Abstract:
This paper presents an experimental report on the conditions to grow films with variable composition in the Ta-B-C triangle using the hot-filament (HF) configuration. The HF-Chemical Vapor Deposition (HFCVD) mode is when the precursors for film growth are obtained exclusively from the gas-phase species. Diamond films were produced by feeding the growth system with hydrogen-diluted methane, beta-boron films by substituting the methane fraction with diborane, and boron carbide using mixtures of both gases. A second operational mode is achieved when filament sublimation is allowed. In this HF-Physical Vapor Deposition (HFPVD) mode the species stemming from filament and reacting with the gas-atmosphere are the precursors for film growth. The deposition of TaC and TaBC films by means of Ta filaments is reported. A very versatile mode was found when the conditions are adapted during the period of the deposition, switching from PVD to CVD to grow diamond on in-situ deposited TaC. (c) 2006 Elsevier B.V. All rights reserved.