[25p-P11-1~16] 13.7 Compound and power devices, process technology and characterization

[25p-P11-6] p-GaN parameter dependence of SRH lifetime obtained from IV characteristics for MOVPE-grown n⁺pp⁺ GaN diodes on GaN

〇Yutaka Tokuda¹, Tetsuo Narita², Kazuyoshi Tomita^2,3, Tetsu Kachi³ (1.Aichi Inst. of Tech., 2.Toyota Central R&D, 3.Nagoya Univ.)

Keywords:lifetime

We have characterized traps in p-GaN using n⁺pp⁺ junctions grown by MOVPE on n⁺-GaN substrates by DLTS, which indicates that 0.88 eV and 0.29 eV hole traps are ascribed to acceptor and donor states of a carbon on nitrogen site (C_N), respectively. In this work, we have obtained the SRH lifetime from IV characteristic for these junctions. The Mg concentrations in p-GaN were in the range from 3x10¹⁶~2x10¹⁸ cm^-3. The samples were annealed at 850℃ for 5 and 300 min. There were the IV regions followed by n=2, from which the SRH lifetimes were extracted. The SRH lifetimes were found to be independent of Mg concentrations. There was no difference of SRH lifetimes in samples annealed for 5 and 300 min. However, the SRH life times in p-GaN were ~300 ps and considerably shorter than the previously reported value of 12 ns in n-GaN grown by MOVPE.