4H-SiC n~+pp~+ Structure Passivated with SIPOS-SiO_2 Compound Layer

A semi insulating polycrystalline silicon (SIPOS) SiO 2 compound sheet is used as a passivating layer of 4H SiC n +pp + structure. After the deposition of SIPOS by LPCVD, a unique thermal oxidation step, annealing in oxygen atmosphere at 900℃ instead of oxide layer deposition, in normal method is adopted to grow a SiO 2 layer over it. The passivating result demonstrates the reasonability of the alternation. Moreover, chief technological parameters that influence the passivating effect are also adjusted and the conclusions have been drawn that there should be excess oxygen in SIPOS layer with depositing temperature lower than 1000℃. The annealing temperature should be high up to 900℃. Experimental data show that SIPOS SiO 2 compound layer can act as an effective passivation sheet of the 4H SiC n +pp + structure to get an ideal breakdown voltage and leakage current.