X-Ray Spectrometer with a Submicron X-Ray Beam for Ulsi Microanalysis

Abstract

ABSTRACTA fluorescent and diffraction X-ray spectrometer with a 0.8 μmϕ Xray beam has been developed. It allows simultaneous measurement of local strains and minute amounts of metal contaminants in fine ULSI devices. The minimum sample size for X-ray diffraction measurement with it is a 0.3 μm diameter by 0.2 μm deep volume. It is applied to analyze strain in Al lines, showing that strain in Al single-layer lines (no barrier) increases significantly as the line width is reduced below 1.5 μm. Introducing barrier metals reduces this dependence of strain on line width. It is also found that hillock and void formation has a very strong correlation to strain.