Method of cleaning support plate
A method of cleaning a support plate according to which, while no waste solution is produced after cleaning the support plate, the support plate can be treated at low cost. The method of cleaning the support plate includes the step of removing an organic substance adhered to the support plate by putting the support plate in contact with oxygen plasma.
1. 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.
2. The method of cleaning the support plate as set forth in claim 1 , wherein:
said putting the support plate in contact with oxygen plasma is putting both sides of the support plate in contact with oxygen plasma.
3. The method of cleaning the support plate as set forth in claim 1 , wherein:
said removing the metal is performed after said removing the organic substance.