Tropel 9000 Interferometer with Multiple Chucks

This is a Tropel Model 9000 laser interferometer. It is used for checking the flatness of wafers and masks up to 5 inches in diameter. It uses a HeNe laser as a monochromatic source, and has a built-in video camera for fringe display on a Sony Black & White monitor. The interferometer is in spectacular condition with the exception of a small scratch near the upper center of the reference prism (outside the field of view of all but the largest wafers). The wafers are held in place by a vacuum chuck and fringe spacing and direction is adjusted via three very fine setting screws located to either side and beneath the chuck holder. The interferometer includes the following chucks: • 2 inch vacuum chuck • 3 inch vacuum chuck • 4 inch vacuum chuck • 5 inch 'bow' chuck Also included is a calibration reference flat (shown in the first photo and as displayed on the monitor). Instrument serial number is 203876. We do not have any documentation - it will need to be sourced elsewhere. Location B7 L2 Photo set 1126