This week, at the 2023 International Electron Devices Meeting (IEEE IEDM 2023), imec showcased their progress in developing aluminum-nitride/gallium-nitride (AlN/GaN) metal-insulator-semiconductor high-electron mobility transistors (MISHEMTs) on 200mm silicon with exceptional output power and energy efficiency at 28GHz. This technology outperforms other GaN MISHEMT devices in terms of performance and possesses a significant cost advantage for industrial manufacturing due to the use of silicon substrates.
Gallium-nitride (GaN) based (MIS)HEMTs offer superior performance over CMOS devices and gallium-arsenide (GaAs) HEMTs in terms of output power and energy efficiency, making them highly sought after for 5G-advanced high-capacity wireless communication applications. Imec's GaN-on-Si MISHEMT technology is particularly tailored for both mobile devices and base stations, offering high performance at low voltages as well as at higher voltages.
Nadine Collaert, imec fellow and program director advanced RF, highlighted the challenge of achieving high operating frequency and delivering high output power with efficiency. The experimental study focused on GaN-on-Si MISHEMTs with AlN barriers, showcasing exceptional performance metrics including saturated output power (PSAT) of 2.2W/mm and power added efficiency (PAE) of 55.5% at 28GHz for low-voltage applications, and a PSAT of 2.8W/mm and PAE of 54.8% at 28GHz for base station applications.
Imec's study also involved the impact of thickness scaling of the AlN and Si3N4 layers, which are used as stop barrier layer and gate dielectric respectively. Additionally, a broader study of on-state breakdown of GaN HEMTs revealed insights into the reliability issues associated with these devices. These foundational studies provide a modeling platform to optimize the design of GaN-based material stack for specific use cases.
Imec's advancements with GaN-on-Si MISHEMT technology demonstrate its potential as a strong foundation for next-generation 5G applications, offering high output power and energy efficiency across various voltage applications.
