Low Field Mobility of Ultra Thin SOI n- and p-MOSFETs: Measurement and Implications on the Performance of Ultra Short MOSFETs

Electron and hole effective mobilities of ultra-thin SOI N- and P-MOSFETs have been measured at different temperatures using a special test structure able to circumvent parasitic resistance effects. At large inversion densities (N/sub inv/) ultra-thin SOI mobility can be higher than in heavily doped bulk MOS due a lower effective field and it is largely insensitive to silicon thickness (T/sub SI/). However, at small Ni/sub inv/ the mobility is clearly reduced for decreasing T/sub SI/. The effective mobility data are used to study the implications for ultra-short MOS transistor performance at device simulation level.