PMOS剂量计对60Co和10 keV光子的剂量响应差异

Difference of dose response of PMOS dosimeter to photons of 60Co and 10 keV photons

摘要:

针对P型金属氧化物半导体(PMOS)剂量计对⁶⁰Co和10 keV光子的剂量响应差异问题，本文对400 nm-PMOS剂量计进行了不同栅压条件下⁶⁰Co γ射线和10 keV X射线的对比辐照试验，并通过中带电压法和电荷泵法分离氧化物陷阱电荷和界面态陷阱电荷的影响，发现PMOS对10 keV光子的响应明显低于⁶⁰Co γ射线，其中主要的差异来自氧化物陷阱电荷，退火的差异表示不同射线辐照下的陷阱电荷竞争机制不同，不同的分析方法也带来一定差异。通过使用剂量因子和电荷产额修正，减小了剂量响应的差异，同时对响应的微观物理机制进行了解释。通过有效剂量修正和电荷产额修正可以很大程度上减小不同能量的剂量响应差异，为PMOS的低能光子辐射环境应用提供了参考。

Abstract:

In order to explore the problem of the difference of dose response of P-channel Metal Oxide Semiconductor(PMOS) dosimeter to photons of ⁶⁰Co and 10 keV photons, comparative irradiation tests of ⁶⁰Co Gamma ray and 10 keV X-ray on 400 nm-PMOS dosimeter with different gate voltages are carried out. The effect of oxide trap charge and interface state trap charge are separated by the mid gap technique and charge pumping method. It is found that the response of PMOS to 10 keV X-ray is significantly lower than that to ⁶⁰Co gamma rays. The main difference is from oxides-trap charge. The difference of annealing indicates that the trap charge competition mechanism is different between gamma and X-rays, and different analysis methods also bring some discrepancy. By using dose factor and charge yield correction, the difference of dose response is reduced, and the microphysical mechanism of the response is explained. The dose response difference between gamma and 10 keV X-rays can be greatly reduced by effective dose correction and charge yield correction, which provides reference for the application of PMOS in low energy photon radiation environment.