Overlay metrology using multiple parameter configurations

摘要

The overlay metrology system includes an overlay metrology tool configurable to generate overlay signals using a plurality of recipes, further directing an illumination beam toward an overlay target, and generating an overlay signal using the particular recipe. Collect radiation emanating from the overlay target in response to at least a portion. The overlay metrology system further acquires two or more overlay signals for a first overlay target using the two or more unique recipes, and subsequently obtains two or more overlay signals for a second overlay target using the two or more unique recipes. obtain an overlay signal, determine candidate overlays for first and second overlay targets based on the two or more overlay signals for each target, and determine a first overlay signal based on the two or more candidate overlays for each target and output overlays for the second overlay targets.