Analysis of thermal stability in underlap and overlap DMG FinFETs including self-heating effects

Abstract

This work investigates the impact of the self-heating effect (SHE) on SOI Dual-Material Gate (DMG) FinFETs with channel engineering including gate underlapped and overlapped structures. Both these structures are compared with conventional DMG FinFET to detect the possible effects of SHE on DC characteristics and thermal parameters. The drop rates of ON current (ION), Off-current (IOFF), Maximum transconductance (gm,max), ION/IOFF ratio, and Drain-induced barrier lowering (DIBL) are calculated to get the precise results. For extensive thermal reliability analysis, the two main distinguishing parameters lattice temperature and thermal resistance are also calculated and their dependency with gate/drain bias and operating temperature are also explored. Comparison between thin and thick BOX devices aimed at distinguishing possible effects of SHE on BOX thickness variation. The result shows that the SHE greatly improves ION/IOFF ratio by 220.8% in gate underlap structure due to large reduction in leakage current. Although lattice temperature is higher in gate overlap structure but thermal resistance decreases by 53.6 % due to its high ON current. Using high-k dielectric BOX materials, small improvement in device SHE characteristics is also accomplished.