Nondestructive determination method of p-type doped 6H-carborundum crystal

Abstract

The invention relates to a nondestructive determination method of p-type doped 6H-carborundum crystal. Spectral measurement is conducted on a to-be-measured p-type doped 6H-SiC crystal sample, the incident direction of an inspecting ray is in the direction of a SiC crystal plate (0001), temperature variation measurement is within the temperature range from room temperature to 673 K, and the temperature interval is 50 K. By analyzing and comparing an A1 longitudinal optical mode sensitive to a carrier, whether or not the sample is p-type doped can be judged according to the intensity and peak position variation of the sample. The method has the advantages that a spectrum analysis method is adopted to conduct inspection and analysis on the carrier concentration of a p-type Al doped 6H-carborundum crystal, electrode coating like Hall measurement is not needed, the to-be-measured sample is not destructive, automatic and programmed control can be achieved in the inspection process, comprehensive inspection can be conducted on products taken out from a factory, and the method can be applied to the inspection of 2, 3, 4 and 6 inch complete wafer product on current markets.

Description

technical field [0001] The invention relates to a performance testing technology of a semiconductor single crystal, in particular to a non-destructive judgment method for a p-type doped 6H-silicon carbide crystal. Background technique [0002] Silicon carbide is the third-generation semiconductor material after the first-generation silicon, germanium, second-generation gallium arsenide, indium phosphide, etc., and belongs to wide-bandgap semiconductors. Compared with the first and second generation semiconductor materials, silicon carbide has better physical and electronic properties and chemical stability. It has high thermal conductivity, strong breakdown field, and large drift rate of saturated electrons, so it has broad prospects in the preparation and application of high-temperature, high-frequency, high-power, corrosion-resistant and radiation-resistant devices, and is widely used in national defense, aerospace, communications, etc. field. [0003] To prepare microel...

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Problems solved by technology

With the non-contact resistivity tester commonly used in the industry, although it is a non-destructive test, only the resistivity of the silicon carbide wafer can be obtained but the conductivity type cannot be obtained.

Of course, the conductivity type of silicon carbide wafers can also be determined by secondary ion mass spectrometer or Hall test system, but they are all destructive tests and can be used for sampling testing, but cannot identify all products in the industrial production process

[0005] Since the activation energy of aluminum ions in the silicon carbide substrate is much higher than that of nitrogen ions, the substrate sheet may show n-type at room temperature, but when the device operates at a higher temperature, the n-type of the substrate may have become It is p-type, which is a fatal problem for the electronic characteristics of the device

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