High-resolution electron-beam induced deposition

Abstract

A finely focused electron beam is used as a source of energy to decompose molecules, e.g., organometallics or hydrocarbons, adsorbed on the surface of a substrate. Films deposited by these means can be used as etch mask for reactive ion etching, as an absorber for various types of radiation, or directly as part of a device structure. A vector scan electron beam system with a LaB6 cathode has been equipped with a temperature controlled reservoir to supply vapors into a differentially pumped sample chamber. The substrate is mounted on a stage which can be cooled or heated in the range of −40 to +110 °C. The ability to utilize backscattered electron micro- scopy is maintained. Area, line, and spot deposition rates have been measured for tungsten hexacarbonyl [W(CO)6] and dimethyl–gold–trifluoro–acetylacetonate [Me2Au(tfac)] at various fluxes, sample temperatures, and current densities. Three-dimensional buildup of tips and free standing lines across holes in membranes and resolution better than 0.25 μm have been achieved. The composition of the deposited films has been analyzed and each deposit is rich in metal and carbon. Tungsten rich deposits can be used as a highly selective etch mask for oxygen plasmas. Effects limiting the ultimate resolution, such as backscattering from the substrate, and scattering from the deposited material are discussed.

Substrate temperature and electron fluence effects on metallic films created by electron beam induced deposition

“…The choice of these three molecules was predicated on their widespread use by the EBID community as precursors, and our understanding of the purely electron stimulated decomposition process. 7,8,10,11,16,19,[21][22][23][24][25][26][27][28][29][30][31][32] In addition, our results can be compared and benchmarked against compositional data that already exist from previous EBID studies where deposition was accomplished under more typical conditions. Our experimental approach involved exposing nanometer thick films of parent precursor molecules to different electron fluences.…”

A critical literature review of focused electron beam induced deposition

“…PE energies used for the deposition were 20 keV ͑+͒, 68 25, ͑͒, 25 and 200 keV ͑छ͒. 69 The gas flux again cannot be compared ͑no numbers are given or different units are used͒.…”

“…Examples are probes ͑functionalized tips for scanning probe microscopy or for local conductivity measurements͒, [6][7][8][9][10][11][12][13][14] conducting or nonconducting joining technique, [15][16][17][18][19][20] conducting wires, [21][22][23][24] mask repair, [25][26][27] electron sources, [28][29][30] micro-Hall and micro superconducting quantum interference devices, 31,32 nanotweezers and gripping devices, 33,34 nano-optic patterns or photonic crystals, 35,36 entire miniature electron optical systems, 37 diodes, 38 and seeds for nanotube growth. 39 Despite its long history, detailed knowledge of the process is still very much dispersed.…”

Fabrication, dynamics, and electrical properties of insulated scanning probe microscopy probes for electrical and electromechanical imaging in liquids

“…% W, 30% C and 15% O. 11 ͑PFM͒ imaging in ambient and liquid environments were measured using an Asylum Research MFP-3D AFM with an additional function generator and lock-in amplifier ͑DS 345 and SRS 844, Stanford Research Systems͒. The scanner head was modified to allow direct access to the tip deflection signals.…”