An electrical method for determining the thickness of metal films and the cross-sectional area of metal lines

Abstract

The electrical thickness of an aluminum-alloy metallization can be determined from resistance measurements of a van der Pauw cross structure at two temperatures, with corrections for the deviation from Matthiessen's rule and for thermal expansion. Thickness determinations, made in this way, agree with those made with a calibrated scanning electron microscope (SEM) to within the uncertainty of the instrument. The electrical cross-sectional area of metal lines can be determined by making resistance measurements at two temperatures.