Molecular dynamics geometry simulations of the SiNxOy/Si < 111 > interfaces

The SiNxOy films were synthesized using a technique of chemical evaporation at low pressures. Films with thickness varying between 10 and 30 nm and wi th N/O ratio between 0 and 1 were obtained. The stoichiometry of these film s was measured after their deposition on Si[111] substrates using an extend ed X-ray absorption fine structure (EXAFS) method. Distances between O-Si a nd N-Si atoms for different N/O ratio and film thickness were determined us ing both the data fitting analysis as well the molecular dynamics simulatio ns. Comparison of the experimentally obtained and molecular dynamics simula ted geometry structure is done. Exchange-correlation potential within a fra mework of the local density functional approach give the similar Si-O and S i-N distances as with inclusions of the non-local many-body screening poten tial. At the same time pressure derivatives within the local density approa ch agree better with experimental data.