SiGe HBT Technology: Future Trends and TCAD-Based Roadmap

A technology roadmap for the electrical performance of high-speed silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs) is presented based on combining the results of various 1-D, 2-D, and 3-D technology computer-aided design (TCAD) simulation tools with geometry scalable compact modeling. The latter, including all known parasitic effects, enables the accurate determination of the figures of merit for both devices and selected benchmark circuits. The presented roadmap defines five major technology nodes with the maximum oscillation frequency of a typical high-frequency device structure as the main device design target under the constraints of various other parameters for generating the doping profiles and for defining the lateral scaling factors. An extensive and consistent set of technology and electrical parameters is provided along with the obtained scaling rules. The expected fabrication-related challenges and possible solutions for achieving the predicted performance are being discussed. It is hoped that the presented roadmap will be useful not only for foundries and equipment manufacturers but also for circuit and system designers enabling better predictions of the capability of SiGe-BiCMOS process technology for new millimeter-wave (mm-wave) and terahertz (THz) applications.