AFM image (0.5 × 0.5 μm
) of the surface morphology after. (a) 1.2 nm Ge at 560°C, (b) 1.5 nm Ge at 580°C, (c) 1.2 nm Ge at 600°C (phase image), on vicinal Si (001) substrates with ~8° off toward ⟨110⟩, (d) height of nanowires vs growth temperature. The black arrows in (a), (b), and (c) denote the miscut direction of the substrates. The dashed line in (d) is for eye-guide. The numbers in (d) are the corresponding amount of nominal Ge deposition.