Trains of temperature pulses generated by multiple excimer laser irradiation (KrF 248 nm; pulse length 25 ns) were used to realize the desorption of carbon and oxygen bonded on <100> Si surfaces. The effect of breaking bonds and desorption is analyzed by use of in-situ Auger electron spectroscopy (AES) as a function of the energy density and the number of applied laser pulses. Results will be presented for the laser-induced desorption of native oxides and specially prepared weak oxides on silicon surfaces.