Patent Document ID: 10013518
Application ID: 13935275
Patent Flag: 1

Claim One:
1. A combined x-ray/optical metrology tool comprising: an x-ray illumination system including an x-ray illumination source and x-ray illumination optics configured to shape and direct an incident x-ray beam to an inspection area of a specimen; an x-ray detector configured to detect an amount of x-ray radiation from the specimen in response to the incident x-ray beam; an optical illumination system including an optical illumination source and optical illumination optics configured to shape and direct an incident optical illumination beam to the inspection area of the specimen; and an optical detector configured to detect an amount of optical radiation from the specimen in response to the incident optical illumination beam; and a geometric model building module configured to generate a geometric model of a structure of the specimen; an optical response function building module configured to generate an optical response model of a response of the structure of the specimen to incident optical radiation based at least in part on the geometric model; an x-ray response function building module configured to generate an x-ray response model of a response of the structure of the specimen to incident x-ray radiation based at least in part on the geometric model, wherein both the optical response model and the x-ray response model include at least one common geometric parameter from the geometric model; and a fitting analysis module configured to: receive a first amount of measurement data indicative of the amount of optical radiation detected from the specimen in response to the optical illumination beam incident on the specimen; receive a second amount of measurement data indicative of the amount of x-ray radiation detected from the specimen in response to the x-ray illumination beam incident on the specimen; determine a value of the at least one common geometric parameter based on a fitting of the optical response model with the first amount of measurement data and a fitting of the x-ray response model to the second amount of measurement data in a combined analysis, wherein the value of the at least one geometric parameter in the fitting of the optical response model is linked to the value of the at least one geometric parameter in the fitting of the x-ray response model by a predetermined function; and output the at least one specimen parameter value for storage in a memory.