An anomalous total dose effect is observed in narrow-width devices fabricated in a 0.2μm partially-depleted silicon-on-insulator (SOI) technology.The previous radiation-induced narrow channel effect manifests itself with obvious threshold voltage shift after the transistors are subjected to total dose radiation in bulk technology.Nevertheless,a sharply increasing off-state leakage current dominates the total dose effects in narrow devices of this partially-depleted SOI technology instead of threshold voltage shifts.A radiation-induced positive charge trapping model is introduced to understand this phenomenon.The enhanced role of shallow-trench oxide induced by compressive mechanical stress in narrow devices is discussed in detail in terms of modification of the edge impurity density and charge trapping characteristics,which affect the total dose sensitivity.