We have grown high quality epitaxial TiN/Si(100) and Cu/TiN/Si(100) heterostructures by pulsed laser deposition. The epitaxial TiN films have the same low (15 µΩ-cm) resistivity as TiSi2 (C-54) phase with excellent diffusion barrier properties. In addition, Schottky barrier height of TiN was close to that of TiSi2 (0.6-0.7 eV). Auger and Raman spectroscopy revealed that the films were stoichiometric TiN and free from oxygen impurities. The x-ray diffraction and transmission electron microscope (TEM) results showed that the TiN films deposited at 600°C were single crystal in nature with epitaxial relationship TiN|| Si. The Rutherford baskscattering channeling yield for TiN films was found to be in the range of 10–13%. The epitaxy of Cu on TiN was found to be cube-on-cube, i.e., Cull<100>TiN||Si. The Cu/TiN and TiN/Si interfaces were found to be quite sharp without any indication of interfacial reaction. The growth mechanism of copper on TiN was found to be three-dimensional. We discuss domain matching epitaxy as a mechanism of growth in these large lattice mismatch systems, where three lattice constants of Si(5.43Å) match with four of TiN(4.24Å) and seven units of Cu(3.62Å) match with six of the TiN. Thus, for next generation of device complementary metal oxide semiconductor structures, Cu/TiN/Si(100) contacts hold considerable promise, particularly since Cu is a low resistivity metal (1.6 µΩ-cm) and is considerably more resistant to electromigration than Al. The implications of these results in the fabrication of advanced microelectronic devices are discussed.