Submicron, fully self-aligned HBT with an emitter geometry of 0.3 mu m

A new fully self-aligned heterojunction bipolar transistor (HBT) process has been developed to fabricate submicron emitter geometries for applications requiring ultra low-power consumption and very high-speed performance, In this novel process approach the emitter, base and collector ohmic contacts are all self-aligned to the emitter mesa, Furthermore, the three ohmic contacts, i.e., emitter, base, and collector are defined and deposited in a single metalization step thereby simplifying the fabrication process, Using this new process we have fabricated HBT emitter geometries as small as 0.3 mu m(2) with RF performance of over 130 GHz, To our knowledge, this is the smallest HBT ever reported.