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Most approaches to implant single or few ions for quantum applications require the use of focused ion beams (FIB). In addition to the detection of ion implantation and laterally precise placement, the first consideration should also be the species as well as the emittance of the ion beam itself. While elements that are gaseous at room temperature can mainly provided by Gas Field Ion Sources or Plasma Ion Sources, most of the metals and semimetals afford the utilization of Liquid Metal Ion Sources (LMIS). Gallium has established in industry and science as easiest and most stable type of LMIS. For quantum applications other ion species like Li, B, C, N, Al, Si, P, Sb, Bi or the rare earth elements became from higher interest [1-6]. We give an overview about published metal alloys for FIBs and give an insight into the development and production of new sources. Finally, we give an outlook on current and future applications and activities. [1] L. Bischoff, et al., Micro Eng. 13, 367 (1991), 10.1016/0167-9317(91)90113-R [2] P. Mazarov, et al., JVST B 27, L47-L49 (2009), 10.1116/1.3253471 [3] L. Bischoff, et al., Appl. Phys. Rev. 3, 021101 (2016), 10.1063/1.4947095 [4] W. Pilz, et al., JVST B 37, 021802 (2019), 10.1116/1.5086271 [5] L. Bischoff, et al., JVST B 38, 042801 (2020), 10.1116/6.0000073 [6] N. Klingner, et al., BJNANO 11, 1742 (2020), 10.3762/bjnano.11.156

We present results for direct maskless magnetic patterning of ferromagnetic nanostructures using a special liquid metal alloy ion source for focused ion beam (FIB) systems. We used a Co36Nd64 alloy as the FIB source [1]. A Wien mass filter allows for quick switching between the ion species in the alloy without changing the FIB source. A 5000×1000×50 nm3 permalloy strip served as the sample. Using the FIB we implanted a 300-nm-wide track with Co ions (see Fig.1). We observed the Co-induced changes by measuring the sample with microresonator ferromagnetic resonance before and after the implantation. Structures as small as 30 nm can be implanted up to a concentration of 10 % near the surface. Such lateral resolution is hard to reach for other lithographic methods. This allows for easy magnetic modification of edge-localized spin waves. In another set of samples, we implanted Dy ions to locally increase the damping in a stripe pattern of ~120-nm-wide strips with 400 nm periodicity on a total area of 1×1 mm². Thus, the Gilbert damping parameter can be easily increased by one order of magnitude with a lateral resolution of about 100 nm. In contrast to electron beam lithography in combination with broad-beam ion implantation, the maskless FIB process does not require the cumbersome and difficult removal of the ion-hardened resist if optical measurements like BLS or TR-MOKE are needed.

The incident ion defines the interaction mechanism with the sample surface caused by the energy deposition and thus has significant consequences on resulting nanostructures [1]. Therefore, we have extended the FIB technology towards the stable delivery of multiple ion species by liquid metal alloy ion sources (LMAIS) [2]. These LMAIS provides single and multiple charged ion species of different masses. As an example we introduce the GaBiLi LMAIS [3]. Such “universal” source enables high resolution imaging with light Li ions and sample modification with Ga or heavy polyatomic Bi clusters, all coming from the same ion source. Light ions are of increasing interest due to the available high resolution in the nanometer range and their special chemical and physical behavior in the substrate. We compare helium and neon ion beams from a helium ion microscope with beams such as lithium, boron, and silicon, obtained from a mass-separated FIB using a LMAIS with respect to the imaging and milling resolution, as well as the current stability [4]. The bombardment of solids by poly-atomic (cluster) ions leads to nonlinear collision cascades in near-surface regions. In comparison with linear cascades by monoatomic ions, much higher energy deposition occurs up to local surface melting [5]. Here, we also report the study on the sputter yield of Si under the bombardment by atomic Bi+ and cluster Bin+ (n = 2-4) ions with the same specific energy related to one incidence single atom [6]. [1] P. Mazarov, V. Dudnikov, A. Tolstoguzov, Electrohydrodynamic emitters of ion beams, Phys. Usp. 63 (2020) 1219. [2] L. Bischoff, P. Mazarov, L. Bruchhaus, and J. Gierak, Liquid Metal Alloy Ion Sources – An Alternative for Focused Ion Beam Technology, Appl. Phys. Rev. 3 (2016) 021101. [3] W. Pilz, N. Klingner, L. Bischoff, P. Mazarov, and S. Bauerdick, Lithium ion beams from liquid metal alloy ion sources, JVSTB 37(2), Mar/Apr (2019) 021802. [4] N. Klingner, G. Hlawacek, P. Mazarov, W. Pilz, F. Meyer, L. Bischoff, Imaging and Milling Resolution of Light Ion Beams from HIM and Liquid Metal Alloy Ion Source driven FIBs, Beilstein J. Nanotechnol. 11 (2020) 1742. [5] L. Bischoff, K.-H. Heinig, B. Schmidt, S. Facsko, and W. Pilz, Self-organization of Ge nanopattern under erosion with heavy Bi monomer and cluster ions, Nucl. Instr. Meth. B 272 (2012) 198. [6] A. Tolstogouzov, P. Mazarov, A. Ieshkin, S.Belykh, N. Korobeishchikov, V. Pelenovich, D.J. Fu, Sputtering of silicon by atomic and cluster bismuth ions: An influence of projectile nuclearity and specific kinetic energy on the sputter yield, Vacuum 188 (2021) 110188.

