Spirals on Si(111) at sublimation and growth: REM and LODREM observations

TL;DR

This study employs advanced Reflection Electron Microscopy techniques, specifically LODREM, to analyze spiral structures on Si(111) surfaces during sublimation and growth, revealing non-local behavior and step dynamics.

Contribution

The paper introduces LODREM as a superior method for detailed observation of surface spirals, demonstrating its effectiveness in studying step spacing and kinetics during crystal growth and sublimation.

Findings

LODREM provides higher resolution images of surface spirals.

Step spacing scales with an exponent near -1/2, indicating non-local kinetics.

Results deviate from classical BCF theory due to slow adatom attachment.

Abstract

Using recently proposed improvements of Reflection Electron Microsopy (REM) we study in perfectly controlled thermodynamics conditions spiral shapes and spirals on Si(111) surface. It is shown that the new method named low distortion reflection electron microscopy (LODREM) is a powerful instrument, resolving in much more details (compared with REM) growth or evaporation spirals at the crystal surface. More precisely, we examine the distance between two successive steps of a spiral at growth (or evaporation) with respect to the supersaturation (or undersaturation). It is found that this distance scales with an exponent close to -1/2. This result, which deviates from the BCF theory originates from a non local behavior with a slow kinetic of attachment of the adatoms at the steps.