中文摘要：

采用直流偏置应力法对蓝宝石衬底上的InGAlN/GaNHEMT器件的电流崩塌效应进行了研究.实验结果表明,在关态和开态应力后,器件直流特性明显退化,退化程度随偏置应力电压和应力时间的累积而增大.理论分析和器件仿真结果表明,关态应力引起的性能退化主要是由栅泄漏电流填充表面态形成的虚栅造成的;而开态应力引起的退化是沟道热电子被势垒层陷阱及表面态俘获产生的.因此,只有消除表面态和势垒层陷阱或者隔绝表面态形成的虚栅才能有效抑制电流崩塌.偏置应力引起的性能退化是可逆过程,在无外界激励时,经过10d左右的静置,器件基本恢复初始性能.

英文摘要：

Drain current collapses under DC-bias-induced stress in passivated InAlN/GaN high electron mobility transistor grown on sapphire substrate were investigated.The experimental results indicated that the degrada-tion of DC characteristics occurred after both the off-state stress and on-state stress,and the degradation degree increases with the accumulation of bias voltage and time.Theoretical analysis and device simulation results shown that the drain current collapse under the off-state stress was due to the virtual gate caused by surface state,while the collapse mechanism under the on-state stress was dominated by the hot-electron effect.In addi-tion,we found that the current collapse under bias-stress was a reversible process.The degraded current can al-most restore to the original values after ten days in the absence of any external exciting source.