超陡倒掺杂分布对超深亚微米金属-氧化物-半导体器件总剂量辐照特性的改善

The improvement on total ionizing dose (TID) effects of the ultra-deep submicron MOSFET featuring delta doping profiles

分析了沟道中超陡倒掺杂和均匀掺杂两种情况下超深亚微米MOS器件的总剂量辐照特性,主要比较了两种掺杂分布的器件在辐照情况下的泄漏电流与阈值电压的退化特性.结果表明,在辐照剂量<500krad情况下,超陡倒掺杂器件的泄漏电流比均匀掺杂器件的泄漏电流低2—3个量级;而在辐照剂量>500krad情况下,由于器件俘获的空穴量饱和,超陡倒掺杂的改善没有那么明显.但超陡倒掺杂的阈值电压漂移量比均匀掺杂的情况小约40mV.超陡倒掺杂有利于改善器件的总剂量辐照特性.文中还给出了用于改善器件辐照特性的超陡倒掺杂分布的优化设计,为超深亚微米器件抗辐照加固提供了依据.

Total ionizing dose （TID） effects of the deep submicron MOSFET （metal oxide semiconductor field effect transistor） with delta doping profiles and uniform doping profiles in the channel region are analyzed in this paper. The influence of both doping profiles on the leakage current and threshold voltage is investigated. The results show that, the leakage current of MOSFET with delta doping profile is 2—3 orders lower than that with the uniform doping profile when the radiation dose is lower than 500 krad. Yet when the radiation dose is higher than 500 krad, the delta doping profile dose not show significant improvement compared with uniform doping profile as the trapped holes in the MOSFET saturate. But the threshold voltage shift is about 40 mV less than that with the uniform doping profile. Therefore, the TID effects of the deep submicron MOSFET can be improved by adopting the delta doping profile. The optimization of the delta-doping profile to further improve the TID effects is also given in this paper, which provides the guideline for the radiation hardened design.