AFM amplitude image of (a) a-Si and (b) a-Ge single layer after annealing at 350°C for 4 h. H flow rate 1.5 ml/min. In (a) bumps (close bubbles with H still inside) are predominant (only one is broken). In (b) large craters, i.e. exploded bumps with escape of H, are by far predominant. Very tiny bumps are also present.
Frigeri et al. Nanoscale Research Letters 2011 6:189 doi:10.1186/1556-276X-6-189