High yield uniformity in pseudo-vertical diamond Schottky barrier diodes fabricated on half-inch single-crystal wafers

Abstract

We fabricated diamond pseudo-vertical Schottky barrier diodes using a half-inch semi-insulative diamond (100) wafer. Most diodes exhibited a large rectifying ratio (>1010) with undetectable leakage current at a reverse bias of 5 V (0.6 MV cm-1), with only 2% of diodes exhibiting an Ohmic-like leakage current. Surface defects were observed under the Schottky barrier diode, and their impacts on electrical properties were analyzed using a Murphy model and correlation factor analysis. We found that most crystalline defects (surface hillocks) were electrically non-active and that non-epitaxial crystallites and process-related field-plate cracks were the main defects that induced a large leakage current. Schottky barrier diodes without such killer defects showed a high electric field strength of ∼5 MV cm-1.