Abstract: An integrated metrology module includes a chuck for holding a sample and positioning the sample with respect to an optical metrology device, a reference chip for the optical metrology device, the reference chip being movable to various positions with respect to the optical metrology device, and a reference chip purge device provides a flow of purge gas or air over the reference chip while the reference chip is in the various positions. The reference chip purge device may be static or movable with the reference chip.

Abstract: An integrated metrology module includes a chuck for holding a sample and positioning the sample with respect to an optical metrology device, a reference chip for the optical metrology device, the reference chip being movable to various positions with respect to the optical metrology device, and a reference chip purge device provides a flow of purge gas or air over the reference chip while the reference chip is in the various positions. The reference chip purge device may be static or movable with the reference chip.

Abstract: Methods and apparatus for substantially continuously measuring the surface of a wafer during a polishing process are disclosed. According to one aspect of the present invention, an apparatus includes a wafer support table that supports a wafer, a polishing pad that polishes a surface of the wafer, and a polishing pad structure that rotates the polishing pad over the surface of the wafer. The apparatus also includes a measuring device which is capable of continuously measuring the surface of the wafer during polishing of the surface of the wafer.

Abstract: A pneumatic bridge air gauge sensor. A measurement leg and a reference leg are used to measure a gap between a measurement probe and a surface. The two legs are initially balanced resulting in no air flow therebetween. A mass air flow sensor coupled between the two legs detects the mass air flow between the two legs resulting from a change in the gap distance from the balanced state.