JPS58200525A - Preparation of substrate for semiconductor device - Google Patents

Abstract

PURPOSE:To form a high quality, wide area single crystal semiconductor film in the uniform thickness on an insulator by transferring a single crystal semiconductor film formed on a semiconductor substrate by the epitaxial growth method onto a substrate providing an insulating layer at least on the surface through an insulating adhesive layer. CONSTITUTION:A high concentration impurity layer 2 having boron is formed on the surface of single crystal silicon substrate 1 having a resistivity of several ohm-cm or higher. Then, a single crystal silicon film 3 having a low impurity concentration is formed by epitaxial growth method under the reduced pressure condition. For example, a silicon dioxide film 4 is formed as an insulating film by the chemical vapor deposition (CVD) method on a single crystal silicon film 3. Meanwhile, an insulating substrate, for example, a quartz glass is prepared in addition to a silicon substrate and an insulating adhesive layer is coated on such insulating substrate. 5 indicates a quartz glass substrate and 6 indicates a high molecular resin film coated through rotating operation. Thereafter, the surface of silicon dioxide film 4 and the surface of high polymer resin film 6 are placed closely in contact and these two substrate are bonded through a heat processing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a single-crystal semiconductor film on a substrate having at least an amorphous substrate formed on the surface thereof.

The tentative technique of forming a single crystal semiconductor film on an insulator is attracting attention because of its advantages in increasing the speed of LSI and making it three-dimensional, and various forming methods have been attempted. For example, an fP3 film such as silicon dioxide is formed on a single-crystal silicon substrate using pridging epitaxy, and a part of the fP3 film is opened to expose the silicon single-crystal surface. A single-crystalline silicon film is formed by depositing a crystalline or polyglazed crystalline silicon film, performing beam annealing such as a laser, or annealing using a rod-shaped heater, bath-melting the silicon film, and growing it epitaxially in an unconducted area where there is no continuous film. The resulting part can be used as a stock to grow a single crystal silicon film on the loquat.

A formation method called graphoepitaxy is also used. In this method, first, a fine groove of about 1 μm in size is formed on the surface of a quartz glass substrate, an amorphous silicon film is deposited on this, and then an amorphous silicon film is deposited using laser beam annealing or a carbon heater. This is a method of converting an amorphous silicon film into a single crystal silicon film. in this way,
The crystal orientation is controlled by grooves formed on the curved surface of the quartz glass substrate, making it possible to align the crystal orientation even without poles. These formation methods involve converting an amorphous or polycrystalline silicon film into a single crystal silicon film by beam annealing or annealing using a carbon heater or the like. With this method, it is easy to obtain single crystal silicon with a size of several μm to several tens of μm, or several nanometers.
Alternatively, it is not easy to obtain single crystal silicon with a large area on the order of several tens of Mml.

In an attempt to form a large-area single-crystal silicon film on an insulator, a P- or N- silicon film is epitaxially grown on a single-crystal silicon substrate having a P+ layer, and then an insulating film is formed on the silicon film. and then depositing polycrystalline silicon with a thickness of several hundred am for a support substrate on top of it.
A known method is to form a single crystal silicon film on a polycrystalline silicon substrate through an insulating layer by removing the single crystal silicon substrate.
hn and C, John Rhee+ J□urna
l of Electrochemical 5oci
etyUol 120 (1973) PP, 1563-1
566-]. However, in this method, a single crystal silicon substrate is exposed to high temperature for a long time when poly-8i is deposited to a thickness of several hundred μm. As a result, diffusion of boron (Bl) from the P layer to the epitaxial film occurs, which impairs the steepness of the impurity distribution at the interface between the epitaxial film and the single crystal silicon substrate. It has the disadvantage that it is difficult to leave it uniformly.Also, when it is on a polycrystalline silicon film,
If the polycrystalline silicon is wrapped around the epitaxial silicon film side, the thickness of the polycrystalline silicon film becomes uneven, and it is difficult to uniformly remove the single-crystalline silicon substrate. The drawback is that the notes also deteriorate.

