Inversion electron effective mobility in SOI NMOSFETs

Abstract

Due to reported advantages over bulk silicon, thin-film SOI has developed the potential of becoming a mainstream digital technology. In order to accurately model SOI device operation, it is necessary to understand further the channel electron mobility behavior. Some work has been done in characterising the electron mobility in SOI devices and an enhanced mobility effect has been reported by several authors for fully-depleted devices. In these works, the mobility was found to increase for thinner films and this mobility enhancement has been attributed to a decreased vertical electric field in the channel. For the same gate drive, (V/sub gs/-V/sub th/), the thinner fully-depleted SOI device has a reduced transverse field and thus a higher mobility. This work examines the effective mobility (/spl mu//sub eff/) as a function of a transverse effective electric field (E/sub eff/) rather than gate voltage or gate drive.<>