【摘要】 由于AlGaN/GaN异质结界面极化效应产生的高浓度和高迁移率的二维电子气(2DEG),使AlGaN/GaN器件在电子器件领域具有显著的应用优势。AlGaN/GaN器件存在的电流崩塌现象限制了器件的实际应用。缓冲层陷阱是导致电流崩塌现象的重要原因之一。概述了AlGaN/GaN器件缓冲层陷阱的研究方法,分析了各种方法的优缺点。重点介绍了基于电容、电流瞬态测试的方法。介绍了基于电容瞬态测试方法中的热激发的电容式深能级瞬态谱(DLTS)、光激发的开启电容恢复和光激发的深能级光谱(DLOS)方法;直接通过电流瞬态测试难以区分陷阱的位置,总结了基于此方法的不同偏压条件下的电流瞬态测试、背栅电流瞬态谱、无栅极的源-漏测试结构分析方法。电容和电流瞬态测试方法具有灵敏度高的优点,适用于缓冲层陷阱的分析,为抑制电流崩塌提供了理论指导。更多还原

【Abstract】 Due to the high concentration and high mobility of the two dimension electronic gas( 2DEG) which is caused by the polarization effect in AlGaN/GaN heterojunction interface,the AlGaN/GaN device has a significant advantage in electronic devices. However,the current collapse phenomenon in AlGaN/GaN device limits its application. The existence of the traps in the buffer layer is an important reason for the current collapse phenomenon. The research methods of the traps in the buffer layer of AlGaN/GaN device are summarized. The advantages and disadvantages of these methods are analyzed. The methods based on the capacitance and current transient measurements are mainly introduced.According to the capacitance transient measurement, the deep level transient spectroscopy( DLTS)measurement excited by heat,and the open capacitance recovery excited by light and deep level optical spectroscopy( DLOS) excited by light are introduced. The location of the trap is difficult to be distinguished by the current transient measurement directly. Based on this method,the analysis methods of the current transient measurement under various bias conditions,back gate current transient spectroscopy and a source-drain test structure without gate are described. Therefore, the capacitance and current transient test methods have the advantage of high sensitivity and are suitable for analysis of the traps in the buffer layer,which provides a theoretical guide for the suppression of the current collapse.更多还原