Optical endpoint detection for chemical mechanical planarization

We present product wafer and laboratory test results of a production worthy , in situ, broadband optical endpoint system in the context of a simple mod el that describes the reflectance of semiconductor wafers during chemical m echanical planarization. Broadband and single wavelength approaches are pre sented. The challenges of extracting precise endpoint measurements on patte rned product wafers in an intrinsically noisy environment are addressed. Fi nally, the benefits: of using such an endpoint system are presented. Experi mental data on tungsten, copper, shallow trench isolation. and interlevel d ielectric layers is presented. (C) 1999 American Vacuum Society. [S0734-211 X(99)04805-2].