https://gistexel.com/wp-content/uploads/2014/08/logo_exel.gif00exelhttps://gistexel.com/wp-content/uploads/2014/08/logo_exel.gifexel2014-09-03 14:06:282014-09-03 14:07:04"Chemical mechanical polishing(CMP) apparatus and CMP method using the same,” US patent No.805697, 1997.