An x-ray diffraction and Raman spectroscopic analysis of thin-films of silicon grown by ultrahigh-vacuum evaporation and the thin-film silicon continuum

Abstract

The analysis presented herein draws upon a reservoir of experimental data that has been harvested from experiments performed on a collection of ultrahigh-vacuum evaporation prepared thin silicon film samples. A molecular beam epitaxy deposition setup was commissioned for the film preparations, these growths being performed for different growth temperatures and substrate selections. Grazing incidence x-ray diffraction and Raman spectroscopic measurements probed each thin silicon film’s microstructure. From the diffraction patterns, through applying Scherrer’s equation, the crystallite dimensions’ dependence on the growth temperature is resolved for each considered substrate selection; these results are confirmed through determinations of the crystallite dimensions through an evaluation of the relevant Raman spectral shifts. From the ensemble of Raman spectra that is available, drawing upon a recently developed Raman spectral processing protocol, full spectral decompositions are pursued. From these decompositions, the location, width, and character of each identified peak are noted, and the evolution of these decompositions in response to growth temperature variations is examined for the different substrate selections. Finally, an interpretation and a discussion about the results are presented, with the concept of thin-film silicon being on a continuum providing the framework for some aspects of this analysis.