Investigation of carrier compensation traps in n−-GaN drift layer by high-temperature deep-level transient spectroscopy

Autor: Weikun Ge, Xuelin Yang, Shan Wu, Lai Wei, Jianfei Shen, Xinqiang Wang, Bo Shen, Ning Tang, Xiaoguang He, Danshuo Liu, Fujun Xu, Huayang Huang
Rok vydání: 2020
Předmět:
Zdroj: Applied Physics Letters. 117:112103
ISSN: 1077-3118
0003-6951
DOI: 10.1063/5.0019576
Popis: Carrier compensation traps in n−-GaN drift layers grown on Si substrates were investigated using high-temperature deep-level transient spectroscopy (DLTS). The upper limit of the temperature range (700 K) allows for the study of deeper levels in the bandgap than those previously reported by conventional DLTS. Three trap states were revealed to be responsible for carrier compensation. Besides the residual carbon (C) acceptor, two deep electron traps detected in the DLTS high-temperature range, labeled E2 and E3 with energies EC of 0.98 and 1.38 eV, respectively, were also found to have contributions to the carrier compensation. A comprehensive investigation combining with positron annihilation spectroscopy measurements revealed that E2 and E3 are related to the (–/2–) and (0/–) acceptor levels of the VGa–ON complex, respectively. The relatively high concentrations of E2 and E3 imply that the VGa–ON complex is an essential carrier compensation source in the drift layer and plays a crucial role in developing kV-class vertical GaN power devices.
Databáze: OpenAIRE