In this paper we present a computationally effective approach to classical molecular dynamic simulation of thin film growth with orientation on cluster supercomputing facilities. The goal of the developed approach is to investigate structural heterogeneities of thin films deposited on substrates at a nanoscale level. These heterogeneities depend on the experimental conditions of a deposition process being used. They have essential influence on practical properties of thin films and their modeling is important for achieving further progress in thin film optical technology. The presented research is focused on silicon dioxide thin films growth. A special force field, oriented on the atomistic description of the silicon dioxide deposition on fused silica substrate, has been developed and applied to the molecular dynamic simulation with the GROMACS package. The validity of the developed simulation approach is verified using atomic clusters consisting of up to 10⁶ atoms and having characteristic dimensions of up to 30 nm. Its computational efficiency is tested using up to 2048 cores. The dependence of achievable efficiency on model parameters is discussed.

The previously developed high-performance method of the atomistic simulation of thin film deposition is applied to the investigation of effects connected with SiO₂ films annealing. It is found that the film density is reduced for about 0.15 g/cm³ under annealing with the temperature of 1300 K. This corresponds to the reduction of the refractive index for approximately 0.03. Concentrations of the non-bridging and threefold coordinated oxygen atoms are reduced up to four times after annealing. The stress value essentially reduces after annealing at 1300 K and the film thickness increases for 3 nm.

The molecular dynamic algorithm for simulation of thin-film growth is reported. The achieved performance of this algorithm is sufficient for detailed investigations of structural effects in thin films with practically meaningful dimensions.

Dependence of stress values in silicon dioxide films on its thickness in the initial stage of film growth was investigated using atomistic molecular dynamics simulation. It was shown that the stress in normally deposited films was compressive and varied slightly with growth of film thickness. The stress in the glancing angle deposited films was several times lower than the stress in the normally deposited films, and varied from compressive stress to tensile stress with increasing film thickness. An essential anisotropy of stress tensor components was revealed for the case of glancing angle deposition. The calculated stress values were in the interval of experimental data.