Figure 1

Nanowires grown on Ga-deoxidized substrate. (A-C) Sideview scanning electron microscope (SEM) images of the three different wafer positions as marked in (D), corresponding to different oxide layer thicknesses. (D) An optical image of a full 2-inch wafer where the oxide has only been removed in the outer part. Area (A) is an example of growth regime 3 and areas (B, C) are from growth regime 2 (see text). The absence of parasitic bulk structures makes area (B) superior to area (C). White scale bars are 1 μ m.