Regarding germanium, an amorphous substrate with a single-crystal germanium film formed on the surface is used as a substrate for forming an electric-V compound semiconductor layer such as gallium arsenide (GaAs) because of its good lattice constant matching, or By selecting an insulating substrate as the amorphous substrate, single-crystal germanium has a higher electron mobility than silicon, which is useful because it can be applied to high-speed MOSFETs, etc.9.

As a method for forming a single crystal germanium film on such an amorphous substrate, for example, an amorphous germanium film is deposited on quartz glass and then annealed with a laser beam to aggregate single crystal grains with a large grain size. There is a way to get a body [Jimin Shih Shi Huang et al. Applied Physics Letters, 1980, vol. 36, 158
One page.

However, the germanium film obtained by such a method is inferior to single crystal germanium obtained by a normal pulling method in terms of crystallinity such as crystal grain size and orientation arrangement. Further, the gallium arsenide film grown on such a germanium film also has poor crystallinity, and when considering application to, for example, solar cells, the efficiency is inferior to that of single crystal gallium arsenide.

Since gallium arsenide has higher electron mobility in crystals than silicon, it is used in field effect transistors (FETs) that can operate at high speeds. In this case, a gallium arsenide epitaxial film is used as the active layer, and a high resistance gallium arsenide single crystal substrate is generally used as the substrate. This high-resistance gallium arsenide single crystal substrate is obtained by doping with chromium (Cr) during growth. However, crystal growth is not easy in terms of controlling the amount of Cr impurities or making the distribution uniform, and it is difficult to obtain high-quality, large-diameter, high-resistance gallium arsenide single crystals at low cost.

The invention is completely different from the conventional formation method described above.It is a non-invention method to create a highly crystalline single crystal semiconductor film with a size of several tens of fins or more, a large area, a uniform film thickness, and few crystal defects. A method for forming a crystalline insulator layer on a crystalline insulator layer is provided.

According to the present invention, a single crystal semiconductor substrate having at least a semiconductor single crystal epitaxial film and an insulating film on the epitaxial film on its surface, and a substrate having an amorphous insulating layer on at least one side of the substrate are provided. After providing an adhesive layer between the amorphous insulating layer and the insulating wire on the epitaxial film of the single crystal semiconductor substrate and fixing it, removing the scratches by polishing and etching the single crystal semiconductor substrate. Accordingly, there is obtained a method for handling a substrate for a semiconductor device, characterized in that the semiconductor single crystal epitaxial film is formed on the substrate having an amorphous insulating layer formed on at least the surface thereof.

The feature of the invention is, in short, that a semiconductor epitaxial group is formed on a semiconductor single crystal substrate, and this film is transferred via an adhesive layer onto a substrate having an amorphous insulating layer on at least the surface. .

Since this method uses a single crystal semiconductor film grown by epitaxial method, it is possible to form a high quality single crystal semiconductor film with few crystal defects and a large area on the +Ie edge body. In addition, since this method does not use seeds, when converting r = q, It has the advantage that even if it is a quality insulator, a large-area, high-quality single-crystal semiconductor film can be easily laminated thereon.

The present invention will be described in detail below using Examples.

In the first embodiment, a silicon epitaxial film is formed on an insulating substrate via an adhesive layer.

FIG. 1 is a schematic cross-sectional view of a silicon single crystal substrate on which a silicon film was grown on a high concentration impurity #I layer as a preliminary preparation, and a Si film was further formed thereon. First of all, single crystal silicon with a thickness of 300μppsg and has a resistivity of several Ω1 or more! A high-concentration impurity layer 2 having boron (of the order of 102 o1 hard/-) is formed on the surface of the lil by, for example, thermal diffusion treatment. Next, a single crystal silicon film 3 having a thickness of about 3 μm and having a low impurity concentration is epitaxially grown under reduced pressure.

Next, as an insulating film, for example, a silicon dioxide film 4 is deposited to a thickness of 5 μm on the single crystal silicon film 3 by chemical vapor deposition (CVD).
(Figure 1).

