Surface Contamination Measurement and Control by Nondestructive Techniques

This paper presents a new technique to measure thin layer contamination on the surface of a material. The technique uses low wavelength ultraviolet irradiation to generate optically stimulated electron emission, also known as photo electron emission, which can be used to evaluate surface cleanliness or surface chemical state. Limited data is presented to show application of this technique to wafer processing, disk lubricant thickness measurement and quality control of printed circuit boards.