Garcia Simon P, Bao Hailing, Hines Melissa A
Department of Chemistry, Cornell University, Ithaca, New York 14853-1301, USA.
Phys Rev Lett. 2004 Oct 15;93(16):166102. doi: 10.1103/PhysRevLett.93.166102. Epub 2004 Oct 14.
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.
在可控流动条件下，对在氢氧化钾溶液中蚀刻的近邻硅（111）表面进行扫描隧道显微镜（STM）研究表明，台阶聚集不稳定性是由于高度依赖台阶位置的蚀刻反应导致蚀刻剂中出现不均匀性所致。其他先前假定的台阶聚集机制，包括各向异性表面扩散、表面应变和杂质沉积，均被确凿排除。这些不均匀性会局部加速表面台阶附近的蚀刻。对该过程进行的动力学蒙特卡罗模拟定性地再现了观察到的形貌。
