CN110600594A - Silicon carbide epitaxial substrate - Google Patents

Abstract

The invention discloses a silicon carbide epitaxial substrate, relates to the technical field of epitaxial substrates, and mainly aims to solve the problem that there are many dislocation defects in the silicon carbide epitaxial layer; the epitaxial substrate includes a base, and the upper part of the base has a A grown and patterned silicon carbide layer, a plurality of microstructures are provided on the upper side of the silicon carbide layer, and the microstructures include a raised part arranged on the silicon carbide layer and a depression formed between two adjacent raised parts part, and a carbon nanotube layer is attached to the inside of the recessed part. In the present invention, the base in the epitaxial substrate has a patterned growth surface, and the patterned surface has a plurality of micron-scale microstructures, so it can reduce dislocation defects in the epitaxial growth process, so the silicon carbide layer epitaxial growth surface The growth reduces the contact area between the epitaxially grown silicon carbide layer and the substrate, reduces the stress between the silicon carbide layer and the substrate during the growth process, and further improves the quality of the epitaxially grown silicon carbide layer.

Description

A silicon carbide epitaxial substrate

technical field

The invention relates to the technical field of epitaxial substrates, in particular to a silicon carbide epitaxial substrate.

Background technique

Emery, also known as silicon carbide, is made of quartz sand, petroleum coke (or coal coke), wood chips (salt needs to be added when producing green silicon carbide) and other raw materials through resistance furnace high temperature smelting. Silicon carbide also exists in nature as a rare mineral, moissanite. Silicon carbide is also called moissanite. Among the non-oxide high-tech refractory materials such as C, N, B, etc., silicon carbide is the most widely used and economical one, which can be called corundum or refractory sand. Silicon carbide has stable chemical properties and high thermal conductivity. , small thermal expansion coefficient, good wear resistance, in addition to being used as abrasives, there are many other uses, silicon carbide is also widely used to make silicon carbide rods for electric heating elements

The silicon carbide epitaxial wafer refers to the regular arrangement of the silicon carbide material molecules under certain conditions, and directional growth on an epitaxial substrate such as a sapphire substrate, and then used to prepare light-emitting diodes, the preparation of high-quality silicon carbide epitaxial wafers It has always been a difficult point of research. In the prior art, the preparation method of the epitaxial substrate is to polish one surface of the sapphire substrate to form a plane, which is then used to grow silicon carbide epitaxial wafers; however, due to the lattice constant and thermal expansion coefficient of the silicon carbide and sapphire substrates different, resulting in more dislocation defects in the silicon carbide epitaxial layer. Moreover, there is a large stress between the epitaxial layer of silicon carbide and the epitaxial substrate, and the greater the stress, the epitaxial layer of silicon carbide will be broken.

Contents of the invention

The object of the present invention is to provide a silicon carbide epitaxial substrate to solve the problem of many dislocation defects in the silicon carbide epitaxial layer.

To achieve the above object, the present invention provides the following technical solutions:

A silicon carbide epitaxial substrate, comprising a substrate, the upper part of the substrate has a silicon carbide layer that can be epitaxially grown and is patterned, and a plurality of microstructures are arranged on the upper side of the silicon carbide layer, and the microstructures include The convex part on the top and the concave part formed between two adjacent convex parts, the inner side of the concave part is attached with a carbon nanotube layer, the carbon nanotube layer is composed of a plurality of carbon nanotubes arranged in parallel, and a plurality of carbon nanotubes The adjacent carbon nanotubes in the extension direction are connected end to end by van der Waals force.

On the basis of the above technical solutions, the present invention also provides the following optional technical solutions:

In an optional solution: the substrate is a single crystal structure.

In an optional solution: the silicon carbide layer has a thickness not less than 200 μm.

In an optional solution: the raised portion is a bar structure made of aluminum oxynitride and has a trapezoidal cross-section, the maximum width of the raised portion is 5 μm-200 μm and the height of the raised portion is 2 μm-50 μm .

In an optional solution: the raised portion is a ring structure made of GaN and has a rectangular cross-section, the width of the raised portion is 8 μm-150 μm, and the height of the raised portion is 4 μm-40 μm.

In an optional solution: a mask layer is provided between the silicon carbide layer and the substrate.

Compared with the prior art, the beneficial effects of the present invention are as follows:

In the present invention, the base in the epitaxial substrate has a patterned growth surface, and the patterned surface has a plurality of micron-scale microstructures, so the dislocation defects in the epitaxial growth process can be reduced, and the carbon nanotube layer The size of the gap is in the order of nanometers, so the epitaxial growth surface of the silicon carbide layer grows, so that the contact area between the epitaxially grown silicon carbide layer and the substrate is reduced, and the stress between the silicon carbide layer and the substrate during the growth process is reduced, thereby A thicker epitaxial silicon carbide layer can be grown, which can further improve the quality of the epitaxial silicon carbide layer.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

FIG. 2 is a partially enlarged structural schematic diagram of A in FIG. 1 .

