An example of chemistry-morphology interaction: making up for the geometric and energetic heterogeneities of the (100)surface of single crystalline silicon by high-temperature treatments in H-2

A lot of work has been carried out to prepare chemically homogeneous
(100) silicon surfaces. The hydrogen-terminated (100) silicon surfaces
are the most promising ones, especially in view of their remarkable
environmental stability. The simplest way to produce hydrogen-terminated
surfaces (attack in water solution of HF of a sacrificial, thermally
grown, oxide) results in strongly heterogeneous rough surfaces (although
with prevailing dihydride terminations). These surfaces can, however, be
flattened and homogenized by treating them in H-2 at high temperature (
> 850 degrees C). The morphological and chemical changes undergone by
the surface during the treatment are studied X-ray photoelectron
spectroscopy, atomic force microscopy, scanning tunnelling microscopy,
infrared absorption spectroscopy in the attenuated total reflection
mode, reflection high energy electron diffraction and thermal programmed
desorption, and the mechanisms responsible for them are discussed.