Patent ID: 7735450

Claim:
A substrate holding apparatus, comprising: a rotatable plating head having an annular seal for holding a substrate while sealing a peripheral portion of a back surface of the substrate; and a throttling mechanism for, through rotation of said rotatable plating head while holding the substrate, creating a negative pressure on a back surface side of the substrate sealed with the annular seal, said throttling mechanism including: an air vent hole in communication with the back surface side of the substrate for venting air from a space defined by the back surface of the substrate when held by said rotatable plating head, two members positioned adjacent to each other and forming a throat portion between them such that an airflow passing through said throat portion is created by rotation of said rotatable plating head and such that velocity of the airflow increases in proportion to rotational speed of said rotatable plating head, and an airflow passage communicating said air vent hole with said throat portion; wherein said two members comprise a lid member covering said air vent hole and an operating member that is fixed on said rotatable plating head.