Polarized Raman spectroscopy clarifies the effect of crystal anisotropy on elastic stress fields developed on the surface of silicon single-crystal

✍ Scribed by Porporati, Alessandro Alan ;Pezzotti, Giuseppe

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 349 KB
• Volume: 208
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.201000006

✦ Synopsis

Abstract

We performed polarized/confocal Raman microprobe measurements in order to visualize the effects of crystallographic orientation and anisotropic volume changes on the elastic stress field developed in single‐crystalline silicon upon impinging its surface with a pyramidal indenter. A theoretical analysis of multiaxial stress‐induced phonon scatter was applied and an improved equation proposed for rationalizing the residual (elastic) stress field stored around an indentation print after load removal. The analysis enabled us to attach a physical meaning to an empirical constant (i.e., the volumetric compaction factor), which was originally introduced by other authors for taking into account the effects of volumetric changes at the center of the indentation print. Such a constant has been introduced for highly compressible solids (e.g., some anomalous glasses), but it is found here to play an important role also in silicon. From a more general viewpoint, we clarify here how crystal anisotropy can play a fundamental role in the residual stress fields stored on silicon surfaces.