Neutral and Ionic Particle Emission From a GaAs Surface Induced by the (harmonic) Frequencies of the Nd:YAG Laser

The emission of ionic and neutral particles, resulting from irradiation of a GaAs surface by 1064, 532, 355 and 266 nm Q-switched Nd:YAG laser light, has been studied. Incident laser power densities up to 9.6 × 107 Watts/cm2 have been applied. For 1064, 532 and 355 nm radiations the ratios of ionic to neutral particle emissions are close to the thermal ratio corresponding to the boiling point of Ga. In the case of 266 nm radiation this ratio appears to be higher, which is probably due to non-thermal ion contributions. For several incident wavelengths the emitted yields of ions and neutrals varied with the fifth power of the incident laser power density. The wave form of the emitted ion pulse and the recorded mass spectrum after irradiation at 266 nm differ significantly from those obtained at the other applied wavelengths.