Method for prolonging service life of silicon carbide epitaxial wafer carrier

Abstract

The invention provides a method for prolonging the service life of a silicon carbide epitaxial wafer carrier. The method comprises the following steps: S1, placing a silicon-surface silicon carbide substrate on a graphite base; s2, adjusting conditions in the reaction chamber and growing a buffer layer; s3, the growth temperature and pressure are kept unchanged, the C / Si ratio is reduced, and then the C / Si ratio is increased in a linear gradual change mode for first-time growth; s4, keeping the growth temperature and pressure unchanged, and continuing n times of rate switching gradient layer growth; s5, conditions in the reaction chamber are adjusted, and growth of an epitaxial layer is completed; s6, after epitaxial layer growth is completed, the growth source and the doping source are closed, finally, argon is used for inflating the pressure of the reaction chamber to atmospheric pressure, and then the chamber is opened to take the wafer. According to the invention, the gradient layer design is optimized by adopting the method of growing the plating layer in a stepped manner, the purposes of compensating the carbon vacancy generated by the buffer layer and inhibiting the formation of the carbon vacancy of the gradient layer are achieved, and the carrier lifetime of the silicon carbide epitaxial wafer is greatly prolonged.

Description

technical field [0001] The invention belongs to the technical field of semiconductor materials, and in particular relates to a method for improving the carrier lifetime of a silicon carbide epitaxial wafer. Background technique [0002] Silicon carbide (SiC), as the third-generation wide-bandgap semiconductor material, has excellent material properties and has great application potential in the fields of high temperature, high frequency, high power, and radiation resistance, especially 4H-SiC bipolar devices due to The characteristics of conductance modulation can achieve ultra-high withstand voltage and ultra-low on-resistance, especially suitable for high-voltage and ultra-high-voltage applications. [0003] The control of carrier lifetime in ultra-thick and low-doped epitaxial materials for ultra-high voltage power electronic devices (>10kV) is very important for realizing low-power bipolar devices. Studies have shown that low minority carrier lifetime is very unfavor...

AI Technical Summary

Problems solved by technology

[0007] Aiming at the problem that the current carrier lifetime of silicon carbide epitaxial wafers is low and effective conductance modulation cannot be realized, the present invention provides a method for improving the carrier lifetime of silicon carbide epitaxial wafers

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