Focused Ion Beam (FIB) processing is established as a well-suited and promising technique in R&D in nearly all fields of nanotechnology for patterning and prototyping on the μm-scale and below. Liquid Metal Alloy Ion Sources (LMAIS) represent an alternative to expand the FIB application fields beside all other source concepts [1]. Due to the interest on light elements, especially boron, various alloys were investigated and characterized. In this contribution we will describe Co31Nd64B5 as the most promising alloy in more detail. The mass spectrum of such a source was obtained in a VELION FIB-SEM system (Raith GmbH) [2]. The source operation life time was longer than 600 μAh and a first imaging characterization showed a lateral resolution of (30 ± 5) nm so far. This LMAIS is suited for several mass-filtered FIB applications like implantation, high rate sputtering, surface patterning or ion lithography [3]. The switching between the certain ion species. B – very light, suitable for ion lithography or writing p-type doping. Co – medium mass for applications in the field of nano-magnetics or CoSi2 for ion beam synthesis of conductive nano-structures on Si. Finally Nd as double charged heavy ion for ion sputtering. The change between ion species can be done in seconds and leads to remarkable expansion of the application spectrum of FIB technology. [1] L. Bischoff, P. Mazarov, L. Bruchhaus, and J. Gierak, Liquid Metal Alloy Ion Sources - An Alternative for Focused Ion Beam Technology; Appl. Phys. Rev. 3 (2016) 021101. [2] L. Bischoff, N. Klingner, P. Mazarov, W. Pilz, and F. Meyer, Boron Liquid Metal Alloy Ion Sources for special FIB applications, JVST B 38 (2020) 042801. [3] L. Bruchhaus, P. Mazarov, L. Bischoff, J. Gierak, A. D. Wieck, and H. Hövel, Comparison of Technologies for Nano Device Prototyping with a Special Focus on Ion Beams – A Review, Appl. Phys. Rev. 4 (2017), 011302.

Light ions are of increasing interest by application of focused ion beam (FIB) techniques due to the available high beam resolution in the nanometer range and their special chemical and physical behavior in the substrate [1, 2]. We compare helium and neon ion beams from a helium ion microscope with ion beams such as lithium, boron, and silicon, obtained from a mass-separated FIB using a liquid metal alloy ion source (LMAIS) with respect to the imaging and milling resolution, as well as the current stability [3]. While He+ offers, experimentally and in simulations, the smallest minimum trench width, light ion species such as Li+ from a LMAIS [4] offer higher milling rates and ion currents while outperforming the milling resolution of Ne+ from a gas field ion source. The comparison allows one to select the best possible ion species for the specific demands in terms of resolution, beam current, and volume and time for milling. References [1] L. Bischoff et al., Appl. Phys. Rev. 3 021101 (2016). [2] P. Mazarov et al., Phys. Usp. 63 1219–1255 (2020). [3] N. Klingner et al., Beilstein J. Nanotechnol. 11 1742–1749 (2020). [4] W. Pilz et al., JVSTB 37 021802 (2019).

