Raman spectra of silicon/germanium alloy thin films based on porous silicon

Abstract

Regularities of composition changes of silicon/germanium alloy thin fi lms formed on a single-crystalline silicon substrate by electrochemical deposition of germanium into a porous silicon matrix with subsequent rapid thermal annealing (RTA) at temperatures of 750–950 °C are studied. An analysis of the samples by Raman spectroscopy showed that an increase of the RTA temperature leads to a decrease in the germanium concentration in the formed fi lm. A decrease of the RTA duration at a given temperature makes it possible to obtain fi lms with a higher germanium concentration and to control the composition of thin silicon/germanium alloy fi lms formed by changing the RTA temperature and duration. The obtained results on controlling the composition of silicon/germanium alloy fi lms can be used to create functional electronic devices, thermoelectric power converters, and optoelectronic devices.