Control of the structure and stress state of thin films and coatings in the process of their preparation by ion-plasma methods

A system analysis of the influence of the substrate temperature during deposition on two main factors (nanodimensionality of structural aggregates and high stresses) responsible for the nonequilibrium state of the materials of ion-plasma-deposited films and coatings has been performed. It has been shown that an increase in the temperature during deposition leads to a preferred growth of nanocrystallites in the direction of incidence of film-forming particles, which, in turn, results in the formation of an anisometric crystal structure. The main causes of the generation of high elastic stresses in ion-plasma condensates are the ion/atom bombardment in the process of deposition (which stimulates the development of compressive stresses) and the difference in the thermal expansion coefficients of the condensate and substrate materials (which initiates the development of thermal stresses; the sign is determined by the difference between the thermal expansion coefficients of the condensate and substrate materials). An increase in the temperature during deposition results in the relaxation of compressive stresses stimulated by the ion/atom bombardment and in an enhancement of the influence of thermal stresses on the state of the ion-plasma condensate. This makes it possible to control the stress state of ion-plasma films and coatings by purposefully varying the substrate temperature during deposition.