Scatterometry Outline Target for Copper Layers in the Semiconductor Process.
Original Publication Date: 2002-Jan-23
Included in the Prior Art Database: 2002-Jan-23
Scatterometry is a method of measuring critical dimensions in the semiconductor manufacturing process. A spectroscopic ellipsometer is used to capture the spectra from a grating of lines and spaces. A modeling and matching process converts the spectra to a measurement. Typical tiling or slotting features that improve chemical mechanical polish (CMP) uniformity, cannot be used beneath the scatterometry grating targets without affecting the measurements. An alternative, outline mark has been developed. It assists with CMP planarization while still allowing accurate scatterometry measurements. CMP is typically used in the copper backend process for manufacturing semiconductors.