Direct barrier evaluation method for SiC devices with junction barrier Schottky structures demonstrated with quasi-continuous spacing variation

Abstract

Junction barrier Schottky (JBS) structures are extensively used in silicon carbide devices; however, the complex surface composition makes the direct barrier evaluation difficult. To exclude the field-dependent distortion on a barrier for a direct unbiased evaluation in JBS structures, this work proposes a new evaluation method with a physics-based derivation and experimental demonstration, where a batch of JBS diodes are fabricated with a quasi-continuous spacing variation distribution achieved by the spreading etching technique. In addition, a detailed analysis based on the field-dependent barrier is provided. The result illustrates the chain-like activation and its saturation limit with a quantitative estimate in the straggle region. With the capability of the high linearity to exploit the statistical information for analysis stability, the proposed indicator could be a quantitative and versatile reference for designers dealing with nonideal surfaces.