Date of Award

Summer 1998

Document Type

Thesis

Degree Name

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

Department

Committee for the Interdisciplinary Program in Materials Science and Engineering

First Advisor

Roland A. Levy

Second Advisor

John Francis Federici

Third Advisor

Trevor Tyson

Abstract

This study focuses on producing thin and thick silicon dioxide films towards the fabrication of integrated optical sensor capable of monitoring and determining in-situ, the concentration of numerous analyze species simultaneously. In this study, diethylsilane (DES) has been used as a precursor to produce silicon dioxide films by low pressure chemical vapor deposition. The films were synthesized with two different flow ratios of oxygen to DES in the temperature range of 550°C to 800°C at a constant pressure of 200mTorr. The films deposited with lower oxygen to DES flow ratio have very high growth rate but suffer from high tensile stress leading to cracks in the films. However the films deposited with higher oxygen to DES flow ratio were crack free. The stress was found to be very low and tensile in these films and tended towards compressive with increasing deposition temperature which is necessary in producing thick films. The films were form and amorphous. The growth rate followed an Arrhenius behavior with an apparent activation energy of 10.59Kcal/mol in case of lower oxygen to DES ratio. Also, depletion was observed with increase in the distance between the wafers. The refractive index of the films were found to be near 1.45 and the films were highly transparent. The thick silicon dioxide films showed excellent properties at a deposition temperature of 775°°C, a pressure of 200mTorr and an oxygen to DES flow ratio of 10:1.

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