Figure 4.

Thickness and line width at various biases. Height/bias dependence for oxide lines (a) and carbonaceous lines (b). AFM topographies and profiles refer to features written at 1 μm s⁻¹. (c to f) Height/bias relation plotted for different Si surfaces, Si:OH or pristine (with native oxide layer), H-terminated, and methyl-terminated; for positive tip bias (carbonaceous), we show the Si(H) surface. Black marks refer to height, and red marks refer to the line width expressed as FWHM. The smallest lateral resolution (<40 nm) is achieved for oxide features on Si(H); similar line width is observed for Si(CH₃), while as the surface becomes more hydrophilic, line width raises above 100 nm (d). As expected, oxide height (c to e) increases linearly with bias for all surfaces in the 5- to 11-V interval with a similar height/bias dependence. With a negative sample bias, the deposition still depends on voltage (f).