采用LPCVD SiN钝化的超薄势垒AlGaN/GaN HEMT以增强高功率应用性能

Abstract Ultra-thin-barrier AlGaN/GaN HEMTs offer a gate-recess-free solution but suffer from high on-resistance and current degradation. In this work, ultra-thin-barrier AlGaN/GaN heterostructures with a 1-nm GaN cap and 5-nm Al 0.22 Ga 0.78 N barrier were fabricated, followed by LPCVD SiN passivation of four different thicknesses (50, 60, 150, and 220 nm) to solve the low carrier density issues associated with thin-barrier structures. The 220 nm LPCVD-SiN passivated device achieves a high I D,max of 907 mA/mm and the lowest on-resistance of 8.9 Ω·mm. In addition, to evaluate the stability of current output, thinner LPCVD-SiN layers exhibit better current stability under ON-state stress up to 150 °C. These findings highlight the benefits of ultra-thin-barrier AlGaN/GaN HEMTs design for future high-power GaN applications.