Figure 2: Secondary electron image scanned with gallium ions at 45 degree sample tilt of 1.5 μm size square-shaped patterns milled in single-crystal silicon showcase different filling algorithms and timing. Meandering vertical lines filling from right to left was used in ((a) and (b)), and filling with concentric annular frames from center outward was used in ((c) and (d)). The full dose was delivered in one scan in (a) and (c), while the dose was distributed to 200 repetitions in (b) and (d). The ion dose is increasing downward along the squares by the same amount in all columns ((a)–(d)).