Method for distinguishing defects in silicon carbide wafer on wafer carbon surface

Abstract

The invention provides a method for distinguishing defects in a silicon carbide wafer on a wafer carbon surface, which comprises the following steps of: placing the silicon carbide wafer in an etching cavity, and etching the carbon surface of the silicon carbide wafer by using microwave plasma; after the silicon carbide wafer is etched for a preset time, taking the silicon carbide wafer out of the etching cavity, and ultrasonically cleaning the silicon carbide wafer with deionized water and alcohol; and determining the defect type according to the morphology and the cross section of the etching pit on the carbon surface of the silicon carbide wafer. According to the method, the etching pits are formed by etching the C surface, and the microtubes and different types of dislocation can be accurately identified according to the morphology and section information of the etching pits; meanwhile, the substrate material can be compared with the dislocation condition of the Si surface, so that the behavior of dislocation in the growth process can be directly observed; the dislocation condition of an epitaxial material and the dislocation condition of an epitaxial surface can be compared, and then dislocation increment and transformation mechanisms are researched.

Description

technical field [0001] This application relates to the field of testing and characterization of semiconductor single crystal materials, and in particular to a method for identifying defects in silicon carbide wafers on the carbon surface of the wafer. Background technique [0002] As a representative of the third-generation wide-bandgap semiconductor materials, silicon carbide (SiC) materials have excellent properties such as large band gap, high carrier saturation migration velocity, high critical breakdown field strength, high thermal conductivity, and good chemical stability. Physical and chemical properties, based on these properties, SiC materials are considered to be ideal materials for high-frequency, high-power, high-temperature and radiation-resistant electronic devices. The devices manufactured with them are widely used in smart grids, rail transit, electric vehicles, radar communications, etc. Has a wide range of applications. [0003] With the gradual improvemen...

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Problems solved by technology

However, the above methods all observe dislocations from the Si surface, so the integrity of the Si surface structure of the substrate will be destroyed, and the sample cannot be used anymore, and it needs to be re-grinded, polished and other processes.

When exploring the transition of dislocations from the substrate to the epitaxial layer, it is also necessary to perform a repetitive process of etching→observation→grinding→polishing, which takes a very long time.

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