JPH10321548A - Manufacture of semiconductor substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify processes, to lower cost and to reduce impurity contamination or the like, even in the case of providing the semiconductor layer of a large film thickness on a support. SOLUTION: By the ion implantation of gaseous hydrogen to a base substrate (single-crystal silicon substrate) provided with an oxidized film on a surface, a defective layer for peeling is formed (P1) in the state of securing an extremely thin single-crystal thin-film layer at a surface layer part at a prescribed depth position (about 1 μm from the surface). After the defective layer has been formed, the oxidized film is removed (P2). Then, by an epitaxial growth method at a low temperature, the epitaxial layer of a prescribed thickness (several tens of μms) is formed (P3) on the single-crystal thin-film layer of the base substrate. Then, to the support (silicon substrate) provided with an insulation film, the base substrate is stuck (P4) at the epitaxial layer and consequently peeled (P5) at the defective layer. Thus, a semiconductor substrate provided with the semiconductor layer (epitaxial layer and thin-film layer) of the thick film is obtained via the insulation film on the support. Thereafter, high temperature annealing (P6) and the surface grinding (P7) of a peeling surface are performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor substrate manufacturing method for manufacturing a semiconductor substrate in which a semiconductor layer for element formation is provided on a support in an insulated state from the support.

[0002]

As this type of semiconductor substrate, for example, an SOI (Silicon On Insul) formed by providing a silicon single crystal layer on a silicon substrate via an insulating film.
ator) There is a substrate. As a method for manufacturing this SOI substrate, for example, a so-called smart cut method using lamination as disclosed in Japanese Patent Application Laid-Open No. 5-211128 has been proposed.

In this method, as shown in FIG. 5, an SOI substrate is manufactured through three stages (processes). That is, in the first stage, as shown in FIG. 5A, a step of ionizing, for example, hydrogen gas and accelerating it with a predetermined implantation energy into the base substrate 1 made of a silicon single crystal substrate is performed. Thereby, the defect layer 2 is formed at a predetermined depth position on the base substrate 1. In this case, the layer above the defect layer 2 in the base substrate 1 becomes the thin film layer 1a corresponding to the silicon single crystal layer to be finally obtained.

In the next second stage, as shown in FIG. 5B, a step of bonding a support 3 made of, for example, a silicon substrate to the upper surface of the base substrate 1 is performed. At this time, an insulating film 4 made of an oxide film is previously formed on the surface (the lower surface in the figure) of the support 3. In the third stage, as shown in FIG. 5C, a step of peeling the thin film layer 1a from the base substrate 1 along the defect layer 2 by heat treatment is performed.

As a result, the thin film layer 1a is laminated on the support 3 with the insulating film 4 interposed therebetween.
As shown in (d), the SOI substrate 6 having the silicon single crystal layer 5 is obtained by polishing the peeled surface. According to this method, a high-quality silicon single crystal layer 5 can be obtained.
It can be reused while reducing its thickness.

By the way, the SOI substrate 6 as described above is
For example, when it is used for a power device system, a surface micro machine, or the like, a large thickness (for example, several μm to several tens μm) of the silicon single crystal layer 5 is required. However, in the above-described conventional manufacturing method, when the thickness of the silicon single crystal layer 5 is to be sufficiently increased, the depth of the ion implantation is sufficiently increased (the position where the defect layer 2 is formed is deepened), and the thickness of the thin film layer 1a is reduced. The thickness must be increased.

[0007] Therefore, the ion implantation energy becomes high and a large amount of power is required, so that it becomes expensive and an expensive ion implanter is also required. In this case, for example, 13.
To form a silicon single crystal layer 5 of 5 μm, 1M
eV implantation energy is required. Furthermore, as the acceleration energy increases, heavy metal knock-on into the thin film layer 1a (silicon single crystal layer 5) which is generated as a by-product causes contamination of impurities such as heavy metals in the thin film layer 1a and thus the silicon single crystal layer 5. There was also a problem that the damage was increased. Further, the number of times of repeated use of the base substrate 1 becomes small.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of manufacturing a semiconductor substrate having a semiconductor layer on a support, which is simple and inexpensive. It is an object of the present invention to provide a method of manufacturing a semiconductor substrate, which can obtain a semiconductor layer having a large size and can minimize impurity contamination of the semiconductor layer.

