Methods for cleaning a surface of a substrate and for increasing the useable lifetime of a photomask substrate are provided. In one method, the surface of a substrate having a contaminating particulate disposed thereon is cleaned by directing a laser towards the substrate, generating a temperature increase in the substrate and transferring thermal energy from the substrate to the particulate to decompose the particulate. The laser has a wavelength that is substantially the same as a local maximum of the substrate absorption spectrum.