辐射感生应力弛豫对AlmGa1－mN/GaN HEMT电学特性的影响

基于电荷控制原理建立了辐射感生Al_mGa_1-mN势垒层应力弛豫对Al_mGa_1-mN/GaN HEMTs器件电学特性影响的解析模型，并进行了仿真分析.结果表明，对于高Al组分HEMTs器件，Al_mGa_1-mN势垒层中辐射感生的应力弛豫影响更为显著.辐射感生应力弛豫不但导致2DEG下降和阈值电压正向漂移，而且能够引起漏极输出电流的明显下降.辐射感生应力弛豫是赝配Al_mGa_1-mN/GaN HEMTs辐射损伤的重要机理之一.关键词：mGa_1-mN/GaN')" href="#">Al_mGa_1-mN/GaNHEMT辐射损伤应力弛豫

The effect of radiation induced strain relaxation on electric performance of AlmGa1-mN/GaN HEMT

A complete model for studying the effect of radiation induced strain relaxation on electric performance of AlGaN/GaN HEMT was built utilizing the degree of strain relaxation related to radiation dose and energy as a basic variable. The effects of radiation induced strain relaxation on carrier density, threshold voltage and I-V characteristic were systematically investigated. The calculation results indicated that decrease in polarization induced charges as a result of strain relaxation causes decrease in carrier density, increase in threshold volgate and degradation in saturation drain current according to a linear rule. All results showed that the effect of radiation induced strain relaxation on HEMTs with high Al content appears more prominent. The calculation results also imply that strain relaxation is one of the important radiation damage mechanisms, the sensitivity of Al content to radiation induced strain relaxation degree need to be considered when improving the figure of merit of HEMTs by virtue of enhancement in Al content.