[0009]

According to a first method of manufacturing a semiconductor substrate of the present invention, ions are implanted at a predetermined depth in a surface portion of a base substrate made of a single crystal semiconductor, so that a surface layer of the base substrate is formed. A defect layer forming step of forming a defect layer for separation in a state where the single crystal thin film layer is secured, and a semiconductor film forming step of forming a single crystal semiconductor film of a predetermined thickness on the single crystal thin film layer on the surface of the base substrate, A bonding step of bonding the base substrate over which the single crystal semiconductor film is formed to the support on the surface of the single crystal semiconductor film, and a separation step of separating the base substrate bonded to the support at a defect layer. It has a feature in that it includes (the invention of claim 1).

According to this, in the defect layer forming step,
A single crystal thin film layer in a form partitioned by a defect layer is formed on a surface portion of a base substrate, and a single crystal semiconductor film having a predetermined thickness is formed in a deposited state on the single crystal thin film layer in a semiconductor film forming step. . Then, in the bonding step, the base substrate is bonded to the support on the surface of the single crystal semiconductor film, and in the separation step, the single crystal semiconductor film and the single crystal thin film layer are separated from the base substrate at the defect layer. Accordingly, a semiconductor substrate in which a semiconductor layer mainly including a single crystal semiconductor film is provided over a support is obtained.

At this time, since the thickness of the semiconductor layer can be adjusted by the thickness of the single crystal semiconductor film formed in the semiconductor film forming step, the single crystal thin film layer formed on the surface of the base substrate in the defect layer forming step can be made extremely thin. While
The thickness of the semiconductor layer can be increased. Therefore, the energy of ion implantation in the defect layer formation step can be reduced, and the contamination of the single crystal thin film layer by heavy metals or the like can be suppressed. In addition, a simple combination of steps can be completed as a whole.

As a result, according to the method of manufacturing a semiconductor substrate according to the first aspect of the present invention, even when a semiconductor layer having a large thickness is provided on a support, simple steps can be performed at low cost. The present invention has an excellent practical effect of being able to suppress impurity contamination and the like.

According to a second method of manufacturing a semiconductor substrate of the present invention,
A defect layer forming step of forming a defect layer for separation in a state where a single crystal thin film layer is secured in a surface layer portion of the base substrate by performing ion implantation to a predetermined depth of a surface portion of the base substrate made of a single crystal semiconductor; A laminating step of laminating the base substrate to the support on the surface of the single crystal thin film layer, a peeling step of separating the base substrate laminated to the support at the defect layer, and a single crystal on the surface of the support. A semiconductor film forming step of forming a single-crystal semiconductor film of a predetermined thickness on the thin film layer (the invention of claim 2).

According to this, in the defect layer forming step,
A single crystal thin film layer in a form separated by a defect layer is formed on a surface layer portion of the base substrate, and in a bonding step, the base substrate is bonded to a support on the surface of the single crystal semiconductor film. Then, in the separation step, the single crystal thin film layer is separated from the base substrate at the defect layer, and in the semiconductor film formation step, a single crystal semiconductor film having a predetermined thickness is deposited on the single crystal thin film layer. Thus, a semiconductor substrate in which a semiconductor layer mainly including a single crystal semiconductor film is provided over a support is obtained.

Also in this case, the thickness of the semiconductor layer can be adjusted by the thickness of the single crystal semiconductor film formed in the semiconductor film forming step, so that the single crystal thin film layer formed on the surface layer of the base substrate in the defect layer forming step is made extremely thin. However, the thickness of the semiconductor layer can be increased. Therefore, the energy of ion implantation in the defect layer formation step can be reduced, and the contamination of the single crystal thin film layer by heavy metals or the like can be suppressed. In addition, a simple combination of steps can be completed as a whole.

