GaN基HEMT器件的表面陷阱电荷输运过程实验研究

An Experimental Investigation into Transportation Process of Trapped Surface Charges of GaN-Based HEMT's

基于特制的无台面AlGaN/GaN HEMT,设计了一种实验方法,用以研究AlGaN/GaN外延表面陷阱态间的电荷输运过程。经实验证实,在器件电流崩塌效应中,存在表面陷阱电荷输运,并确定了相关时间常数。针对应力后电流崩塌驰豫过程,实验监测到小于0.1 s和大于10 s两类时间常数,其中较大的常数对应于表面陷阱电荷的输运过程。此结论可望用于对AlGaN/GaNHEMT电流崩塌效应进一步的理论探索和相关的器件研究。

Based on a specially designed AlGaN/GaN HEMT, transportation process of the trapped surface charges is investigated. It is confirmed that such process affects the current collapse effect. The relative time constants are determined by the experiment. With the measurements of current collapse effects, two different types of time constants, which are smaller than 0. 1 s and larger than 10 s, respectively, are detected. The larger type corresponds to transportation process of the trapped surface charges. This conclusion may be used in further theoretic study and device development of AlGaN/GaN HEMT＇ s.