Method for processing and using SiC substrate without positioning edge

Abstract

The invention provides a method for processing a SiC substrate without a positioning edge. The method comprises the following steps: orienting the excircle of a SiC crystal; crystal cutting; the cutting blade is baked from the cutting base and taken out, the carbon-silicon surface of the head blade or the tail blade of the cutting blade is marked, and the cutting blade is cleaned to remove residual cutting fluid on the surface; orienting head and tail pieces: orienting the head and tail cutting pieces of the SiC crystal, and verifying the [1-100] and [11-20] directions of the head piece or the tail piece of the marked cutting piece; orientation of non-head and non-tail wafers: overlapping the non-head and non-tail wafers with the head wafer and / or the tail wafer to enable the tool marks of the non-head and non-tail wafers to coincide, then performing orientation along the off-axis direction of the wafer, and determining the off-axis direction and the polar surface of the wafer; carbon / silicon surface marking and crystal orientation marking; and carrying out subsequent process treatment on the marked wafer to obtain the SiC substrate without the positioning edge. When the positioning-edge-free SiC substrate prepared in the invention is used as a seed crystal or a substrate for growing a SiC crystal or an epitaxial wafer, the defects of microtubules, stress and the like in the crystal can be effectively reduced, and the quality of the material is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of single crystal processing, and in particular relates to a processing and using method of a SiC substrate without positioning edges. Background technique [0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art. [0003] Silicon carbide (SiC) is a relatively mature third-generation semiconductor material. It has excellent semiconductor properties such as high temperature resistance, high thermal conductivity, and high breakdown voltage, enabling SiC-based devices to work under extreme conditions. At the same time, SiC, as an important substrate material, can be used for epitaxial growth of gallium nitride, graphene, etc. At present, β-SiC substrates such as 4H-SiC and 6H-SiC are widely used in high-power power electronic devices, microwave radio frequency devices and optoelectronic devices. [0004] SiC is a...

AI Technical Summary

Problems solved by technology

[0006] (1) During the process of grinding out the positioning edge of the crystal end face, the chance of crystal cracking is relatively high;

[0007] (2) The ground crystal is no longer a complete circle. When this type of substrate is used as the seed crystal, defects such as micropipes and stress accumulation will appear in the grown SiC single crystal, which will affect the quality of the single crystal;

[0008] (3) As the diameter of the crystal increases, in order to intuitively distinguish the main positioning edge and the secondary positioning edge, the length of the two positioning edges also needs to increase accordingly, resulting in a decrease in the available area of ​​the substrate

[0012] However, in this method, there are still two positioning edges on the SiC substrate, and the stress near the positioning edges has not been substantially improved.

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