As a result, according to the method of manufacturing a semiconductor substrate according to the second aspect of the present invention, even when a semiconductor layer having a large film thickness is provided on a support, it is possible to reduce the cost by a simple process. The present invention has an excellent practical effect of being able to suppress impurity contamination and the like.

At this time, in each of the above-described manufacturing methods, the ion implantation in the defect layer forming step is performed with the oxide film formed on the surface of the base substrate, and the oxide film is removed after the defect layer is formed. (The invention according to claim 3). According to this, the oxide film can prevent the single crystal thin film layer from being contaminated by impurities such as heavy metals during ion implantation as much as possible.

In the first method of manufacturing a semiconductor substrate, the defect layer formed in the base substrate must be maintained as it is from the step of forming the defect layer to the step of peeling. However, when a high temperature acts on the base substrate in the semiconductor film forming step, the implanted ions may be detached from the base substrate, and the function as a defect layer for separation may be impaired. Therefore, it is desirable that the step of forming a semiconductor film in the first method for manufacturing a semiconductor substrate is performed at a low temperature such that the implanted ions are not desorbed from the base substrate.
Invention), thereby preventing the implanted ions from desorbing from the base substrate.

In the defect layer forming step in each of the above-described manufacturing methods, impurity contamination occurs to some extent in the single crystal thin film layer with ion implantation. Also in this case, when a high temperature acts on the base substrate in the semiconductor film forming step, impurities contained in the single crystal thin film layer may diffuse into the formed single crystal semiconductor film and become contaminated. Therefore, it is desirable that the semiconductor film forming step be performed at a temperature at which diffusion of impurities from the single crystal thin film layer to the single crystal semiconductor film is suppressed (the invention of claim 5). The diffusion of contamination can be effectively prevented.

In the semiconductor film forming step, as a method for forming a single crystal semiconductor film in a deposited state on the single crystal thin film layer, a crystal is grown in accordance with the crystal axis of the single crystal thin film layer. There is an epitaxial growth method (the invention of claim 6), which makes it possible to form a high-quality single crystal semiconductor film. Further, as an apparatus for realizing this epitaxial growth method, a molecular beam epitaxy apparatus can be used (the invention of claim 7).
Thus, the step of forming a single crystal semiconductor film can be performed at a relatively low temperature.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION

(1) First Embodiment Hereinafter, the present invention will be described with reference to an SOI (Silicon On Insul) in which a thick silicon single crystal layer is provided on a silicon substrate via an insulating film.
ator) A first embodiment applied to the manufacture of a substrate.
3, 4, 5, 6, and 7) will be described with reference to FIGS.

First, as shown in FIG. 2F, a semiconductor substrate (SOI substrate) 11 manufactured by the method of this embodiment is formed of, for example, a silicon oxide film on a support 12 formed of, for example, a silicon substrate. The semiconductor device includes a semiconductor layer 14 for element formation made of silicon single crystal via an insulating film 13. The semiconductor layer 14 has a large thickness (for example, about several μm to several tens of μm), and is used for, for example, a power device system or a surface micro machine. At this time, as will be described later in detail, the semiconductor layer 14 is composed of an epitaxial layer 15 which is a single crystal semiconductor film constituting the majority and a very thin thin film layer 1 on the upper surface thereof.
And 6.

Now, a method of manufacturing the semiconductor substrate 11 will be described in the following order. FIG. 1 schematically illustrates a process of manufacturing the semiconductor substrate 11 according to the present embodiment. That is, first, in the process P1, a defect layer forming process is performed. In this step P1, as shown in FIG. 2A, for example, hydrogen gas is ionized and implanted into the base substrate 17 made of a single-crystal silicon substrate at a predetermined implantation energy at a surface portion thereof. Done. In this case, ion implantation is performed at low energy (for example, 1
Since it is performed at 50 keV, a relatively inexpensive and general-purpose ion implanter having a small amount of current can be used.

