Suppression of Electron Mobility Degradation in (100)-Oriented Double-Gate Ultrathin Body nMOSFETs

Electron mobility in ultrathin body MOSFETs in double-gate (DG) operation has been investigated with SOI thickness of less than 4 nm for the first time. Although mobility degradation in DG compared to single gate occurs with SOI thickness of larger than 2 nm, the degradation is suppressed with SOI thickness of 1.7 nm. This suppression mechanism is explained by strong quantum confinement effect by an extremely thin SOI layer.