An apparatus for holding a wafer and a method for immersion lithography. The apparatus, including a wafer chuck having a central circular vacuum platen, an outer region, and a circular groove centered on the vacuum platen, a top surface of the vacuum platen recessed below a top surface of the outer region and a bottom surface of the groove recessed below the top surface of the vacuum platen; one or more suction ports in the bottom surface of the groove; and a hollow toroidal inflatable and deflatable bladder positioned within the groove.

 
Web www.patentalert.com

> Device for radiation therapy

~ 00354