Thus, a defect layer 18 for separation is formed at a predetermined depth position (for example, a position 1 μm from the surface) of the base substrate 17 by the implanted ions. In the surface layer of the base substrate 17, an extremely thin single-crystal thin-film layer 17a made of silicon single crystal (to become the thin film layer 16 later) is formed in a form partitioned by the defect layer 18. . The overall thickness of the base substrate 17 is:
In an initial state (before reuse), the thickness is, for example, about 600 μm.

At this time, although not shown, an oxide film for preventing contamination during ion implantation is formed on the surface of the base substrate 17, and the ion implantation is performed through the oxide film. It has become. After the defect layer 18 is formed by ion implantation, in step P2, the oxide film is removed by, for example, wet etching the surface of the base substrate 17.

In the next step P3, a semiconductor film forming step of forming a single crystal semiconductor film of a predetermined thickness in a deposited state on the single crystal thin film layer 17a on the surface of the base substrate 17 is performed. In this embodiment, as a method for forming a single crystal semiconductor film,
An epitaxial growth method using a molecular beam epitaxial growth apparatus (abbreviated as MBE apparatus) is used. As a result, as shown in FIG.
A silicon single crystal grows in a deposited state on a in accordance with its crystal axis, and an epitaxial layer 15 as a single crystal semiconductor film is formed to a predetermined thickness (for example, tens of μm).

At this time, in the present embodiment, the epitaxial growth is performed at a relatively low temperature (for example, 500 ° C. or lower), and by employing the MBE apparatus, the epitaxial layer 15 having a high purity at a low temperature can be obtained. Can be formed. Thus, the defect layer 18 of the base substrate 17
It is possible to prevent implanted ions (hydrogen ions) from being desorbed from the substrate, and the defect layer 18 can be maintained. In addition, the single crystal thin film layer 1
Even if some impurity contamination occurs in 7a, it is possible to prevent the contaminant from diffusing into the epitaxial layer 15 as much as possible.

In the next step P4, a laminating step of laminating the base substrate 17 on which the epitaxial layer 15 is formed to the support (silicon substrate) 12 is performed.
In this step P4, as shown in FIG. 2C, the base substrate 17 is placed on the support 12 on which the insulating film (oxide film) 13 is formed in advance and which is mirror-polished.
(B) is adhered in an upside down state, that is, on the surface of the epitaxial layer 15. This bonding is performed by a known method of bonding using a direct bonding method or an electrostatic pressure or the like. Thus, as shown in FIG. 2D, the epitaxial layer 1 is formed on the support 12 with the insulating film 13 interposed therebetween.
5. Single crystal thin film layer 17a, defect layer 18, and base substrate 1
7 are integrated into a stacked form.

Subsequently, in step P5, a peeling step of separating the base substrate 17 bonded to the support 12 at the defect layer 18 is performed. In this step P5, for example, 1000
This is based on the occurrence of cracks in the defect layer 18 inside the base substrate 17 as shown in FIG. With this, the base substrate 1
7 single crystal thin film layer 17a provided on defect layer 18
The semiconductor layer 14 having a sufficiently large thickness (the epitaxial layer 15 and the thin film layer) is formed on the support 12 with the insulating film 13 interposed therebetween. The semiconductor substrate 11 having 16) is obtained.

Thereafter, in step P6, the obtained semiconductor substrate 11 is subjected to high-temperature annealing at a temperature of, for example, 800 ° C. or higher. As a result, the recovery of the defect on the peeled surface, the strengthening of the bond, the removal of the surface oxide, the partial flattening due to the silicon flow, and the like are achieved. Further, in step P7, the surface of the peeled surface is polished. With this,
The unevenness of the peeled surface is removed, and the semiconductor substrate 11 is finished as shown in FIG.

