Passivation of InP-based HBTs for high bit rate circuit applications

Abstract

We have studied different materials (silicon nitride, silicon oxide, polyimide) for passivating InP-based HBTs, and their influence on the device electrical performances. Polyimide was found to induce the least degradation after passivation. A double heterojunction InP/InGaAs HBT fabrication process, including polyimide passivation and planarization, has been assembled, allowing us to realize high bit-rate circuits, such as a 36 Gb/s 2:1 multiplexer.