Deep submicron InP DHBT technology with electroplated emitter and base contacts

Abstract

We report the development of a wide bandwidth InP double heterojunction bipolar transistor technology that utilizes novel electroplating processes to form the emitter and base contacts. The technology enables the fabrication of HBTs with deep submicron emitter-base junction dimensions and self-aligned base ohmic contacts. Using this technology, HBTs have been fabricated with emitter junction widths scaled to 0.25 /spl mu/m. These devices demonstrated peak f/sub /spl tau// and f/sub max/, values of over 300 GHz. The transistors also support high current density operation (J/sub E/>7 mA//spl mu/m/sup 2/) and have a low collector-base capacitance to collector current ratio (C/sub cb//I/sub c//spl sim/0.55 ps/V), an important parameter for digital logic speed.