空间用GaN功率器件单粒子烧毁效应激光定量模拟技术研究

Research on Single Event Burnout of GaN power devices with femtosecond pulsed laser

利用飞秒脉冲激光对氮化镓(GaN)功率器件进行单粒子烧毁效应定量评估技术研究,针对器件结构建立脉冲激光有效能量传输模型,理论计算了激光有效能量与重离子线性能量传输(LET)的等效关系并开展了试验验证.考虑器件材料反射率与吸收系数对激光的影响,针对介质层界面间的激光多次反射进行参数修正,减小有源区有效能量计算误差.选择一款氮化镓高电子迁移率晶体管(GaN HEMT)与一款肖特基势垒二极管(SBD)功率器件作为典型案例,分别开展飞秒脉冲激光正面与背部辐照试验,计算诱发单粒子烧毁的有效能量,并得到不同入射激光波长的烧毁等效LET阈值,对比了模型理论计算值与实际测量值.同时,研究结果对材料参数未知的GaN功率器件,提供了正面与背部辐照模型的激光试验波长选择参考.该工作将为激光定量评估空间用GaN等宽禁带半导体器件的单粒子烧毁效应机理研究及加固设计与验证提供技术支撑.

The femtosecond pulsed laser is used to study the quantitative evaluation technology of the single event burnout(SEB)effect in GaN power devices.In this work,we establish two pulsed-laser effective energy transmission models for different device structures,analyzing and verifying the equivalent relationship between the effective laser energy and the heavy ion linear energy transmission(LET).The critical parameters of models are confirmed,including laser parameters and device parameters.The interface reflectivity between the layers is mainly considered.Meanwhile,the parameters are corrected by the multiple reflections between the interfaces,and the laser energy of the second reflection of the metal layer is considered.These measures can be used to reduce the error of the effective energy in the device active area.In addition,we validate the models experimentally.A gallium nitride high electron mobility transistor(GaN HEMT)and a schottky barrier diode(SBD)power device are used in the experiment on the irradiation by a femtosecond pulse laser.The effective laser energy thresholds and the laser equivalent LET threshold with two incident wavelengths of the SEB are calculated.The theoretical calculation value and the actual measured value are compared.The selcction basis of the laser wavelengths is given by the detailed study.The support for the laser quantitative evaluation and the protection design of the SEB in GaN power devices is provided by this work.