Work

Regrowth-Free GaN RF HEMTs Achieving f max of 403 GHz via Periodic Contact Structures

Year: 2025

Type: article

Abstract: A regrowth-free sub-THz HEMT is demonstrated using a periodic contact scheme that transforms conventional linear contacts into a configuration with far better overall contact resistance (RC). This method yielded a consistent lowRCdown to 0.15 Ωmm. Furthermore, this technique is based on a Au-free low-temperature annealing metalization (Ti/Al), which results in extremely smooth edges, allowing for sub 500 nm channel scaling. These features enabled – for the first time – the demonstration of regrowth-free GaN RF HEMT withft/fmaxof 176/403 GHz. These results are comparable to the best GaN HEMTs with similar geometry, highlighting the enormous potential of periodic contact structures for high performance RF and sub-THz devices.

Source: IEEE Electron Device Letters

DOI: 10.1109/led.2025.3633055

Authors: Mohammad Rezaei, Hongkeng Zhu, Amirhossein Esteghamat, Elison Matioli

Institution: École Polytechnique Fédérale de Lausanne

Language: English

Topic: GaN-based semiconductor devices and materials

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: National Natural Science Foundation of China, Bundesamt für Energie

Awards: G1084188530, G7267964585