| 摘要 |
<p>A method for optimizing CMP (chemical mechanical polishing) processing of semiconductor wafers on a CMP machine. The optimization method includes the steps of polishing a test series of semiconductor wafers on a CMP machine. During the CMP processing, a film thickness is measured at a first point proximate to the center of each respective wafer using a film thickness detector coupled to the machine. A film thickness at a second point proximate to the outside edge of the respective wafers is also measured. Based upon the in-process film thickness measurements at the first point and the second points, the optimization process determines a polishing profile describing a removal rate and a removal uniformity with respect to a set of process variables. The process variables include different CMP machine settings for the polishing process, such as the amount of down force applied to the wafer. The polishing profile is subsequently used to polish production wafers accordingly. For each production wafer, their respective removal rate and removal uniformity is determined by measuring a film thickness at the center of each production wafer and a film thickness at the outside edge of each production wafer using the film thickness detector. Based upon these measurements, the set of process variables is adjusted in accordance the removal rate and the removal uniformity measurements to optimize the CMP process for the production wafer as each respective wafer is being polished.</p> |
