Reliability enhancement in high-performance MOSFETs by annular transistor design

Abstract

The use of annular MOSFET design, which has demonstrated total-dose radiation immunity in CMOS circuits, can improve the hot-carrier reliability of CMOS circuits by reducing the drain electric field compared to conventionally designed MOSFETs. A theoretical analysis of the annular n-MOSFET in saturation verifies the reduction of the drain electric field in properly designed MOSFETs. Hot-carrier data for an enclosed 0.25-/spl mu/m n-MOSFET demonstrate an improvement in hot-carrier lifetime by more than 3x compared to a conventional device in the same technology.