Carrier activation in Mg implanted GaN by short wavelength Nd:YAG laser thermal annealing

Abstract

Activation of Mg-implanted GaN has been investigated by the combination of thermal and laser annealing. The laser annealing was carried out using third harmonic generation (λ = 355 nm) of a Nd:YAG laser. Mg ion activation and reduction of implanted-defects after various annealing processes have been analyzed with Raman spectroscopy. The sample that was thermally annealed at 700 °C for 20 min; followed by laser annealing, with energy density of 0.35 mJ cm−2, is found to be effective for p-type conversion in electrical characteristics. The value for sheet resistance and hole mobility is 1.7 × 103 Ω/□ and 40 cm2 Vs−1; respectively. Positron annihilation revealed that the vacancy clusters created in the sub-surface region, by thermal annealing dissolved following laser annealing, leading to the p-type conversion of GaN.