Patent ID: 8193007

Claim:
A method of controlling a fabrication cluster for processing of a substrate in an etch process, the fabrication cluster having equipment settings and process parameters, the method comprising: selecting two or more etch stage measurement objectives; setting the two or more etch stage measurement objectives; obtaining etch stage measurements using selected two or more optical metrology devices and a selected etch process sensor device, the etch sensor device configured to measure a process parameter with high correlation to the etch process stage; obtaining actual etch stage data for each of the etch stage measurements using one or more reference measurement technologies; developing a correlation of etch stage measurements to actual etch stage data; extracting an etch measurement value using the developed correlation algorithm and etch stage measurements obtained using the selected two or more optical metrology devices and the selected etch process sensor device; transmitting the etch measurement value to the fabrication cluster; and modifying an equipment setting and/or process parameter based on the transmitted etch stage data, wherein a second optical metrology device of the two or more selected optical metrology devices includes a plurality of interferometers or reflectometers disposed above the etch chamber using viewports so as to allow transmission of a plurality of illumination beams and detection of a plurality of diffraction beams.