Increase in Reverse Operation Limit by Barrier Height Control of Diamond Schottky Barrier Diode

Diamond is a promising material for high-power and low-loss semiconductor devices. However, the reported reverse blocking electric field of diamond-based power devices is as low as 2 MV/cm, and their performance is worse than ideal. We have developed reach-through-type Schottky barrier diodes (SBDs) with various Schottky barrier heights (SBHs) by changing metals. SBDs with high SBH show low leakage current and high operation limit of 3.1 MV/cm. This indicates that the reverse operation limit of diamond SBDs is determined not by leakage through defects but by carrier transport through the barrier. Reduction of specific on-resistance increases Baliga's figure of merit to 51 MW/cm
²
, which is tenfold higher than the Si limit.