Lateral and Vertical Scaling of High-f_(max) InP-Based HBTs

摘要

Design approach to improving f_(max) of InP-based HBTs by combining lateral scaling (lithographic scaling) and vertical scaling (improving f_T) is discussed. An HBT scaling model is formulated to provide means of analyzing the essential impact of scaling on f_(max). The model was compared with measurements of single and double heterojunction bipolar transistors with different f_T and various emitter sizes. While a high f_(max) of 313 GHz was achieved using submicron HBT with high f_T, it was found that further improvement could have been obtained by reducing the emitter resistance, which has imposed considerable limit on lateral scaling.