Performing chemical mechanical polishing of oxides and metals using sequential removal on multiple polish platens to increase equipment throughput

Abstract

A chemical mechanical polisher is provided comprising multiple polish platens to sequentially remove any fixed amount of oxide or metal on a semiconductor wafer. Each polish platen polishes a fraction of the total oxide removed. Total oxide removal is achieved after completing polishing on all available polish platens assigned for polishing. Reduced oxide removed enables a high oxide removal rate on each polish platen, thus reducing polish time. Sequential polishing on multiple polish platens reduces polish time especially for high oxide removal in the range greater than 0.5 micrometer to greater than 1 micrometer. A higher polish rate and shorter polish time results in shorter polish pad conditioning time. Multiple polish platens coupled with more than one consecutive wafer-carrier head, each following the previous wafer-carrier head in completing sequential polishing, improves machine throughput by eliminating machine idle time caused by events other than actual oxide or metal polishing. The throughput can be further increased by polishing more than one wafer simultaneously at the same polish platen by: (1) employing wafer-carrier heads that hold a set of wafers, (2) providing sets of wafer-carrier heads which follow the same path simultaneously and polish simultaneously at the same polish platen or (3) employing a combination of both methods. The polishing of metals enables use of different polish pad materials and slurry chemistries for each polish platen.

Dependencies are inferred from the claim text.