This substrate was anodized in a 50% HF solution. The current density at this time is 100 mA / c
m ² . The porosity rate at this time is 8.4 μm /
min. And a P-type (1
The entire 00) Si substrate 121 was made porous in 24 minutes. In this anodization, only the P-type (100) Si substrate was made porous, and the Si epitaxial layer 122 did not change. Next, on the surface of the epitaxial layer 122, another S having a 5000 Å oxide layer 125 formed on the surface thereof is formed.
i substrate 124 is overlaid, and 800 ° C. in a nitrogen atmosphere,
The two Si substrates were firmly bonded together by heating for 0.5 hour. Then, a hydrofluoric nitric acid acetic acid solution (1:
The porous Si substrate 123 was removed by etching using 3: 8). Then, the porous Si substrate 123 having a thickness of 200 μm was removed in 2 minutes.

As a result of cross-sectional observation with a transmission electron microscope, S
No new crystal defect was introduced into the i layer 122, and it was confirmed that good crystallinity was maintained.

(Embodiment 8) The N-type Si layer 122 is formed by implanting protons into the surface of a P-type (100) Si substrate 121 having a diameter of 3 inches and a thickness of 200 microns.
Was formed to a thickness of 1 micron. H ⁺ injection amount is 5 × 1
0 ¹⁵ (ions / cm ² ). 50% on this substrate
In an HF solution of The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate 121 with a thickness of 200 microns is
It became porous in 24 minutes. As described above, in this anodization, only the P-type (100) Si substrate 121 was made porous, and the N-type Si layer 122 remained unchanged. Then this N
5000 Å oxide layer 1 on the surface of type Si layer 122
By stacking another Si substrate 124 on which 25 is formed and heating in a nitrogen atmosphere at 800 ° C. for 0.5 hour,
The two Si substrates were firmly bonded together. Then, using a hydrofluoric nitric acid acetic acid solution (1: 3: 8), the porous Si substrate 1
23 was removed by etching. Then, the porous Si substrate 123 having a thickness of 200 μm was removed in 2 minutes.

As a result of cross-sectional observation by a transmission electron microscope, S
No new crystal defect was introduced into the i layer 122, and it was confirmed that good crystallinity was maintained.

(Embodiment 9) A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm was used.
Anodization was performed in a 0% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the total P-type (100) Si substrate with a thickness of 200 microns is 2
It became porous in 4 minutes.

MBE (Molecular Beam Epitaxy: Molecular B) is formed on the P-type (100) porous Si substrate 11.
The Si epitaxial layer 12 was grown to a thickness of 0.5 μm by the electron epitaxy method. The deposition conditions are as follows. Temperature: 700 ° C. Pressure: 1 × 10 ⁻⁹ Torr Growth rate: 0.1 nm / sec

Next, on the surface of this epitaxial layer 12, another Si having a 5000 Å oxide layer 14 formed on the surface was formed.
The bases 13 are overlapped and placed in a nitrogen atmosphere at 800.degree.
The two Si substrates were firmly bonded together by heating for 5 hours. Then, Si ₃ N _{4 is formed} by the low pressure CVD method.
The two Si substrates bonded to each other were coated to a thickness of 0.1 μm. After this, only the nitride film on the porous substrate was removed by reactive ion etching. Then, the porous Si substrate 11 was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then, the porous Si substrate 11 having a thickness of 200 microns was removed in 2 minutes.
After removing the Si ₃ N ₄ layer 15, a substrate having a single crystal Si layer having a thickness of 0.5 μm was formed on the SiO ₂ layer 14.

As a result of cross-sectional observation by a transmission electron microscope, S
No new crystal defects were introduced into the i-layer, and it was confirmed that good crystallinity was maintained.

(Example 10) A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 microns was subjected to anodization in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes.

On the P-type (100) porous Si substrate 11, the Si epitaxial layer 12 was grown to a thickness of 0.5 μm by the plasma CVD method. The deposition conditions are as follows. Gas: SiH ₄ High frequency power: 100 W Temperature: 800 ° C. Pressure: 1 × 10 ^-2 Torr Growth rate: 2.5 nm / sec

Next, on the surface of this epitaxial layer 12, another Si having a 5000 Å oxide layer 14 formed on the surface was formed.
The two Si substrates were firmly bonded together by stacking the substrates and heating them in a nitrogen atmosphere at 800 ° C. for 0.5 hours. Then, two Si substrates bonded with Si ₃ N ₄ were coated with a thickness of 0.1 μm by the low pressure CVD method. Then, only the nitride film on the porous substrate 11 was removed by reactive ion etching. Then, the porous Si substrate 11 was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then, the porous Si substrate 11 having a thickness of 200 microns was removed in 2 minutes.
After removing the Si ₃ N ₄ layer 15, 0.5 on the SiO ₂
A substrate having a single crystal Si layer 12 having a thickness of μm could be formed.

Further, when the thickness of the obtained single crystal Si layer was examined by using scanning ellipsometry, the difference between the maximum value and the minimum value of the thickness of the single crystal Si layer in the plane of the 3-inch wafer was It was suppressed to 5% or less with respect to the maximum value.

As a result of the observation by the defect revealing etching using the Silet etching, the dislocation defect density is 1
It is suppressed to × 10 ³ / cm ² or less, and no new crystal defect is introduced in the single crystal Si layer forming step,
It was confirmed that good crystallinity was maintained.

For the single crystal Si layer, MOS ct
When the minority carrier lifetime was measured using the method, a high value of 2.0 × 10 ⁻³ sec was shown.

Example 11 A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm was anodized in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes.

The Si epitaxial layer 12 was formed on the P-type (100) porous Si substrate 11 by the bias sputtering method.
Were grown to a thickness of 0.5 micron. The deposition conditions are as follows. RF frequency: 100 MHz High frequency power: 600 W Temperature: 300 ° C. Ar gas pressure: 8 × 10 ⁻³ Torr Growth time: 60 minutes Target DC bias: −200 V Substrate DC bias: +5 V

Next, on the surface of this epitaxial layer 12, another Si having a 5000 Å oxide layer 14 formed on the surface was formed.
The two Si substrates were firmly bonded together by stacking the substrates and heating them in a nitrogen atmosphere at 800 ° C. for 0.5 hours. Two Si substrates bonded with Si ₃ N ₄ were coated by the low pressure CVD method to a thickness of 0.1 μm. Thereafter, only the nitride film on the porous substrate was removed by reactive ion etching. Then, hydrofluoric nitric acid acetic acid solution (1:
The porous Si substrate 11 was removed by etching using 3: 8). Then, the porous Si substrate 11 having a thickness of 200 microns was removed in 2 minutes. After removing the Si ₃ N ₄ layer 15, 0.5 μm is formed on the SiO ₂ layer 14.
It was possible to form a substrate having a single crystal Si layer 12 having a thickness of.

Further, the same effect was obtained when Apiezon wax was coated instead of the Si ₃ N ₄ layer, and only the porous Si substrate could be completely removed.

Example 12 A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm was anodized in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes.

The Si epitaxial layer 12 was grown to a thickness of 0.5 μm on the P-type (100) porous Si substrate 11 by the liquid phase growth method. The growth conditions are as follows. Solvent: Sn Growth temperature: 900 ° C. Growth atmosphere: H ₂ Growth time: 10 minutes Target DC bias: -200V Substrate DC bias: + 5V

Next, on the surface of the epitaxial layer 12, another Si having a 5000 Å oxide layer 14 formed on the surface was formed.
The bases 13 are overlapped and placed in a nitrogen atmosphere at 800.degree.
The two Si substrates were firmly bonded together by heating for 5 hours. Two Si substrates bonded with Si ₃ N ₄ were coated to a thickness of 0.1 μm by the low pressure CVD method. Thereafter, only the nitride film on the porous substrate was removed by reactive ion etching. Then, the porous Si substrate 11 was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then, the porous Si substrate 11 having a thickness of 200 microns was removed in 2 minutes. Si
₃ After removal of the N ₄ layer 15 is 0 on the SiO ₂ layer 14.
A substrate having a single crystal Si layer 12 having a thickness of 5 μm could be formed.

Further, the same effect was obtained when Apiezon wax was coated instead of the Si ₃ N ₄ layer, and it was possible to completely remove only the porous Si substrate.

Example 13 A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm was subjected to anodization in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes.

