Continuity and topography of ultrathin diamond-like carbon films characterized by scanning electron microscopy energy dispersive x-ray analysis and atomic force microscopy

Diamond-like-carbon coatings used as wear and corrosion barriers for hard d isk drives are very thin and extremely smooth layers. Good morphological ch aracterization of these ultrathin films is crucial to the good performance of the drive and has been attempted by scanning electron microscopy, energy dispersive x-ray (EDX) analysis and contact mode atomic force microscopy ( AFM). Pure secondary electron images were obtained by subtracting out the b ackscattered component of the detected signal. EDX analysis was used for es timating the electron stopping power and the thickness of the coatings. Run -on spot analysis mode, EDX also permitted to check the continuity of these thin films. Contact mode AFM microscopy was carried out for a range of for ce set points. The contrast was found independent of force set point. Conti nuum mechanics calculations and preliminary adhesion measurements indicate that the contrast observed is purely topographic (R-a = 1 nm). Finally, com paring the results, we found that the three different techniques complement each other to yield a more complete morphological characterization of thes e ultrathin films. (C) 1999 American Vacuum Society. [S0734-2101(99)02801-8 ].