High-resolution transmission electron microscopy (HRTEM) shows that amorphous-tetrahedral diamondlike carbon(a-tC)films grown by pulsed-laser 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 density. The bulk of the film between these two layers has higher density. For films grown under the most energetic conditions, there exists a superdensea-tClayer between the interface and bulk layers. The density of all four layers, and the thickness of the surface and interfacial layers, correlate well with the energetics of the depositing carbon species. ©1998 American Institute of Physics.