[TuP3B] B. RF and THz devices

[TuP3B-01] Impact of Base Under-Cut Etching on The Performance of Type-II
InP/GaAsSb DHBTs

〇Mojtaba Ebrahimi Maroufi¹, Akshay Mahadev Arabhavi¹, Sara Hamzeloui¹, Filippo Ciabattini¹, Olivier Ostinelli¹, Colombo Bolognesi¹ (1. ETH Zurich (Switzerland))

The present study contrasts two different approaches in the fabrication of Type-II InP/GaAsSb DHBTs. Specifically, the base under-cut etching of the DHBTs. Base under-cut etching significantly affects the device yield, gain, and RF performance of the transistors. Excellent performance metrics are achieved with a 92% yield and a 50% higher gain for eliminating base under-cut etching in the manufacturing of Type-II DHBTs. Nonetheless, base under-cut etching is crucial for achieving superior RF performance.