Estudo do efeito de auto-aquecimento em transistores SOI com estrutura de canal gradual - GC SOI MOSFET.

Abstract

This work presents the study of Self-Heating (SH) effect in Graded-Channel Silicon-On-Insulator (GC SOI) nMOSFETs. The SOI technology characteristics are described with special attention to the GC SOI nMOSFET characteristics. A SelfHeating (SH) analysis was performed using conventional Silicon-On-Insulator (SOI) in comparison to Graded-Channel (GC) SOI nMOSFETs devices. The analysis was performed comparing devices with the same mask channel length and with the same effective channel length. Two-dimensional numerical simulations were performed considering the lattice heating in both cases. The models and the thermal conductive constant used in these simulations are also presented. It has been demonstrated that conventional and GC devices with the same mask channel length present 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 lengths, the SH is less pronounced in GC transistors as the mask channel length has to be increased in order to compensate the current difference. This analysis is also carried through varying it temperature of 200K to 400K and analogous results had been observed despite the effect being more intense in low temperatures.