Patent ID: 7650029

Claim:
A method for using an imaging system in relation to a plurality of material layers having different depths relative to the imaging system, comprising: causing a focal plane of the imaging system to correspond to a first of said plurality of material layers, and acquiring and storing a first image including at least a portion of the first material layer having a first feature of interest thereon; causing said focal plane to change to correspond to a second of said plurality of material layers and acquiring a second image including at least a portion of the second material layer having a second feature of interest thereon; processing said first and second images using a processor to automatically compute a vertical alignment measurement between said first and second features of interest; and using the alignment measurement to move at least one of the first and second layers relative to the other layer to bring the first and second layers into vertical alignment with each other, wherein said plurality of material layers have different depths relative to the imaging system.