Title:  Using SiGe HBTs for Quantum Science at Deep Cryogenic Temperatures

Committee: 

Dr. Cressler, Advisor     

Dr. Khan, Chair

Dr. Mourigal

Dr. Davidovic

Abstract: The objective of the proposed research is to investigate the feasibility of using SiGe HBTs for quantum science applications at deep cryogenic temperatures, including quantum computing and superconducting nanowire single photon detectors. The requirement for these applications are detailed, and four aspects of SiGe HBT technology, including cryogenic characterizations, device physics, compact modeling, and circuit designs will be explored in the preliminary research and proposed research to assess to feasibility of using SiGe HBT in these applications. In particular, the preliminary research on cryogenic characterizations demonstrate the lowest operating temperature of SiGe HBT in literature. Transport physics study reveals new transport mechanism with a physical models in TCAD. Furthermore, the variability of SiGe HBTs (both DC and RF characteristics) are studied to assess large-scale usage of this technology in deep cryogenic applications. The proposed research will build on top of the experimental and physical foundation from preliminary research, and explores the compact modeling of SiGe HBTs and some circuit constraint due to the presence of variability.