Automated process control using an adjusted metrology output signal

摘要

Provided is a method for controlling a fabrication cluster using an optical metrology system that includes an optical metrology tool, an optical metrology model, and a profile extraction algorithm. The method comprises: selecting a number of rays for the illumination beam, selecting beam propagation parameters, using a processor, determining beam propagation parameters from the light source of the to the sample structure, determining the beam propagation parameters from the sample structure to the detector, calculating intensity and polarization of each ray on the detector, generating a total intensity and polarization of the diffraction beam, calculating a metrology output signal from the total intensity and polarization, extracting the one or more profile parameters using the metrology output signal, transmitting at least one profile parameter to a fabrication cluster, and adjusting at least one process parameter or equipment setting of the fabrication cluster.

主权项

1. A method for controlling a fabrication cluster using an optical metrology system, the optical metrology system including an optical metrology tool, an optical metrology model, and a profile extraction algorithm, the optical metrology model including a model of the optical metrology tool and a profile model of the sample structure, the profile model having sample profile parameters, the optical metrology tool having a light source, an illumination beam, optical elements, a diffraction beam, and a detector, the method comprising:
(a) selecting a number of rays for the illumination beam used in the optical metrology tool model, each ray having a cross section; (b) selecting beam propagation parameters for the optical metrology tool model; (c) using a processor:
(c1) determining beam propagation parameters for each ray of the selected number of rays from the light source of the optical metrology tool to the sample structure;(c2) determining the beam propagation parameters for each ray of the selected number of rays from the sample structure to the detector;(c3) calculating intensity and polarization of each ray of the diffraction beam on the detector;(c4) calculating a total intensity and polarization of the diffraction beam by integrating over the cross section of the diffraction beam;(c5) calculating an metrology output signal from the total intensity using measured diffraction signals obtained with an optical metrology tool, the metrology output adjusted using a signal adjuster; and(c6) extracting the one or more profile parameters using the metrology output signal and the profile extraction algorithm using a profile extractor; d) transmitting at least one profile parameter of the structure to a fabrication cluster, the fabrication cluster having process parameters and equipment settings; and e) adjusting at least one process parameter and/or equipment setting of the fabrication cluster based on the at least one profile parameter of the structure;wherein the at least one profile parameter of the structure comprises a width, height, and sidewall angle of the structure.