Imec bryder grænser med ny RF GaN-on-Si transistor
Med sigte på brug i bl.a. de næste generationer af højeffektive 6G power amplifiers præsenterer imec RF GaN-on-Si transistor med hidtil uset høj ydelse og effektivitet (in english).
Imec, a world-leading research and innovation hub in nanoelectronics and digital technologies, has set a new benchmark in RF transistor performance for mobile applications. They present a gallium nitride (GaN) MOSHEMT (metal-oxide-semiconductor high-electron-mobility transistor) on silicon (Si) that achieves both record efficiency and output power for an enhancement-mode (E-mode) device operating at low supply voltage.
In parallel, imec also demonstrated a record-low contact resistance which is essential to further boost output power in future designs. The results mark a crucial step toward integrating GaN technology into next-gen mobile devices, particularly those targeting the 6G FR3 band between 7 and 24GHz. The results will be presented at the 2025 Symposium on VLSI Technology and Circuits in Kyoto, Japan.
Today’s mobile networks largely operate below 6GHz, but to meet the data rate demands of future 6G systems, a shift to higher frequencies is needed. In these bands, current mobile solutions based on gallium arsenide (GaAs) HBTs (heterojunction bipolar transistor) struggle to maintain performance.
Their efficiency and gain degrade significantly above 10 to 15GHz, leading to fast battery drain and poor energy use in user equipment. GaN is widely recognized as a promising alternative because of its higher power density and breakdown voltage. While GaN transistors on silicon carbide (SiC) have shown strong RF performance in high-frequency base station applications, the cost and limited wafer scalability of SiC remain barriers for the mobile market.
Silicon is a more scalable and cost-effective platform but building high-efficiency GaN transistors on it has been challenging due to the lattice and thermal mismatch between the two materials, which can compromise material quality and device reliability. The challenge is even greater for E-mode designs –which are preferred in mobile for their fail-safe operation and low power consumption – because it typically requires thinning the transistor barrier and channel under the gate.
