ABSTRACT

The RADiation sensitive metal-oxide-semiconductor field-effect-transistors (RADFETs) were irradiated with gamma rays up to absorbed dose of 110 Gy(H₂O). The results of threshold voltage, V_T, during irradiation with various positive gate biases showed the increase in V_T with gate bias. The threshold voltage shift, ΔV_T, during irradiation was fitted very well. The contributions of both the fixed traps (FTs) and switching traps (STs) during radiation on ΔV_T were analyzed. The results show the significantly higher contribution of FTs than STs. A function that describes the dependence of threshold voltage shift and its components on gate bias was proposed, which fitted the experimental values very well. The annealing at the room temperature without gate bias of irradiated RADFETs was investigated. The recovery of threshold voltage, known as fading, slightly increase with the gate bias applied during radiation. The ΔV_T shows the same changes as the threshold voltage component due to fixed states, ΔV_ft, while there is no change in the threshold voltage component due to switching traps, ΔV_st.

摘要

辐射敏感金属氧化物半导体场效应晶体管 (RADFET) 被伽马射线照射，吸收剂量高达 110 Gy(H ₂ O)。在用各种正栅极偏压照射期间阈值电压V _T的结果表明V _T随栅极偏压而增加。辐照期间的阈值电压偏移 Δ V _T非常适合。固定陷阱 (FT) 和开关陷阱 (ST) 在辐射期间对 Δ V _T的贡献进行了分析。结果表明，FTs 的贡献明显高于 STs。提出了描述阈值电压偏移及其分量对栅极偏置的依赖性的函数，该函数与实验值非常吻合。研究了辐射 RADFET 在没有栅极偏置的情况下在室温下的退火。阈值电压的恢复（称为衰减）随着辐射期间施加的栅极偏置而略微增加。由于固定状态Δ V _ft，Δ V _T显示出与阈值电压分量相同的变化，而由于开关陷阱Δ V _st，阈值电压分量没有变化。