p-GaN与Ni/Pt欧姆接触的研究

本文对p-GaN与Ni/Pt形成欧姆接触及其电流传输机制进行了研究。I-V变温测试曲线是线形的,表明Ni/Pt与p-GaN之所以能形成欧姆接触,是因为Ni/Pt与p-GaN接触在空气中退火时界面处的p-GaN空穴浓度增加了,从而降低了有效势垒高度。在148K～323K范围内,单位接触电阻R_c随测试温度T的升高趋于呈指数下降,表明Ni/Pt与p-GaN欧姆接触的电流传输机制遵循热电子发射。

Study of Ni/Pt Ohmic Contacts to P-type GaN

In this paper,the formation and current transmission mechanisms of Ni/Pt Ohmic contacts to p-type GaN are investigated.The linear I-V curves indicate that the formation of the Ohmic contact between the Ni/Pt and the GaN is attributed to the decrease of the effective barrier height with the increase of the hole concentration at the interface of p-type GaN contacts with the Ni/Pt when annealing in air.In the range from 148K to 323K,the specific contact resistance R_c is decreased exponentially with the test temperature T.This indicates that the current transmission mechanism of the Ni/Pt Ohmic contacts to the p-type GaN abides by the thermionic emmission theory.