Electrical Characteristics of Metal Contacts to Laser-Irradiated N-Polar n-Type GaN

Electrical characteristics of metal contacts to a laser-irradiated thin-film N-polar n-type GaN surface are investigated. It is shown that the laser irradiation of the N-polar n-GaN results in a significant increase (as high as 3.0 times 10²⁰ cm^-3) in the electron concentration and a decrease in the Schottky barrier height by 0.05 eV (0.28 eV), as estimated using Pt-based Schottky diodes (X-ray photoemission spectroscopy). Ti/Al contacts to the laser-irradiated N-polar sample exhibit an excellent Ohmic behavior with thermal stability up to 600degC, indicating that the laser irradiation treatment can be a very promising technology in practical applications.