Global thickness measurement system for metal layer on wafer

In VLSI manufacturing processes, metal layers are often used, such as Cu, Al and W, etc. It is required to accurately detect the metal layer thickness distribution on wafer, which is important for the process parameter design. Therefore, a fast and nondestructive nanometer detecting technology is needed for this measurement. In this study, we proposed and designed a global nanometer metal film thickness measurement system, which is based on eddy current testing method. Through a proper testing scheme and a new calibration method, the distribution of the global thickness of the metal layer on wafer could be measured accurately and quickly.