Self-heating effects in SiGe heterojunction bipolar transistor with different Ge grading profile

Abstract

A comparative account of self heating effect of four SiGe HBTs with different Ge grading profiles, designated as Hybrid Trapezoidal (HT), Symmetrically Triangular (ST), Linear Increasing (LI), and Conventional Trapezoidal (CT) with maximum Ge contents of 20%, is presented. Based on an experimentally validated model of the Silvaco TCAD tool, the properties of the four HBTs are simulated. It is observed that both self heating and local temperature increase due to higher device power dissipation. The effect of energy balance and non iso thermal energy balance effect is observed in SiGe HBT with different Ge base profile have been studied in terms of DC, AC, and RF performances and compared.