The incident ion defines the interaction mechanism with the sample surface caused by the energy deposition and thus has significant consequences on resulting nanostructures [1]. In addition, nanofabrication requirements for FIB technologies are specifically demanding in terms of patterning resolution and stability [2]. Therefore, we have extended the technology towards a stable supply of multiple ion species selectable into a nanometer scale focused ion beam by employing a liquid metal alloy ion source (LMAIS) [3]. This LMAIS provides single and multiple charged ion species of different masses, resulting in significantly different interaction mechanisms. Nearly half of the elements of the periodic table are thus made available in the FIB technology because of continuous research in this area [4]. This range of ion species with different mass or charge can be beneficial for various nanofabrication applications. Recent developments could make these sources to an alternative technology feasible for nanopatterning challenges. In this contribution, the operation principle, first results and prospective domains for modern FIB applications will be presented. As examples, we will introduce the AuGeSi and GaBiLi LMAIS [5, 6]. Both sources provide light and heavy ions available from a single source to tailor chemical and physical properties of resulting nanostructures. GaBiLi enables high resolution imaging with light Li ions and sample modification with Ga or heavy polyatomic Bi clusters, all coming from one ion source. For sub-10 nm focused ion beam nanofabrication and microscopy, the GaBiLi-FIB could benefit of providing additional ion species in a mass separated FIB without changing the ion source. [1] P. Mazarov, V. Dudnikov, A. Tolstoguzov, Electrohydrodynamic emitters of ion beams, Phys. Usp. 63, 1219 (2020). [2] L. Bruchhaus, P. Mazarov, L. Bischoff, J. Gierak, A. D. Wieck, and H. Hövel, Comparison of technologies for nano device prototyping with a special focus on ion beams: A review, Appl. Phys. Rev. 4, 011302 (2017). [3] L. Bischoff, P. Mazarov, L. Bruchhaus, and J. Gierak, Liquid Metal Alloy Ion Sources – An Alternative for Focused Ion Beam Technology, Appl. Phys. Rev. 3, 021101 (2016). [4] J. Gierak, P. Mazarov, L. Bruchhaus, R. Jede, L. Bischoff, Review of electrohydrodynamical ion sources and their applications to focused ion beam technology, JVSTB 36, 06J101 (2018). [5] W. Pilz, N. Klingner, L. Bischoff, P. Mazarov, and S. Bauerdick, Lithium ion beams from liquid metal alloy ion sources, JVSTB 37, 021802 (2019). [6] N. Klingner, G. Hlawacek, P. Mazarov, W. Pilz, F. Meyer, and L. Bischoff, Imaging and milling resolution of light ion beams from helium ion microscopy and FIBs driven by liquid metal alloy ion sources, Beilstein J. Nanotechnol. 11, 1742 (2020).

The application of Focused Ion Beams (FIB) has become a well-established and promising technique for patterning and prototyping on the nm-scale in research and development. Light ions in the range of m = 1 … 28 u (hydrogen to silicon) are of increasing interest due to the available high beam resolution in the nm range and their special chemical and physical behavior in the substrate. In this work helium and neon ion beams from a Helium Ion Microscope (HIM) are compared with ion beams like beryllium, lithium, boron, carbon and silicon obtained from a mass separated FIB using Liquid Metal Alloy Ion Sources (LMAIS) with respect to their imaging and milling resolution.

