Comparison of deposition methods for ultra thin DLC overcoat film for MR head

To improve overcoat films for giant magnetoresistive (GMR) heads, we developed a commercial multi-film deposition system capable of performing three diamond-like carbon (DLC) deposition methods, i.e. electron cyclotron resonance-chemical vapor deposition (ECR-CVD), ion beam deposition (IBD), and filtered cathodic vacuum are (FCVA); pre-cleaning with Ar sputtering etch; and Si adhesion layer deposition. In comparative evaluations of 50-nm-thick films deposited on a Si wafer, ta-C film by FCVA shows higher hardness/density compared to DLC films by ECR-CVD or IBD. Scratch testing and electron spectroscopy for chemical analysis (ESCA) measurements of films prepared by ECR-CVD and FCVA on an Al2O3TiC substrate indicate that substrate bias enhances mixing between the carbon film and either the Si film or Al2O3TiC substrate such that good adhesion occurs. (C) 2001 Elsevier Science B.V. All rights reserved.