Patent ID: 7321426
Filing Date: 2008-01-22
Classification: G01N

Abstract:
1. A method for operating an optical metrology tool, the method comprising: collecting a first set of optical metrology data from a first patterned target, the first patterned target comprising a first set of one or more thin films on a first patterned layer; determining a first value set for one or more metrology attributes of the first set of one or more thin films; collecting a second set of optical metrology data from a second patterned target, the second patterned target comprising a second set of one or more thin films on a second patterned layer, the second patterned layer being substantially similar to the first patterned layer; determining a second value set for the one or more metrology attributes of the second set of one or more thin films; generating an empirical model using the first set of optical metrology data, the second set of optical metrology data, the first value set, and the second value set; collecting a third set of optical metrology data from a third patterned target on a first test sample, the third patterned target comprising a third set of one or more thin films on a third patterned layer, the third patterned layer being substantially similar to the first patterned layer; determining a third value set for the one or more metrology attributes of the third set of one or more thin films using the empirical model; and outputting the third value set as attribute values of the first test sample.