Analysis of Self-Heating Effect in Graded-Channel Silicon-on-Insulator nMOSFETs

Abstract

This paper presents a Self-Heating (SH) analysis using conventional Silicon-On-Insulator (SOI) in comparison to Graded- Channel (GC) SOI nMOSFETs devices. The analysis is performed comparing devices with the same mask channel length and with the same effective channel length. Two-dimensional numerical simulations are performed in both studies considering the lattice heating. The models and the thermal conductive constant used in these simulations are also presented. It is demonstrated that GC devices with the same mask channel length presents similar occurrence of SH independently of the length of lightly doped region despite the larger drain current. On the other hand, for similar effective channel length, the SH is less pronounced in GC transistors as the mask channel length has to be increased in order to compensate the current difference.