MOS器件辐照引入的界面态陷阱性质

通过分析总剂量辐照产生的界面陷阱的施主和受主性质 ,用半导体器件模拟软件 Medici模拟了NMOS、PMOS器件加电下辐照后的特性。结果表明 ,对于 NMOSFET,费米能级临近导带 (N沟晶体管反型 )时 ,受主型界面态为负电荷 ,施主型界面态陷阱为中性 ,使界面态陷阱将引起的阈值电压漂移 ;而对 PMOSFET,当费米能级临近价带 (P沟晶体管反型 )时 ,施主型界面态陷阱带正电荷 ,受主型界面态陷阱为中性 ,界面态陷阱将引起负的阈值电压漂移。理论模拟的转移特性与测试结果吻合。文中从器件工艺参数出发 ,初步建立了总剂量电离辐照模型 ,该模型对于评估器件总剂量加固水平提供了一种理论方法

Donor/Acceptor Nature of Radiation-Induced Interfaced Traps in MOS Devices

Donor/Acceptor nature of total dose radiation-induced interfaced traps is analyzed in the paper. With two-dimensional semiconductor device simulator Medici the post-irradiation behavior of the MOSFET has been simulated. It can be seen that when the Fermi level is near conduction band(inversion for N-channel transistor), the acceptor interface traps are negatively charged and the donor interface traps are neutral, leading to a positive threshold voltage shift resulted from the interface traps. When the Fermi level is near the valence band (inversion for P-channel transistor), the acceptor interface traps are neutral, and the donor interface traps are positively charged, leading to a negative threshold voltage shift resulted from the interface traps. The model is in good agreement with numerical calculation and experimental results. An excellent evaluation approach is provided for accurately prediction of total dose radiation hardening to ionizing radiation.