Capacitance and conductance dispersion in AlGaN/GaN heterostructure  

作　　者：闫大为 王福学 朱兆旻 程建敏 顾晓峰 

机构地区：[1]Key Laboratory of Advanced Process Control for Light Industry(Ministry of Education),Department of Electronic Engineering,Jiangnan University

出　　处：《Journal of Semiconductors》2013年第1期35-38,共4页半导体学报（英文版）

基　　金：Project supported by the Fundamental Research Funds for the Central Universities of China (Nos.JUSRP111A42,JUSRP211A37,JUSRP20914,JUSRP11230);the State Key Laboratory of ASIC & System,China (No.11KF003);the Natural Science Foundation of Jiangsu Province,China (No.BK2012110)

摘　　要：The dispersion mechanism in Al0：27Ga0：73N/GaN heterostructure was investigated using frequencydependent capacitance and conductance measurements.It was found that the significant capacitance and conductance dispersion occurred primarily for measurement frequency beyond 100 kHz before the channel cutoff at the interface,suggesting that the vertical polarization electrical field under the gate metal should be closely related with the observed dispersive behavior.According to the Schottky-Read-Hall model,a traditional trapping mechanism cannot be used to explain our result.Instead,a piezoelectric polarization strain relaxation model was adopted to interpret the dispersion.By fitting the obtained capacitance data,the corresponding characteristic time and charge density were determined 10..8 s and 5.26 1012 cm..2 respectively,in good agreement with the conductance data and theoretical prediction.The dispersion mechanism in Al0：27Ga0：73N/GaN heterostructure was investigated using frequencydependent capacitance and conductance measurements.It was found that the significant capacitance and conductance dispersion occurred primarily for measurement frequency beyond 100 kHz before the channel cutoff at the interface,suggesting that the vertical polarization electrical field under the gate metal should be closely related with the observed dispersive behavior.According to the Schottky-Read-Hall model,a traditional trapping mechanism cannot be used to explain our result.Instead,a piezoelectric polarization strain relaxation model was adopted to interpret the dispersion.By fitting the obtained capacitance data,the corresponding characteristic time and charge density were determined 10..8 s and 5.26 1012 cm..2 respectively,in good agreement with the conductance data and theoretical prediction.

关 键 词：capacitance dispersion AlGaN/GaN heterostructure strain relaxation model 

分 类 号：TN386[电子电信—物理电子学]