GaAlAs/GaAs HETEROSTRUCTURE BIPOLAR TRANSISTORS: EXPERIMENT AND THEORY.

Abstract

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; and (e) device design issues such as single and double heterostructures and the key speed determining factors of a given design. The author describes experimental and theoretical understanding related to these issues by correlating measurements on self-aligned (refractory ohmic contacts) and nonself-aligned mu m-size device structures with simulations using two-dimensional heterostructure drift-diffusion models, and Ebers-Moll-based circuit models.