Abstract <p>The paper shows that the structural and phase composition of copper-carbon coatings can be controlled not only by the annealing temperature, but also by the conditions of heat treatment: the presence of a chemically active atmosphere, its pressure and composition. Heat treatment at reduced pressure or in vacuum is promising, which allows eliminating the influence of thermal destruction processes, as well as establishing the mechanisms of the effect of temperature on the activation of phase transformations. In the work, heat treatment of the deposited carbon and copper coatings was carried out at various temperatures both in vacuum (8 Pa) and in air. The choice of the annealing temperature was determined by the thermal stability of the carbon component of the coating (up to 350°C). Composite coatings were deposited using various vacuum methods characterized by the energy of carbon ions, as well as the ion current density. Using Raman spectroscopy, the size of C clusters and the ratio of <i>sp</i>³-hybridized bonds in the carbon matrix were analyzed. It is shown that the minimum sizes of clusters, the fusion of which forms carbon particles, are characteristic of coatings applied by the pulse evaporation method of a composite copper-carbon cathode, with the cluster size being 2.5 nm. The maximum sizes of carbon clusters for the high-pulse magnetron sputtering method at a frequency of 5 kHz are found to be 7.8 nm. It is established that the physical and mechanical properties of the coatings depend on the modes and conditions of heat treatment.</p>