Mikrotechnik für Raumfahrtanwendungen

This contribution describes the preparation, based upon a chemically amplified novolak resist (CAR), electron beam lithography, and ECR plasma etching, of structures with a high aspect ratio (10∶1) and lateral dimensions in the sub-micrometer range (150nm–300nm) which may serve as collector surfaces for sub-μm dust particles in a space experiment.     

Scalable digital hardware for a trapped ion quantum computer

Quantum Information Processing - Many of the challenges of scaling quantum computer hardware lie at the interface between the qubits and the classical control signals used to manipulate them....     

Contact and proximity lithography using 193 nm Excimer laser in Mask Aligner

In this paper we describe the use of an Excimer laser for full-field lithography in a Mask Aligner. The DUV light from the Excimer laser is homogenized by using micro lens based optical integrators instead of a macro lens array. A simulation of the intensity distribution for 5 μm squares was performed to visualize the diffraction effects and to show the potential of 193 nm illumination. It is demonstrated that compared to the conventional homogenization optics the MO Exposure Optics further improves the illumination uniformity, calculated as 1.8% for MO Exposure Optics and 2.9% for the A-Optics. Moreover the improved optical setup allows a modification of the angular spectrum by using exchangeable illumination filter plates (IFP). Compared to the A-Optics the main improvement effect of MO Exposure Optics is detectable in the patterning of layouts containing critical dimension from 8 μm down to 2 μm.     

Evaluation of chemically amplified deep UV resis for micromachining using e-beam lithography and dry etching

The electron-beam response of new chemically amplified positive multi-component ARCH-resist family (ARCH and ARCH2) and the suitability of pattern transfer through single layer has been evaluated. The electron-beam lithographic parameters for thicker layers (1–2μm) of these resists and the optimization possibilities of the exposure and etching conditions were investigated as well. Under fixed resist-handling processes, both resists exhibit high sensitivity (< 10μC/cm²) and an enormous high contrast. The study includes the effects of resist-process variations on the global 3-D resist-relief structure. Vertical side-walls of the resist profile is a necessary condition for a successful deep-, and a good CD-controlled anizotropical pattern transfer with high aspect ratio of structures into the substrate.     

Silicon stencil masks for masked ion beam lithography proximity printing

Silicon membranes with 2 μm to 6 μm thickness and ≈ 10×10 mm² mask field have been fabricated with the help of electrochemical etch stop techniques. The Si foil was coated with 0.3 μm thick PECVD Si₃N₄. Shaped electron beam lithography was done in ARCH (OCG) positive resist. RIE etching into the nitride layer was done with CHF₃/Ar/SF₆. Silicon trench etching was based on Cl₂/Ar/BCl₃ plasma chemistry implementing gas chopping. Ion beam proximity printing of the Silicon stencil mask structures was done with 55 keV Helium ions into 0.4 μm thick AZ PN114 negative resist using the Alpha ion projector of the Society for the Advancements of Microelectronics in Austria in the MIBL (Masked Ion Beam Lithography) mode. Pattern transfer of a mask feature of less than 100 nm diameter (25:1 aspect ratio in the stencil mask) could be demonstrated even for a mask to wafer gap of 1 mm. The prospects of fabricating large area (> 100×100 mm²) Silicon stencil masks for MIBL printing of gate levels for

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ystems (MEMS) is discussed.     

Blocking in digital cross-connect systems

A background discussion of blocking in space switch fabric architectures is presented. The analysis of blocking during broadcasting is discussed, followed by an explanation of the results of the analysis. Conclusions and some possible solutions to blocking during broadcasting are presented     

Compact, microchip-based systems for practical applications of ultracold atoms

We present a set of building blocks for constructing and utilizing compact, microchip-based, ultrahigh vacuum (UHV) chambers for the practical deployment of cold- and ultracold-atom systems. We present two examples of chip-compatible approaches for miniaturizing UHV chambers—double-magneto-optical-trap cells and channel cells—as well as compact, free-space optical systems into which these cells can be easily inserted and quickly swapped. We discuss progress in atom chip technology, including miniature through-chip electrical feedthroughs and optical windows for transferring light between the trapping region on the chip and the ambient environment. As an example of the latter, we present some of the first through-chip fluorescence images of a Bose–Einstein condensate. High numerical apertures can be achieved with this technique, allowing for submicron resolution. Whether for optical detection, trapping, or control, such fine resolution will have numerous applications in quantum information, especially for experiments based on ultracold atoms trapped in optical lattices.     

Knowing when not to use the Internet: Shyness and adolescents’ on-line and off-line interactions with friends

The goal of the study was to explore the content of on-line and off-line peer interactions among shy and non-shy adolescents. Participants were 148 ten-to-eighteen year old adolescents in Rome, Italy (n = 98) and Ottawa, Canada (n = 50). Participants completed self reports of shyness and loneliness and web logs of their interactions with friends both in person and on-line. Among the results, there was little general difference in the general content and emotion expressed during the two modalities of interaction with friends, both of which were used in a wide variety of ways. Importantly, shy participants used the on-line modality more extensively than their non-shy counterparts to express negative emotions and to convey content regarding negative exchanges with peers. Such use of electronic communication may be an important contributor to their loneliness.