9415404 Stavola Hydrogen is a common and highly reactive impurity in semiconductors. It has been known for more than a decade that hydrogen forms complexes with deep level impurities and modifies their electrical properties, but these hydrogen containing complexes have remained poorly understood because it has not been possible to obtain structure sensitive data. Previously the PI discovered that complexes of hydrogen with transition metal impurities in silicon can be formed in sufficient number. This research will take advantage of this finding to use structure sensitive methods like infrared absorption and electron paramagnetic resonance spectroscopies. The microscopic structures and electrical properties of several hydrogenated deeplevel defects will be investigated using these techniques. The primary goal of this work is to develop a fundamental understanding of several model systems that will provide a foundation for understanding complexes with deep-level defects in semiconductors. %%% Hydrogen is frequently introduced into semiconductor materials where it modifies the electrical properties of defects an impurities. This is particularly true, for example, in the polycrystalline or amorphous semiconductors used in solar cell or flat panel display technologies where the presence of hydrogen is necessary to improve material characteristics. It has not been understood at a fundamental level how hydrogen affects defect properties because, previously, it had been difficult to determine the microscopic structures of the hydrogen defects. In this work, structure-sensitive measurements will be made to elucidate the properties of several hydrogen containing defects in Si that can be used as models to help understand how semiconductor defects interact with hydrogen. ***
