Patent ID: 7145642

Claim:
A wafer support device comprising: a fixed base; a guiding device on said fixed base; a movable base disposed so as to move in a vertical direction with respect to the fixed base by said guiding device; a first pressing device fixed on the fixed base, said first pressing device pressing said movable base; a θ stage rotatably disposed on said movable base with the vertical direction as a rotation axis; a linear motor fixed on said fixed base; a contact bar disposed on said movable base; a load control device controlling a load of pressing; and a controller controlling a pressing force by said first pressing device based on said load detected by a load sensor, wherein said first pressing device has a cylinder which is fixed on said fixed base and has a main pressurizing chamber and a sub-pressurizing chamber, a piston rod vertically moving in the main pressurizing chamber and the sub-pressurizing chamber, respectively, a main pressure controller controlling a pressure in said main pressurizing chamber, and a sub pressure controller controlling a pressure in said sub-pressurizing chamber.