0013-4651/2012/159(11)/D637/5/$28.00 © The Electrochemical Society Characteristics of a Pd/AlGaN/GaN Transistor Processed Using the Sensitization, Activation, and Electroless Plating (EP) Approaches Chien-Chang Huang,a Huey-Ing Chen,b Tai-You Chen,a Chi-S

The characteristics of a Pd/AlGaN/GaN high electron mobility transistor (HEMT) processed using the sensitization, activation, and electroless plating (EP) deposition approach are studied and demonstrated. A dense and uniform Pd seed layer is achieved by using the additional sensitization and activation processes. Therefore, the superior characteristics in turn-on voltage (1.79 V), gate leakage current (9 nA), maximum extrinsic transconductance (95.8 mS/mm), and maximum drain saturation current (373.8 mA/mm) are obtained for a 1 μm gate HEMT at 300 K. As increasing the temperature from 300 to 600 K, the reduced variation and degradation rates are also found for the studied EP-gate device. Furthermore, superior hydrogen gas sensing performance, including large drain current change (34.1 mA/mm) and high sensing response (3469%), is observed under 1 % H2/air ambience. Consequently, the studied EP-gate AlGaN/GaN HEMT shows the promise for high-performance electronic device and hydrogen sensor applications