Schottky barrier diodes isolated by local oxidation of SiC (LOCOSiC) using pre-amorphization implantation technology

In this paper, the local oxidation of SiC (LOCOSiC) isolation using pre-amorphization implantation technology is integrated into the 4H-SiC Schottky barrier didoes (SBD) fabrication to evaluate its isolation ability due to the high sensitivity of SBD to those defects induced by process. Using Ar plasma treatment, the barrier height can be centralized at ~1.1 eV with reduced variation, which lies in between commonly-used SBDs with Ti (1.0 eV) and Ni (1.2 eV), considering cut-in voltage, leakage and breakdown voltage (V_BD). Furthermore, at high reverse bias (−200 V), the leakage of the SBDs isolated by LOCOSiC is only ~10⁻⁵ A/cm² at room temperature, 200× lower than that of the SBDs isolated by deposited SiO₂, because the smoother topography is beneficial to release the field crowding effect. The maximal V_BD achieves 515 V only with simple field plate termination. The electric field simulation suggests that the thermally grown field oxide with better quality retards the breakdown at the edge of the metal pad on field oxide.