The substrate used for preparation of samples is Si(111), but similar results are obtained for Cu foil substrates (Supplementary Fig. 6). a Topography and elastic moduli of samples 25C, 54V, and 155S. The same scale is used in E mappings of the three samples for easier comparison; note that E of 54V is saturated in a high fraction of the mapping. b Histograms of E for several indicated samples. E increases from the columnar to the vaulted structure (upper histogram) and decreases for the sedimentary structure (lower histogram). c E values with the highest weights in the histogram plotted against film thickness, h, of all samples. The change of E vs. h corresponds to the transition from columnar to Volmer–Weber silicon growth, which is the region where column tops touch and form a vaulted structure.