Straining of monocrystalline silicon thin films with the use of porous silicon as stress generating nanomaterial

Abstract

A simple and low cost technological approach for the straining of thin crystalline silicon (Si) films using porous silicon (PS) as stress generating nanomaterial is reported. Structural analysis of the PS∕Si structures is performed by transmission electron microscopy. Raman scattering spectroscopy is used for the evaluation of stress and strain values in the strained thin Si films. Depending on the thickness of the strained Si films, the maximum strain values are found to be in a range from 1% to 1.4%. Various modifications of electronic properties of the strained Si films are observed by photoluminescence spectroscopy. For example, strain induced redshift of the Si energy band gap and splitting of the valence band are detected.