Figure 2.

Etching test on lines written alternatively by oxidation or carbon deposition. On the left, AFM topography and height profiles of single lines written with opposite bias (±10-V tip bias, 0.5-μm s⁻¹ writing speed). On the right, the same pattern after 1-min etching in aqueous HF 5 wt.%. The carbonaceous residual shows etch resistance while oxide is readily removed. Scale bare is 1 μm in both.