GaAs/InGaP HBT devices and circuits

An enhanced GaAs/InGaP HBT process has been developed at GMMT for the implementation of high performance digital and microwave circuit functions. Improvements have been made in device characteristics, with small area devices exhibiting current gain (/spl beta/) values of over 150, following a better understanding of the contributions of various parts of the geometry to the base current. This paper will give a description of the enhanced process, and of the benefits in performance, yield and uniformity which have been achieved. This will be followed by a discussion of the issues of device modelling and reliability, and conclude with an examination of some circuit designs which have been constructed using the design models.