Anisotropic chemical etching of semipolar {10(1)over-bar(1)over-bar}/{10(1)over-bar 1} ZnO crystallographic planes: polarity versus dangling bonds

作者：Palacios Lidon E; Perez Garcia B; Vennegues P; Colchero J; Munoz Sanjose V; Zuniga Perez J^*

来源：Nanotechnology, 2009, 20(6): 065701.

DOI：10.1088/0957-4484/20/6/065701

ZnO thin films grown by metal-organic vapor phase epitaxy along the nonpolar [11 (2) over bar0] direction and exhibiting semipolar {10 (1) over bar(1) over bar}/{10 (1) over bar 1} facets have been chemically etched with HCl. In order to get an insight into the influence of the ZnO wurtzite structure in the chemical reactivity of the material, Kelvin probe microscopy and convergent beam electron diffraction have been employed to unambiguously determine the absolute polarity of the facets, showing that {10 (1) over bar 1} facets are unstable upon etching in an HCl solution and transform into (000 1)/{10 (1) over bar(1) over bar} planes. In contrast, {10 (1) over bar(1) over bar} facets undergo homogeneous chemical etching perpendicular to the initial crystallographic plane. The observed etching behavior has been explained in terms of surface oxygen dangling bond density, suggesting that the macroscopic polarity plays a secondary role in the etching process.

• 出版日期2009-2-11