On the other hand, an insulating substrate such as quartz glass is prepared separately from such a substrate, and an insulating adhesive is applied on the insulating substrate. For example, a polyimide-based or ladder-type silicone-based highly heat-resistant polymer resin is used as the adhesive material having loquats. These polymer resins can be applied by spin coating onto an insulating substrate.
Uniform on the order of μm! Noodles can be formed. Figure 2 shows this situation. Figure 2 is base & V? In the schematic plan view, 5 is a quartz glass substrate, and 6 is a spin-coated polymer resin film.

Next, the surface of the silicon dioxide film 4 shown in FIG. 1 and the surface of the polymer side fat film 6 shown in FIG. 2 were soaked in honey for 200 minutes.
The two substrates shown in Figures 1 and 2 are bonded together by heat treatment at ~400°C (Figure 3).

Next, the silicon substrate 1 and high concentration impurity layer 2 of the wafer shown in FIG. 3 are removed by polishing and etching.

First, apply normal lapping and polishing.
A silicon substrate 1 having a thickness of approximately 00 μm is thinned to approximately 30 μm. Next, the silicon substrate is etched using an etching solution such as an alkaline aqueous solution mainly containing potassium hydroxide (KOf()), which has a large etching rate between the silicon substrate 1 containing low concentration impurities and the high density non-concentration layer 2. When etching 1, the etching stops at the interface between silicon substrate 1 and high concentration impurity layer 2 (FIG. 4).

Next, the high concentration impurity layer 2 and the low concentration impurity single crystal silicon film 3 are etched using an etching solution such as a mixed solution of nitric acid, hydrofluoric acid, and acetic acid that has a greatly different etching rate. The etching rate with respect to the single crystal silicon film 3 can be set to about 50:1, and the high concentration impurity layer 2 can be removed by etching without substantially etching the single crystal silicon film 3 (FIG. 5).

In this way, a single crystal silicon film having a uniform thickness of about 2.6±0.3 μm could be formed on the insulator. Furthermore, by applying mechanochemical boriding processing to such a single crystal silicon film! Ill,
A single crystal silicon film with a thickness of 0.7±0.1 μm was also formed.

Although the explanation has been made using quartz glass as an example of an insulating substrate, the invention is not limited to this. For example, as shown in FIG. 6, a silicon substrate 7 is thermally oxidized to form a silicon dioxide film 8 on the surface.
81 may be used.

Furthermore, a silicon substrate containing a high concentration of impurities may be used as the substrate on which silicon is epitaxially formed.

Further, the adhesive layer is not limited to a polymer resin film, and for example, a glass layer can be used.

For example, as shown in FIG. 7, a metal film, such as a lead (Pb) evaporation film 9, is formed on the surface of an insulating substrate, such as quartz glass 5. As mentioned above, a silicon substrate containing a single crystal silicon film and a silicon dioxide film, and a quartz glass substrate containing a vapor-deposited film were deposited using a method similar to that shown in Fig. 3. Heat treated with For example, by depositing a vapor-supplied N film with a thickness of about 0.3 μm and heat-treating it at about 600°C, lead reacts with the quartz glass and silicon dioxide film, resulting in a thickness of 1 μm.
A layer of lead glass with a thickness of about , :: is formed and the two substrates are bonded together. Then, by polishing and etching processes similar to those described in FIGS. 4 and 5, as shown in FIG. A silicon film 3 can be formed.

In the non-example, a polycrystalline silicon film is not deposited to form an insulating substrate for supporting a single-crystalline silicon film.
Single-crystal silicon family is not exposed to high temperatures for long periods of time. Impurity diffusion from the impurity layer to the single crystal silicon film is significantly reduced. In addition, the troublesome problem of the polycrystalline silicon getting mixed into the monocrystalline silicon layer during polycrystalline silicon deposition can be avoided.

Since the single crystal silicon film obtained by such a method is originally grown by homoepitaxial growth Lm, it has few crystal defects, is of high quality, and has the same area as the substrate surface. Furthermore, by using the method of the present invention,
After forming a device element on a single-crystal silicon film, a single-crystal silicon film can be formed again on top of the device element.
It is also possible to make I three-dimensional.