Focused Ion Beam (FIB) processing has been developed into a well-established and still promising technique in nearly all fields of nano-technology in particular for direct patterning and proto-typing on the µm scale and well below. Beside new ion source developments based on gas field emission (GFIS), on ionic liquids (ILIS), on magneto-optical traps (MOTIS) or on ICP or ECR sources for Xe-FIB as well as the nearly exclusively used gallium Liquid Metal Ion Sources (LMIS), the replacement of Ga by alloys therein with an adapted FIB optics design can open bright field of new employments. Local ion implantation, ion beam mixing, ion beam synthesis or Focused Ion Beam Lithography (IBL) in the µm- or nm range can benefit from ion species purposely selected in parallel to gallium or noble gases. Therefore, exploring the Liquid Metal Alloy Ion Sources (LMAIS) potential represent a promising alternative to expand the global FIB application fields. Especially, IBL as direct, resistless and three-dimensional patterning enables a simultaneous in-situ process control by cross-sectioning and inspection. Thanks to this nearly half of the elements of the periodic table are made available in the FIB technology as a result of continuous research in this area during the last forty years. Key features of a LMAIS are long life-time, high brightness and stable ion current. Recent developments could make these sources as an alternative technology feasible for nano patterning challenges e.g. to tune electrical, optical, magnetic or mechanic properties. In this contribution the operation principle, the preparation and testing technology as well as prospective domains for modern FIB applications will be presented. As an example we will introduce a Ga35Bi60Li5 LMAIS in detail. It enables high resolution imaging with light Li ions and sample modification with Ga or heavy polyatomic Bi clusters, all coming from one ion source. L. Bischoff, P. Mazarov, L. Bruchhaus, and J. Gierak, Appl. Phys. Rev. 3, 021101 (2016).

Nanofabrication requirements for FIB technologies are specifically demanding in terms of patterning resolution, stability and the support of new processing techniques. Additionally, the type of ion defines the nature of the interaction mechanism with the sample and thus has significant consequences on the resulting nanostructures [1]. Therefore, we have extended the technology towards the stable delivery of multiple ion species selectable into a nanometer scale focused ion beam by employing a liquid metal alloy ion source (LMAIS) [2]. This LMAIS provides single and multiple charged mon- as well as polyatomic ion species of different masses, resulting in significantly different interaction mechanisms. Nearly half of the elements of the periodic table are thus made available in the FIB technology as a result of continuous research in this area [3]. This range of ion species with different mass or charge can be beneficial for various nanofabrication applications. Recent developments could make these sources to an alternative technology feasible for nanopatterning challenges. In this contribution, the operation principle, the preparation and testing process as well as prospective domains for modern FIB applications will be presented. As an example we will introduce the GaBiLi LMAIS. It enables high resolution imaging with light Li ions and sample modification with Ga or heavy polyatomic Bi clusters, all coming from one ion source. For sub-10 nm focused ion beam nanofabrication and microscopy, the GaBiLi-FIB or the AuSiGe-FIB could benefit of providing additional ion species in a mass separated FIB without changing the ion source. [1] L. Bruchhaus, P. Mazarov, L. Bischoff, J. Gierak, A. D. Wieck, and H. Hövel, Comparison of technologies for nano device prototyping with a special focus on ion beams: A review, Appl. Phys. Rev. 4, 011302 (2017). [2] L. Bischoff, P. Mazarov, L. Bruchhaus, and J. Gierak, Liquid Metal Alloy Ion Sources – An Alternative for Focused Ion Beam Technology, Appl. Phys. Rev. 3 (2016) 021101. [3] J. Gierak, P. Mazarov, L. Bruchhaus, R. Jede, L. Bischoff, Review of electrohydrodynamical ion sources and their applications to focused ion beam technology, JVSTB 36 (2018). [4] W. Pilz, N. Klingner, L. Bischoff, P. Mazarov, and S. Bauerdick, Lithium ion beams from liquid metal alloy ion sources, JVSTB 37(2), Mar/Apr (2019).

Focused Ion Beams (FIB) gain an increasing interest in the field of nanotechnology particular for prototyping of microelectronic devices, patterning of 2D materials, high resolution imaging or high resolution ion lithography1. Concerning ion beam resolution and minimization of unwanted damage, light ions like He or Li are preferred candidates. Liquid metal alloy ion sources (LMAIS) with a life time of more than 1000 µAh on the basis of Ga35Bi60Li5 and Sn95Li5 alloys were developed, characterized and finally applied in a commercial mass-separated VELION FIB-SEM system (Raith GmbH). The resolution for imaging and also for the formation of nanostructures using a thin gold film was determined. In the case of Li ions from the mass separated FIB a lateral resolution of 5.6 nm could be obtained in first experiments2 and the sputter yield was determined to 0.4 for 35 keV Li ions on Au. For reference, the helium ion microscope (HIM) has a lateral resolution of about 0.5 nm and 1.8 nm, for He and Ne respectively, He has a sputter yield of 0.13. For sub-10 nm focused ion beam nanofabrication and microscopy, the GaBiLi-FIB or the SnLi-FIB could therefore be considered alternatives to the HIM with the benefit of providing additional ion species in a mass separated FIB without changing the ion source. 1 L. Bischoff et al. Appl. Phys. Rev. 3, 021 101 (2016). 2 W. Pilz et al. J. Vac. Sci. Technol. B A-18-399 (submitted, 2018). 3 G. Hlawacek et al. J. Vac. Sci. Technol. B 32, 020 801 (2014).

