电离辐射对部分耗尽SOI器件关态电流的影响

Total dose dependence of off currents in the irradiated PD-SOI devices

针对辐射前后环栅与条栅结构部分耗尽绝缘体上硅(SOI,Silicon On Insula-tor)器件关态电流的变化展开实验,研究结果表明辐射诱使关态电流增加主要取决于侧壁泄漏电流、背栅寄生晶体管导通、带-带隧穿与背栅泄漏电流的耦合效应.在条栅结构器件中,辐射诱生场氧化层固定电荷将使得器件侧壁泄漏电流增加,器件前、背栅关态电流随总剂量变化明显;在环栅结构器件中,辐射诱使背栅晶体管开启将使得前栅器件关态电流变大,而带-带隧穿与背栅泄漏电流的耦合效应将使得器件关态电流随前栅电压减小而迅速增加.基于以上结果,可通过改良版图结构以提高SOI器件的抗总剂量电离辐射能力.

Total dose dependence of off currents in the partially depleted SOI devices with standard and enclosed gate structures was presented. The experimental results show that increases in the radiation induced off current are result from the effect of trench sidewall leakage, the conduction of back gate parasitic transistor and the coupling effect of band-to-band tunneling and back gate leakage currents. In the standard structures, trench sidewall leakages are increased by the positive charge trapping in the field oxide, thus the off currents in the front and back gate is increased significantly. In the enclosed gate structures, increases in the off cur- rent are more caused by the conduction of back gate parasitic transistors and the drain current dependence on total dose at negative gate-source voltage are caused by the coupling effects of band-to-band tunneling and back gate leakage currents. These results can be used for hardness assurance by improving of device layout struc- tures.