[21a-W541-1~12] 13.8 Compound and power electron devices and process technology

[21a-W541-10] Constant capacitance DLTS measurements of MOCVD n-GaN with high ratios of N_t/N_d

〇(M1)Shougo Ueda¹, Kazuki Miyamoto¹, Yutaka Tokuda¹ (1.Aichi Inst. of Tecnol.)

Keywords:GaN,Nt/Nd

We have characterized traps in Si doped n-GaN with high ratios of N_t/N_d using DLTS. When the doping concentration of Si approaches 10¹⁶ cm^-3, high ratios of N_t/N_d is expected, where the constant capacitance DLTS will be applied. The sample used was Si-doped (4.1x10¹⁶ cm^-3) n-GaN grown by MOCVD on n⁺-GaN substrate.
Different peak temperatures for electron trap E3 were observed at 280.7K and 282.3K in the capacitance DLTS spectra depending on their peak heights. The trap concentration was estimated by the conventional method for capacitance DLTS, giving N_t/N_d of 0.9 and 0.15 at the peak temperatures of 280.7 and 282.3 K, respectively. This suggests that the origin of different peak temperatures is not ascribed to the different traps, but to the high ratios of N_t/N_d. In fact, the constant capacitance DLTS reveals the same peak temperature at 283.3 K for both samples with different ratios of N_t/N_d. Trap concentration is now being estimated using CV analysis.