Measurement based accurate definition of the SOA edges for SiGe HBTs

Abstract

This paper presents a non-destructive method to characterize the SiGe HBTs (heterojunction bipolar transistors) at very high currents/voltages, close to the functional boundaries of the transistor operation. Based on this measurement, a focus is made at high currents where the snapback behavior is observed using IC/VBE measurement setup. This analysis has been carried out for different transistor geometries. The first and second snapback locus in the IC-VCB characteristic has been discussed. A comparison of the measurements with the HICUM model shows accurate simulation results close to and even beyond the second flyback locus.