A method for forming a SiC ohmic electrode and repairing GaN for a SiC / GaN composite device

Abstract

The application discloses a method for forming a SiC ohmic electrode and repairing GaN of a SiC / GaN composite device, which comprises the following steps: introducing nitrogen and ammonia during SiC ohmic annealing, and controlling the gas flow, temperature, gas pressure and time, so that a good ohmic contact is formed on the surface of SiC, and the nitrogen vacancy damage of the GaN surface caused by high-temperature annealing is repaired. The damage will cause a large barrier when a GaN ohmic / Schottky contact is prepared subsequently, and a good ohmic / Schottky contact cannot be formed, thereby affecting the device characteristics. The SiC ohmic contact prepared after ammonia-nitrogen mixed annealing has good characteristics, the barrier of the repaired GaN surface is greatly reduced, and the metal electrode contact characteristics of the GaN surface are good. The annealing method solves the process incompatibility problem of the SiC / GaN composite device, and has the advantages of low equipment requirement and simple process.

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