2D-TCAD Process Calibration for a High Speed QSA SiGe:C HBT Verified with SSRM

Abstract

In this work, a 2D-TCAD process simulation platform for high speed bipolar HBT devices with ƒT/ƒmax values exceeding 200GHz is presented. The process simulations implement a consistent model describing the diffusion behavior of boron and carbon in silicon and silicon germanium. In particular, the model successfully accounts for coupled diffusion of carbon and silicon point defects under several RTA conditions. The Kick-Out and Frank-Turnbull reactions model the carbon diffusion. Extended short-loop experiments under equilibrium and non-equilibrium conditions increased the accuracy of the simulations. It is shown that 2D-TCAD process simulations, calibrated with SIMS and TEM pictures, can be successfully complemented with the use of SSRM measurements, which provide emitter-base and collector- base junction delineation and two-dimensional carrier distributions. An excellent agreement in vertical and lateral electrical junction depths between SSRM measurements and the 2D-TCAD simulations validates the 2D process calibration.