MOVPE growth of in situ SiNx/AlN/GaN MISHEMTs with low leakage current and high on/off current ratio

• High-performance in situ SiNx/AlN/GaN MISHEMTs grown by metalorganic vapor phase epitaxy (MOVPE).
• Reduced access resistance by regrown highly doped n-GaN source/drain with a two-step Si doping profile.
• High-quality SiNx gate dielectric in situ grown by MOVPE for suppressed leakage current and small trap state density.
• The fabricated 0.33 μm-gated MISHEMT exhibited a maximum drain current density of 1550 mA/mm and an on/off current ratio over 107.

We report the MOVPE growth of high-performance AlN/GaN MISHEMTs using regrown n-type GaN (n-GaN) as source/drain (S/D) and in situ SiNx as gate dielectric. The n-GaN S/D and in situ SiNx were investigated for minimizing on-resistance and suppressing gate leakage current, respectively. The results showed that a two-step Si doping profile for the n-GaN greatly reduced the access resistance, and small gate leakage as well as low trap state density were achieved with the in situ SiNx gate dielectric. The fabricated 0.33 μm-gated MISHEMT exhibited a maximum drain current density of 1550 mA/mm and an on/off current ratio over 107.