A critical literature review of focused electron beam induced deposition

Abstract

An extensive review is given of the results from literature on electron beam induced deposition. Electron beam induced deposition is a complex process, where many and often mutually dependent factors are involved. The process has been studied by many over many years in many different experimental setups, so it is not surprising that there is a great variety of experimental results. To come to a better understanding of the process, it is important to see to which extent the experimental results are consistent with each other and with the existing model. All results from literature were categorized by sorting the data according to the specific parameter that was varied ͑current density, acceleration voltage, scan patterns, etc.͒. Each of these parameters can have an effect on the final deposit properties, such as the physical dimensions, the composition, the morphology, or the conductivity. For each parameter-property combination, the available data are discussed and ͑as far as possible͒ interpreted. By combining models for electron scattering in a solid, two different growth regimes, and electron beam induced heating, the majority of the experimental results were explained qualitatively. This indicates that the physical processes are well understood, although quantitatively speaking the models can still be improved. The review makes clear that several major issues remain. One issue encountered when interpreting results from literature is the lack of data. Often, important parameters ͑such as the local precursor pressure͒ are not reported, which can complicate interpretation of the results. Another issue is the fact that the cross section for electron induced dissociation is unknown. In a number of cases, a correlation between the vertical growth rate and the secondary electron yield was found, which suggests that the secondary electrons dominate the dissociation rather than the primary electrons. Conclusive evidence for this hypothesis has not been found. Finally, there is a limited understanding of the mechanism of electron induced precursor dissociation. In many cases, the deposit composition is not directly dependent on the stoichiometric composition of the precursor and the electron induced decomposition paths can be very different from those expected from calculations or thermal decomposition. The dissociation mechanism is one of the key factors determining the purity of the deposits and a better understanding of this process will help develop electron beam induced deposition into a viable nanofabrication technique.

Tuning the electrical conductivity of Pt-containing granular metals by postgrowth electron irradiation

“…The origin of carbon removal was attributed to local heating [27,37] and knock-on [38] effects. In our experiment, these effects cannot be at the origin of carbon removal because the current and energy of the electron beam are too small [8]. Rather, we speculate that the loss of carbon is due to an electron-beam induced reaction of carbon with the residual gas molecules (in particular H2O and O2) present in the SEM chamber at the base pressure of 4 10−6 mbar.…”

“…In the last years, among the techniques used to prepare granular metals focused electron beam induced deposition (FEBID) has received much attention [2,8]. FEBID is a versatile direct-write technique employed to fabricate samples at nanoscale.…”

Enhanced spin accumulation at room temperature in graphene spin valves with amorphous carbon interfacial layers

“…This process is well established 22 and has been used, for example, to fabricate complex carbon structures, 23 conducting bridges, 24 and contacts with carbon nanotubes. 19 Carbon precursors can either be introduced externally using a gas source or simply be present as residual hydrocarbons at the background pressure of a scanning electron microscope (SEM) chamber.…”

Optimized cobalt nanowires for domain wall manipulation imaged by in situ Lorentz microscopy

“…FEBID uses a focused electron beam to locally decompose an organometallic gas injected in the proximity of a substrate and induces the growth of a deposit of the metal on the substrate surface. 17,18 By tuning multiple growth parameters, high purity deposits can be produced. Particularly cobalt (Co) nanostructures have been obtained with purities up to 95% so these deposits present optimal properties matching those of the bulk counterpart.…”