Annealing before gate metal deposition related noise performance in AlGaN/GaN HEMTs

For a further improvement of the noise performance in AlGaN/GaN HEMTs,reducing the relatively high gate leakage current is a key issue.In this paper,an experiment was carried out to demonstrate that one method during the device fabrication process can lower the noise.Two samples were treated differently after gate recess etching:one sample was annealed before metal deposition and the other sample was left as it is.From a comparison of their Ig-Vg characteristics,a conclusion could be drawn that the annealing can effectively reduce the gate leakage current.The etching plasma-induced damage removal or reduction after annealing is considered to be the main factor responsible for it.Evidence is given to prove that annealing can increase the Schottky barrier height.A noise model was used to verify that the annealing of the gate recess before the metal deposition is really effective to improve the noise performance of AlGaN/GaN HEMTs.