Modeling on oxide dependent 2DEG sheet charge density and threshold voltage in AlGaN/GaN MOSHEMT

作     者：J.Panda K.Jena R.Swain T.R.Lenka 

作者机构：Microelectronics and VLSI Design Group Department of Electronics and Communication Engineering National Institute of Technology Silchar 

出 版 物：《Journal of Semiconductors》 (半导体学报（英文版）)

年 卷 期：2016年第37卷第4期

页      面：44-49页

核心收录：

学科分类：080903[工学-微电子学与固体电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

主　　题：2DEG AlGaN GaN heterojunction MOSHEMT trap capacitance 

摘      要：We have developed a physics based analytical model for the calculation of threshold voltage, two dimensional electron gas（2DEG） density and surface potential for Al Ga N/Ga N metal oxide semiconductor high electron mobility transistors（MOSHEMT）. The developed model includes important parameters like polarization charge density at oxide/Al Ga N and Al Ga N/Ga N interfaces, interfacial defect oxide charges and donor charges at the surface of the Al Ga N barrier. The effects of two different gate oxides（Al_2O_3 and HfO_2/ are compared for the performance evaluation of the proposed MOSHEMT. The MOSHEMTs with Al_2O_3 dielectric have an advantage of significant increase in 2DEG up to 1.2 10^（13） cm^2 with an increase in oxide thickness up to 10 nm as compared to HfO_2 dielectric MOSHEMT. The surface potential for HfO_2 based device decreases from 2 to –1.6 e V within10 nm of oxide thickness whereas for the Al_2O_3 based device a sharp transition of surface potential occurs from 2.8to –8.3 e V. The variation in oxide thickness and gate metal work function of the proposed MOSHEMT shifts the threshold voltage from negative to positive realizing the enhanced mode operation. Further to validate the model,the device is simulated in Silvaco Technology Computer Aided Design（TCAD） showing good agreement with the proposed model results. The accuracy of the developed calculations of the proposed model can be used to develop a complete physics based 2DEG sheet charge density and threshold voltage model for Ga N MOSHEMT devices for performance analysis.