Leakage current analysis of diamond Schottky barrier diodes by defect imaging

•Leakage current of diamond pVSBDs was analyzed using a defect visualization method.•H2/CO2 plasma treatment forms several types of etch pits at the defects on diamond.•High leakage SBDs contain a high density of defects revealed as deep etch pits.•Blocking voltage of the SBDs is clearly dependent on the number of deep etch pits.

The leakage current of pseudo-vertical-type diamond Schottky barrier diodes (SBDs) was analyzed using a defect visualization technique. Even under a low electrical field, 50% of the fabricated diamond SBDs exhibited a high leakage current that cannot be explained by any of the carrier transport mechanisms through the Schottky barrier. The SBDs with high leakage current were confirmed to contain a high density of dislocations that are revealed as deep etch pits by H2/CO2 plasma treatment. The maximum operation voltage of the SBDs is clearly dependent on the number of deep etch pits.