The Si epitaxial layer 12 is formed on the P-type (100) porous Si substrate 11 by the low pressure CVD method to a thickness of 0.5.
It was grown to a thickness of microns. The deposition conditions are as follows. Source gas: SiH ₄ Carrier gas: H ₂ Temperature: 850 ° C. Pressure: 1 × 10 ^-2 Torr Growth rate: 3.3 nm / sec

Next, on the surface of the epitaxial layer 12, another Si having a 5000 Å oxide layer 14 formed on the surface was formed.
The bases 13 are overlapped and placed in a nitrogen atmosphere at 800.degree.
By heating for 5 hours, the two Si substrates were firmly bonded together. Then, Si ₃ N _{4 is formed} by the low pressure CVD method.
The two Si substrates bonded to each other were coated with a thickness of 0.1 μm. Then, only the nitride film 15 on the porous substrate 11 was removed by reactive ion etching. Then, the porous Si substrate 11 was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then, the porous Si substrate 11 having a thickness of 200 microns was removed in 2 minutes. After removing the Si ₃ N ₄ layer 15, SiO ₂
A substrate having a single crystal Si layer having a thickness of 0.5 μm could be formed on the layer 14.

When SiH ₂ Cl ₂ is used as the source gas, it is necessary to raise the growth temperature by several tens of degrees.
The enhanced etching properties typical of porous substrates were maintained.

(Example 14) A Si epitaxial layer 112 was grown to a thickness of 1 micron by a CVD method on a P-type (100) Si substrate 111 having a diameter of 3 inches and a thickness of 200 micron. The deposition conditions are as follows. Reaction gas flow rate: SiH ₄ Cl ₂ 1000 SCCM H ₂ 230 l / min. Temperature: 1080 ° C. Pressure: 80 Torr Time: 2 min.

This substrate was anodized in a 50% HF solution. The current density at this time is 100 mA / c
m ² . Also, the porosity rate at this time is 8.4 μm.
m / min. And P with a thickness of 200 microns
The entire mold (100) Si substrate was made porous in 24 minutes. In this anodization, only the P-type (100) Si substrate was made porous, and the Si epitaxial layer 122 did not change. Next, on the surface of the epitaxial layer 112, a Si substrate 11 having a 5000 Å oxide layer formed on the surface thereof
The four Si substrates were superposed on each other and overheated in a nitrogen atmosphere at 800 ° C. for 0.5 hour to firmly bond the two Si substrates. Si ₃ N ₄ was bonded by the low pressure CVD method 2
A sheet of Si substrate was coated to a thickness of 0.1 μm. Then
Only the nitride film on the porous substrate is removed by reactive ion etching. Then, a hydrofluoric nitric acid acetic acid solution (1: 3:
The porous Si substrate 11 was removed by etching using 8). Then, the porous Si substrate 113 having a thickness of 200 μm was removed in 2 minutes.

After removing the Si ₃ N ₄ layer 116, the Si ₃
A substrate having a single crystal Si layer 112 having a thickness of 1 μm on O ₂ could be formed.

Further, when the thickness of the obtained single crystal Si layer was examined by using scanning ellipsometry, the difference between the maximum value and the minimum value of the thickness of the single crystal Si layer in the plane of the 3-inch wafer was It was suppressed to 5% or less with respect to the maximum value.

As a result of observing the plane of the single crystal Si layer with a transmission electron microscope, the dislocation defect density was suppressed to 1 × 10 ³ / cm ² or less, and new crystal defects were found in the single crystal Si layer forming step. It was not introduced, and it was confirmed that good crystallinity was maintained.

For the single crystal Si layer, MOS ct
When the minority carrier lifetime was measured using the method, a high value of 2.0 × 10 ⁻³ sec was shown.

(Embodiment 15) A Si epitaxial layer 112 is formed on a P-type (100) Si substrate 111 having a diameter of 3 inches and a thickness of 200 microns by a CVD method.
Grow to a thickness of 5 microns. The deposition conditions are as follows. Reaction gas flow rate: SiH ₂ Cl ₂ 1000 SCCM H ₂ 230 l / min. Temperature: 1080 ° C. Pressure: 80 Torr Time: 1 min.

The substrate was anodized in a 50% HF solution. The current density at this time is 100 mA / c
m ² . The porosity rate at this time is 8.4 μm /
min. And a P-type (1
The entire 00) Si substrate 111 was made porous in 24 minutes. In this anodization, only the P-type (100) Si substrate 11 was made porous, and the Si epitaxial layer 112 remained unchanged.

Next, on the surface of the epitaxial layer 112, a Si substrate 11 having a 5000 Å oxide layer formed on the surface thereof is formed.
4 were overlapped and heated in a nitrogen atmosphere at 800 ° C. for 0.5 hour to firmly bond both Si substrates. Then, Si ₃ N ₄ was coated on the two bonded Si substrates to a thickness of 0.1 μm by the low pressure CVD method. Subsequently, only the nitride film 116 on the porous substrate 113 was removed by reactive ion etching. Then
Porous Si using hydrofluoric nitric acid acetic acid solution (1: 3: 8)
The base 113 was removed by etching. Then, the porous Si substrate 113 having a thickness of 200 microns is
Removed in 2 minutes. After removing the Si ₃ N ₄ layer 116, a substrate having a single crystal Si layer 112 having a thickness of 0.5 μm was formed on the SiO ₂ layer 115. As a result of a cross-sectional observation with a transmission electron microscope, no new crystal defects were introduced into the Si layer, and it was confirmed that good crystallinity was maintained.

(Example 16) N-type Si layer 11 was formed by implanting protons into the surface of P-type (100) Si substrate 111 having a diameter of 3 inches and a thickness of 200 microns.
2 was formed with a thickness of 1 micron. H ⁺ injection volume is 5 ×
It was 10 ¹⁵ (ions / cm ² ). 50
Anodizing was carried out in a HF solution at a concentration of 2.8%. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. The entire P-type (100) Si substrate 111 having a thickness of 200 microns was made porous in 24 minutes. In this anodization, only the P-type (100) Si substrate 111 is made porous and the N-type S
The i layer 112 did not change. Next, another Si substrate 114 having a 5000 Å oxide layer 115 formed on the surface thereof is superposed on the surface of the N-type Si layer 112, and heated in an oxygen atmosphere at 800 ° C. for 0.5 hour to obtain two layers. S
The i substrate was firmly attached. Then, two Si substrates bonded with Si ₃ N ₄ were bonded to each other by a low pressure CVD method.
It was coated to a thickness of 1 μm. Next, only the nitride film on the porous substrate was removed by reactive ion etching. Then, using a hydrofluoric nitric acid acetic acid solution (1: 3: 8), the porous S
The i substrate 113 was removed by etching. Then, the porous Si substrate 113 having a thickness of 200 μm is formed.
Was removed in 2 minutes. After removing the Si ₃ N ₄ layer 116, a single crystal S having a thickness of 1.0 μm is formed on the SiO _2.
A substrate having the i layer 112 could be formed. As a result of a cross-sectional observation with a transmission electron microscope, no new crystal defects were introduced into the Si layer, and it was confirmed that good crystallinity was maintained.

Example 17 A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm was subjected to anodization in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes.

M on P type (100) porous Si substrate 31
BE (Molecular Beam Epitaxy: Molecular Be)
The Si epitaxial layer 32 was grown to a thickness of 0.5 micron by the am epitaxy method. The deposition conditions are as follows. Temperature: 700 ° C. Pressure: 1 × 10 ⁻⁹ Torr Growth rate: 0.1 nm / sec

Next, an oxide layer 36 having a thickness of 1000Å was formed on the surface of the epitaxial layer 32. 500 on the surface
Another Si substrate 33 having a 0Å oxide layer 34 formed thereon and the oxide layer 36 are superposed on each other, and the oxide layer 36 is superposed in a nitrogen atmosphere at 800 ° C. at 0.
Both were firmly bonded by heating for 5 hours. Si ₃ N ₄ was bonded by the low pressure CVD method 2
A Si substrate was coated with a thickness of 0.1 μm. Then
Only the nitride film on the porous substrate was removed by reactive ion etching. Then, a hydrofluoric nitric acid acetic acid solution (1: 3:
8) was used to remove the porous Si substrate 31 by etching. Then, the porous Si substrate 31 having a thickness of 200 μm was removed in 2 minutes. Si ₃ N ₄ layer 3
After removing 5, the thin film single crystal Si layer 3 is formed on the SiO _2.
A substrate having 2 could be formed. As a result of a cross-sectional observation with a transmission electron microscope, no new crystal defects were introduced into the Si layer, and it was confirmed that good crystallinity was maintained.

Example 18 A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm was anodized in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes. The P-type (100) porous Si
The Si epitaxial layer 32 was grown on the base 31 by the plasma CVD method to a thickness of 5 μm. The deposition conditions are as follows. Gas: SiH ₄ High frequency power: 100 W Temperature: 800 ° C. Pressure: 1 × 10 ^-2 Torr Growth rate: 2.5 nm / sec

Next, an oxide layer 36 having a thickness of 1000 Å was formed on the surface of the epitaxial layer 32. After that, another Si substrate 33 having a 5000 Å oxide layer 34 formed on its surface is formed.
And the oxide layer 36 are overlapped with each other, and the mixture is heated in a nitrogen atmosphere to 80
Both were firmly bonded by heating at 0 ° C. for 0.5 hour. Two Si substrates bonded with Si ₃ N ₄ were coated with a thickness of 0.1 μm by the low pressure CVD method. Next, only the nitride film on the porous substrate was removed by reactive ion etching. Next, the porous Si substrate 31 was removed by etching using a KOH solution (6M). Then, Si with a thickness of 200 microns is made porous.
The substrate 31 was removed in 2 minutes. After removing the Si ₃ N ₄ layer, single crystal Si having good crystallinity on SiO ₂
A substrate with layer 32 could be formed.

