Patent ID: 6623597
Filing Date: 2003-09-23
Classification: C23C,H01J,H01L,Y10S

Abstract:
An apparatus for a semiconductor wafer, the apparatus comprising:a process chamber; a circular chuck disposed in said process chamber, said chuck having a portion dedicated to support a semiconductor wafer thereon; and a focus ring disposed at the outer periphery of said chuck, said focus ring having a stepped inner periphery comprising a cylindrical lower surface extending around said portion of the chuck, a cylindrical upper surface having a diameter greater than that of said cylindrical lower surface and extending upwardly substantially beyond the upper surface of said portion of the chuck dedicated to support a semiconductor wafer so as to focus the processing medium onto the wafer held by said chuck, and a collector interposed between said lower surface and said upper surface, said collector being located beneath said upper surface and radially outwardly of said lower surface so as to collect contaminants from said upper surface towards said chuck and thereby prevent the contaminants form falling onto a wafer held by the chuck.