Coalescence of cylindrical islands on the crystal surface accompanied by correlated changes of their heights and radii

Coalescence of an ensemble of cylindrical faceted islands comprising N components and K chemical compounds on the crystal surface is studied in case of layer-by-layer growth of islands accompanied by correlated changes of their heights and base radii. Steps, generated on the surface of the islands by twinning dislocations, are assumed to be the sources of layers. The following correlation between the height H and the base radius R of an island is found: (HH0) = (RR0)js where jS = 2σSβ1S(σ1SβS). This correlation is expressed in terms of thermodynamic and kinetic parameters of an island of the S compound, such as the specific free energies of the surfaces of the step edges σS and σ1S on a lateral and the top facets respectively, and corresponding generalized specific flows βS and β1S. Analytical solutions of the basis system of equations are obtained. Necessary conclusions as to formation of the final structure of the continuous thin film are given. Limiting cases, when growth of cylindrical islands in the stage of coalescence is needle-like or tablet-like, are analyzed. The asymptotical dependencies obtained in this work differ from those found both in case of normal growth mechanism of the islands and in case of their needle-like or tablet-like growth proceeding layer by layer. Theoretical results are compared to experimental data on vacuum condensation through thermal evaporation of the PbTe films on the KCl substrate, and they show good agreement.