Device processing, fabrication and analysis of diamond pseudo-vertical Schottky barrier diodes with low leak current and high blocking voltage

Abstract

Diamond pseudo-vertical structure Schottky barrier diodes (PVSBD) have been fabricated by developing a simple and efficient fabrication technology, in which 14 µm thick p − layer was selectively etched out and ohmic contact was made onto the low resistive p + layer from topside. The electrical characteristics were evaluated by fabricating Mo/Diamond Schottky barrier diodes in pseudo-vertical structure. With the fabricated structure, a high blocking voltage of 1.6 kV with a low leakage current density in order of 10 − 7 ~ 10 − 6 A/cm 2 could be obtained, without any edge termination. The reverse characteristics of the SBDs exhibited a hard breakdown at 1.6 kV, and causing breakdown of the diamond surface itself in a particular case. The later case indicated the presence of sub-surface leak path causing current leakage in one direction in near surface region, and a model has been proposed to explain this.