阅读说明：本技术 一种碳化硅外延衬底 (Silicon carbide epitaxial substrate ) 是由 郑友进 黄海亮 左桂鸿 王丹 于 2019-09-20 设计创作，主要内容包括：本发明公开了一种碳化硅外延衬底,涉及外延衬底技术领域,主要为了解决碳化硅外延层存在较多位错缺陷的问题；该外延衬底,包括基底,所述基底上部具有可外延生长且呈图案化的碳化硅层,碳化硅层上侧设置有多个微结构,所述微结构包括设置在碳化硅层上的凸起部和相邻两个凸起部之间形成的凹陷部,凹陷部内侧贴附有碳纳米管层。本发明中外延衬底中的基底具有图形化的生长面,该图案化的表面具有多个微米级的微结构,因此可减小外延生长过程中的位错缺陷,因此碳化硅层外延生长面生长,使得外延生长的碳化硅层与基底之间的接触面积减小,减小了生长过程中碳化硅层与基底之间的应力可进一步提高外延的碳化硅层的质量。(The invention discloses a silicon carbide epitaxial substrate, relates to the technical field of epitaxial substrates, and mainly aims to solve the problem that a silicon carbide epitaxial layer has more dislocation defects; the epitaxial substrate comprises a base, wherein the upper part of the base is provided with a patterned silicon carbide layer which can be epitaxially grown, a plurality of microstructures are arranged on the upper side of the silicon carbide layer, each microstructure comprises a protruding part arranged on the silicon carbide layer and a recessed part formed between two adjacent protruding parts, and a carbon nanotube layer is attached to the inner side of each recessed part. The substrate in the epitaxial substrate has a patterned growth surface, and the patterned surface has a plurality of micron-sized microstructures, so that dislocation defects in the epitaxial growth process can be reduced, the epitaxial growth surface of the silicon carbide layer grows, the contact area between the epitaxially grown silicon carbide layer and the substrate is reduced, the stress between the silicon carbide layer and the substrate in the growth process is reduced, and the quality of the epitaxial silicon carbide layer can be further improved.)

1. The silicon carbide epitaxial substrate comprises a substrate (1), wherein a patterned silicon carbide layer (2) which can be epitaxially grown is arranged on the upper portion of the substrate (1), and is characterized in that a plurality of microstructures are arranged on the upper side of the silicon carbide layer (2), each microstructure comprises a protruding portion (4) arranged on the silicon carbide layer (2) and a recessed portion (5) formed between two adjacent protruding portions (4), a carbon nanotube layer (6) is attached to the inner side of each recessed portion (5), each carbon nanotube layer (6) is formed by arranging a plurality of carbon nanotubes in parallel, and adjacent carbon nanotubes in the extending direction of the plurality of carbon nanotubes are connected end to end through Van der Waals force.

2. Silicon carbide epitaxial substrate according to claim 1, characterized in that the base (1) is a monocrystalline structure.

3. 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. Silicon carbide epitaxial substrate according to any one of claims 1 to 3, characterized in that the projections (4) have a pillar structure composed of aluminum oxynitride and having a trapezoidal cross section, the maximum width of the projections (4) being 5 μm to 200 μm and the height of the projections (4) being 2 μm to 50 μm.

5. Silicon carbide epitaxial substrate according to any of claims 1 to 3, characterized in that the protrusions (4) are of a ring-and-stripe structure composed of GaN and having a rectangular cross section, the width of the protrusions (4) being 8 μm to 150 μm and the height of the protrusions (4) being 4 μm to 40 μm.

6. Silicon carbide epitaxial substrate according to claim 5, characterized in that a mask layer (3) is provided between the silicon carbide layer (2) and the base (1).

