Process and Performance Improvements to Type-Ⅱ GaAsSb/InP DHBTs

摘要

GaAsSb/InP type-Ⅱ transistors have been fabricated with f_T > 325 GHz and f_(MAX) > 275 GHz. This work will examine the layer structure design criteria allowing the f_r to improve from 244 GHz to 358 GHz and the effects this has on the corresponding f_(MAX). Additionally, the process improvements to control the undercut into the active region during the base contact isolation etch will be discussed. These modifications improved f_(MAX) from 225 GHz to 279 GHz.