Reduction of Defects in Ultra-Thin SIMOX

University Of Arizona, Tucson AZ

Investigators

Abstract

This project addresses fundamental research issues in formation mechanisms of structural defects in ultra-thin SIMOX-SOI (Separation by IMplanted OXygen-Silicon On Insulator) materials and into the correlation between these structural defects and processing conditions. Finding the cause of defect formation and providing effective solutions to minimize defect density in ultra-thin layers are significant challenges, being approached by integrated structural, chemical, and electrical characterization with modeling of diffusional, growth, and ripening processes of precipitates to gain greater fundamental un-derstanding. This involves (1) microstructural and chemical analysis of newly designed ultra-thin SIMOX samples, by employing transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), electron energy loss spectroscopy (EELS) and Auger electron spectros-copy (AES); (2) determination of the buried oxide integrity by C-V and I-V measurements; (3) in-depth understanding of the formation and growth mechanisms of the defects; (4) systematic evaluation of the formation of defects as a function of growth conditions by identifying the factors that control defect formation and incorporation; (5) comparison of the samples before and after annealing to study the dif-fusion properties of Si interstitials; and (6) modeling of the precipitate growth and coarsening. An-nealing effects including temperature variations, annealing times, and ramping and cooling rates will be investigated. In situ experiments will be conducted in TEM by using a heating holder (up to 1200 C) to investigate the dynamic structural evolution in real-time. This research project is collaborative be-tween the Department of Materials Science and Engineering and the Department of Mechanical and Aerospace Engineering, University of Arizona. %%% The project addresses basic research issues in a topical area of materials science with high technologi-cal relevance. Advanced characterization techniques allow greater understanding and control of ele-mentary processes involved in SOI (silicon on insulator) technology which will allow advances in fun-damental materials science and technology. The basic knowledge and understanding gained from the research is expected to contribute to next generation microelectronic materials. An important feature of the program is the integration of research and education through the training of students in a funda-mentally and technologically significant area. ***