电容-电压法研究Al_xGa_1-xN/GaN异质结压电极化效应（英文）  

Piezoelectric Polarization Effect in AlxGa1-xN/GaN Heterostructures through Capacitance Voltage Method

作　　者：俞慧强[1] 沈波[1] 周玉刚[1] 张荣[1] 刘杰[1] 周慧梅[1] 施毅[1] 郑有炓[1] Someya T Arakawa Y 

机构地区：[1]南京大学物理系,固体微结构国家重点实验室 [2]Research Center for Advanced Science and Technology and Institute of Industrial Science,University of Tokyo

出　　处：《发光学报》2001年第S1期61-66,共6页Chinese Journal of Luminescence

基　　金：国家自然科学基金资助项目 ( 6 980 6 0 0 6 ,6 9976 0 41和 6 99870 0 1) ;国家重点基础研究课题专项支持 (G2 0 0 0 0 6 83) ;国家高技术研究和发展项目;日本科学促进协会前沿研究项目 (JSPS RFTF96P0 0 2 0 1)~~

摘　　要：制备了基于调制掺杂Al0 2 2 Ga0 78N/GaN异质结的Pt/Al0 2 2 Ga0 78N/GaN肖特基二极管。由于Al0 2 2Ga0 78N势垒层中的极化场不同 ,不同Al0 2 2 Ga0 78N势垒层厚度的二极管的电容 电压特性显著不同。根据对样品电容 电压特性的数值模拟 ,在Al0 2 2 Ga0 78N势垒层厚度为 30nm和 4 5nm的样品中 ,异质界面的极化电荷面密度为 6 78× 1 0 12 cm-2 。在Al0 2 2 Ga0 78N势垒层厚度为 75nm的样品中 ,极化电荷面密度降为 1 30×10 12 cm-2 。这种极化电荷面密度的降低是由于GaN上Al0 2 2 Ga0 78N势垒层由于厚度增加而产生应变的部分弛豫。本工作也提供了一种定量表征AlxGa1-xN/GaN异质结中极化电荷面密度的方法。Pt/Al 0 22Ga 0 78N/GaN Schottky diodes were prepared based on modula tion doped Al 0 22Ga 78N/GaN heterostructures. The capacitance v oltage profilings of the diodes with various thickness of the Al 0 22Ga 0 78N barrier sh ow significant differences due to the change of the polarization field in these samples. Numerical simulation based on the experimental results indicates that the sheet density of the polarization induced charges at the heterointerface is 6 78×10 12cm -2 in the samples with the Al 0 22Ga 0 78N thickness of 30nm or 45nm. The charge density reduces to 1 30×10 12cm -2 in the sample with the Al 0 22Ga 0 78N thickness of 75nm. It is thought that the reduction of the polarization induced charges at the heter ointerface is due to the partial relaxation of the Al 0 22Ga 0 78 N l ayer on GaN. This work also provides a technique for quantitative characterizati on of the polarization charge in Al xGa 1-xN/GaN heterostructures

关 键 词：压电极化 异质结 电容电压方法 

分 类 号：O482.31[理学—固体物理]