Method and apparatus for determining electromagnetic properties of a process layer using scatterometry measurements

摘要

A method for determining electromagnetic properties of a process layer includes providing a wafer having a grating structure and a process layer formed over the grating structure. The thickness of the process layer is measured. At least a portion of the process layer and the grating structure is illuminated with a light source. Light reflected from the illuminated portion of the grating structure and the process layer is measured to generate a reflection profile. An electromagnetic property of the process layer is determined based on the measured thickness and the reflection profile.