中文摘要：

考虑了势垒层、缓冲层体陷阱及表面电荷的浓度变化对电流坍塌和膝点电压的影响,发现表面电荷和势垒层体陷阱浓度的变化对沟道电子的浓度影响较小,表面电荷浓度变化下的膝点电压的偏移和坍塌强度的大小与势垒层势阱能量的变化有着主要的关系.缓冲层有着比势垒层更强的局域作用,势垒层和缓冲层的体陷阱浓度在一定范围变化时的膝点电压偏移主要是由沟道电子浓度的变化而引起的,但偏移量却比表面电荷浓度变化的情况下小很多.势阱能量的变化是造成膝点电压偏移的重要原因,坍塌强度主要取决于势阱能量和沟道的电子浓度.

英文摘要：

In this article,we comprehensively showed the impact of barrier layer traps,buffer layer traps and surface charge on current collapse and knee voltage change,pointed out that the change in the concentration of surface charge and barrier layer traps have little influence on the 2DEG density in the channel. When the concentration of surface charge changes, the knee voltage drift and strength of current collapse are in close connection with the change of potential energy in quantum well. Buffer layer has stronger local effect than barrier layer,when the concentration of bulk traps change in these layers,knee voltage drift is mainly caused by the change of 2DEG density,but has less change compared with the situation of surface charge. Potential energy changes in the quantum well is an important reason for the change of knee voltage,the strength of current collapse is determined by the size of potential energy and 2DEG density.