Further, when the thickness of the obtained single crystal Si layer was examined by using scanning ellipsometry, the difference between the maximum value and the minimum value of the thickness of the single crystal Si layer in the plane of the 3-inch wafer was found to be It was suppressed to 5% or less with respect to the maximum value of.

Further, as a result of the plane observation of the single crystal Si layer by a transmission electron microscope, the dislocation defect density is suppressed to 1 × 10 ³ / cm ² or less, and new crystal defects are not generated in the single crystal Si layer forming step. It was not introduced, and it was confirmed that good crystallinity was maintained.

For the single crystal Si layer, MOS ct
When the minority carrier lifetime was measured using the method, a high value of 2.0 × 10 ⁻³ sec was shown.

Example 19 A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm was subjected to anodization in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And 200
The entire P-type (100) Si substrate with a micron thickness was made porous in 24 minutes. A Si epitaxial layer 32 was grown to a thickness of 1 micron on the P-type (100) porous Si substrate 31 by a bias sputtering method.
The deposition conditions are as follows. RF frequency: 100 MHz High frequency power: 600 W Temperature: 300 ° C. Ar gas pressure: 8 × 10 ⁻³ Torr Growth time: 120 minutes Target DC bias: −200 V Substrate DC bias: +5 V

Next, an oxide layer 36 having a thickness of 1000Å was formed on the surface of the epitaxial layer 32. After that, another Si substrate 33 having a 5000 Å oxide layer 34 formed on its surface is formed.
And the oxide layer 36 are overlapped with each other, and the mixture is heated in a nitrogen atmosphere to 80
Both were firmly bonded by heating at 0 ° C. for 0.5 hour. Two Si substrates bonded with Si ₃ N ₄ were coated with a thickness of 0.1 μm by the low pressure CVD method. Then, only the nitride film on the porous substrate 31 was removed by reactive ion etching. Then, the porous Si substrate 31 was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then, the porous Si substrate 31 having a thickness of 200 μm was removed in 2 minutes. Si
After removing the ₃ N ₄ layer, a substrate having a single crystal Si layer 32 having crystallinity on SiO ₂ could be formed.

Further, the same effect can be obtained when Apiezon wax is coated instead of the Si ₃ N ₄ layer 35, and only the porous Si substrate 35 can be completely removed.

Example 20 A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm was anodized in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And 200
The entire P-type (100) Si substrate with a micron thickness was made porous in 24 minutes. A Si epitaxial layer 32 was grown on the P-type (100) porous Si substrate 31 by a liquid phase growth method to a thickness of 5 μm. The growth conditions are as follows. Solvent: Sn Growth temperature: 900 ° C. Growth atmosphere: H ₂ Growth time: 10 minutes

Next, an oxide layer 36 having a thickness of 1000Å was formed on the surface of the epitaxial layer 32. After that, another Si substrate 33 having a 5000 Å oxide layer 34 formed on its surface is formed.
And the oxide layer 36 were brought into close contact with each other and heated at 700 ° C. for 0.5 hour to firmly bond the both. Two Si sheets that are made by bonding Si ₃ N ₄ by the low pressure CVD method.
The substrate was coated with a thickness of 0.1 μm. Next, only the nitride film on the porous substrate was removed by reactive ion etching. Then, the porous Si substrate 31 was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then, Si with a thickness of 200 microns is made porous.
The substrate 31 was removed in 2 minutes. After removing the Si ₃ N ₄ layer 35, a substrate having a single crystal Si layer 32 on SiO ₂ could be formed. Further, the same effect was obtained when Apiezon wax was coated instead of the Si ₃ N ₄ layer, and only the porous Si substrate could be completely removed.

When the thickness of the obtained single crystal Si layer was examined by scanning ellipsometry, the difference between the maximum value and the minimum value of the thickness of the single crystal Si layer in the plane of the 3-inch wafer was found to be It was suppressed to 5% or less with respect to the maximum value of.

Further, as a result of the plane observation of the single crystal Si layer by a transmission electron microscope, the dislocation defect density is suppressed to 1 × 10 ³ / cm ² or less, and new crystal defects are not formed in the single crystal Si layer forming step. It was not introduced, and it was confirmed that good crystallinity was maintained.

For the single crystal Si layer, MOS ct
When the minority carrier lifetime was measured using the method, a high value of 2.0 × 10 ⁻³ sec was shown.

Example 21 A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm was subjected to anodization in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And 200
The entire P-type (100) Si substrate with a micron thickness was made porous in 24 minutes. P-type (100) porous S
The Si epitaxial layer 32 was grown at a low temperature of 1.0 micron on the i substrate 31 by the low pressure CVD method. The deposition conditions are as follows. Source gas: SiH ₄ Carrier gas: H ₂ Temperature: 850 ° C. Pressure: 1 × 10 ^-2 Torr Growth rate: 3.3 nm / sec

Next, an oxide layer 36 having a thickness of 1000Å was formed on the surface of the epitaxial layer 32. After that, another Si substrate 33 having a 5000 Å oxide layer 34 formed on its surface is formed.
And the oxide layer 36 were brought into close contact with each other and heated at 700 ° C. for 0.5 hour to firmly bond the both. Si ₃ N ₄ was coated on the two bonded Si substrates with a thickness of 0.1 μm by low pressure CVD. Then, only the nitride film 35 on the porous substrate 31 was removed by reactive ion etching. Then, a hydrofluoric nitric acid acetic acid solution (1: 3:
8) was used to remove the porous Si substrate 31 by etching. Then, the porous Si substrate 31 having a thickness of 200 μm was removed in 2 minutes. Si ₃ N ₄ layer 3
After removing No. 5, a substrate having a single crystal Si layer 32 on SiO ₂ could be formed.

When SiH ₂ Cl ₂ is used as the source gas, it is necessary to raise the growth temperature by several tens of degrees.
The enhanced etching properties typical of porous substrates were maintained.

(Example 22) A Si epitaxial layer 132 was grown to a thickness of 1 micron by a CVD method on a P-type (100) Si substrate 131 having a diameter of 3 inches and a thickness of 200 microns. The deposition conditions are as follows. Reaction gas flow rate: SiH ₂ Cl ₂ 1000 SCCM H ₂ 230 l / min. Temperature: 1080 ° C. Pressure: 80 Torr Time: 2 min.

This substrate was anodized in a 50% HF solution. The current density at this time is 100 mA / c
m ² . In addition, the porosification rate at this time is 8.4.
μm / min. The entire P-type (100) Si substrate 131 having a thickness of 200 μm was made porous in 24 minutes. As described above, in this anodization, P type (1
00) Only the Si substrate 131 was made porous, and the Si epitaxial layer 132 did not change. Next, an oxide layer 137 is formed on the surface of the epitaxial layer 132, another Si substrate 134 having an oxide layer 135 of 5000 Å formed on the surface is superposed on the oxide layer 137, and the temperature is set to 800 ° C. in a nitrogen atmosphere at 0 ° C. The two Si substrates were firmly bonded together by heating for 5 hours. 0.1 μm on two Si substrates bonded with Si ₃ N ₄ by low pressure CVD method
Coated with a thickness of. Thereafter, only the nitride film on the porous substrate was removed by reactive ion etching. Then
The porous Si substrate 133 was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). As a result, the porous Si substrate 133 having a thickness of 200 μm becomes 2
Removed in minutes. After removing the Si ₃ N ₄ layer 136,
Single crystal Si layer 132 having a thickness of 1 μm on SiO ₂
A substrate having

As a result of cross-sectional observation with a transmission electron microscope, S
No new crystal defects were introduced into the i-layer, and it was confirmed that good crystallinity was maintained.

(Embodiment 23) A Si epitaxial layer 132 is formed on a P-type (100) Si substrate 131 having a diameter of 4 inches and a thickness of 500 μm by a CVD method.
It was grown to a thickness of 5 microns. The deposition conditions are as follows. Reaction gas flow rate: SiH ₂ Cl ₂ 1000 SCCM H ₂ 230 l / min. Temperature: 1080 ° C. Pressure: 80 Torr Time: 1 min.