Although not shown, the peeling step P
5, the base substrate 17 from which the single crystal thin film layer 17a has been separated
The side is used for manufacturing the next semiconductor substrate 11, for example, after the peeled surface is polished. In this case, the base substrate 17
The thickness dimension reduced by one use is kept to 2 μm or less, and one base substrate 17 can be repeatedly used many times.

As described above, according to the present embodiment, the support 12
A semiconductor substrate 11 having a semiconductor layer 14 with a sufficiently large thickness suitable for use in, for example, a power device system or a surface micro machine, which has a semiconductor layer 14 with an insulating film 13 interposed therebetween, is obtained. I was able to. At this time, since the formation of the thick semiconductor layer 14 was made possible by the formation of the epitaxial layer 15 by the epitaxial growth method in the semiconductor film formation step P3, the single crystal thin film layer 17a peeled off from the base substrate 17 was made extremely thin. In other words, the depth of the ion implantation (depth of formation of the defect layer 18) in the defect layer formation step P1 can be reduced regardless of the thickness of the semiconductor layer 14 to be obtained.

Therefore, the conventional silicon single crystal layer 5
In order to increase the thickness of the semiconductor layer 14, unlike the case where the depth of the ion implantation must be increased, the defect layer forming step P 1
In this case, the energy of the ion implantation can be reduced, and an expensive ion implanter is not required. Accordingly, the contamination of the single crystal thin film layer 17a with heavy metals and the like can be suppressed to an extremely small level, and the epitaxial layer 15 made of a high quality silicon single crystal film can be obtained by the epitaxial growth method. Moreover, a simple combination of steps can be completed as a whole.

Particularly, in this embodiment, in the defect layer forming step P1, the ion implantation is performed in a state where the oxide film is formed on the surface of the base substrate 17, so that the oxide film
Contamination due to impurities such as heavy metals during ion implantation can be suppressed, and the semiconductor film forming step P3 is performed at a low temperature at which diffusion of impurities from the single crystal thin film layer 17a to the epitaxial layer 15 is suppressed. Therefore, even if the single crystal thin film layer 17a is slightly contaminated with impurities due to the ion implantation, the contaminant is removed from the epitaxial layer 15a.
It can be prevented from diffusing inside as much as possible.

As a result, according to the method of manufacturing the semiconductor substrate 11 of this embodiment, the semiconductor layer 14 having a large thickness can be obtained in a simple process and at low cost.
Excellent practical effect that the quality of No. 4 can be made sufficiently high can be obtained. Moreover,
The number of times the base substrate 17 is repeatedly used can be greatly increased.

In the above embodiment, only the surface of the thin film layer 16 (single crystal thin film layer 17a) is polished in the step (P7) of polishing the surface of the peeled surface. The whole can be removed.
According to this, the semiconductor layer 14 is composed only of the epitaxial layer 15, so that the semiconductor layer 14 with higher quality can be obtained.

(2) Second Embodiment Next, a second embodiment (corresponding to claim 2) of the present invention will be described with reference to FIGS. Also in this embodiment, the present invention is applied to the manufacture of an SOI substrate in which a thick silicon single crystal layer is provided on a silicon substrate via an insulating film, and the same parts as those in the first embodiment are used. For, the detailed description will be omitted, and some reference numerals will be used in common. Hereinafter, different points will be mainly described.

As shown in FIG. 4E, a semiconductor substrate (SOI substrate) 21 manufactured by the method of the present embodiment is formed on an insulating film made of, for example, a silicon oxide film on a support 12 made of, for example, a silicon substrate. 13, a semiconductor layer 22 for element formation made of silicon single crystal is provided. The semiconductor layer 22 also has a large thickness (for example, about several μm to about several tens of μm), and is used for, for example, a power device system or a surface micro machine. At this time, the semiconductor layer 22 is composed of an extremely thin thin film layer 23 and an epitaxial layer 24 which is a single crystal semiconductor film constituting most of the upper surface thereof.

