Annealing effects on the optical properties of semiconducting boron carbide

Authors

R. B. Billa, University of Nebraska - Lincoln
Tino Hofmann, University of Nebraska - LincolnFollow
Mathias Schubert, University of Nebraska - LincolnFollow
Brian W. Robertson, University of Nebraska - LincolnFollow

Date of this Version

2009

Comments

Published in JOURNAL OF APPLIED PHYSICS 106 (2009). Copyright 2009. Used by permission.

Abstract

Infrared vibrations of as-deposited and annealed semiconducting boron carbide thin films were investigated by midinfrared spectroscopic ellipsometry. The strong boron-hydrogen resonance at ~2560 cm⁻¹ in as-deposited films reveals considerable hydrogen incorporation during plasma-enhanced chemical vapor deposition. Extended annealing at 600 °C caused significant reduction in film thickness, substantial reduction of boron-hydrogen bond resonance absorption, and development of distinct blue-shifted boron-carbon and icosahedral vibration mode resonances. Our findings suggest that annealing results in substantial loss of hydrogen and in development of icosahedral structure, accompanied by strain relaxation and densification.