This substrate was anodized in a 50% HF solution. The current density at this time is 100 mA / c
m ² . The porosity rate at this time is 8.4 μm /
min. The entire P-type (100) Si substrate 131 having a thickness of 500 μm was made porous.
In this anodization, only the P-type (100) Si substrate 131 was made porous, and the Si epitaxial layer 132 remained unchanged.

Next, an oxide layer 137 having a thickness of 1000Å was formed on the surface of the epitaxial layer 132. afterwards,
Another Si substrate 134 having a 5000 Å oxide layer 135 formed on the surface is brought into close contact with the oxide layer 137, and 700 ° C.
Both were firmly bonded by heating for 0.5 hour. Si ₃ N ₄ was bonded by low pressure CVD 2
A single Si substrate was coated and deposited to a thickness of 0.1 μm, and only the nitride film 136 on the porous substrate 133 was removed by reactive ion etching. Then, a hydrofluoric nitric acid acetic acid solution (1:
3: 8) was used to etch away the porous Si substrate. Then, the porous Si substrate having a thickness of 500 microns was removed in 7 minutes. Si ₃ N ₄ layer 136
After removing, the substrate having the single crystal Si layer 132 on SiO ₂ could be formed.

When the thickness of the obtained single crystal Si layer was examined by using scanning ellipsometry, the difference between the maximum value and the minimum value of the thickness of the single crystal Si layer in the plane of the 4-inch wafer was found to be Was suppressed to 8% or less with respect to the maximum value of.

Further, as a result of the plane observation of the single crystal Si layer by a transmission electron microscope, the dislocation defect density was suppressed to 1 × 10 ³ / cm ² or less, and a new crystal defect was found in the single crystal Si layer forming step. It was not introduced, and it was confirmed that good crystallinity was maintained.

Further, for the single crystal Si layer, MOS ct
When the minority carrier lifetime was measured using the method, a high value of 2.1 × 10 ⁻³ sec was shown.

(Example 24) N-type Si layer 13 was formed by implanting protons into the surface of P-type (100) Si substrate 131 having a diameter of 3 inches and a thickness of 200 microns.
2 was formed with a thickness of 1 micron. H ⁺ injection volume is 5 ×
It was 10 ¹⁵ (ions / cm ² ). 50
Anodizing was carried out in a HF solution at a concentration of 2.8%. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. The entire P-type (100) Si substrate 131 having a thickness of 200 μm was made porous in 24 minutes. In this anodization, only the P-type (100) Si substrate 131 is made porous, and the N-type S
The i layer 132 did not change. Next, on the surface of the epitaxial layer 132, the oxide layer 13 having a thickness of 1000 Å is formed.
7 was formed. After that, 5000 Å oxide layer 13 on the surface
Another Si substrate 134 on which No. 5 was formed and the oxide layer 137 were brought into close contact with each other and heated at 700 ° C. for 0.5 hour to firmly bond the two Si substrates. Reduced pressure CV
Two Si substrates to which Si ₃ N ₄ was adhered were coated by the D method to a thickness of 0.1 μm. Next, only the nitride film on the porous substrate was removed by reactive ion etching. Then, the porous Si substrate 133 was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then
The porous Si substrate with a thickness of 200 microns was removed in 2 minutes. After removing the Si ₃ N ₄ layer 136, a substrate having a single crystal Si layer 132 on SiO ₂ could be formed. As a result of cross-sectional observation with a transmission electron microscope, S
No new crystal defects were introduced into the i-layer, and it was confirmed that good crystallinity was maintained.

(Example 25) A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 microns was subjected to anodization in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes.

M on P type (100) porous Si substrate 41
BE (Molecular Beam Epitaxy: Molecular Be)
The Si epitaxial layer 42 was grown to a thickness of 0.5 μm by the am epitaxy method. The deposition conditions are as follows. Temperature: 700 ° C. Pressure: 1 × 10 ⁻⁹ Torr Growth rate: 0.1 nm / sec

Next, an oxide layer 45 having a thickness of 1000 Å was formed on the surface of the epitaxial layer 42. Then, another Si substrate 43 having a 5000 Å oxide layer 44 formed on the surface is formed.
And the oxide layer 45 are overlapped with each other, and the oxide layer 45 is placed in a nitrogen atmosphere at 80
By heating at 0 ° C. for 0.5 hour, the two Si substrates were firmly bonded together. Then, the porous Si substrate 41 was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then, the porous Si substrate 41 having a thickness of 200 μm was removed in 2 minutes.

A substrate having a thin film single crystal Si layer 42 on SiO ₂ could be formed. As a result of cross-sectional observation with a transmission electron microscope, no new crystal defects were introduced in the Si layer,
It was confirmed that good crystallinity was maintained.

(Example 26) A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 microns was subjected to anodization in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes. The P-type (100) porous Si
The Si epitaxial layer 42 was grown on the substrate 41 by plasma CVD to a thickness of 5 μm. The deposition conditions are as follows. Gas: SiH ₄ High frequency power: 100 W Temperature: 800 ° C. Pressure: 1 × 10 ^-2 Torr Growth rate: 2.5 nm / sec

Next, an oxide layer 45 having a thickness of 1000Å was formed on the surface of the epitaxial layer 42. Then, another Si substrate 43 having a 5000 Å oxide layer 44 formed on the surface is formed.
And the oxide layer 45 are overlapped with each other, and the oxide layer 45 is placed in a nitrogen atmosphere at 80
By heating at 0 ° C. for 0.5 hour, the two Si substrates were firmly bonded together. Next, the porous Si substrate 41 was removed by etching using a 6M KOH solution.

As described above, ordinary Si single crystal KOH
The etching rate for a solution of 6 M is about 1 micron per minute, but the etching rate of the porous layer is increased by a factor of 100. Then, the porous Si substrate having a thickness of 200 microns was removed in 2 minutes.

A single crystal Si layer having good crystallinity could be formed on SiO ₂ .

(Example 27) A P-type (100) single crystal Si substrate having a diameter of 5 inches and a thickness of 600 μm was subjected to anodization in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate with a thickness of 600 microns is
It became porous in 70 minutes. The Si epitaxial layer 42 was grown to a thickness of 1 micron on the P-type (100) porous Si substrate 41 by the bias sputter method. The deposition conditions are as follows. RF frequency: 100 MHz High frequency power: 600 W Temperature: 300 ° C. Ar gas pressure: 8 × 10 ⁻³ Torr Growth time: 120 minutes Target DC bias: −200 V Substrate DC bias: +5 V

Next, an oxide layer 45 having a thickness of 1000Å was formed on the surface of the epitaxial layer 42. Then, another Si substrate 43 having a 5000 Å oxide layer 44 formed on the surface is formed.
Were stacked and heated in a nitrogen atmosphere at 800 ° C. for 0.5 hour to firmly bond the two Si substrates. Then, the porous Si substrate 41 was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then 6
Porous Si substrate 4 having a thickness of 00 microns
1 was removed in 7 minutes.

A substrate having a single crystal Si layer 42 having good crystallinity on SiO ₂ could be formed.

The thickness of the obtained single crystal Si layer was examined by using scanning ellipsometry, and the difference between the maximum value and the minimum value of the thickness of the single crystal Si layer in the plane of the 5 inch wafer was found to be Was suppressed to 8% or less with respect to the maximum value of.

Further, as a result of the plane observation of the single crystal Si layer by a transmission electron microscope, the dislocation defect density is suppressed to 1 × 10 ³ / cm ² or less, and new crystal defects are not generated in the single crystal Si layer forming step. It was not introduced, and it was confirmed that good crystallinity was maintained.

Further, for the single crystal Si layer, MOS ct
When the minority carrier lifetime was measured using the method, a high value of 2.1 × 10 ⁻³ sec was shown.

Example 28 A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm was anodized in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes. The Si epitaxial layer 4 is formed on the P-type (100) porous Si substrate 41 by the liquid phase growth method.
2 was grown to a thickness of 5 microns. The growth conditions are as follows. Solvent: Sn Growth temperature: 900 ° C. Growth atmosphere: H ₂ Growth time: 10 minutes

Next, an oxide layer 45 having a thickness of 1000Å was formed on the surface of the epitaxial layer 42. Then, another Si substrate 43 having a 5000 Å oxide layer 44 formed on the surface is formed.
Were adhered to each other and heated at 700 ° C. for 0.5 hour to firmly bond the two Si substrates. Then, the porous Si substrate 41 was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then, the porous Si substrate 41 having a thickness of 200 μm was removed in 2 minutes.

A substrate having a single crystal Si layer on SiO ₂ could be formed.