Next, a second example in which a germanium single crystal film is formed on an insulating substrate will be described. First, germanium i with a thickness of about 2 μm was epitaxially grown on a silicon substrate having a resistivity on the order of several Ω·1. For epitaxial growth, chemical vapor deposition (CVD) is used to grow germanium (
The thermal decomposition of GeHa) was carried out at approximately 600°C. Next, a 3 μm thick silicon dioxide film was deposited on the epitaxially grown single crystal germanium film by CVD.

A schematic cross-sectional view of the silicon substrate obtained in this way is shown in Figure 9.
As shown in the figure.

On the other hand, apart from such a silicon substrate, a quartz glass substrate was prepared as an amorphous substrate, and an adhesive layer was deposited on this quartz glass substrate. The following steps are almost the same as those in the first embodiment, so the explanation will be omitted. In this way, a polyimide resin film 15, which is an adhesive layer, and a silicon dioxide film are formed on a quartz glass substrate 14 as shown in FIG. A germanium single crystal film 12 could be formed on the laminated film 13.

In this embodiment, a silicon substrate was used as the substrate for germanium, but it is clear that a germanium substrate may also be used.

Furthermore, the adhesive layer is not limited to polyimide, and the adhesive layer is not limited to polyimide.
The silicon-based 8fh film and lead glass described in the embodiment may also be used in a similar manner. Furthermore, the substrate to which the germanium epitaxial film is transferred is not limited to the quartz glass substrate, but may also be other S@ glasses, silicon substrates with a silicon dioxide film formed on the surface by thermal oxidation or CVD, or ceramics. etc.

Since the single-crystal germanium film thus obtained is originally an epitaxially grown film, it has few crystal defects and is of high quality, and can have a large area similar to the size of the substrate. Also, after forming a device on a semi-crystalline germanium film by using the method of the present invention,
On top of that, a semiconductor single crystal film of germanium, silicon, etc. can be entirely formed again, and the device can be made more conservative.

As a third embodiment, a case will be explained in which a germanium monocrystalline crystal is used as a semiconductor single crystal substrate in the case of epitaxially growing gallium arsenide.

It has a resistivity of several Ω・1, has a diameter of 2 inches, and has a surface orientation (
A gallium arsenide single crystal film was epitaxially grown on a germanium single crystal substrate having a chemical vapor deposition (CVD) of 100% by chemical vapor deposition (CVD). The raw material gas is trimethyl gallium C (CHs ) S Ga).

and arsine, As1(,'J) were used for vapor phase growth by thermal decomposition of these gases.
A gallium arsenide single-crystal film was grown, and on top of that, four loquat films were applied using the CVJ method. For example, silicon nitride (SisN4) g was deposited to a thickness of about 0.3 μm as an insulating film. A schematic cross-sectional view of such a germanium single crystal substrate is shown in FIG.

On the other hand, apart from the germanium single crystal substrate, a quartz glass substrate was prepared as an amorphous insulator substrate, and a polyimide resin was deposited on the quartz glass substrate as a contact layer. The following steps are almost the same as in the first example, so detailed explanation will be omitted.

In this way, as shown in a schematic cross-sectional view in FIG. A gallium arsenide film 22 was successfully formed. A mixed solution of hydrofluoric acid, nitric acid, and ice vinegar was used as the etching solution for germanium.

Furthermore, in Hitoshi's example, a germanium substrate was used as the substrate on which gallium arsenide was epitaxially deposited, but a germanium substrate with a nigermanium epitaxial film on the surface, a silicon substrate, a silicon substrate with a H'(I K'/IJ con-epitaxial film, a silicon substrate with a surface A silicon substrate or the like on which a germanium film is epitaxially formed may also be used.

Furthermore, the adhesive layer is not limited to polyimide, and silicon-based resin may also be used. Further, if a silicon dioxide film is provided on the silicon nitride film 23, the first example-c4, er, □-i1 machine. 1, 3□□ can also be used.

Insulating substrates are not limited to quartz glass substrates; other types of glass and ceramics can also be used.

A silicon substrate with a silicon dioxide film formed on its surface may also be used.

