Characterization of boron carbide thin films fabricated by plasma enhanced chemical vapor deposition from boranes

Authors

Sunwoo Lee, Syracuse UniversityFollow
John Mazurowski, Syracuse University
G. Ramseyer, General Electric CompanyFollow
Peter A. Dowben, University of Nebraska-LincolnFollow

Date of this Version

November 1992

Comments

Published by Am Inst of Physics. J. Appl. Phys. 72 (lo), 15 November 1992. Copyright 1992. Permission to use. http://www.aip.org/.

Abstract

We have fabricated boron carbide thin films on Si(111) and other substrates by plasma-enhanced chemical-vapor deposition (PECVD). The PECVD of boron carbides from nido-cage boranes, specially nido-pentaborane(9) (B₅H₉), and methane ( CH₄) is demonstrated. The band gap is closely correlated with the boron to carbon ratio and can range from 0.77 to 1.80 eV and is consistent with the thermal activation barrier of 1.25 eV for conductivity. We have made boron carbide by PECVD from pentaborane and methane that is sufficiently isotropic to obtain resistivities as large as 10¹⁰ Ω cm at room temperature. This material is also shown to be suitable for photoactive p-n heterojunction diode fabrication in combination with Si( 111).