Improving the metallic content of focused electron beam-induced deposits by a scanning electron microscope integrated hydrogen-argon microplasma generator

Abstract

Articles you may be interested inPolymethyl methacrylate/hydrogen silsesquioxane bilayer resist electron beam lithography process for etching 25 nm wide magnetic wires J. Vac. Sci. Technol. B 32, 021601 (2014); 10.1116/1.4867753 Modular ultrahigh vacuum-compatible gas-injection system with an adjustable gas flow for focused particle beam-induced deposition Electrodes for carbon nanotube devices by focused electron beam induced deposition of gold Local coinjection of a ͑H 2 -Ar͒ microplasma jet and Cu͑O 2 C 5 F 6 H͒ 2 molecules during focused electron beam-induced deposition ͑FEBID͒ was studied with respect to changes in the Cu:C ratio of deposits. Microplasma-assisted FEBID ͑30 keV and 1 nA͒ decreased codeposition of carbon, oxygen, and fluorine originating from the chamber background and the precursor molecule. The copper metal content could be increased to 41 at. %, being almost four times more than in conventional FEBID deposits without coinjection. Conventional FEB deposits from Cu͑O 2 C 5 F 6 H͒ 2 resulted in 11-12 at. % Cu content. Microplasma post-treatments of conventional FEB deposits resulted in volume changes, surface roughening, and an increase of the overall Cu content to 27 at. %. The removal mechanisms were of nonthermal nature. At repulsive bias potentials from 0 to +30 V, a pure chemical etching of the carbonaceous matrix by atomic hydrogen radials occurred. At attractive bias potentials of up to Ϫ30 V, a more efficient ion induced chemical sputtering regime prevailed where Ar + ions break carbon bonds, which in turn will be passivated by atomic hydrogen radicals to form volatile hydrocarbon compounds.

Formation of pure Cu nanocrystals upon post-growth annealing of Cu–C material obtained from focused electron beam induced deposition: comparison of different methods

“…For the 15 μm long lines we used 100 µs dwell time per pixel, 0.5 nm pixel distance, and 300 line repetitions with a refreshment time of 3 s. The beam current was 1 nA, which corresponds to the dose of 9 nC/µm 2 and exposure time of 900 s. Tip deposits were obtained by the stationary dot exposure mode exposing a pixel for two minutes. Line and freestanding-rod deposits with (hfac)CuDMB and (hfac)CuVTMS from earlier FEBID experiments [39,40] were performed with a single scan at around 30 nm/s with 600 pA.…”

Dissociative electron attachment and electronic excitation in Fe(CO)5

“…5 The second common problem is that the purity of the deposits is often low -the inter-actions with secondary electrons lead to incomplete separation of ligands. A number of purification techniques has been suggested to compensate for this effect-for example reductive by atomic hydrogen 6 or oxidative with electron impact stimulated water, 7 but making a pure deposit directly would be preferable. For iron pentacarbonyl it has been shown that under specific ultrahigh vacuum conditions the autocatalytic decomposition leads to the purity of up to 95%.…”

Mechanism-based design of precursors for focused electron beam-induced deposition

“…[46] However, in the FEBID process, nanostructures deposited from these precursors contain significant carbon contamination. [47,48] UHV surface science studies of precursors containing bidentate chelating ligands found that the electronsimulated reactions are comprised of two steps, as seen for precursors containing exclusively monodentate ligands. However, the chemical reactions for these more complex precursors are less well-defined than for precursors that only contain simple monodentate ligands.…”