| 摘要 |
<p>An apparatus (200) for and method of determining the states on a wafer (W) to be processed, e.g., whether residue in the form of metal in left on the surface (230) of a wafer after chemical-mechanical polishing. The method comprises the steps of calculating first spectral signatures (Fig. 7) from a first set of measurement sites on one or more training wafers. Each measurement site is known to be one of two or more states. In the case of only two states, the states could be 'residue present' and 'residue absent' states. The next step involves correlation (Figs. 12A and 12B) the first spectral signatures to the states on the training wafer(s). The next step then involves calculating second spectral signatures from a second set of measurement sites on a wafer where the states are unknown. The final step is determining the states on the wafer to be processed based on the second spectral signatures.</p> |