Since the gallium arsenide single crystal film obtained by such a method is originally a film grown epitaxially, it has few crystal defects, has high quality, and has the same size as the substrate. In addition, since an inexpensive amorphous material such as glass is used as the substrate, it is easy to increase the diameter and has excellent insulation properties, so when forming a device such as an FET, for example, floating The storage space is small, and the high speed, which is a major advantage of gallium arsenide, is greatly developed.

Alternatively, after a device is formed on the surface of a silicon single crystal substrate, a gallium arsenide single crystal film can be formed thereon, making it possible to stack the device and make it more flexible.

Although it has been described above that a single crystal film of silicon, germanium, or gallium arsenide is formed on an amorphous insulator in Example 1-i3, this invention is not limited to this, and InP , InAs, AJt-xGaxAsI
It can also be applied to general I-■ group compound semiconductors such as nGaAsP.

As described above, the present invention is completely different from conventional methods in that a single crystal semiconductor film epitaxially grown on a semiconductor substrate is transferred via an insulating adhesive layer onto a substrate having an insulating layer on at least the surface. According to the present invention, a monocrystalline semiconductor family of high quality, large area, and uniform thickness can be formed on an insulator compared to conventional methods.

[Brief explanation of the drawing]

FIG. 1 shows a schematic cross-sectional view of a silicon substrate including a single crystal silicon film epitaxially grown on a heavily doped layer and a silicon dioxide film thereon. FIG. 2 is a schematic cross-sectional view of a quartz glass substrate whose surface is coated with polymer @ fat. FIG. 3 is a schematic cross-sectional view showing a state in which a silicon substrate and a quartz glass substrate are bonded together. FIG. 4 is a schematic cross-sectional view showing a state in which only the silicon substrate has been removed. FIG. 5 is a schematic cross-sectional view showing a silicon-based structure and a state in which the impurity 'f/In- has been removed once again. FIG. 6 is a schematic view of the l#r plane showing a state in which a polymer resin is coated on a silicon substrate whose surface has been thermally oxidized. FIG. 7 is a schematic cross-sectional view of a quartz glass substrate on which a vapor deposition film is formed. FIG. 8 is a schematic cross-sectional view of a substrate when a glass layer is used as an insulating adhesive layer. FIG. 9 is a schematic cross-sectional view of a silicon substrate on which a single crystal germanium film is epitaxially grown. FIG. 10 is a schematic cross-sectional view showing a state in which a silicon substrate is bonded to a quartz glass substrate via an adhesive layer, and then the silicon substrate is removed, leaving a germanium film. FIG. 11 shows a schematic cross-sectional view of a germanium single crystal substrate in which a gallium oxide single crystal film and a silicon quaternide film are laminated on this il@. FIG. 12 is a schematic cross-sectional view showing a state in which a germanium substrate is bonded to a quartz glass substrate via an adhesive layer, and then the germanium substrate is removed, leaving a gallium arsenide film. The numbers in the figure indicate the following. 1.7.11...Silicon substrate, 2...High ik impurity layer, 3...Single crystal silicon film, 4, 8.8', 1
3...Needed silicon film, quartz glass substrate, 6
, 15°25...Polymer @ fat film, 9...Vapour-deposited film,
DESCRIPTION OF SYMBOLS 10... Lead glass layer, 12... Kermanium single crystal film, 14.24... Quartz glass plate, 21... Germanium single crystal substrate, 22... Gallium arsenide single crystal group, 23...・Chamber [Hisilicon film. 'r person-1"□), 'y-tj)': 5
Jin Figure 5 Figure 7 Figure 6 Figure 8 Figure 9 Figure 11

Claims (1)

[Claims] A single crystal semiconductor substrate having on its surface at least a semiconductor single crystal epitaxial film and an insulating film on the epitaxial film, and a substrate having an amorphous insulating layer on at least one side,
After providing and solidifying an adhesive layer between the amorphous insulating layer of the substrate and the insulating film on the epitaxial film of the single crystal semiconductor substrate, the single crystal semiconductor substrate is polished and etched. A method of manufacturing a substrate for a semiconductor device, comprising forming the semiconductor single crystal epitaxial film on the substrate having an amorphous insulating layer on at least one side by removing the amorphous insulating layer.