Etchant anisotropy controls the step bunching instability in KOH etching of silicon

STM investigations of vicinal Si(111) surfaces etched in KOH solutions under controlled flow conditions show that step bunching instability is due to inhomogeneities that develop in the etchant as the result of highly step-site-specific etching reactions. Other previously postulated mechanisms for s...

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Bibliographic Details
Published inPhysical review letters Vol. 93; no. 16; p. 166102
Main Authors Garcia, Simon P, Bao, Hailing, Hines, Melissa A
Format Journal Article
LanguageEnglish
Published United States 15.10.2004
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Summary:STM investigations of vicinal Si(111) surfaces etched in KOH solutions under controlled flow conditions show that step bunching instability is due to inhomogeneities that develop in the etchant as the result of highly step-site-specific etching reactions. Other previously postulated mechanisms for step bunching, including anisotropic surface diffusion, surface strain, and impurity deposition, are conclusively ruled out. The inhomogeneities locally accelerate etching near surface steps. Kinetic Monte Carlo simulations of this process qualitatively reproduce the observed morphologies.
ISSN:0031-9007
DOI:10.1103/physrevlett.93.166102