(Example 29) A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 microns was subjected to anodization in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes. The Si epitaxial layer 42 was grown to a thickness of 0.1 micron on the P-type (100) porous Si substrate 41 by the low pressure CVD method. The deposition conditions are as follows. Source gas: SiH ₄ Carrier gas: H ₂ Temperature: 850 ° C. Pressure: 1 × 10 ^-2 Torr Growth rate: 3.3 nm / sec

Next, an oxide layer 45 having a thickness of 1000 Å was formed on the surface of the epitaxial layer 42. Then, another Si substrate 43 having a 5000 Å oxide layer 44 formed on the surface is formed.
Were adhered to each other and heated at 700 ° C. for 0.5 hour to firmly bond the two Si substrates. Then, the porous Si substrate 41 was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then, the porous Si substrate 41 having a thickness of 200 microns was removed in 2 minutes.

A substrate having a single crystal Si layer 42 on SiO ₂ could be formed. When SiH ₂ Cl ₂ was used as the source gas, the growth temperature had to be raised by several tens of degrees, but the accelerated etching characteristic peculiar to the porous substrate was maintained.

Example 30 A Si epitaxial layer 142 having a thickness of 1 micron was grown on a P-type (100) Si substrate 141 having a diameter of 3 inches and a thickness of 200 micron by the CVD method. The deposition conditions are as follows. Reaction gas flow rate: SiH ₂ Cl ₂ 1000 SCCM H ₂ 230 l / min. Temperature: 1080 ° C. Pressure: 80 Torr Time: 2 min.

This substrate was anodized in a 50% HF solution. The current density at this time is 100 mA / c
m ² . Also, the porosity rate at this time is 8.4 μm.
m / min. And the entire P-type (100) Si substrate having a thickness of 200 μm was made porous. In this anodization, only the P-type (100) Si substrate 141 was made porous, and the Si epitaxial layer 142 remained unchanged. Next, on the surface of the epitaxial layer 142, another Si substrate 1 having a 5000 Å oxide layer 145 formed on the surface thereof is formed.
The two Si substrates were firmly bonded together by stacking 44 and heating in a nitrogen atmosphere at 800 ° C. for 0.5 hours. Then, the porous Si substrate was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then
The porousized Si substrate with a thickness of 200 microns was removed in 2 minutes.

A substrate having a single crystal Si layer 142 having a thickness of 1 μm on SiO ₂ could be formed. As a result of a cross-sectional observation with a transmission electron microscope, no new crystal defects were introduced into the Si layer, and it was confirmed that good crystallinity was maintained.

(Example 31) A Si epitaxial layer 142 was formed on a P-type (100) Si substrate 141 having a diameter of 3 inches and a thickness of 200 microns by a CVD method.
It was grown to a thickness of 5 microns. The deposition conditions are as follows. Reaction gas flow rate: SiH ₂ Cl ₂ 1000 SCCM H ₂ 230 l / min. Temperature: 1080 ° C. Pressure: 80 Torr Time: 1 min.

This substrate was anodized in a 50% HF solution. The current density at this time is 100 mA / c
m ² . The porosity rate at this time is 8.4 μm /
min. And a P-type (1
The entire 00) Si substrate 141 was made porous in 24 minutes. In this anodization, the P-type (100) Si substrate 141 is used.
Only Si was made porous and there was no change in the Si epitaxial layer 142.

Next, an oxide layer 146 having a thickness of 1000Å was formed on the surface of the epitaxial layer 142. afterwards,
Another Si substrate having a 5000 Å oxide layer 145 formed on the surface was brought into close contact with the surface, and heated at 700 ° C. for 0.5 hour to firmly bond the two Si substrates. Then
The porous Si substrate was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then, the porous Si substrate having a thickness of 200 microns was removed in 2 minutes.

A substrate having a single crystal Si layer on SiO ₂ could be formed. As a result of cross-sectional observation with a transmission electron microscope, S
No new crystal defects were introduced into the i-layer, and it was confirmed that good crystallinity was maintained.

(Example 32) N-type Si layer 14 was formed by implanting protons into the surface of P-type (100) Si substrate 141 having a diameter of 3 inches and a thickness of 200 microns.
2 was formed to a thickness of 1 micron. H ⁺ injection volume is 5 ×
It was 10 ¹⁵ (ions / cm ² ). 50
Anodizing was carried out in a HF solution at a concentration of 2.8%. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate with a thickness of 200 microns is 2
It became porous in 4 minutes. In this anodization, P type (10
0) Only the Si substrate 141 is made porous and the N-type Si layer 14 is formed.
No change in 2. Next, this epitaxial layer 1
An oxide layer 146 having a thickness of 1000 Å was formed on the surface of 42. Then, another Si substrate having a 5000 Å oxide layer 145 formed on the surface thereof is brought into close contact with the oxide layer 146, and 70
By heating at 0 ° C. for 0.5 hour, the two Si substrates were firmly bonded together. Then, the porous Si substrate was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then, the porous Si substrate having a thickness of 200 microns was removed in 2 minutes.

A substrate having a single crystal Si layer on SiO ₂ could be formed.

When the thickness of the obtained single crystal Si layer was examined by using scanning ellipsometry, the difference between the maximum value and the minimum value of the thickness of the single crystal Si layer in the plane of the 3-inch wafer was found to be It was suppressed to 5% or less with respect to the maximum value.

Further, as a result of the plane observation of the single crystal Si layer by a transmission electron microscope, the dislocation defect density was suppressed to 1 × 10 ³ / cm ² or less, and new crystal defects were not formed in the single crystal Si layer forming step. It was not introduced, and it was confirmed that good crystallinity was maintained.

For the single crystal Si layer, MOS ct
When the minority carrier lifetime was measured using the method, a high value of 2.2 × 10 ⁻³ sec was shown.

(Example 33) A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 microns was subjected to anodization in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes.

M on P type (100) porous Si substrate 51
The Si epitaxial layer 52 was grown at a low temperature of 0.5 micron by the BE method. The deposition conditions are as follows. Temperature: 700 ° C. Pressure: 1 × 10 ⁻⁹ Torr Growth rate: 0.1 nm / sec

Next, the surface of the epitaxial layer 52 is optically polished, and fused silica glass (fused quartz) is used.
The rtz glass) substrates were superposed and heated in a nitrogen atmosphere at 800 ° C. for 0.5 hours to firmly bond the two substrates. Si by low pressure CVD method
Two substrates with ₃ N ₄ laminated to a thickness of 0.1 μm were coated. Then, only the nitride film 54 on the porous substrate 51 was removed by reactive ion etching. Next, using a hydrofluoric nitric acid acetic acid solution (1: 3: 8), the porous Si substrate 5
1 was removed by etching. Then, the porous Si substrate 51 having a thickness of 200 μm was removed in 2 minutes. After removing the Si ₃ N ₄ layer 54, a substrate having a single crystal Si layer 52 with a thickness of 0.5 μm could be formed on a fused glass substrate 53.

As a result of cross-sectional observation with a transmission electron microscope, S
No new crystal defects were introduced into the i-layer, and it was confirmed that good crystallinity was maintained.

Example 34 A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm was anodized in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes.

A Si epitaxial layer 52 is formed on the P-type (100) porous Si substrate 51 by plasma CVD.
It was grown to a micron thickness. The deposition conditions are as follows. Gas: SiH ₄ High frequency power: 100 W Temperature: 800 ° C. Pressure: 1 × 10 ⁻² Torr Growth rate: 2.5 nm / sec

Next, a glass substrate 53 having a softening point around 500 ° C., which is obtained by optically polishing the surface of the epitaxial layer 52, is superposed on the surface of the epitaxial layer 52, and 450 ° C. at 0.5 ° C. in a nitrogen atmosphere.
By heating for two hours, the two substrates were firmly bonded. Two substrates with Si ₃ N ₄ bonded to a thickness of 0.1 μm were coated by the low pressure CVD method. Then, only the nitride film 54 on the porous substrate 51 was removed by reactive ion etching. The porous Si substrate was then etched away using a KOH 6M solution. Then, 20
A porous Si substrate with a thickness of 0 micron is
Removed in 2 minutes. After removing the Si ₃ N ₄ layer, a single crystal S having a thickness of 5 μm is formed on the low softening point glass substrate 53.
The i layer 52 was formed.

Example 35 A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm was anodized in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes.

A Si epitaxial layer was grown to a thickness of 1.0 micron on the P-type (100) porous Si substrate 51 by the bias sputter method. The deposition conditions are as follows. RF frequency: 100 MHz High frequency power: 600 W Temperature: 300 ° C. Ar gas pressure: 8 × 10 ⁻³ Torr Growth rate: 120 minutes Target DC bias: −200 V Substrate DC bias: +5 V

Next, the surface of the epitaxial layer 52 is superposed with a glass substrate 53 having a softening point around 500 ° C. which has been optically polished, and it is placed in a nitrogen atmosphere at 450 ° C. at 0.5 ° C.
By heating for two hours, the two substrates were firmly bonded. Two substrates having Si ₃ N ₄ bonded to a thickness of 0.1 μm were coated by the low pressure CVD method. Next, only the nitride film on the porous substrate was removed by reactive ion etching. After that, the porous Si substrate 51 was removed by etching using a hydrofluoric nitric acid acetic acid solution (1: 3: 8). Then, the porous Si having a thickness of 200 microns is formed.
The substrate 51 was removed in 2 minutes. After removing the Si ₃ N ₄ layer 54, a substrate having a single crystal Si layer 52 having a thickness of 1.0 μm could be formed on the low melting point glass substrate. Further, the same effect can be obtained by coating apiezon wax instead of the Si ₃ N ₄ layer, and only the porous Si substrate 51 can be removed.

