Work

Enhanced RF Performance of InAlGaN/GaN HEMTs on Si Substrates with Thin GaN Channel and Quaternary Barrier Optimization

Year: 2025

Type: article

Abstract: This study demonstrates quaternary In0.05Al0.25GaN/GaN high electron mobility transistors (HEMTs) fabricated on Si substrates, incorporating a 50 nm thin GaN channel layer. The devices exhibit high carrier density, an impressive On-Off current ratio (∼109), a high transconductance (Gm) of 400 mS mm−1, and a wide Gm peak width (1.85 V @ 90% Gm), making them well suitable for radio-frequency (RF) applications. Compared to conventional devices utilizing AlGaN and a 500 nm GaN channel as the active layer, the proposed structure achieves a remarkable improvement in On-Off current ratio (enhanced by 103), a more positive threshold voltage (Vth around −1.5 V), and a 15% increase in Gm peak width. Additionally, the device with a 200 nm gate length demonstrates a high cutoff frequency (f t ) of 49.1 GHz and maximum oscillation frequency (f max) of 113.8 GHz. These findings underscore the potential of InAlGaN HEMTs with a thin GaN channel layer for high-frequency and RF applications.

Source: ECS Journal of Solid State Science and Technology

DOI: 10.1149/2162-8777/adc556