Figure 5
Successive Ge growth on patterned Si substrates with “V”-shaped stripes for two different substrate temperatures of T s = 520°C (top) and 600°C (bottom) as seen by STM (500 × 500 nm2 images). The Ge coverage increases from 4.5 ML on the left hand side where sidewall ripple formation starts, to 5.1 ML in the middle, to finally to 6 ML, respectively, 7 ML on the right hand side. The average ripple height at 4.5 ML coverage is 9.3 ± 0.5 Å at 520°C and 5.7 ± 0.5 Å at 600°C. Dome islands are only formed at the higher growth temperature and are aligned at the bottom of the grooves. The surface orientation maps of the STM images are shown as insets in which the observed {001}, {105}, {113}, and {15 3 23} facet spots are indicated by the symbols