Advanced Si/SiGe HBT architecture for 28-nm FD-SOI BiCMOS

This paper presents a novel Fully Self-Aligned (FSA) Si/SiGe HBT architecture using Selective Epitaxial Growth (SEG) and featuring an Epitaxial eXtrinsic Base Isolated from the Collector (EXBIC). The one is integrated into the bulk area of the 28-nm FD-SOI CMOS technology developed at STMicroelectronics. All the parameters of the architecture such as the boron-doped base link, the emitter width and height, the pedestal oxide and sidewall thicknesses are evaluated by TCAD simulation. A low base-collector capacitance, independent from the extrinsic base doping is obtained. Optimized architecture exhibits 420 GHz fT and 780 GHz fMAX.