Patent ID: 8097087

Claim:
A method of cleaning a support plate, the support plate being a support plate prior to attachment to a substrate or a support plate from which a substrate has been separated, the method consisting of: adhering a metal and an organic substance to the support plate, the metal being at least one of Al, Ti, Zr, Cd, Au, Ag, Pt, Pd, Zn, Ni, and Cu; removing the organic substance adhered to the support plate by putting the support plate in contact with oxygen plasma; and removing the metal adhered to a surface of a front side of the support plate by irradiating laser light onto the support plate, wherein said removing metal adhered to the surface of the front side of the support plate by irradiating laser light onto the support plate includes irradiating laser light onto the support plate such that the laser light is directed from a backside of the support plate, the backside of the support plate being opposite the front side of the support plate.