Work

Selective injection AlGaN/GaN heterojunction bipolar transistors with patterned regrown base contacts

Year: 2025

Type: article

Abstract: We demonstrate graded AlGaN/GaN heterojunction bipolar transistors (HBTs) with selective injection of minority carriers across a p-GaN base and patterned regrown base contacts. The selective injection design regulates minority carrier transport under emitter–base forward bias through a thin base region, while thick and highly doped p+ GaN regrown layers patterned alongside the thin base regions are utilized to lower the base contact resistance. With SiO2 employed as a spacer between the emitter and the p+ regrown layers, the device with an interdigitated emitter/base-contact stripe design displayed a maximum collector current density (IC) of 101 kA/cm2 and a maximum current gain (β) of 70 at IC ∼1 kA/cm2 and ∼11 for IC > 50 kA/cm2. The reported results demonstrate the potential of the selective injection approach to break the long-existing HBT design trade-off between base resistance and current gain for next-generation radio frequency and millimeter wave applications.

Source: APL Electronic Devices

DOI: 10.1063/5.0249838

Authors: Chandan Joishi, Sheikh I. Rahman, Zhanbo Xia, Shahadat H. Sohel, Siddharth Rajan

Institution: The Ohio State University

Language: English

Topic: GaN-based semiconductor devices and materials

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: diamond

Funder: Office of Naval Research

Award: G3946830623