In Situ Laser Light Scattering: II . Relationship to Silicon Surface Topography

Abstract

This paper reports ex situ angle‐resolved light scattering (ARLS) measurements from silicon wafers, prepared to various stages during pre‐epitaxial bake and silicon molecular beam epitaxial (MBE) growth, in a study of the topographic sensitivity of the in situ laser light scattering (LLS) technique described in Part I . Comparison with stylus profilometer traces and transmission electron micrographs confirms that LLS is a sensitive probe of surface topography, on a lateral scale of ∼0.5–10 wavelengths depending on scattering geometry, in general accordance with smooth surface scattering theory. A vertical sensitivity to uniformly distributed roughness of subnanometer amplitude is demonstrated. The ARLS patterns are also shown to be related to differential phase contrast images (analogous to conventional Nomarski images but obtained using a laser scanning optical microscope) of the silicon surfaces.