Abstract
The regularities of chemical contact-exchange deposition of thin copper films on porous silicon are investigated. Aqueous and aqueous-alcoholic solutions of copper sulfate with hydrofluoric acid additives are used for copper deposition. The optimal ratio of solution component concentrations is determined, which allows controlling the kinetics of the deposition process and obtaining shiny copper films with good adhesion to the silicon substrate. It is established that copper is deposited on porous silicon in the form of a film consisting of micro- and nanometer-sized grains. The packing density and the size of copper grains are determined by both the deposition time and the pore diameter of porous silicon. It is shown that at a porosity of up to 10%, copper grains nucleate only on the vertices of silicon nanocrystallites of the porous silicon matrix. An increase in porosity leads to the simultaneous nucleation of copper grains on the inner surface of the pore channels and the vertices of silicon nanocrystallites. Reflection spectra of nanocomposite films were recorded. It was found that the maximum intensity of the absorption band, caused by surface plasmon resonance, is characteristic of a film deposited for 5 min. from an alcohol-containing solution on porous silicon, which was formed on the silicon wafer of n-type with resistivity 0.01 and orientation (111). Thus, by varying the pore sizes of the porous layer and the deposition conditions, it is possible to manufacture various types of thin-film nanocomposite structures from silicon and copper, promising for use as functional nanomaterials in electronics and photonics.