The influence of vibroacoustics on self-organizing of SiGe nanostructures onto silicon substrate

Abstract

Microprocessor electronics is based on silicon technology. The growth of microprocessor circuit's speed, the increase of elements integration, the development of Si light-emitting semiconductor devices demands the introduction of new functional principles and technologies in silicon electronics. Recently optical lithography cannot provide the necessary level of miniaturization. Electron-beam and scanning lithography are also unproductive. The object of researches was Ge/Si (001) heterosystems with nanoislands obtained using different technological conditions. In Ge/Si heterosystems the kinetics of formation of nanoislands is still not completely clear, beginning from the definition of critical thickness of nanolayer, vibroacustics, temperatures. Raman spectroscopy (RS), high resolution X-ray diffractometry and scanning atomic force microscopy (AFM) for research of physical mechanisms of nanoislands formation, character of deformation fields and processes of diffusion of silicon from substrate in wetting layer and nanoislands were applied. Such combination of analysis methods has allowed to obtain structure's parameters as elastic deformations, structure, density of nanoislands, their sizes and form variation generated at different physical conditions (temperature, acoustic vibration). The photon (optical and acoustic) spectrums of self-organized nanostructures, generated during molecular-beam epitaxy (MBE) growth of Ge on Si substrate have been investigated using method of RS. The componental structure and values of elastic deformations in nanoislands obtained by the variation of epitaxial temperature at identical thickness of deposited Ge layer and by variation of Ge layer thickness at identical temperature has been estimated by atomic force microscopy method.