Liquid-precursor electron-beam-induced deposition of Pt nanostructures: dose, proximity, resolution

While electron-beam-induced deposition (EBID) from various gaseous precursors has been known and studied for decades, EBID from bulk liquid precursors is very much in its infancy and the following is only the second report on this technique. Here we present liquid-precursor (LP-)EBID of platinum (Pt) nanostructures from a dilute aqueous solution of chloroplatinic acid (H2PtCl6). We investigate how the lateral size of Pt nanoparticles (NPs) varies with charge dose, and how already deposited Pt NPs are affected by the subsequent deposition of their neighbors (proximity effect). We also demonstrate LP-EBID of dense arrays of small Pt dots (60 nm pitch, 30 nm diameter) and thin Pt lines (60 nm pitch, 25 nm width), which compare favorably with the typical resolution of resist-based electron-beam lithography.