Growing Si–Si 1− x Ge x –(Ge 2 ) 1− y (GaAs) y structures in a single technological cycle

Abstract

Abstract The technology of creating Si–Si 1− x Ge x –(Ge 2 ) 1− y (GaAs) y heterostructures on a single-crystal substrate has been tested. The functional layers are deposited from a limited tin melt solution in a single process cycle, which is optimal from the application’s point of view. The observed growth kinetics is theoretically analysed within the framework of an approach based on considering the kinetics of diffusing nanoclusters. A model describing the growth of epitaxial films from a confined molten solution is proposed, consistent with experimental results. Technological and physical conditions for the growth of crystalline perfect epitaxial layers with smooth changes in chemical composition (0 ≤ y ≤ 0.69) have been established. The possibility of controlling the composition and structure of crystallised layers by changing such parameters as temperature interval, distance between substrates and cooling rate has been shown. The tested technology allowed broad-spectrum photodetectors obtained with an extended spectral range of photosensitivity. An explanation for the reduction of the red boundary of photosensitivity is proposed, and the prospect of using varisonic structures for solving applied problems of photosensorics is shown.