Raman Mapping and Delineation of III-V Semiconductor Band Bending Characteristics

Abstract

Raman spectroscopy has previously been used to ascertain the nature and extent of band bending at III-V semiconductor interfaces. Many previous investigations have focused on samples cleaved in vacuum and subsequently exposed to oxygen gas or a thin metal deposition; generally, specific polarizations of incident and scattered light are applied and collected in order to specify and isolate the desired phonon peaks under investigation1,2. We demonstrate herein a more general and easily applied method to investigate III-V interfaces by Raman spectroscopy using analysis of the longitudinal optical (LO) and transverse optical (TO) phonons; furthermore, we provide a means by which the ratios resulting from such experimentation may be normalized. Interfaces can be deeply buried under tens or hundreds of nm of material and still be investigated, unlike the case with photoelectron spectroscopy; furthermore, this technique can provide electronic mapping of such interfaces with micron sensitivity.