AMORPHOUS-TETRAHEDRAL DIAMOND-LIKE CARBON LAYERED STRUCTURES RESULTING FROM FILM GROWTH ENERGETICS

High-resolution transmission electron microscopy (HRTEM) shows that am orphous-tetrahedral diamond like carbon (a-tC) films grown by pulsed-l aser deposition on Si(100) consist of three-to-four layers, depending on the growth energetics. We estimate the density of each layer using both HRTEM image contrast and Rutherford backscattering spectrometry. The first carbon layer and final surface layer have relatively low den sity. The bulk of the film between these two layers has higher density . For films grown under the most energetic conditions, there exists a superdense a-tC layer between the interface and bulk layers. The densi ty of all four layers, and the thickness of the surface and interfacia l layers, correlate well with the energetics of the depositing carbon species. (C) 1998 American Institute of Physics.