pad cell size application_number US 47460595 A description the invention will be described in conjunction with pad conditioning for chemical mechanical polishing cmp the major emphasis of cmp today is for planarizing interlevel dielectrics on a semiconductor wafer however other uses are also possible such as selectively removing metals and planarizing bare silicon wafers the invention is equally applicable to these uses cmp involves both chemical and mechanical abrasion chemical abrasion is accomplished using a slurry to chemically weaken the surface of a wafer mechanical abrasion is accomplished using a polishing pad against which a wafer surface is pressed both the polishing pad and the wafer are rotated to cause the removal of surface material the removed material is then washed over the edges of the polishing pads and into a drain by adding additional slurry cmp planarization produces a smooth damage free surface for subsequent device processing it requires fewer steps than a deposition etchback planarization and has good removal selectivity and rate control for silicon dioxide removal rates on the order of 60 80 rim rain for a thermal oxide and 100 150 nm min for an lpcvd low pressure chemical vapor deposition oxide can be achieved the preferred embodiment the invention is shown in fig2 cmp machine 100 contains a polishing pad 114 secured to a platen 112 polishing pad 114 typically comprises polyurethane however it will be apparent to those skilled in the art that other materials such as those used to make pads for glass polishing may be used in addition the hardness of polishing pads 114 may vary depending on the application platen 112 is operable to rotate during polishing rotating carrier 118 is operable to position wafer 116 on polishing pad 114.