Focused Ion Beam (FIB) processing has been developed into a well-established and still promising technique for direct patterning and proto-typing on the nm scale. Exploring the Liquid Metal Alloy Ion Sources (LMAIS) potential represents a promising alternative to expand the global FIB application fields. Especially, Ion Beam Lithography (IBL) as direct, resistless and three-dimensional patterning enables a simultaneous in-situ process control by cross-sectioning and inspection. Thanks to this, nearly half of the elements of the periodic table are made available in the FIB technology as a result of continuous research in this area during the last forty years. Key features of a LMAIS are long life-time, high brightness and stable ion current. Recent developments could make these sources to an alternative technology feasible for nano-patterning challenges, e.g. to tune electrical, optical, magnetic or mechanical properties. In this contribution the operation principle, the preparation and testing process as well as prospective domains for modern FIB applications will be presented. As an example we will introduce a Ga35Bi60Li5 LMAIS in detail. It enables high resolution imaging with light Li ions and sample modification with Ga or heavy polyatomic Bi clusters, all coming from one ion source. L. Bischoff, P. Mazarov, L. Bruchhaus, and J. Gierak, Appl. Phys. Rev. 3, 021101 (2016).

Focused Ion Beam (FIB) processing, which is nearly exclusively based on gallium Liquid Metal Ion Sources (LMIS) [1] expands more and more to other ion species also by implementation of other types of ion sources. Many applications in nano-technology could benefit from ion species other than gallium, like local doping by ion implantation, ion beam mixing, ion beam synthesis [2], or direct milling using various ions [3]. The application of Gas Field Ion Sources (GFIS) opens the sub-nm range for ion microscopy in the case of He [4]. A key parameter of FIB applications is the spatial resolution in terms of full width at half maximum (FWHM) of the beam profile, which can be described by e.g. two Gaussian functions or a Holtsmark distribution. Three main parts contribute to the obtainable resolution: a source term containing the virtual source size and the magnification, the spherical aberration, describing geometrical effects and the chromatic aberration depending on the energy spread of the ion source [5]. All contents are influenced by the ion source itself as well as the performance of the ion optics. For an optimum image resolution another shape of the beam profile with a sharp tip should be chosen by a suited alignment than for surface patterning by ion milling where more parallel slopes of the distribution a preferred. For a minimum feature size the beam interaction with the surface as well as the combination of ion species and target material must be put into consideration. In this contribution the beam resolution will be basic discussed for a broad spectrum of ions beginning for light species, Helium Ion Microscope (Fig. 1) and Be from an AuSiBe LMAIS in a mass separated FIB (Fig. 2) up to very heavy ones, like Au, Bi and polyatomic clusters from them. The obtainable FIB resolution in the image and the patterning mode will be compared and discussed. [1] J. Gierak; Focused ion beam technology and ultimate applications, Sem. Sci. Technol. 24 (2009), 1. [2] L. Bischoff, P. Mazarov, L. Bruchhaus and J. Gierak; Liquid metal alloy ion sources – An alternative for focused ion beam technology, Appl. Phys. Rev. 3 (2016), 021101. [3] S. Bauerdick et al.; Multispecies focused ion beam lithography system and its applications, J. Vac. Sci. Technol. B 31 (2013), 06F404-1. [4] G. Hlawacek, V. Veligura, R. van Gastel, and B. Poelsema; Helium ion microscopy, J. Vac. Sci. Technol. B 32 (2014), 020801-1. [5] R.G. Forbes in Charged Particle Optics, ed. J. Orloff, CRC Press (2009).

