Xiao 9704072 This Small Business Innovation Research Phase II project will develop a surface-sensitive low-energy-X-ray-fluorescence (LEXRF) instrument to meet the thin film metrology needs prioritized in the National Technology Roadmap for Semiconductors. The continued increase of device densities in silicon-based integrated circuits requires more deposition steps of thinner films, which in turn demands better metrology for process development and quality control. During the Phase II program, a LEXRF instrument will be constructed which includes a polycapillary optic designed in Phase I to collect a large solid angle of X-rays and focus them onto a sample to increase the X-ray intensity by two orders of magnitude. The focused beam provides submillimeter spatial resolution in measuring various thin films important to the semiconductor industry. The last phase of the program will demonstrate the capabilities of the LEXRF system at a major semiconductor tool company. The commercial potential of the proposed LEXRF instrument lies in its ability to provide elemental and thickness analysis to identify defective thin film deposition processes at the earliest opportunity, thus avoiding the considerable financial loss associated with rejections at the end of the production line. The proposed LEXRF system will also provide feedback to fine-tune the deposition process on a continual basis to increase the production yield. p:/sbir/yhashimi/abstracts/9704072.doc