Ultra-Low Contact Resistivity of < $0.1~\Omega\cdot$ mm for Au-Free TixAly Alloy Contact on Non-Recessed i-AlGaN/GaN

A robust process for Au-free ohmic contact formation is demonstrated by a direct contact of TixAly alloy film on non-recessed i-AlGaN/GaN. Using this novel TixAly alloy instead of multilayers as contact metals, an ultra-low contact resistivity of <; 0.1 Ω· mm is achieved for Ti
₅
Al
₁
alloy on i-AlGaN/GaN after 880 °C/60s annealing.