For future nanoelectronic devices – such as room-temperature single electron transistors – the site-controlled formation of single Si nanocrystals (NCs) is a crucial prerequisite. Here, we report an approach to fabricate single Si NCs via medium-energy Si+ or Ne+ ion beam mixing of Si into a buried SiO2 layer followed by thermally activated phase separation. Binary collision approximation and kinetic Monte Carlo methods are conducted to gain atomistic insight into the influence of relevant experimental parameters on the Si NC formation process. Energy-filtered transmission electron microscopy is performed to obtain quantitative values on the Si NC size and distribution in dependence of the layer stack geometry, ion fluence and thermal budget. Employing a focused Ne+ beam from a helium ion microscope, we demonstrate site-controlled self-assembly of single Si NCs. Line irradiation with a fluence of 3000 Ne+/nm2 and a line width of 4 nm leads to the formation of a chain of Si NCs, and a single NC with 2.2 nm diameter is subsequently isolated and visualized in a few nanometer thin lamella prepared by a focused ion beam (FIB). The Si NC is centered between the SiO2 layers and perpendicular to the incident Ne+ beam.

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PECVD and PEALD of ruthenium films using RuEtcp 2 as a precursor and N 2 /H 2 /Ar plasma as a reducing agent were characterized. A self-adjusting process to overcome the previously reported inhibition of Ru PEALD on TaN substrates was investigated. Ellipsometric modelling of Ru films was demonstrated providing information on both film thickness and estimated Ru content. The physical properties of PECVD/PEALD Ru films were compared to characteristics of sputtered Ru films within the categories resistivity, impurites, crystal structure, conformity and Cu plating. As a result, ToFSIMS, ERDA and 3D atomprobe revealed the presence of carbon impurities in PECVD and PEALD Ru films, dependent on deposition temperature and plasma power. Nevertheless, highly conductive Ru-C films were produced via PECVD and PEALD achieving resistivities equal to PVD Ru. For all types of Ru films, the size effect played a significant role at thicknesses below 10 nm; Cu plating and crystallization behaviour appeared similar. Direct Cu fill potential of different Ru films was discussed for damascene structures and through silicon vias.

Microstructure evolution of Ru layer deposited in N 2 gas has been investigated and compared with that deposited in Ar gas for Cu diffusion barrier application. Deposition of Ru in N 2 results in high N dissolution, seemingly uniformly distributed in the Ru layer. The film microstructure is a mixture of nanocrystals and amorphous Ru instead of the columnar structure observed when deposited in argon. Annealing at T Ͼ 250°C causes N out-diffusion and crystallization of the amorphous Ru. Voids were observed at Cu/Ru interface in Ru deposited in N 2 when annealed at T Ն 275°C as a consequence of N out-diffusion.The possibility of Ru performing as a diffusion barrier and a seed layer for direct deposition of Cu stimulated interest in Ru thin films. 1,2 Its low solubility in Cu 3 is an advantage because the impurity effect on Cu resistivity is reduced. Ru is also compatible with the established chemical vapor deposition and atomic layer deposition technologies 4 unlike the conventional Ta/TaN barriers. Therefore, the interest in Ru is consistent with the current trend in research to move away from the physical-vapor-deposition-based TaN/Ta/Cu technology where conformality is a real challenge. Despite these merits, Chan et al. 1 reported that a 15 nm Ru layer in Cu/Ru/Si system failed when annealed at 450°C for 10 min, warranting in-depth studies of its barrier properties. In our previous study, 5 we showed that the Ru barrier performance significantly improves when the film is sputtered in a N 2 atmosphere as compared to an Ar atmosphere. The high level of dissolved N in Ru was suspected to be the reason for this improvement, but no direct evidence could then be reported. Subsequent work in analytical electron microscopy has given clear evidence for N dissolution in Ru when sputtered in N 2 atmosphere. This paper reports these findings, including evidence for cavity/void formation at Cu/Ru interface during N out-diffusion from the Ru films upon annealing.A ϳ12 to 17 nm thick Ru layer ͑99.95% purity͒ was sputter deposited onto p-Si͑111͒ and p-Si͑111͒ with SiO 2 cover in Ar or N 2 atmosphere as described in our previous paper. 5 Cu ͑99.99% pure͒ was then sputtered onto the Ru layer under the same sputtering conditions, but with only Ar as the sputtering gas, to give the following sets of samples: . In this nomenclature, Ru-N refers to Ru film deposited in N 2 atmosphere, while Ru refers to that deposited in Ar. The samples were then annealed for 30 min at progressively increasing temperatures up to 900°C in a high-vacuum ambient of 10 −5 Torr.Cross-sectioned samples were examined in an FEI Tecnai F30 ͑300 kV͒ transmission electron microscope ͑TEM͒ equipped with electron energy loss spectroscopy ͑EELS͒ and energy dispersed X-ray spectroscopy ͑EDX͒ detectors for elemental analysis. The TEM samples were prepared conventionally using a mechanical grinder and polisher, dimpling, and ion milling. Figure 1 shows a series of high-resolution TEM micrographs of the Ru and Ru-N layers in the as-deposited state and annealed at 275, ...

Partially amorphous Nd-Fe-B ribbons containing 20 or 50 wt% Fe in excess of the nominal composition Nd2Fel,B with 2.9 wt% Cu and 9.7 wt% Zr (referred to Nd,Pe,,B) were prepared by melt-spinning. After a heat treatment the material consists of a mixture of three parts: hard magnetic grains of the Nd,Fel,B phase with a-Fe grains and, in the case of 20 wt% excess Fe, small amounts of a metastable cubic phase, NdzFez3B3. Samples with 20 wt% Fe show a superposition of anisotropic magnetoresistance and giant magnetoresistance (GMR) effects, depending on structural changes caused by heat treatments at various annealing temperatures. For measurements with the applied field both parallel and perpendicular to the sample current an isotropic positive magnetoresistance ratio, MR = [R(H) -R(O)]/R(O), called inverse GMR has been found for samples with 50 wt% excess Fe.