FORMATION AND EVOLUTION OF THE PHASE-COMPOSITION AND ASSOCIATED PROPERTIES DURING THE GROWTH OF THIN-FILMS

A complete system of equations describing the evolution of the phase c omposition of islands in the Ostwald ripening stage during the growth of thin films is derived and a solution is found. The distribution fun ction of islands of solid solutions is obtained for different growth m echanisms. A general approach to controlling the phase composition and associated properties (electrical, optical, strength, and so on) in t he multicomponent systems formed is developed. The investigation is co nducted for the example of thin multicomponent films. It is shown that the greatest possibilities for controlling these properties are at th e Ostwald ripening stage and in the presence of nonlinear phenomena su ch as self-oscillation or self-organization, A relation is found betwe en the size acid composition of the new-phase nuclei which form during the condensation of films of solid solutions. A system of equations d escribing the evolution of the distribution function of properties in island films of solid solutions as a function of the external paramete rs of the system is derived and solved. It is shown that a strong depe ndence of the composition on the external parameters appears for islan ds with radius R less than or equal to 10(-8) m, irrespective of the t ype of material. A diagram of the coexistence of the corresponding pro perties in concentration-temperature coordinates is constructed for is land films of stoichiometric compounds; this makes it possible to dete rmine the necessary conditions for obtaining such films. It is predict ed that various properties in multicomponent systems which undergo a f irst-order phase transition can vary periodically in time and space. ( C) 1997 American Institute of Physics.