Optical and physicochemical properties of hydrogenated silicon nitride thin films: Effect of the thermal annealing |
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Authors: | M Boulesbaa |
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Institution: | Département d’Electronique et des Télécommunications, Université Kasdi Merbah Ouargla, Ouargla, Algérie |
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Abstract: | The effect of thermal annealing on the optical and physicochemical properties of hydrogenated silicon nitride films was studied. These films were deposited by plasma-enhanced chemical vapor deposition from a mixture of silane, ammonia, and nitrogen. Subsequently, the films were annealed at various temperatures ranging from 400°C to 1000°C. The properties of the films were studied using ellipsometry and Fourier transform infrared spectroscopy. The Maxwell Garnet model considers the silicon nitride material as heterogeneous with three distinct phases: silicon, stoichiometric silicon nitride, and hydrogen. Based on the ellipsometric analysis, the annealing treatment leads to reduce the volume fraction of both hydrogen and silicon. As a result, the stoichiometry parameter significantly increases from 1.24 to 1.32 making it closer to the stoichiometric silicon nitride one. According to the infrared data, a noticeable decrease in the total hydrogen concentration in the films was obtained with respect to the annealing temperature. |
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Keywords: | Ellipsometry infrared spectroscopy silicon nitride thermal annealing |
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