A surface reconstruction functioning as a micro mask during in-situ layer-by-layer etching of GaAs(111)B using AsBr_3

摘要

The effect of the surface reconstructions on GaAs(111)B during the layer-by-layer etching using AsBr_3 as an etchant gas was investigated. The surface reconstructions strongly affect the etching kinetics, the etching rate observed from reflection high-energy electron diffraction (RHHED) intensity oscillations. It is found that the sudden drop in etching rate in the ((19)~(1/2) x (19)~(1/2))-like temperature region is clearly observed. This means the surface covered with ((19)~(1/2) x (19)~(1/2))-like reconstruction has the resistance to AsBr_3. Moreover, the kinetic-roughening was observed in the temperature region, where both ((19)~(1/2) x (19)~(1/2)) domain and the (2 x 2) domain coexist. This means the ((19)~(1/2) x (19)~(1/2)) domain locally covering the surface acts a micro etching-mask and then the etching mode become not layer-by-layer fashion. These results indicate that this etching process is highly sensitive to the surface reconstruction, and can use the surface reconstruction as a functioning etching mask.