Processing-induced electron traps in n-type GaN

We have used deep-level transient spectroscopy (DLTS) to investigate the electron trap defects introduced in n-GaN during the fabrication of Pt Schottky contacts by electro-deposition, electron beam deposition and sputter deposition under three different deposition conditions. The results indicate that electro-deposition is the only one of these processes that does not introduce any defects. Diodes fabricated by this technique also have the best rectification properties. Both electron beam deposition and sputter deposition introduce electron traps in concentrations that increase towards the Pt/GaN interface. However, sputter deposition at a lower power and higher pressure results in significantly reduced defect concentrations and improved rectification properties.