One of the most important elements of a Focused Ion Beam (FIB) system is the ion source which has to guarantee a stable, long life working in the needed application field with the required properties. Main points are the achievable focus of the spot, the ion current, the energy and also the ion species itself. At present nearly half of elements of the periodic table can be used in FIB equipment to modify or tune locally electrical, optical, mechanic or magnetic properties. Depending on the special task very different types of ion sources can be found. Among them the Liquid Metal Ion Sources (LMIS) mostly used for Ga and derived from that the Liquid Metal Alloy Ion Sources (LMAIS) [1] are most popular ones having a brightness of 106 A/cm² sr. The obtainable resolution is a few nm with ion currents of some pA. In a similar manner Ionic Liquid Ion Sources (ILIS) work using salts or certain compounds from which positive and negative mono- and polyatomic ions can be emitted [1,2]. Due to the limited ion current in such sources to lower than 100 nA and so applications like larger volume removing are restricted. ECR or RF plasma sources can fill the gap working with heavy Xe ions and currents up to 2 µA [3,4]. In the last decade a long known source was rediscovered – the Gas Field Ion Source (GFIS) and generate the initial point for the successful development of the Helium Ion Microscope (HIM) [5]. A final lateral spot size of about half nm opens new prospects in the field of ion microscopy and nano-engineering. Another modern and interesting approach is the magneto-optical trap ion source (MOTIS) successful demonstrated for Cr and Li ions [6]. All ion sources used in FIB systems will be compared, characterized, discussed and described with a typical application. [1] L. Bischoff, P. Mazarov, L. Bruchhaus, and J. Gierak, Liquid Metal Alloy Ion Sources – An Alternative for Focused Ion Beam Technology, Appl. Phys. Rev. 3 (2016) 021101. [2] A. N. Zorzos and P. Lozano, The use of ionic liquid ion sources in focused ion beam applications, J. Vac. Sci. Technol. B 26 (2008) 2097. [3] A. Delobbe, O. Salord, T. Hrncir, A. David, P. Sudraud and F. Lopour, High Speed TEM Sample Preparation by Xe FIB, Microsc. Microanal. 20 (2014) 298. [4] T.L. Burnetta, R. Kelley, B. Winiarski, L. Contreras, M. Daly, A. Gholinia, M.G. Burke, and P.J. Withers, Large volume serial section tomography by Xe Plasma FIB dual beam Microscopy, Ultramicroscopy 161 (2016) 119. [5] G. Hlawacek, V. Veligura, R. van Gastel, and B. Poelsema, Helium ion microscopy, J. Vac. Sci. Technol. B 32 (2014) 020801. [6] B. Knuffman, A. V. Steele, J. Orloff, M. Maazouz, and J. J. McClelland, A Focused Ion Beam Source Based On Laser-Cooled Atoms, AIP Conference Proceedings 1395 (2011) 85.

