US Patent 11756840 Reflectance measurement system and method thereof

A system includes a factory interface, an etching tool, and at least one measuring device. The factory interface is configured to carry a wafer. The etching tool is coupled to the factory interface and configured to process the wafer transferred from the factory interface. The at least one measuring device is equipped in the factory interface, the etching tool, or the combination thereof. The at least one measuring device is configured to perform real-time measurements of reflectance from the wafer that is carried in the factory interface or the etching tool.