Deep Level Centers in Carbon-Doped High Resistivity GaN

The deep levels of carbon doped high resistivity (HR) GaN samples grown by metal-organic chemical vapor deposition (MOCVD) has been investigated using thermally stimulated current (TSC) spectroscopy and high temperature (HT) Hall measurement. Two different thickness of 100 and 300 nm were used to be compared. It was found that four distinct deep levels by TSC and one deep level by HT Hall measurement were observed in both samples, which means great help for the decrease of leakage current and lifetime limitations of device utilizing the structure. The activation energy of these levels was calculated and their possible origins were also proposed. The low temperature traps, might be related to VN, 0.50 and 0.52eV related to incorporate a high level carbon, 0.57eV related to VGa, 0.59eV related to CGaor NGa, 0.91 and 0.97eV related to interstitial N1.