*** 9660014 Krishnan This Small Business Innovation Research Phase I project will test a novel method for spectroscopic ellipsometry (SE) which is capable of lower cost and higher response rates than conventional SE instruments. SEs are used to measure thin film thickness, chemical composition, and defect concentrations in multi-layer films. However, speed and cost limit the use of SEs for real-time thin film process control applications. The proposed research exploits the facts that a diffraction grating not only disperses incident light into a spectrum, but also provides several orders of diffraction that contain information about the polarization state of the light. These two characteristics of gratings make it possible to design a Grating Division of Amplitude Photopolarimeter (G-DOAP) for spectroscopic ellipsometry. The G-DOAP is capable of (i) high temporal resolution and (ii) low cost manufacture because it contains no moving parts and has fewer optical elements than conventional SE equipment. In Phase I, this firm will develop and characterize the performance of a laboratory breadboard G-DOAP. They will also investigate analytical and numerical methodologies to achieve feedback control of thin film deposition using SE data. The G-DOAP is a recent invention, initially developed with NSF-DMR funding, and patented in 1995. The G-DOAP's spectroscopic capabilities have yet to be demonstrated and are a key issue for the proposed Phase I research. The research will be performed in collaboration with the University of New Orleans. If successful, the research will show feasibility of low-cost, high-speed spectroscopic ellipsometry for intelligent control of thin film deposition processes. The proposed spectroscopic ellipsometer (SE) would impact state of he art MBE, MOVPE, and MOCVD techniques by allowing growth of semiconductor materials under high-speed, real-time control, currently unavailable. Appreciable market share for the SE is also anticipated in semiconductor ex-situ chara cterization applications. ***
