Apparatus and method for mounting a wafer in a polishing machine

摘要

A wafer mounting plate for use in a polishing apparatus is disclosed. The wafer mounting plate includes a metal plate and a screen mounted to a top surface of the metal plate. The metal plate is normally formed of circular shape and provided with a plurality of vacuum passageways therethrough. The metal plate has a bottom surface for engaging a membrane member and a wafer by vacuum through the plurality of vacuum passageways, and a top surface for engaging a pressurizing means, such as a pneumatic gasket. The screen mounted to the top surface of the metal plate has a multiplicity of apertures each of a size not larger than 0.5 mm in diameter. The screen is mounted sandwiched between the top surface of the metal plate and the pressurizing means. The screen effectively prevents debris of a wafer breakage from entering a vacuum system that is used for holding the wafer on the wafer mounting plate. The invention further discloses a wafer carrying head for use in a chemical mechanical polishing apparatus which includes a carrier body, a pressurizing means and a support plate equipped with a screen thereon.