Dynamics of Laser-induced Chemical Etching of GaAs（100） Surface by Chlorine with a Pulsed Laser Radiation at 1064nm

The supersonic molecular beam and an angle-resolved time-of-flight （TOF） techniques are used to study the dynamics of laser-induced chemcial etching of GaAs（100） with Cl₂ at 1064 nm. The mass, velocity and flux distributions of the main products are determined at different surface temperatures. The desorption yields have been measured as a function of laser fluence and the results imply that the desorption process can be characteried by laser induced thermal desorption. The yields of the reaction products can be increased with raising the incident treanslational energy（E_T） and its normal component （E_n） of Cl₂ molecules. A possible mechanism for the laser-induced etching of Cl₂/ GaAs（100） mainly consists of the direct dissociative chemisorption of Cl₂ on the surface, surface reaction of adsorbed Cl atoms with GaAs and the laser-induced thermal desorption of reaction products.