Technical Field

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

Background

Carborundum, also known as silicon carbide, is produced by high-temperature smelting of quartz sand, petroleum coke (or coal coke), wood dust (salt is required for producing green silicon carbide), etc. in a resistance furnace. Silicon carbide also has a rare mineral in nature, morusite. Silicon carbide is also known as carbo-silica. In the modern C, N, B and other non-oxide high-tech refractory raw materials, silicon carbide is the most widely and economically used one, and may be named as corundum or refractory sand, because of its chemical stability, high heat conductivity, small thermal expansion coefficient and good wear resistance, it has many other uses besides being used as abrasive, and it is also used in great amount to make silicon carbide rod for electric heating element

The silicon carbide epitaxial wafer is characterized in that silicon carbide material molecules are regularly arranged and directionally grown on an epitaxial substrate such as a sapphire substrate under a certain condition, and then the silicon carbide epitaxial wafer is used for preparing a light emitting diode. In the prior art, a method for preparing an epitaxial substrate comprises the steps of polishing one surface of a sapphire substrate to form a plane, and then growing a silicon carbide epitaxial wafer; however, the epitaxial layer of silicon carbide has more dislocation defects due to the difference in lattice constants and thermal expansion coefficients of the silicon carbide and sapphire substrates. Moreover, a large stress exists between the silicon carbide epitaxial layer and the epitaxial substrate, and the silicon carbide epitaxial layer is broken when the stress is larger.

Disclosure of Invention

The invention aims to provide a silicon carbide epitaxial substrate to solve the problem that a silicon carbide epitaxial layer has more dislocation defects.

In order to achieve the purpose, the invention provides the following technical scheme:

the utility model provides a carborundum epitaxial substrate, includes the base, but base upper portion has epitaxial growth and be patterned carborundum layer, and carborundum layer upside is provided with a plurality of microstructures, the microstructure is including the bellying that sets up on carborundum layer and the depressed part that forms between two adjacent bellyings, and the carbon nanotube layer is attached to the depressed part inboard, the carbon nanotube layer comprises a plurality of carbon nanotube parallel arrangement, passes through van der Waals' force end to end between the adjacent carbon nanotube in the extending direction among a plurality of carbon nanotubes.

On the basis of the technical scheme, the invention also provides the following optional technical scheme:

in one alternative: the substrate is a single crystal structure.

In one alternative: the silicon carbide layer has a thickness of not less than 200 μm.

In one alternative: the protruding part is a bar structure which is composed of aluminum oxynitride and has a trapezoidal section, the maximum width of the protruding part is 5-200 μm, and the height of the protruding part is 2-50 μm.

In one alternative: the protruding part is of a ring strip structure which is made of GaN and has a rectangular cross section, the width of the protruding part is 8-150 mu m, and the height of the protruding part is 4-40 mu m.

In one alternative: a mask layer is arranged between the silicon carbide layer and the substrate.

Compared with the prior art, the invention has the following beneficial effects:

the substrate in the epitaxial substrate has a patterned growth surface, the patterned surface is provided with a plurality of micron-sized microstructures, so that dislocation defects in the epitaxial growth process can be reduced, the size of a gap of the carbon nanotube layer is nano-micron, the epitaxial growth surface of the silicon carbide layer grows, the contact area between the epitaxially grown silicon carbide layer and the substrate is reduced, the stress between the silicon carbide layer and the substrate in the growth process is reduced, the epitaxial silicon carbide layer with larger thickness can grow, and the quality of the epitaxial silicon carbide layer can be further improved.

Drawings

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

Fig. 2 is a partially enlarged schematic structural view of a portion a in fig. 1.

FIG. 3 is a schematic view of a projection structure of a pillar structure according to the present invention.

FIG. 4 is a schematic view of a protrusion structure of the ring strip structure of the present invention.

Notations for reference numerals: the mask layer comprises a substrate 1, a silicon carbide layer 2, a mask layer 3, a convex part 4, a concave part 5 and a carbon nano tube layer 6.

Detailed Description

The present invention will be described in detail with reference to the following embodiments, wherein like or similar elements are designated by like reference numerals throughout the several views, and wherein the shape, thickness or height of the various elements may be expanded or reduced in practice. The examples are given solely for the purpose of illustration and are not intended to limit the scope of the invention. Any obvious modifications or variations can be made to the present invention without departing from the spirit or scope of the present invention.