Laser micromachining of sputtered DLC films

• Published in: Applied surface science 2006-04, Vol.252 (13), p.4914-4918
• Main Authors: Fu, Y.Q., Luo, J.K., Flewitt, A.J., Ong, S.E., Zhang, S., Milne, W.I.
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; DLC; Exact sciences and technology; Laser micromachining; Materials science; Mechanical and acoustical properties; Methods of deposition of films and coatings; film growth and epitaxy; Microcantilever; Physical properties of thin films, nonelectronic; Physics; Structure and morphology; thickness; Surface treatments; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2005.06.054

DLC films with different thicknesses (from 100 nm to 1.9 μm) were deposited using sputtering of graphite target in pure argon atmosphere without substrate heating. Film microstructures (sp 2/sp 3 ratio) and mechanical properties (modulus, hardness, stress) were characterized as a function of film thickness. A thin layer of aluminum about 60 nm was deposited on the DLC film surface. Laser micromachining of Al/DLC layer was performed to form microcantilever structures, which were released using a reactive ion etching system with SF 6 plasma. Due to the intrinsic stress in DLC films and bimorph Al/DLC structure, the microcantilevers bent up with different curvatures. For DLC film of 100 nm thick, the cantilever even formed microtubes. The relationship between the bimorph beam bending and DLC film properties (such as stress, modulus, etc.) were discussed in details.