When the thickness of the obtained single crystal Si layer was examined by using scanning ellipsometry, the difference between the maximum value and the minimum value of the thickness of the single crystal Si layer in the plane of the 3 inch wafer was It was suppressed to 5% or less with respect to the maximum value.

Further, as a result of the plane observation of the single crystal Si layer by the transmission electron microscope, the dislocation defect density was suppressed to 1 × 10 ³ / cm ² or less, and new crystal defects were not formed in the single crystal Si layer forming step. It was not introduced, and it was confirmed that good crystallinity was maintained. When the minority carrier lifetime of the single crystal Si layer was measured by the MOS ct method, a high value of 2.0 × 10 ⁻³ sec was obtained.

Example 36 A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 microns was subjected to anodization in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes.

On the P-type (100) porous Si substrate 51, a Si epitaxial layer was grown to a thickness of 10 μm by the liquid phase growth method. The growth conditions are as follows. Solvent: Sn Growth temperature: 900 ° C Growth atmosphere: H ₂ Growth time: 20 minutes

Next, a glass substrate 53 having a softening point is superposed on the surface of the epitaxial layer 52, which is optically polished at around 800 ° C., and is 750 ° C. at 0.5 ° C. in a nitrogen atmosphere.
By heating for two hours, the two substrates were firmly bonded together. Si ₃ N ₄ 0.1 μm by low pressure CVD method
The two substrates, which were laminated to each other with a thickness of 1 mm, were coated. Then, only the nitride film on the porous substrate was removed by reactive ion etching. Next, hydrofluoric / nitric acid solution (1: 3: 8)
Was used to etch away the porous Si substrate. Then, the porous Si having a thickness of 200 microns is formed.
The substrate 51 was removed in 2 minutes. After removing the Si ₃ N ₄ layer 54, a substrate having a single crystal Si layer 52 having a thickness of 10 μm could be formed on the glass substrate 53. Also,
A similar effect was obtained by coating with apiezon wax instead of the Si ₃ N ₄ layer, and only the porous Si substrate could be completely removed.

(Example 37) A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 microns was subjected to anodization in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes.

A Si epitaxial layer 52 of 1.0 is formed on the P-type (100) porous Si substrate 51 by the low pressure CVD method.
It was grown to a thickness of microns. The deposition conditions are as follows. Source gas: SiH ₄ 800 SCCM Carrier gas: H ₂ 150 l / min. Temperature: 850 ° C. Pressure: 1 × 10 ⁻² Torr Growth rate: 3.3 nm / sec

Next, a fused silica glass substrate 53, which has been optically polished, is superposed on the surface of the epitaxial layer 52 and heated in a nitrogen atmosphere at 800 ° C. for 0.5 hour, whereby the two substrates are solidified. Pasted together

Si ₃ N ₄ was added to 0.1 μm by the low pressure CVD method.
The two substrates deposited and adhered to each other with a thickness of m were coated. Thereafter, only the nitride film on the porous substrate was removed by reactive ion etching. Next, the porous Si substrate 51 was removed by etching using a hydrofluoric / nitric acid / acetic acid solution. Then, a porous S having a thickness of 200 microns is formed.
The i-substrate was removed in 2 minutes. After removing the Si ₃ N ₄ layer, a substrate having a single-crystal Si layer 52 having a thickness of 1.0 μm was formed on the quartz glass substrate 53. When SiH ₂ Cl ₂ was used as the source gas, the growth temperature had to be raised by several tens of degrees, but the accelerated etching characteristic peculiar to the porous substrate was maintained.

(Example 38) A Si epitaxial layer 152 was grown to a thickness of 1 micron by a CVD method on a P-type (100) Si substrate 151 having a diameter of 4 inches and a thickness of 300 micron. The deposition conditions are as follows. Reaction gas flow rate: SiH ₂ Cl ₂ 1000 SCCM H ₂ 230 l / min. Temperature: 1080 ° C. Pressure: 80 Torr Time: 2 min.

This substrate was anodized in a 50% HF solution. The current density at this time is 100 mA / c
m ² . Also, the porosity rate at this time is 8.4 μm.
m / min. And P with a thickness of 300 microns
The entire mold (100) Si substrate 151 was made porous in 36 minutes. As described above, in this anodization, the P-type (10
0) Only the Si substrate 151 was made porous, and the Si epitaxial layer 152 did not change. Next, an optically polished fused silica glass substrate 154 is superposed on the surface of the epitaxial layer 152, and the surface is
By heating at 0.5 ° C. for 0.5 hour, the two substrates were firmly bonded. Si ₃ N ₄ was reduced to 0.
The two substrates were deposited at a thickness of 1 μm and bonded together. Then, the nitride film 155 on the porous substrate 153 is formed.
Only those were removed by reactive ion etching. Next, the porous Si is added using a hydrofluoric / nitric acid solution (1: 3: 8).
The substrate was etched away. Then, the porous Si substrate 153 having a thickness of 300 microns was removed in 4 minutes. After removing the Si ₃ N ₄ layer 155, a 1 μm-thick single-crystal Si
A substrate having the layer 152 was formed. As a result of a cross-sectional observation with a transmission electron microscope, no new crystal defects were introduced into the Si layer, and it was confirmed that good crystallinity was maintained.

(Example 39) A Si epitaxial layer 152 was formed on a P-type (100) Si substrate 151 having a diameter of 3 inches and a thickness of 200 microns by a CVD method.
Grow to a thickness of 5 microns. The deposition conditions are as follows. Reaction gas flow rate: SiH ₂ Cl ₂ 1000 SCCM H ₂ 230 l / min. Temperature: 1080 ° C. Pressure: 80 Torr Time: 1 min.

This substrate was anodized in a 50% HF solution. The current density at this time is 100 mA / c
m ² . The porosity rate at this time is 8.4 μm /
min. And a P-type (1
00) The entire Si substrate 151 was made porous in 24 minutes. In this anodization, only the P-type (100) Si substrate was made porous, and the Si epitaxial layer 152 did not change.

Next, a fused silica glass substrate 154, which has been optically polished, is superposed on the surface of the epitaxial layer 152 and heated at 800 ° C. for 0.5 hours in a nitrogen atmosphere to firmly bond the two substrates. Pasted together Decompression C
Si ₃ N ₄ was deposited to a thickness of 0.1 μm by the VD method, and the two bonded substrates were covered. Thereafter, only the nitride film 155 on the porous substrate 153 was removed by reactive ion etching. Next, the porous Si substrate was etched away using a hydrofluoric / nitric acid solution (1: 3: 8). Then, the porous Si substrate 153 having a thickness of 200 microns was removed in 2 minutes. Si ₃
After removing the N ₄ layer 155, a substrate having a single-crystal Si layer 152 having a thickness of 0.5 μm was formed on the glass substrate 154. As a result of a cross-sectional observation with a transmission electron microscope, no new crystal defects were introduced into the Si layer, and it was confirmed that good crystallinity was maintained.

(Example 40) The N-type Si layer 15 was formed by implanting protons into the surface of a P-type (100) Si substrate 151 having a diameter of 4 inches and a thickness of 300 microns.
2 was formed with a thickness of 1 micron. H ⁺ injection volume is 5 ×
It was 10 ¹⁵ (ions / cm ² ). 50
Anodizing was carried out in a HF solution at a concentration of 2.8%. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. The whole P-type (100) Si substrate 151 having a thickness of 300 microns was made porous in 37 minutes. In this anodization, only the P-type (100) Si substrate is made porous, and the N-type Si layer 1
52 had no change. Next, the N-type Si layer 152
The two substrates were firmly bonded by superposing a fused silica glass substrate 154 having its surface optically polished and heating at 800 ° C. for 0.5 hour in a nitrogen atmosphere.

Si ₃ N ₄ was added to 0.1 μm by the low pressure CVD method.
The two substrates which were deposited to a thickness of m and bonded together were covered. Next, only the nitride film 155 on the porous substrate 153 was removed by reactive ion etching. Next, the porous Si substrate was removed by etching using a hydrofluoric-nitric-acetic acid solution. Then, the porous Si substrate 151 having a thickness of 300 microns was removed in 4 minutes. Si ₃ N ₄
After removing the layer 155, 1.
A substrate having a single-crystal Si layer 152 having a thickness of 0 μm was formed.

