Ion channeling studies of the crystalline perfection of epitaxial layers

Abstract

Ion channeling and backscattering of 450‐ to 1340‐keV protons were used to study the crystalline perfection of heteroepitaxial Si layers of thicknesses between 1 and 3 μm. An approximate calculation of the dechanneling background was used to obtain the depth profiles of crystalline imperfections in the epitaxial layers. Both the plural scattering theories of Meyer and Keil et al. were used in the calculation and are shown to give similar profiles. Channeling measurements as a function of sample temperature, beam energy, and layer removal were used to check the self‐consistency of the analysis. Analysis of these measurements for a given sample gave the same depth profile (±20%) confirming the validity of the technique. The technique provides a convenient evaluation of epitaxial layers containing large numbers of crystalline imperfections.