High thermal stability AlGaAs/InGaAs enhancement-mode pHEMT Using Pd buried-gate technology

In this work, two enhancement-mode (E-mode) GaAs-based high electron mobility transistors (HEMTs), grown by molecular beam epitaxy (MBE) system, have been fabricated and investigated. We evaporated traditional platinum (Pt) and palladium (Pd) as Schottky contact metals to observe high-temperature performance. Following the 1 mum Pt/Ti/Au gate and Pd/Ti/Au gate metals deposition, the devices were thermally annealed at 200degC. Two devices DC and RF performance from 0degC to 100degC were measured. Because the platinum skins into Schottky Layer, the DC and RF characteristics were affected. Experimentally, the palladium gate device showed better DC, RF, and high-temperature characteristics. These advantages suggest that the palladium device is suitable for high-speed and high-power integrated circuit applications.