中文摘要：

门极换流晶闸管（GCT）关断过程中的动态雪崩效应是导致其失效的关键因素。本文采用Sentaurus仿真软件对4 500V非对称GCT关断过程中的动态雪崩效应进行了研究,建立了用于描述动态雪崩过程中等离子体边缘移动速度的二维解析模型,分析了电流丝产生的原因及其影响因素,研究了GCT的失效机理。结果表明,GCT发生动态雪崩时会产生单个纵向贯穿整个器件的电流丝,这是由p阳极区的空穴注入所致,并且空穴注入会减慢电流丝的移动速度,从而降低了GCT关断的可靠性。

英文摘要：

Dynamic avalanche effect occurred during the turn-off of gate commutated thyristor（GCT）is a key factor causing its failure.The dynamic avalanche effect in 4 500 Vasymmetry GCT was studied by Sentaurus device simulator.A two-dimension analytical model was built to describe the moving speed of the plasma front in dynamic avalanche process.The origin of current filament and its influencing factors were analyzed and the failure mechanism of GCT was revealed.The results show that a anode-oriented current filament run through the whole device will be generated when the dynamic avalanche occurs in GCT during turn-off,which is caused by the hole injection of the p anode region.Furthermore,the hole injection will slow down the movement of the current filament,degrading the reliability with respect to the turn-off of GCT.