Probe-based lithography, including: depositing a preceramic polymer on a substrate; writing nanoscale features in the polymer by locally transforming the preceramic polymer via a chemical reaction causing it to undergo a permanent phase change into hardened, ceramic material, the chemical reaction activated with a prescribed activation energy supplied by heat and/or pressure applied by a probe tip; then depositing new layers and continuing according to a desired three-dimensional pattern; either by (a) removing unactivated preceramic polymer utilizing a removal solvent, or (b) cross-linking unactivated preceramic polymer to act as a support medium that isolates a formed ceramic structure mechanically and/or electrically; and where the ceramic pattern is made electrically conductive by (a) incorporating dopant elements into or onto the preceramic polymer, or (b) performing the write step in a chemically-active environment that supplies dopant atoms during the chemical reaction.