Layer thickness measurements using photoelectron spectroscopy

摘要

According to one embodiment of the invention, photoelectron spectroscopy is used to determine the thickness of one or more layers in a single or multi-layer structure on a substrate. The thickness may be determined by measuring the intensities of two photoelectron species or other atom-specific characteristic electron species emitted by the structure when bombarded with photons. A predictive intensity function that is dependent on the thickness of a layer is determined for each photoelectron species. A ratio of two predictive intensity functions is formulated, and the ratio is iterated to determine the thickness of a layer of the structure. According to one embodiment, two photoelectron species may be measured from a single layer to determine a thickness of that layer. According to another embodiment, two photoelectron species from different layers or from a substrate may be measured to determine a thickness of a layer.