Patent ID: 8256774

Claim:
A chucking member rotating with a substrate while chucking an edge of the substrate, the chucking member comprising: a rotatable body; a chucking pin coupled with a top of the rotatable body to be eccentric from a rotation center of the rotatable body and configured to chuck the edge of the substrate, the chucking pin comprising: a first front end portion disposed at a front end relative to a flow of an air current generated by a rotation of the substrate while chucking the substrate and having a first tip; and a first back end portion disposed at a back end relative to the flow of the air current, wherein the chucking pin includes a top surface inclined downwardly toward the first back end portion from the first front end portion; a rotation shaft coupled with a bottom of the rotatable body to be rotatable with the rotatable body, wherein the chucking pin includes a streamline shape, and wherein the rotatable body includes a streamline shape.