Date of Award

Fall 1995

Document Type

Thesis

Degree Name

Master of Science in Engineering Science- (M.S.)

Department

Committee for the Interdisciplinary Program in Materials Science and Engineering

First Advisor

Roland A. Levy

Second Advisor

Lev N. Krasnoperov

Third Advisor

N. M. Ravindra

Abstract

Boron nitride thin films were synthesized on Si and quartz wafers by low pressure chemical vapor deposition using borane triethylamine complex and ammonia as precursors. The films were processed at 400°C, 475°C and 550°C at a constant pressure of 0.5 Torr and at different precursor flow ratios.

The films deposited were uniform, amorphous and the composition of the films varied with deposition temperature and precursor flow ratios. The thickness of the film increased with increasing flow ratio, but, decreased with increasing temperature. The stresses in the film were either mildly tensile or compressive.

The least dielectric constant for the films that could be attained was 2.73 at 550°C and at high flow ratios of NH3/TEAB (50/1). Thus, stoichiometric boron nitride films tend to have a lower dielectric constant. The limitation of attaining lower values could be due to the presence of carbon as an impurity in the film and the presence of mobile charge carriers in the films as well as at the substrate-film interface as seen from the capacitance-voltage characteristics.

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