The patterning of samples using Focused Ion Beams (FIB) is very popular, widely used both for industrial [1] and emerging nanoscience prototyping applications [2]. This FIB technique allows 3D and direct patterning of target materials using a finely focused pencil of ions having speeds of several hundreds of km/seconds at impact with a penetration range of a few tens of nanometres. Thanks to this, local information and/or modifications can be obtained at the target surface. In what the ion nature is concerned, apart that many elements can be used in FIB technology as pure elements or in the form of alloys, gallium (Ga+ ions) is often preferred. Traditionally for several decades FIB technology has been mainly based on gallium Liquid Metal Ion Sources (LMIS). LMIS are also known as electrohydrodynamically (EHD) driven ion emitters operating in a cone-jet mode. The very high brightness, long lifespan, small source size, and easy handling of this emitter remain its chief and most decisive advantages. On the other hand, some weaknesses are also well known that inhibit the resolution of EHD/LMIS-based FIBs. Therefore progress on ion sources operational characteristics still remains very desirable. In this presentation we will first summarize our work aiming at understanding, optimizing and evaluating gallium LMIS “needle type” performances. In particular stable operation at lowest possible emission currents will be detailed. The gains in terms of patterning resolution and beam selectivity [3], we will evaluate, are firm evidence that progresses can still be expected from this mature technology. We will then review and detail the advantages of Liquid Metal Alloy Ion Sources (LMAIS) that represent a promising alternative to expand the already remarkable application field and potential of FIB machines in the field of nanosciences. Indeed selecting the best suited elements transported in a focused ion beam can open new nanofabrication routes. In this presentation we will explain that nearly half of the elements of the periodic table can already be made available to the FIB technology as a result of a continuous research effort in this area [4] and how, in our opinion, nanofabrication shall now take benefit of these capabilities. Finally we will introduce our new addition to the arsenal of EHD driven devices: The Ionic Liquid Ion Sources (ILIS). ILIS are capable to produce ion beams through field-evaporation, also in the cone-jet mode, but from room temperature molten-salts [5]. The possibility of extracting both positive and negative ions at emission current several orders of magnitude below LMIS standards is already a very appealing perspective in terms of source virtual source size and brightness. Then we will show that ILIS allows to access new ionic species thanks to the almost limitless chemical engineering latitude of molten salts. Moreover subsequent tuning can be achieved via selecting the tip polarity, the ion emission current and the ion landing energy. We will show the possibility to achieve a new kind of FIB patterning using a beam of chemically reactive ion radicals native in the transported beam. This represents a formidable perspective for FIB technology. In conclusion we will summarize our vision on the future of FIB technology based on electrohydrodynamically (EHD) driven emitters operating in the conejet mode, both in terms of performances, versatility and on the science frontiers these might help to push. [1] J. Orloff, Scientific American Oct. 1994, pp.74-79 [2] J. Gierak Nanofabrication 2014; Volume 1: pp. 35–52 [3] J. Gierak and R. Jede, Patent US8546768 B2, WO2010029270A1; Sept 2008 [4] L. Bischoff, P. Mazarov, L. Bruchhaus, and J. Gierak, Appl. Phys. Rev. 2016; 3: pp. 021101 [5] C. Perez-Martinez, J. Gierak, and P. C. Lozano, P106 (Invited), EIPBN Conference, May 31- June 3, 2016, Pittsburgh, PA

Today Focused Ion Beam (FIB) processing is nearly exclusively based on gallium Liquid Metal Ion Sources (LMIS). But, many applications in the µm- or nm range could benefit from ion species other than gallium: local ion implantation, ion beam mixing, ion beam synthesis or Focused Ion Beam Lithography (IBL). Therefore Liquid Metal Alloy Ion Sources (LMAIS) represent a promising alternative to expand remarkable the application fields for FIB. Especially the IBL process shows potential advantages over e.g. electron beam (EBL) or other lithography techniques: direct, resistless, and three-dimensional patterning, enabling a simultaneous in-situ process control by cross sectioning and inspection. Taking additionally into account that the used ion species influence significantly the physical and chemical nature of the resulting nanostructures -in particular the electrical, optical, magnetic and mechanic properties- leading to a large potential application area which can be tuned by choosing a well suited LMAIS. Nearly half of the elements of the Periodic Table are recently available in FIB technology as a result of continuous research in this area during the last forty years. Key features of a LMAIS are long life-time, high brightness and stable ion current. Recent developments could make these sources feasible for nano patterning issues as an alternative technology more in research than in industry. The authors will review existing LMAIS, working with pure elements (LMIS) other than Ga or binary or ternary alloys, their physical properties as well as the fabrication technology and prospective domains for modern FIB applications. Other emerging ion sources will be also presented and their performances discussed.

