Effects of plasma etching on DLC films

Magnetron sputtered diamond like carbon (DLC) films were etched in oxygen r eactive ion etching (RIE) plasmas. The hydrogenated films etch 35% slower t han the non-hydrogenated films. Etch rates increase with power. The anisotr opy decreases with both pressure and power. Processes at 6.5 Pa yield aniso tropies of over 0.9, with etch rates up to 185 nm/min for the hydrogenated films. Raman analysis indicates that these oxygen RIE processes etch prefer entially non-crystalline carbon atoms in the hydrogenated films, the remain ing film has more sp bound carbon atoms than the original DLC film. This ph enomenon occurs in a much lesser degree for the non-hydrogenated films, and Raman analysis indicates that the sp(2)-bound carbon atoms etch at approxi mately the same rate as the non-crystalline bound atoms. (C) 1999 Elsevier Science S.A. All rights reserved.