Fig. 3 is a structural schematic diagram of the raised part of the column structure in the present invention.

Fig. 4 is a structural schematic diagram of the raised portion of the ring bar structure in the present invention.

Reference numerals: substrate 1 , silicon carbide layer 2 , mask layer 3 , raised portion 4 , depressed portion 5 , carbon nanotube layer 6 .

Detailed ways

The following embodiments will describe the present invention in detail with reference to the drawings. In the drawings or descriptions, similar or identical parts use the same symbols, and in practical applications, the shape, thickness or height of each component can be enlarged or reduced. The various embodiments listed in the present invention are only used to illustrate the present invention, and are not intended to limit the scope of the present invention. Any obvious modifications or changes made to the present invention do not depart from the spirit and scope of the present invention.

Example 1

Please refer to FIGS. 1 to 3. In an embodiment of the present invention, a silicon carbide epitaxial substrate includes a substrate 1, the upper part of the substrate 1 has a silicon carbide layer 2 that can be epitaxially grown and patterned, and the upper side of the silicon carbide layer 2 is A plurality of microstructures are provided, and the microstructures include a protrusion 4 disposed on the silicon carbide layer 2 and a depression 5 formed between two adjacent protrusions 4, and carbon nanometers are attached to the inside of the depression 5. The tube layer 6, the carbon nanotube layer 6 is composed of a plurality of carbon nanotubes arranged in parallel, and the adjacent carbon nanotubes in the extension direction of the plurality of carbon nanotubes are connected end to end by van der Waals force,

The silicon carbide layer 2 has a thickness of not less than 200 μm, and the raised portion 4 is a columnar structure made of aluminum oxynitride with a trapezoidal cross-section. The maximum width of the raised portion 4 is 5 μm-200 μm and the raised portion 4 The height is 2 μm-50 μm, and the substrate 1 is a single crystal structure;

The base 1 in the epitaxial substrate has a patterned growth surface, and the patterned surface has a plurality of micron-scale microstructures, so dislocation defects during the epitaxial growth process can be reduced, and the carbon nanotube layer 6 The pore size of the silicon carbide layer is on the order of nanometers, so the epitaxial growth surface of the silicon carbide layer 2 grows, so that the contact area between the epitaxially grown silicon carbide layer 2 and the substrate 1 is reduced, and the silicon carbide layer 2 and the substrate 1 are reduced during the growth process. The stress between them can grow a thicker epitaxial silicon carbide layer 2 , which can further improve the quality of the epitaxial silicon carbide layer 2 .

Example 2

Please refer to FIG. 4 , the difference between the embodiment of the present invention and embodiment 1 is that the raised portion 4 is a ring structure made of GaN and has a rectangular cross-section, and the width of the raised portion 4 is 8 μm- 150 μm and the height of the raised portion 4 is 4 μm-40 μm; a mask layer 3 is provided between the silicon carbide layer 2 and the substrate 1 .

The above is only a specific implementation of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope of the present disclosure. should fall within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be determined by the protection scope of the claims.

Claims (6)

1. A silicon carbide epitaxial substrate, comprising a substrate (1), the upper part of the substrate (1) has a silicon carbide layer (2) that can be epitaxially grown and patterned, characterized in that, on the silicon carbide layer (2) A plurality of microstructures are provided on the side, and the microstructures include a protrusion (4) disposed on the silicon carbide layer (2) and a depression (5) formed between two adjacent protrusions (4), A carbon nanotube layer (6) is attached to the inside of the depression (5), and the carbon nanotube layer (6) is composed of a plurality of carbon nanotubes arranged in parallel, and the adjacent carbon nanotubes in the extension direction of the plurality of carbon nanotubes The nanotubes are connected end to end by van der Waals force. 2. The silicon carbide epitaxial substrate according to claim 1, characterized in that the substrate (1) is a single crystal structure. 3. The silicon carbide epitaxial substrate according to claim 1, characterized in that the silicon carbide layer (2) has a thickness not less than 200 μm. 4. The silicon carbide epitaxial substrate according to any one of claims 1-3, characterized in that, the raised portion (4) is a bar structure made of aluminum oxynitride and has a trapezoidal cross-section, and the raised portion (4) The maximum width of the raised portion (4) is 5 μm-200 μm and the height of the raised portion (4) is 2 μm-50 μm. 5. The silicon carbide epitaxial substrate according to any one of claims 1-3, characterized in that, the raised portion (4) is a ring structure made of GaN and has a rectangular cross-section, and the raised portion The width of (4) is 8 μm-150 μm and the height of the raised portion (4) is 4 μm-40 μm. 6. The silicon carbide epitaxial substrate according to claim 5, characterized in that a mask layer (3) is arranged between the silicon carbide layer (2) and the substrate (1).