GaAlAs/GaAs heterostructure bipolar transistors: Experiment and theory

Important to the ultimate usability and scalability of the heterostructure bipolar transistor (HBT) are our understanding of such physical and technological factors as: (a) primary parasitic effects such as surface and bulk recombination, (b) transport and storage of carriers in extrinsic and intrinsic regions, (c) secondary parasitic effects such as offset voltage, (d) effects of choice of technology and processes such as implantation etc.; and (e) device design issues such as single and double heterostructures and the key speed determining factors of a given design. This extended abstract describes experimental and theoretical understanding related to there issues by correlating measurements on self-aligned (refractory ohmic contacts) and non-self-aligned micrometer size device structures with simulations using two-dimensional heterostructure drift-diffusion models, and Ebers-Moll based circuit models. We also summarize our technologies for shallow and small junctions that address the above factors and which will be important in scaled device.