Patent ID: 6579150
Filing Date: 2003-06-17
Classification: B24B

Abstract:
A chemical mechanical polishing apparatus for a polishing process generating an acoustical emission equipped with acoustical and optical end point detection devices comprising:a polishing pad holder for holding a polishing pad thereon; means for rotating said polishing pad holder; a sample holder for holding a sample to be polished thereon; means for rotating and traversing said sample holder on said polishing platen; an enclosure for enclosing said polishing pad holder and said sample holder; an optical projector and a sensor therein for projecting and receiving an optical signal to and from a surface of a sample being polished through a window in said polishing pad for determining an end point of said CMP process; and an acoustical sensor mounted in said enclosure for sensing acoustically an end point of the polishing process as the point when a change in the acoustical emission of at least 30% occurs.