Fig. 1. Schematic layout of the experimental system. Water vapor deposits on the cold sample surface under vacuum (LV), and the electron beam responsible both for charging and imaging the deposited layer is injected from an SEM column at ultra-high vacuum (UHV). The secondary electrons detector is also shown. Inset shows an image of deposited ASW layer in ESEM vacuum chamber.

Fig. 2. SEM image of ASW layer deposited at 1.2 Torr vapor pressure, on charged sapphire surface: (a) complete area affected by surface charge; (b) high-magnification image of ASW, with the left-hand side of the image showing cauliflower-like shaped grains affected by the surface charge and the right-hand side showing the dense and flat ASW.

Fig. 3. (a) ASW deposited on sapphire substrate before charging; (b) ASW target deposited at 1.9 Torr, after 60 s charging; (c) ASW target deposited at 1.5 Torr, after 60 s charging; and (d) ASW target deposited at 1.5 Torr, after 120 s charging.

Fig. 4. (a) ASW target deposited at 1.5 Torr, after 60 s charging; (b) ASW target deposited at 1.5 Torr, after 120 s charging; (c) ASW target deposited at 1.9 Torr, after 60 s charging.

Fig. 5. ASW deposited at 0.7 Torr, on a buffer ASW layer after 60 s charging at 1.57 nA.

Table 1. Effect of deposition condition on ASW target morphology.