Laser-assisted deposition of GaAs, AlAs and [AIGa]As thin films on Ge(100) substrates from trimethylgallium-trimethylarsenic and trimethylaluminumtrimethylarsenic Lewis acid-base adduct source materials is reported. A parametric study has been performed in which reactive gas pressure, substrate temperature, laser fluence, laser wavelength (248 nm or 193 nm). and orientation of the laser beam with respect to the substrate have been varied. In the case of irradiation parallel to the substrate, stoichiometric films of GaAs and [AIGa]As have been obtained. The data suggest that for irradiation perpendicular to the substrate a competition exists between desorption and photodeposition, which adversely affects film stoichiometry under the conditions studied.