Patent ID: 7573582

Claim:
A computer program product tangibly embodied on a computer readable medium containing instructions for controlling an in-line monitoring system so as to execute a sequence of successive monitorings of respective thicknesses of a subject uppermost film deposited on an underlying multi-layer structure in each of a plurality of manufacturing stages, the underlying multi-layer structure comprising a plurality of thin films formed on a substrate by previous manufacturing stages, the monitoring system having a thickness memory for storing the thickness data of each of the thin films of the underlying multi-layer structure, the thickness data being determined before the subject uppermost film is formed on the underlying multi-layer structure, the computer program product including a plurality of sub-programs, each of the sub-programs being configured to determine only a corresponding thickness of the subject uppermost film at one of the plurality of manufacturing stages, the sub-program corresponding to a subject manufacturing stage comprising: instructions configured to measure an optical spectrum profile of the subject uppermost film formed on the underlying multi-layer structure; instructions configured to read the thickness data of each of the thin films of the underlying multi-layer structure from the thickness memory; instructions configured to calculate a plurality of theoretical optical spectrum profiles of the subject uppermost film based upon corresponding candidate film thicknesses of the subject uppermost film, using a measurement recipe for the subject uppermost film and the thickness data of each of the thin films of the underlying multi-layer structure; and instructions configured to search one of the theoretical profiles of the optical spectrum of the subject uppermost film, which is closest to the measured optical spectrum profile of the subject uppermost film so as to determine a thickness of the subject uppermost film by the closest theoretical profile.