Fig. 1. Standard floating process needed for all foil production techniques. (a) After a silicon wafer or glass plate (grey) is covered with a thin water soluble sacrificial layer (green), the desired foil material is placed on it (blue). (b) When slowly floating the wafer, the sacrifice layer dissolves, leaving the foil swimming on the water surface. (c, d) After the whole foil is floated, it is contacted with a target holder where it sticks due to adhesion.

Fig. 2. (a) Sample points on a glass plate (top) as well as three example profiles of foils (bottom) obtained with 4% Formvar in dichlorethane. (b) Average thicknesses and standard deviation for the 10 samples that we prepared for each concentration. Each data point represents the 6–7 measuring points shown in (a).

Fig. 3. Distribution of a target thickness of a foil mounted on a target holder. The thickness was determined on each hole with the spectral refractometer. In the area relevant for experiments the variation does not exceed 10%.

Fig. 4. Two different 100 nm foils on a target holder. The emergence of bubbles can clearly be seen with Formvar (a) while there are no defects in the polystyrene foil (b).