AlGaN/GaN HEMT在不同温度下的退化规律及退化机理  

Degradation Law and Degradation Mechanisms of AlGaN/GaN HEMTs Under Different Temperatures

作　　者：郭春生[1] 任云翔[1] 高立[2] 冯士维[1] 李世伟[1] 

机构地区：[1]北京工业大学电子信息与控制工程学院,北京100124 [2]中国电子技术标准化研究所,北京100176

出　　处：《半导体技术》2016年第8期636-639,共4页Semiconductor Technology

摘　　要：基于温度步进应力实验,研究了AlGaN/GaN HEMT器件在不同温度应力下的退化规律及退化机理。实验发现：在结温为139~200℃时,AlGaN/GaN HEMT器件的漏源电流随退化时间逐渐减小;而在结温为200~352℃时,漏源电流随退化时间逐渐增大。分析表明：结温低于200℃时,AlGaN施主原子的离化导致肖特基势垒高度升高;而在结温高于200℃时,表面氧杂质的扩散导致肖特基势垒高度逐渐降低。通过计算肖特基势垒高度,进一步定量的验证势垒高度的变化。而势垒高度的变化又引起阈值电压的漂移,进而影响漏源电流的变化。因此漏源电流的退化主要是由于势垒高度的变化引起的。Based on the step-temperature stress experiment,the degradation law and degradation mechanisms of the Al Ga N / Ga N HEMT device under different temperature stresses were investigated.Through experiments,it is found that the drain-source current of the Al Ga N / Ga N HEMT decreases with the aging time when the junction temperature ranges from 139 ℃ to 200 ℃; while the drain-source current increases with the aging time when the junction temperature ranges from 200 ℃ to 352 ℃. The analysis indicates that when the junction temperature is less than 200 ℃,the ionization of Al Ga N donor atoms may lead to the raise of the Schottky barrier height; and when the junction temperature is higher than 200 ℃,the diffusion of surface oxygen impurities may cause the Schottky barrier height of the Al Ga N / Ga N HEMT device to fall. By calculating the Schottky barrier height,the variation of the barrier height is further quantitatively verified. The change of the barrier height may lead to the shift of the threshold voltage,resulting in the change of drain-source current. Therefore,the degradation of the drain-source current is mainly caused by the change of the Schottky barrier height.

关 键 词：ALGAN/GAN HEMT 温度步进应力 结温 肖特基势垒高度 阈值电压 

分 类 号：TN386[电子电信—物理电子学]