When the thickness of the obtained single crystal Si layer was examined by scanning ellipsometry, the difference between the maximum value and the minimum value of the thickness of the single crystal Si layer in the plane of the 4-inch wafer was found to be It was suppressed to 6% or less of the maximum value.

Further, as a result of the plane observation of the single crystal Si layer by a transmission electron microscope, the dislocation defect density is suppressed to 1 × 10 ³ / cm ² or less, and new crystal defects are not generated in the single crystal Si layer forming step. It was not introduced, and it was confirmed that good crystallinity was maintained. In addition, when the lifetime of the minority carrier of the single crystal Si layer was measured by using the MOS ct method, a high value of 2.2 × 10 ⁻³ sec was shown.

That is, according to the present invention, in order to obtain a Si crystal layer having a crystallinity as excellent as that of a single crystal wafer on a light-transmitting insulator substrate typified by glass, productivity, uniformity, and It is possible to provide a method for forming a semiconductor substrate that is excellent in terms of controllability and economy. Further according to the invention,
The advantages of the conventional SOI device can be utilized, and a method for forming a semiconductor substrate having a wide range of applications can be provided.

Example 41 A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm was subjected to anodization in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes.

M on P type (100) porous Si substrate 61
The Si epitaxial layer 62 was grown to a thickness of 0.5 μm by the BE method. The deposition conditions are as follows. Temperature: 700 ° C. Pressure: 1 × 10 ⁻⁹ Torr Growth rate: 0.1 nm / sec

Next, a fused silica glass substrate 63 that has been optically polished is superposed on the surface of the epitaxial layer 62, and heated at 800 ° C. for 0.5 hour in a nitrogen atmosphere to solidify the two substrates. Pasted together Then
The porous Si substrate 61 was removed by etching using a hydrofluoric / nitric acid / acetic acid solution. Then, the porous Si substrate 61 having a thickness of 200 microns was removed in 2 minutes. A substrate having a single-crystal Si layer 62 having a thickness of 0.5 μm was formed on the quartz glass substrate 63. As a result of a cross-sectional observation with a transmission electron microscope, no new crystal defects were introduced into the Si layer, and it was confirmed that good crystallinity was maintained.

Example 42 A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm was anodized in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes. An Si epitaxial layer 62 was grown on a P-type (100) porous Si substrate 61 to a thickness of 5 μm by a plasma CVD method. The deposition conditions are as follows. Gas: SiH ₄ High frequency power: 100 W Temperature: 800 ° C. Pressure: 1 × 10 ⁻² Torr Growth rate: 2.5 nm / sec

Next, a glass substrate having a softening point around 500 ° C., which has been optically polished on the surface of the epitaxial layer 62, is superposed and heated in a nitrogen atmosphere at 450 ° C. for 0.5 hour to obtain two layers. The substrates were firmly attached. Then KOH. Using a 6M solution, the porous Si substrate 61 was removed by etching. Then, the porous Si substrate 61 having a thickness of 200 microns was removed in 2 minutes. A base having a single-crystal Si layer 62 having a thickness of 5 μm was formed on the low softening point glass base 63.

(Example 43) A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 microns was subjected to anodization in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes.

The Si epitaxial layer 62 is formed on the P-type (100) porous Si substrate 61 by the bias sputtering method.
Was grown to a thickness of 1.0 micron. The deposition conditions are as follows. RF frequency: 100 MHz High frequency power: 600 W Temperature: 300 ° C. Ar gas pressure: 8 × 10 ⁻³ Torr Growth rate: 120 minutes Target DC bias: −200 V Substrate DC bias: +5 V

Next, a glass substrate 63 having a softening point around 500 ° C., which has been optically polished on the surface of the epitaxial layer 62, is superposed on the surface of the epitaxial layer 62.
By heating for two hours, the two substrates were firmly bonded. Next, the porous Si substrate 61 was removed by etching using a NaOH 7M solution.

As described above, the normal Si single crystal 7M
The etch rate for NaOH solutions is on the order of less than 1 micron per minute, but the etch rate for the porous layer is increased by a factor of 100. That is, the porous Si substrate 61 having a thickness of 200 microns was removed in 2 minutes. A base having a single-crystal Si layer 62 having a thickness of 1.0 μm was formed on the low-melting glass base 63.

Further, when the thickness of the obtained single crystal Si layer was examined by using scanning ellipsometry, the difference between the maximum value and the minimum value of the thickness of the single crystal Si layer in the plane of the 3-inch wafer was found to be It was suppressed to 5% or less with respect to the maximum value.

Further, as a result of the plane observation of the single crystal Si layer by a transmission electron microscope, the dislocation defect density was suppressed to 1 × 10 ³ / cm ² or less, and new crystal defects were not found in the single crystal Si layer forming step. It was not introduced, and it was confirmed that good crystallinity was maintained. When the lifetime of the minority carrier of the single crystal Si layer was measured by using the MOS ct method, it showed a high value of 2.1 × 10 ⁻³ sec.

Example 44 A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 μm was anodized in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes.

On the P type (100) porous Si substrate 61, the Si epitaxial layer 62 was grown to a thickness of 10 μm by the liquid phase growth method. The growth conditions are as follows. Solvent: Sn Growth temperature: 900 ° C Growth atmosphere: H ₂ Growth time: 20 minutes

Next, a glass substrate 63 having a softening point around 800 ° C., which is optically polished on the surface of the epitaxial layer 62, is superposed, and it is placed in a nitrogen atmosphere at 750 ° C. at 0.5 ° C.
By heating for two hours, the two substrates were firmly bonded. Next, the porous Si substrate 61 was removed by etching using a hydrofluoric / nitric acid / acetic acid solution. Then, the porous Si substrate 61 having a thickness of 200 microns was removed in 2 minutes. A base having a single-crystal Si layer 62 having a thickness of 10 μm was formed on a glass base 63.

(Example 45) A P-type (100) single crystal Si substrate having a diameter of 3 inches and a thickness of 200 microns was subjected to anodization in a 50% HF solution. The current density at this time was 100 mA / cm ² . At this time, the rate of making porous is 8.4 μm / min. And the entire P-type (100) Si substrate having a thickness of 200 microns is
It became porous in 24 minutes.

The Si epitaxial layer 52 is formed on the P-type (100) porous Si substrate 61 by the low pressure CVD method to 1.0.
It was grown to a micron thickness. The deposition conditions are as follows. Source gas: SiH ₄ 800 SCCM Carrier gas: H ₂ 150 l / min. Temperature: 850 ° C. Pressure: 1 × 10 ⁻² Torr Growth rate: 3.3 nm / sec

Next, a fused silica glass substrate 63 that has been optically polished is superposed on the surface of the epitaxial layer 62, and heated in a nitrogen atmosphere at 800 ° C. for 0.5 hour to firmly bond the two substrates. Pasted together Then
The porous Si substrate 61 was removed by etching using a hydrofluoric / nitric acid / acetic acid solution. Then, the porous Si substrate 61 having a thickness of 200 microns was removed in 2 minutes. A substrate having a single-crystal Si layer 62 having a thickness of 1.0 μm was formed on the quartz glass substrate 63. When SiH ₂ Cl ₂ was used as the source gas, the growth temperature had to be raised by several tens of degrees, but the accelerated etching characteristic peculiar to the porous substrate was maintained.

(Example 46) A Si epitaxial layer 162 was grown to a thickness of 1 micron by a CVD method on a P-type (100) Si substrate 161 having a diameter of 4 inches and a thickness of 300 micron. The deposition conditions are as follows. Reaction gas flow rate: SiH ₂ Cl ₂ 1000 SCCM H ₂ 230 l / min. Temperature: 1080 ° C. Pressure: 80 Torr Time: 2 min.

This substrate was anodized in a 50% HF solution. The current density at this time is 100 mA / c
m ² . Also, the porosity rate at this time is 8.4 μm.
The entire P-type (100) Si substrate 161 having a thickness of 300 μm at m / min was made porous in 37 minutes. In this anodization, a P-type (100) Si substrate 16
Only 1 was made porous, and the Si epitaxial layer 162 did not change. Next, a fused quartz glass substrate 164 that had been optically polished was superposed on the surface of the epitaxial layer, and heated at 800 ° C. for 0.5 hour in a nitrogen atmosphere, whereby the two substrates were firmly bonded. Next, the porous Si substrate 163 was removed by etching using a hydrofluoric / nitric acid solution (1: 3: 8). Then, the porous Si substrate 163 having a thickness of 300 microns becomes 4
Removed in minutes. A base having a single-crystal Si layer 162 having a thickness of 1 μm was formed on the quartz glass base 164.

When the thickness of the obtained single crystal Si layer was examined by using scanning ellipsometry, the difference between the maximum value and the minimum value of the thickness of the single crystal Si layer in the plane of the 4-inch wafer was It was suppressed to 7% or less of the maximum value.

