Trench型N-Channel MOSFET低剂量率效应研究

Total ionizing radiation effects of low dose in Trench N-Channel MOSFET

基于抗辐射100V Trench型N-Channel MOSFET开展了不同剂量率的总剂量辐射实验并进行了分析,创新性提出了器件随低剂量率累积以及不同偏置状态下的变化趋势和机理,给出了器件实验前后的转移曲线和直流参数,进行了二维数值仿真比较,证明了实验和仿真的一致性。研究表明:随高剂量率的剂量增加,器件阈值电压(V_(TH))发生了明显负向漂移现象,导通电阻(R_(DSON))出现5%左右的降低,击穿电压(BV_(DS))保持基本不变;低剂量率下总剂量效应与高剂量率有明显不同,阈值电压漂移量减小,同时出现正向漂移现象;此时导通电阻(R_(DSON))和击穿电压(BV_(DS))较高剂量率变化量进一步下降。研究认为,低剂量率下器件界面缺陷电荷增加变多,使得阈值电压的漂移方向发生改变,同时低剂量率实验周期是高剂量率的500倍,退火效应也较高剂量率的明显,导致器件参数辐射前后差异性减小。

Total dose experiment of different dose rates of the radiation hardened 100V trench-type N-Channel MOSFET has been studied in this paper.The change trend and mechanism of the device are innovatively put forward with the accumulation of low dose rates and different bias states.The transfer curve and DC parameters are given before and after the device experiment.The two-dimensional numerical simulation is carried out to prove the consistency of the experiment and simulation.The results show that:(1)With the increase of dose at high dose rate,the threshold voltage(V_(r))of the device has a big shift,and the conduction resistance(R_(pson))and breakdown voltage(BV_(ps))are basically stable;(2)The total dose effect at low dose rate is significantly different from that at high dose rate.The threshold voltage shift is reduced and the positive drift phenomenon occurs.The increase of the interface charge of the device changes the shift direction of the threshold voltage.There is a certain annealing effect,which leads to the decrease of the difference of the device parameters during the experiment.