Figure 1
From: Ultra-steep side facets in multi-faceted SiGe/Si(001) Stranski-Krastanow islands
AFM images of the cupola islands. (a) 3D AFM micrograph (2.5 × 2.5 μm2) of SiGe islands measured after sample mounting on a wedge shape sample holder with tilt angle αtilt = 14°. (b) Larger scale (8 × 4 μm2) AFM micro-graph of the non-tilted sample for comparison, where the color scale represents the local surface slope with respect to the (001) surface in the range from 0° to 68° (surface angle image), as indicated by the color bar on the right hand side, where the surface slopes of the characteristic dome facets are indicated. Evidently, most of the islands exhibit very steep side facets at the perimeter that are inclined by up to 68° (red color) with respect to the (001) surface normal.