Submicrometer AlGaAs/GaAs Heterostructure Bipolar Transistor with High Gain.

We describe the realization of self-aligned AlGaAs/GaAs heterostructure bipolar transistors with submicrometer emitter stripe width, current gain of 120, and a maximum operating current density greater than 10 sup 5 sup Acm sup (-2). The high current gain was achieved by passivating the extrinsic base region with thin AlGaAs.