Silicon and silicon related films were deposited onto glass slides and silicon wafers by electron-beam evaporation of silicon in oxygen and nitrogen atmospheres. An ionizer consisting of a heated tungsten wire biased with a negative voltage enhanced the opportunity of reactive deposition. Substrate temperature, chamber pressure, deposition rate, and biasing voltage were the controlled variables. The film reactive indices were measured using spectro-photometry and ellipsometry to examine the effects of these four variables. The refractive index obtained from silicon films is 4.18-4.42 and the refractive indices for silicon oxides range from 1.57 to 3.93. No evidence of silicon nitride formation was found. Statistics analyses of the results suggest chamber pressure and deposition rate are equally important factors in changing the refractive index. Biasing voltage has less effect. To produce the lowest refractive index, the rate must be as low as possible (less than 5 A/s), oxygen pressure must be high (2 x 10-4 Torr), while electrical biasing must exist. Changing the biasing from 100 V to 500 V has little effect on refractive index.
Library of Congress Subject Headings
Optical coatings; Optical films; Thin films; Silicon compounds
Department, Program, or Center
Center for Materials Science and Engineering
Yeh, Jen-Yu, "Electron-bean biased reactive evaporation of silicon, silicon oxides, and silicon nitrides" (1991). Thesis. Rochester Institute of Technology. Accessed from
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