Effect of High-Voltage Heterojunction Bipolar Transistor Collector Design on f(T) and f(MAX)

摘要

High-speed InGaP/GaAs heterojunction bipolar transistors (HBTs) for high-voltage circuit applications have been investigated. In order to obtain ideal IV characteristics, a lightly doped (N(DC)=7.5 x 10 to the 15th power cm(-3)) thick fabricated have shown breakdown voltage exceeding 65 V. Device operated at up to 60V bias, which is the highest operating voltage reported up to date for single heterojunction HBTS. Peak f(T) and f(MAX) values of 18 GHz and 29 GHz, respectively, have been achieved on a device with emitter area of 4x12.5 micrometer squared. Both f(T) and f(MAX) degrades with higher bias, which is related to the elongation of the collector depletion width.