Patent ID: 9710728
Date: 2017-07-18
CPC Classifications: G03F,G06K,G06T

Claim:
1. A method comprising: receiving a first amount of image data including a first plurality of images of a first plurality of measurement sites on a surface of a specimen with known values of at least one parameter of interest, wherein each of the measurement sites includes the same nominal structures at the same nominal locations within each of the measurement sites, wherein a measurement signal value is associated with each pixel of each of the first plurality of images, and wherein the first amount of image data is derived from measurements performed by at least one measurement technique; determining a feature extraction model based on a portion of the first amount of image data, wherein the feature extraction model reduces a dimension of the portion of the first amount of image data; and training an image based measurement model based on features extracted from the portion of the first amount of image data and the known values of the at least one parameter of interest; receiving a second amount of image data including a second plurality of images of a second plurality of measurement sites, wherein a measurement signal value is associated with each pixel of each of the second plurality of images, and wherein the second amount of image data is derived from measurements performed by the same at least one measurement technique; extracting image features from the second amount of image data; determining values of at least one parameter of interest associated with each of the second plurality of measurement sites based on a fitting of the extracted features to the trained image based measurement model; and storing the values of the at least one parameter of interest in a memory.