动态偏置频率对X射线总剂量效应的影响

Effect of frequency of dynamic bias to total dose effect of X-rays

辐射偏置条件是影响MOSFET(Metal Oxide Silicon Field Effect Transistor),总剂量辐射效应的主要因素之一,因为辐射时栅氧化层中电荷的产生、传输与俘获都与辐射偏置有关。本文采用10 keV X射线对MOSFET在不同频率的动态偏置条件下进行总剂量辐射,分析了MOSFET辐照前后的阈值电压的漂移量和辐射感生电荷对阈值电压的影响。实验结果表明,动态偏置频率越高,辐射对MOSFET电特性的影响越小,产生的辐射感生电荷越少。

Bias voltage applied to MOSFET during irradiation has a major impact on the device response because charge yield, transport, and trapping in oxide are all bias dependent. NMOSFET and PMOSFET under different frequency of dynamic bias were irradiated by 10 keV X-rays to study the total dose effect. The shifts of threshold voltage of the MOSFETs before and after irradiation and effects of the radiation-induced charge on the threshold voltage of MOSFETs are analyzed in this paper. The results showed that the higher the frequency of pulse signal is, the less threshold shift and concentration of the radiation-induced charge were observed at the same pulsed voltage.