As a result of observing the plane of the single crystal Si layer with a transmission electron microscope, the dislocation defect density was suppressed to 1 × 10 ³ / cm ² or less, and new crystal defects were found in the single crystal Si layer forming step. It was not introduced, and it was confirmed that good crystallinity was maintained. When the minority carrier lifetime of the single crystal Si layer was measured by the MOS ct method, a high value of 2.0 × 10 ⁻³ sec was obtained.

(Example 47) A Si epitaxial layer 162 was formed on a P-type (100) Si substrate 161 having a diameter of 3 inches and a thickness of 200 microns by a CVD method.
It was grown to a thickness of 5 microns. The deposition conditions are as follows. Reaction gas flow rate: SiH ₂ Cl ₂ 1000 SCCM H ₂ 230 l / min. Temperature: 1080 ° C. Pressure: 80 Torr Time: 1 min.

The substrate was anodized in a 50% HF solution. The current density at this time is 100 mA / c
m ² . The porosity rate at this time is 8.4 μm /
min and a P-type (10
0) The entire Si substrate 161 was made porous in 24 minutes.
In this anodization, only the P-type (100) Si substrate 161 was made porous, and the Si epitaxial layer 162 did not change. Next, a fused quartz glass substrate 164 having been subjected to optical polishing is superposed on the surface of the epitaxial layer 162 and heated at 800 ° C. for 0.5 hour in a nitrogen atmosphere, whereby the two substrates were firmly bonded to each other. . Next, the porous Si substrate 163 was removed by etching using a hydrofluoric / nitric acid / acetic acid solution. Then, the porous Si substrate having a thickness of 200 microns was removed in 2 minutes. A single-crystal Si layer having a thickness of 0.5 μm was formed on the glass substrate. As a result of cross-sectional observation with a transmission electron microscope,
No new crystal defects were introduced in the layer, and it was confirmed that good crystallinity was maintained.

(Example 48) N-type Si layer 1 was formed by implanting protons into the surface of P-type (100) Si substrate 161 having a diameter of 3 inches and a thickness of 200 microns.
62 was formed to a thickness of 1 micron. H ⁺ injection volume is 5
× 10 ¹⁵ (ions / cm ² ). 5
Anodization was performed in a 0% HF solution. The current density at this time was 100 mA / cm ² . The porosification rate at this time was 8.4 μm / min, and the entire P-type (100) Si substrate 161 having a thickness of 200 μm was made porous in 24 minutes. In this anodization, only the P-type (100) Si substrate 161 is made porous and the N-type Si
Layer 162 did not change. Next, a fused quartz glass substrate 164 that has been optically polished is superposed on the surface of the epitaxial layer 162, and is placed at 800 ° C. and 0.8 ° C. in a nitrogen atmosphere.
By heating for 5 hours, the two substrates were firmly bonded. Next, the porous Si substrate 163 was removed by etching using a hydrofluoric / nitric acid solution (1: 3: 8). Then, the porous Si having a thickness of 200 microns is formed.
Substrate 163 was removed in 2 minutes. A single-crystal Si layer 162 having a thickness of 1.0 μm was formed on the glass substrate 164. As a result of a cross-sectional observation with a transmission electron microscope, no new crystal defects were introduced into the Si layer, and it was confirmed that good crystallinity was maintained.

(Example 49) A P-type (100) single crystal Si substrate having a diameter of 6 inches and a thickness of 600 microns was subjected to anodization in a 50% HF solution. The current density at this time was 10 mA / cm ² . A porous layer having a thickness of 20 microns was formed on the surface in 10 minutes. Low pressure CVD on the P-type ((100) porous Si substrate)
By the method, a Si epitaxial layer was grown to a thickness of 0.5 μm. The deposition conditions are as follows. Gas: SiH ₂ Cl ₂ (0.6 l / min), H ₂ (1
00 l / min) Temperature: 850 ° C. Pressure: 50 Torr Growth rate: 0.1 μm / min.

Next, the surface of this epitaxial layer is exposed to 50
nm. 0.8 μm on the thermal oxide film thus obtained.
Another silicon substrate having a micron oxide layer on its surface was overlaid and heated in a nitrogen atmosphere at 900 ° C. for 1.5 hours to firmly bond the two substrates.

After that, 5 from the back side of the silicon substrate.
80 micron grinding and polishing was performed to expose the porous layer.

[0295] The Si ₃ N ₄ by plasma CVD method 0.
The two substrates were deposited to a thickness of 1 μm and bonded together. Next, only the nitride film on the porous substrate was removed by reactive ion etching.

After that, the bonded substrates were selectively etched using a hydrofluoric nitric acid acetic acid solution. After 15 minutes, only the single crystal Si layer remains without being etched, and the single crystal Si layer remains.
As an etch stop material, the porous Si layer was selectively etched and completely removed.

The etching rate of the non-porous Si single crystal with respect to the etching solution was extremely low and was 40 even after 15 minutes.
Å, the selectivity with the etching rate of the porous layer was very large, and the etching amount in the non-porous Si layer was practically negligible. After the removal of the Si ₃ N ₄ layer, 0.5 μm
A single-crystal Si layer having a thickness of μm was formed.

Further, the same effect was obtained when Apiezon wax or electron wax was coated instead of the Si ₃ N ₄ layer, and only the porous Si layer could be completely removed.

When the thickness of the obtained single crystal Si layer was examined by scanning ellipsometry, the difference between the maximum value and the minimum value of the thickness of the single crystal Si layer in the plane of the 6-inch wafer was It was suppressed to 10% or less with respect to the maximum value.

Further, as a result of the plane observation of the single crystal Si layer by a transmission electron microscope, the dislocation defect density was suppressed to 1 × 10 ³ / cm ² or less, and new crystal defects were not formed in the single crystal Si layer forming step. It was not introduced, and it was confirmed that good crystallinity was maintained. When the minority carrier lifetime of the single crystal Si layer was measured by the MOS ct method, a high value of 2.0 × 10 ⁻³ sec was obtained.

[0301]

As described in detail above, the semiconductor member of the present invention has a single crystal semiconductor region having a large carrier lifetime and extremely few defects on an insulator with excellent film thickness uniformity. Can be applied to various semiconductor devices. Further, the semiconductor member of the present invention can be applied to a semiconductor device capable of high-speed response and having high reliability. In addition, the semiconductor member of the present invention uses expensive SOS or SI.
It is an alternative to MOX.

[Brief description of the drawings]

FIG. 1 is a schematic view schematically showing one example of steps of a method for manufacturing a semiconductor member of the present invention.

FIG. 2 is a schematic view schematically showing one example of steps of a method for manufacturing a semiconductor member of the present invention.

FIG. 3 is a schematic view schematically showing one example of steps of a method for manufacturing a semiconductor member of the present invention.

FIG. 4 is a schematic view schematically showing one example of steps of a method for manufacturing a semiconductor member of the present invention.

FIG. 5 is a schematic view schematically showing one example of steps of a method for manufacturing a semiconductor member of the present invention.

FIG. 6 is a schematic view schematically showing one example of steps of a method for manufacturing a semiconductor member according to the present invention.

FIG. 7 is a schematic view schematically showing one example of steps of a method for manufacturing a semiconductor member of the present invention.

FIG. 8 is a schematic view schematically showing one example of steps of a method for manufacturing a semiconductor member of the present invention.

FIG. 9 is a schematic view schematically showing one example of the steps of the method for manufacturing a semiconductor member of the present invention.

FIG. 10 is a schematic view schematically showing one example of steps of a method for manufacturing a semiconductor member of the present invention.

FIG. 11 is a schematic view schematically showing one example of steps of a method for manufacturing a semiconductor member according to the present invention.

FIG. 12 is a schematic view schematically showing one example of steps of a method for manufacturing a semiconductor member of the present invention.

FIG. 13 is a schematic view schematically showing one example of the steps of the method for manufacturing a semiconductor member of the present invention.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H01L 21/762 H01L 21/76 D

Claims (2)

[Claims] 1. A semiconductor member in which a non-porous silicon single crystal semiconductor region is arranged on a region made of an insulating material, wherein the dislocation defect density in the non-porous silicon single crystal semiconductor region is 2.0 ×. A semiconductor member having a carrier lifetime of 10 ⁴ / cm ² or less and a carrier lifetime of 5.0 × 10 ^-4 sec or more. 2. A semiconductor member in which a non-porous silicon single crystal semiconductor region is arranged on a region made of an insulating material, wherein the dislocation defect density in the non-porous silicon single crystal semiconductor region is 2.0 ×. 10 ⁴ / cm ² or less, the carrier lifetime is 5.0 × 10 ⁻⁴ sec or more, and the difference between the maximum value and the minimum value of the thickness of the silicon single crystal semiconductor region is 10% or less of the maximum value. Is a semiconductor member.