Interface tailoring for adhesion enhancement of diamond-like carbon thin films

• Published in: Diamond and related materials 2012-05, Vol.25, p.8-12
• Main Authors: Salvadori, M.C., Teixeira, F.S., Araújo, W.W.R., Sgubin, L.G., Brown, I.G.
• Format: Article
• Language: English
• Subjects: Adhesion; Adhesive bonding; Carbon; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Defects and impurities: doping, implantation, distribution, concentration, etc; Diamond-like carbon; Diamond-like carbon films; Enhanced adhesion; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Interface tailoring; Ion bombardment; Materials science; Mechanical and acoustical properties; Physical properties of thin films, nonelectronic; Physical radiation effects, radiation damage; Physics; Raman spectroscopy; Silicon; Silicon substrates; Specific materials; Structure of solids and liquids; crystallography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Thin films
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2012.02.005

We have explored the suitability and characteristics of interface tailoring as a tool for enhancing the adhesion of hydrogen-free diamond-like carbon (DLC) thin films to silicon substrates. DLC films were deposited on silicon with and without application of an initial high energy carbon ion bombardment phase that formed a broad Si–C interface of gradually changing Si:C composition. The interface depth profile was calculated using the TRIDYN simulation program, revealing a gradient of carbon concentration including a region with the stoichiometry of silicon carbide. DLC films on silicon, with and without interface tailoring, were characterized using Raman spectroscopy, scanning electron microscopy, atomic force microscopy and scratch tests. The Raman spectroscopy results indicated sp3-type carbon bonding content of up to 80%. Formation of a broadened Si:C interface as formed here significantly enhances the adhesion of DLC films to the underlying silicon substrate. ► Substrate adhesion of DLC thin films is enhanced by preliminary interface tailoring. ► Initial high energy carbon ion bombardment produced a broad, graded Si–C interface. ► Significantly thicker DLC films can be deposited without delamination.