At this time Focused Ion Beam (FIB) technology is dominated by gallium Liquid Metal Ion Sources (LMIS). But, despite new developments like He/Ne ion microscopes or Xe-FIBs many applications in the µm- or nm range could benefit from ion species other than gallium or noble gases: local ion implantation, ion beam mixing, ion beam synthesis or even Focused Ion Beam Lithography. For this special use cases Liquid Metal Alloy Ion Sources (LMAIS) represent a promising alternative to expand the remarkable application fields for FIB [1]. Switching between the certain species obtained from a chosen alloy using an ExB mass filter in the ion optical column can be applied to change significantly different physical and chemical characteristics of the resulting nanostructures. In other words the electrical, optical, magnetic and/or mechanic properties can be tuned. This offers a large application potential by choosing a well suited LMAIS. Now nearly half of the elements of the Periodic Table are available in FIB technology. Main properties of a modern LMAIS should be long life-time, high brightness and stable ion current emission. This contribution will involve the physical basics and experimental results of LMAIS, their physical properties and questions of the preparation technology for elementary as well as binary and ternary alloys as source material. Furthermore selected applications of these sources in highly focused beams are given feasible for nano patterning issues as an alternative technology more in research than in industry. [1] L. Bischoff, P. Mazarov, L. Bruchhaus, and J. Gierak, Liquid metal alloy ion sources—An alternative for focused ion beam, Appl. Phys. Rev. 3 (2016) 021101.

Presently Focused Ion Beam (FIB) processing is dominated by gallium Liquid Metal Ion Sources (LMIS). But, beside new developments in this field like He/Ne ion microscopes or Xe-FIBs many applications in the µm- or nm range could benefit from ion species other than gallium or noble gases: local ion implantation, ion beam mixing, ion beam synthesis or even Focused Ion Beam Lithography. Therefore Liquid Metal Alloy Ion Sources (LMAIS) represent a promising alternative to expand the remarkable application fields for FIB [1,2]. Simple switching between the certain ion species using an ExB mass filter can be applied to change significantly the physical and chemical nature of the resulting nanostructures -in other words the electrical, optical, magnetic and mechanic properties. This offers a large application potential which can be tuned by choosing a well suited LMAIS. Now nearly half of the elements of the Periodic Table are available in FIB technology. Main properties of a modern LMAIS are long life-time, high brightness and stable ion current. This contribution will cover the physical basics and experimental results of LMAIS, their physical properties (I-V characteristics, energy spread) and questions of the preparation technology using elementary as well as binary and ternary alloys as source material. Furthermore selected applications will be presented to underline the impact of these sources in modern nanotechnology by highly focused ion beams. Recent developments could make these sources feasible for nano patterning issues as an alternative technology more in research than in industry. References [1] L. Bischoff: “Application of mass-separated focused ion beams in nano-technology”, Nucl. Instr. Meth. B 266 (2008), 1846. DOI:10.1016/j.nimb.2007.12.008 [2] L. Bischoff, P. Mazarov, L. Bruchhaus, and J. Gierak: „Liquid Metal Alloy Ion Sources - An Alternative for Focused Ion Beam Technology” , Appl. Phys. Rev. 3 (2016) 021101-1-30 [3] L. Bischoff and Ch. Akhmadaliev: “An alloy liquid metal ion source for lithium”, J. Phys. D: Appl. Phys. 41 (2008) 052001. DOI:10.1088/0022-3727/41/5/052001

Recently, mass separated focused ion beams (FIB) become an increasing interest for local doping in nano-devices for optical, electrical or magnetic applications [1]. So on the basis of very stable metallic glass alloys, like AuSi or AuGe with a low melting point at 365°C different ion sources were developed and tested due to their performance in FIB systems. In detail, Au68Ge22B5Ni5, Au80Si12Sb8, Au68Ge28Mn10 alloys were analysed concerning the on-set and emission behaviour and the mass spectra. Among clusters, molecular ions, single and doubly charged species such important ions like boron for p-doping in silicon, antimony for n-doping in silicon or manganese for quantum dot fabrication in II-VI semiconductors (CdSe, CdS, ZnS) could be extracted. [1] L. Bischoff, NIM B266 (2008) 1846.

A Silver-Germanium Liquid Alloy Ion Source (LAIS) was developed and is available. Good beam performance was obtained for application in any commercial focused ion beam (FIB) system. Emission current dependent measurements were carried out of the mass spectra and energy spreads of all ion components. The ratios of doubly- and singlecharged clusters to single-charged monomer ions were determined. The AgGe-LMAIS can be very helpful for controlled formation of silver quantum wires. [1] Thibaut Capron et.al. Phys. Rev. B77, 033102 (2008).