Growth competition during glancing angle deposition of nanorod honeycomb arrays

Arrays of Ta nanorods were grown by glancing angle deposition (GLAD) onto honeycomb Cr nanodot patterns that were evaporated onto Si substrates through a self-assembled monolayer of SiO2 nanospheres. Statistical size analyses from arrays of rods with variable average length l and width w, with 210nm⩽l⩽650nm and 109nm⩽w⩽304nm, show that the distribution in w broadens with increasing l and decreasing w, but remains approximately constant with a fixed l∕w ratio. This is attributed to an intercolumnar growth competition that exacerbates nanorod size fluctuations but scales with rod size. These results suggest that the overall nanostructure shapes during low-temperature GLAD are independent of material-specific length scales and are, therefore, completely controlled by the geometric shadowing.