采用T型栅结构的高性能Ga2O3 MOSFET  

High Performance Ga2O3 MOSFET with T-Shaped Gate Structure

作　　者：马灵[1] 吕元杰[2] 刘宏宇 蔡树军[1,2] 冯志红[2] Ma Ling;LüYuanjie;Liu Hongyu;Cai Shujun;Feng Zhihong(The 13th Research Institute,CETC,Shijiazhuang 050051,China;Science and Technology on ASIC Laboratory,Shijiazhuang 050051,China)

机构地区：[1]中国电子科技集团公司第十三研究所,石家庄050051 [2]专用集成电路重点实验室,石家庄050051

出　　处：《半导体技术》2020年第6期444-448,共5页Semiconductor Technology

基　　金：河北省优秀青年基金项目(F2019516004)。

摘　　要：基于n型β-Ga2O3制备了具有T型栅结构的高性能Ga2O3金属氧化物半导体场效应晶体管(MOSFET)。采用金属有机化学气相沉积(MOCVD)法在Fe掺杂的半绝缘β-Ga2O3衬底上同质外延生长200 nm厚的Si掺杂n型β-Ga2O3沟道层,掺杂浓度为5×10^17 cm^-3。器件采用栅长为1μm的T型栅结构,栅源间距为2μm,栅漏间距为18μm;采用原子层沉积(ALD)法生长的高介电常数氧化铪(HfO2)作为栅介质。研制的器件漏源饱和电流密度达到115.8 mA/mm,比导通电阻为52.82 mΩ·cm^2。T型栅结构有效抑制了Ga2O3沟道中的峰值电场强度,提升了器件的耐压特性;而高介电常数的HfO2介质有效降低了器件的漏电流,器件的击穿电压达到1953 V,开关比高达109,器件功率品质因子为77.2 MV/cm^2。High performance gallium oxide(Ga2O3)metal-oxide-semiconductor filed-effect transistors(MOSFETs)with T-shaped gate structure were fabricated based on n-typeβ-Ga2O3.A 200 nm Sidoped n-typeβ-Ga2O3 channel layer with a doping concentration of 5×1017 cm-3 was homoepitaxial grown on a Fe-doped semi-insulatingβ-Ga2O3 substrate by metal organic chemical vapor deposition(MOCVD)method.T-shaped gate structure with the gate length of 1μm was adopted.The gate-to-source and gateto-drain distances are 2 and 18μm,respectively.Moreover,hafnium oxide(HfO2)with a high dielectric constant grown by atomic layer deposition(ALD)method was used as gate dielectric.The fabricated device has a high saturation drain current density of 115.8 mA/mm,a low specific on-resistance of 52.82 mΩ·cm2.The T-shaped gate structure suppresses the peak electric filed intensity in the Ga2O3 channel effectively,and the breakdown characteristics of the device are improved.Besides,the HfO2 dielectric with a high dielectric constant reduces the leakage current of the device effectively.The fabricated device demonstrates a high breakdown voltage of 1953 V,an on/off ratio of 109,and a power figure of merit of 77.2 MV/cm2.

关 键 词：氧化镓(Ga2O3) 金属氧化物半导体场效应晶体管(MOSFET) T型栅 击穿电压 功率品质因子 

分 类 号：TN386[电子电信—物理电子学]