FIG. 3 schematically shows the steps of manufacturing the semiconductor substrate 21 according to the present embodiment. That is, first, the process Q
In 1, a defect layer forming step is performed. In this step Q1, as in step P1 of the first embodiment, ion implantation of hydrogen gas is performed on the base substrate 17 made of a single crystal silicon substrate having an oxide film (not shown) formed on the surface. Then, as shown in FIG. 4A, a peeling defect layer 18 is formed at a predetermined depth position (for example, at a position 1 μm from the surface) of the base substrate 17. Further, a very thin single crystal thin film layer 17 made of silicon single crystal is
a (which will later become the thin film layer 23) is formed in a form partitioned by the defect layer 18. In step Q2, the oxide film is removed from the surface of the base substrate 17 by, for example, wet etching.

In the next step Q3, a bonding step of bonding the base substrate 17 to the support 12 is performed. In this step Q3, as shown in FIG. 4B, the base substrate 1 on which the insulating film 13 is formed in advance is
7 are bonded in an upside down state, that is, on the surface of the single crystal thin film layer 17a. As a result, as shown in FIG. 4C, the single-crystal thin-film layers 17a,
The defect layer 18 and the bulk portion of the base substrate 17 are integrated in a stacked form.

Subsequently, in step Q4, a peeling step of separating the base substrate 17 bonded to the support 12 by the defect layer 18 by performing a high-temperature heat treatment is performed. As a result, the single crystal thin film layer 17a provided on the defect layer 18 of the base substrate 17 is peeled off and transferred to the surface side of the support 12, and the upper surface of the single crystal thin film The support 12 having the thin film layer 23 made of a crystal is obtained. Next, in step Q5, a high-temperature annealing process is performed on the support 12. This high-temperature annealing is performed in the epitaxial device. As a result, defect recovery of the peeled surface, strengthening of bonding, removal of surface oxide, partial flattening due to silicon flow, and the like are achieved.

Then, in step Q6, as shown in FIG. 4E, a predetermined thickness (for example, tens of μm) is formed on the thin film layer 23 on the surface of the support 12 by an epitaxial growth method in an epitaxial apparatus. A semiconductor film forming step of forming the epitaxial layer 24 as a single crystal semiconductor film in a deposited state is performed. Also in this case, the epitaxial growth is performed at a relatively low temperature, and even if some impurity contamination occurs in the thin film layer 23 (single crystal thin film layer 17a), the impurity is prevented from diffusing into the epitaxial layer 24. It is done.

Thereafter, in a step Q7, a step of polishing the surface of the epitaxial layer 24 is performed, whereby irregularities on the surface of the epitaxial layer 24 are removed.
Is completed. The surface polishing step Q7 may be executed as needed according to the surface condition of the epitaxial layer 24. The base substrate 17 from which the single-crystal thin film layer 17a has been peeled off in the peeling step Q4 has its peeled surface polished, and is repeatedly used for manufacturing the next semiconductor substrate 21.

According to the method of manufacturing the semiconductor substrate 21 of this embodiment, as in the case of the first embodiment, the semiconductor layer 22 having a large thickness can be obtained in a simple process at low cost. Moreover, an excellent practical effect that the quality of the semiconductor layer 22 can be made sufficiently high can be obtained. Further, the number of times of repeated use of the base substrate 17 can be greatly increased.

In the second embodiment, the semiconductor film forming step Q6, that is, the step of forming the epitaxial layer 24 is omitted.
Although it is performed at a relatively low temperature, since there is no possibility that the peeling step Q4 has already been completed and adversely affects the defective layer 18 from the beginning, diffusion of impurities from the thin film layer 23 does not matter. For example, the epitaxial layer 24 may be formed at a high temperature.

In each of the above embodiments, MBE is used as an epitaxial device. However, CVD can be used. In this case, a high vacuum can be obtained and hydrogen adhering to the substrate surface can be removed in situ. It is desirable to use an apparatus provided with a cleaning mechanism capable of performing the cleaning. As a source gas, disilane, dichlorosilane, or the like can be used.

