Study of Fin Profiles and MuGFETs built on SOI Wafers with a Nitride-Oxide Buried Layer (NOx-BL) as the Buried Insulator Layer

Multiple-gate-MOSFETs (MuGFET) have better short-channel effects (SCE) control than planar MOSFET and MuGFETs are good candidates to replace planar bulk MOSFET for low power applications. A key feature in the MuGFETs is the recess and undercut of the fins in the buried oxide. Undercut improves gate control of the channel at fin and BOx interface, but also undermines the fin stability, and increases susceptibility to gate etch defects. This paper introduces SOI wafers with nitride buried dielectric that eliminates the undercut, while maintaining good gate control of the channel through higher buried insulator dielectric constant.