Diamond-like carbon films deposited using a broad, uniform ion beam from an RF inductively coupled CH4-plasma source

Diamond-like carbon (DLC) films with 12-25 GPa hardnesses and 3-400 nm thicknesses were deposited on silicon, Al2O3-TiC substrates, and permalloy coated with Al2O3-TiC substrates using a broad, uniform ion beam from an RF, inductively coupled, CH4-plasma (ICP) source (30 cm). The deposition process represents a significant advance in the ability to: (1) accomplish the desired balance between mechanical, optical and electrical properties by utilizing different RF powers to vary the plasma density and electron temperature; (2) improve step coverage when the film is deposited on patterned or rough substrates; (3) carry out reliable fault-free and long duration operation. The RF inductively coupled ion beam source can be operated with highly reactive ion beam processes for long periods of time. In particular, the source demonstrates excellent compatibility with pure oxygen. The ability of an O-2-plasma to etch hydrocarbon precipitates allowed us to utilize this procedure as an effective "on-line" ion source clean-up. Highly reproducible deposition rates (< 5% from run to run for over several hundred hours) have been achieved by utilizing a CH4-plasma conditioning procedure for the plasma-surface interaction stabilization. The deposition uniformity was within 5% over 9 in. Deposition kinetics as well as the mechanical and electrical properties have been investigated and discussed. (C) 1998 Elsevier Science S.A.