Laser-induced activation of p-type GaN with the second harmonics of a Nd :YAG laser

Magnesium-doped p-type GaN has been activated by irradiation with photons o f 532 nm wavelength from the second harmonic of a Q-switched neodymium-dope d ytterbium aluminum garnet (Nd:YAG) laser. With appropriate laser fluence levels and irradiation pulse numbers, such a laser-induced activation proce ss resulted in a hole concentration about the same as that obtained through the conventional thermal activation technique. Temperature measurement rev ealed that the laser-induced process is very unlikely to be thermal. It was speculated that the process might involve the photon-induced breaking of t he H-Ma bonds.