Substantiation of the scientific solution for the deposition of nanofilms on a substrate with surface reconstruction
The article considers the problem of choosing the architecture of buffer layers in the development of typical models of various heterostructures with a controlled level of mechanical stresses and a low density of defects in the volume and at the boundaries of the layers. It has been established that these characteristics depend on the quality of the surface of the initial substrate plates, the procedure for preparing the substrates for the epitaxy process, and the composition of the buffer layers. It is noted that the quality of the surface of the substrates is most objectively assessed by the amount of sticking of directly spliced plates. It is shown that the sticking value below 10 7 Pa is the value most often observed in the experiment. In this case, the surface of the substrates is characterized by a fairly noticeable roughness, it contains various contaminating elements and chemical compounds, clusters and dust particles, as well as structural defects of various dimensions. In addition, the surface of the substrate is restructured in a certain way so that the “dangling” bonds are closed to each other. The influence of the real structure of the substrate surface and the compatibility of materials on the quality of the epitaxial film is shown. In the case of small differences in the lattice parameters, the expediency of preliminary deposition of a low-temperature underlying layer on the substrate is substantiated. And with sufficiently different lattice parameters - additional transition layers with a changing ratio of components in the composition or in the form of superlattices.