High frequency silicon bipolar transistor with SIPOS (Semi-insulating polycrystalline silicon) heterojunction emitter and ion implanted rapid thermal annealed base region

The research program described in this report is directed toward the investigation of concepts for improved high-frequency, high-speed, silicon bipolar transistors. The research is focused in three major areas: (1) deposition and characterization of semi-insulating polycrystalline silicon (SIPOS) as a heterojunction emitter. (2) use of ion implantation and rapid thermal annealing (RTA) for forming the base of bipolar transistors, (3) investigation of other technologies such as oxide isolation and polycrystalline silicon contacts to reduce parasitic effects to improve limitations at high frequencies. The research ranges from fundamental studies of structural, chemical, electrical, and optical properties of SIPOS deposited over a wide range of compositions on various substrates to the fabrication of transistors with polycrystalline and SIPOS emitters. Much effort has also been directed toward the ion implanted base where numerous techniques for forming the shallow implant and maintaining the profile during further processes were investiggated.