In addition, the present invention is not limited to the above-described embodiments. For example, the material of the support may be a ceramic substrate or a quartz substrate. Further, the material used for ion implantation is not limited to hydrogen gas, but a rare gas such as helium or neon, fluorine, or chlorine gas can also be used. Needless to say, an appropriate peeling temperature and a temperature in each step and the like vary depending on the type of ions. Further, the thickness and the like of each part are merely examples, and the present invention can be appropriately changed and implemented without departing from the scope of the invention.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention and is a view schematically showing a manufacturing process of a semiconductor substrate.

FIG. 2 is a longitudinal sectional view schematically showing a state in a manufacturing process.

FIG. 3 is a view corresponding to FIG. 1, showing a second embodiment of the present invention;

FIG. 4 is a diagram corresponding to FIG. 2;

FIG. 5 is a diagram corresponding to FIG. 2 showing a conventional example.

[Description of References] In the drawings, 11 and 21 are semiconductor substrates, 12 is a support, 13
Is an insulating film, 14 and 22 are semiconductor layers, 15 and 24 are epitaxial layers (single-crystal semiconductor films), 17 is a base substrate, 1
7a indicates a single crystal thin film layer, and 18 indicates a defect layer.

Claims (7)

[Claims] 1. A method for manufacturing a semiconductor substrate (11) in which a semiconductor layer (14) for element formation is provided on a support (12) in an insulated state from the support (12). By performing ion implantation to a predetermined depth of the surface portion of the base substrate (17) made of a single crystal semiconductor, a single crystal thin film layer (17a) is secured to the surface portion of the base substrate (17). A defect layer forming step (P1) for forming a defect layer (18), and a single crystal thin film layer (17) on the surface of the base substrate (17).
a) a semiconductor film forming step (P3) of forming a single-crystal semiconductor film (15) having a predetermined thickness on the single-crystal semiconductor film (1);
Laminating step (P4) of laminating base substrate (17) on which 5) is formed on the surface of single crystal semiconductor film (15).
And a base substrate (17) bonded to the support (12).
A separating step (P5) of separating the semiconductor substrate at the defect layer (18). 2. A method for manufacturing a semiconductor substrate (21) in which a semiconductor layer (22) for element formation is provided on a support (12) so as to be insulated from the support (12). By performing ion implantation at a predetermined depth in the surface portion of the base substrate (17) made of a single crystal semiconductor, a single crystal thin film layer (17a) is secured in the surface layer portion of the base substrate (17). A defect layer forming step (Q1) for forming a defect layer (18), and laminating the base substrate (17) on the surface of the single crystal thin film layer (17a) with respect to the support (12). Step (Q3), a base substrate (17) bonded to the support (12)
(Q4) in which a single crystal semiconductor film (24) having a predetermined thickness is formed on the single crystal thin film layer (23) on the surface of the support (12). A method for manufacturing a semiconductor substrate, comprising: a film forming step (Q6). 3. The ion implantation in the defect layer forming step (P1, Q1) is performed with an oxide film formed on the surface of the base substrate (17), and after the formation of the defect layer (18). 3. The method according to claim 1, wherein the oxide film is removed. 4. The semiconductor substrate forming method according to claim 1, wherein the semiconductor film forming step (P3) is performed at such a low temperature that the implanted ions are not desorbed from the base substrate (17). Production method. 5. The semiconductor film forming step (P3, Q6).
5. The method according to claim 1, wherein the step is performed at a temperature at which diffusion of impurities from the single crystal thin film layer to the single crystal semiconductor film is suppressed. Of manufacturing a semiconductor substrate. 6. The semiconductor film forming step (P3, Q6).
6. The method of manufacturing a semiconductor substrate according to claim 1, wherein the method is performed by an epitaxial growth method. 7. The semiconductor film forming step (P3, Q6).
7. The method according to claim 6, wherein the step (b) is performed using a molecular beam epitaxy apparatus.