Chemical mechanical polish process control for improvement in within-wafer thickness uniformity

摘要

A method of performing chemical mechanical polish (CMP) processes on a wafer includes providing the wafer; determining a thickness profile of a feature on a surface of the wafer; and, after the step of determining the thickness profile, performing a high-rate CMP process on the feature using a polish recipe to substantially achieve a within-wafer thickness uniformity of the feature. The polish recipe is determined based on the thickness profile.

主权项

1. An apparatus for performing a Chemical Mechanical Polish (CMP), the apparatus comprising:
a wafer processing platform, comprising:
a thickness-measuring device configured to measure a thickness profile of a feature across a surface of a wafer, the thickness profile indicating the thickness of the feature at multiple points and in multiple dimensions across the surface of the wafer;a controller coupled to the thickness-measuring device, wherein the controller is configured to determine a polish recipe from the thickness profile, and wherein the polish recipe is for substantially compensating for a non-uniformity in the thickness profile;a zoned high-rate CMP platen configured to polish the feature using the polish recipe, with different zones of the high-rate CMP platen configured to apply different pressures on different zones of the wafer;an un-zoned low-rate CMP platen configured to polish the feature at a rate lower than a rate of the high-rate CMP platen; andan unzoned buffing CMP platen; wherein the thickness-measuring device measures the thickness profile prior to the wafer being placed into the high-rate CMP platen; wherein the wafer processing platform is configured to transfer the wafer to the thickness measuring device prior to transferring the wafer to the high rate CMP platen and the low rate CMP platen; and wherein the polish recipe includes a first predetermined polishing time calculated to achieve a predetermined substantial within-wafer thickness uniformity stop for the high-rate CMP platen, a first predetermined wafer thickness stop for the low-rate CMP platen and a second predetermined polishing time to achieve a second predetermined wafer thickness stop for the buffing CMP platen.