Open AccessHigh breakdown voltage AlGaN/GaN HEMT with high‐K/low‐K compound passivation
Author(s) -
Du Jiangfeng,
Chen Nanting,
Pan Peilin,
Bai Zhiyuan,
Li Liang,
Mo Jianghui,
Yu Qi
Publication year - 2015
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2014.3252
Subject(s) - passivation , materials science , high electron mobility transistor , optoelectronics , dielectric , electric field , capacitance , field effect , layer (electronics) , transistor , electrical engineering , voltage , electrode , nanotechnology , chemistry , physics , engineering , quantum mechanics
A novel high breakdown voltage (BV) AlGaN/GaN high‐electron mobility transistor (HEMT) with a high‐K/low‐K compound passivation layer is proposed. The compound passivation layer is formed by blocks of low‐K dielectric (Si 3 N 4 ) embedded in a high‐K passivation layer (La 2 O 3 ). Owing to their different dielectric constants, there is a discontinuity of the horizontal electrical field at the high‐K/low‐K interface, which can introduce a new electric field peak in the nearby channel in the semiconductor and can also modulate the distribution of the electric field along the channel. Hence, enhancement of BV can be achieved. Compared to the typical field‐plate structure, high‐K/low‐K passivation introduces no parasitic capacitance. On the basis of the physical mechanism, several design principles for the high‐K/low‐K passivation layer are presented. Numerical simulation demonstrates a BV of 1400 V for the proposed device with four blocks of low‐K dielectric embedded in a high‐K passivation, compared to the BVs of 917 and 288 V for the device with high‐K passivation and the device with low‐K passivation, respectively.