Wet processes are gaining a renewed interest for removal of high dose ion implanted photoresist (II-PR) in front-end-of-line semiconductor manufacturing because of their excellent selectivity towards the wafer substrate and gate materials. The selection of wet chemistries is supported by an insight into the resist degradation by ion implantation. In this work, different analytical techniques have been applied for in-depth characterization of the chemical changes in 248 nm DUV PR after arsenic implantation. A radical mechanism of resist degradation is proposed involving cross-linking and chain scission reactions. The cross-linking of the resist is dominant especially for high doses and energies. It leads to significant depletion of hydrogen and formation of carbon macroradicals that recombine to form C-C cross-linked crust. Moreover, formation of ab-unsaturated ketonic and/or quinonoid structures by cross-linking reactions is suggested. In addition, the dopant species may provide rigid points in the PR matrix by chemical bonding with the resist. For higher doses and energies further dehydrogenation occurs, which leads to formation of triple bonds in the crust. Different p-conjugated structures are formed in the crust by cross-linking and dehydrogenation reactions. No presence of amorphous carbon in the crust is revealed. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3597176] All rights reserved.

In this paper, we show the results of experiments of InAs nanowire (NW) growth on (111)-oriented Si wafers. The NWs, grown at 620 degrees C by metal-organic vapor-phase epitaxy, are vertically aligned and similar to 30 nm in diameter. Their structural properties are studied by transmission electron microscopy, evidencing a polytypic character, and the vibrational properties by Raman spectroscopy. An assessment of their electrical transport properties is carried out by measuring back-gated, single InAs NW field-effect transistors. The absence of a catalyst ensures the compatibility of the NW growth process with current CMOS technology. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

We demonstrate excitation and detection of Raman scattering of a silicon substrate through a 15 nm gold nanoslit. Along with the nanoslit, a plasmonic cavity is fabricated to optimize optical transmission through the slit. Using a polarization analysis we prove that the plasmons enhanced transmission is responsible for the detection of the Raman scattered photons of the silicon substrate through the nanoslit. The optical cavity between the nanoslit and the Si substrate further enhances this backward photon transmission. This opens up prospects for new tools for near-field Raman spectroscopy and sub-wavelength measurements.

We report a change in the semimetallic nature of single-layer graphene after exposure to oxygen plasma. The resulting transition from semimetallic to semiconducting behavior appears to depend on the duration of the exposure to the plasma treatment. The observation is confirmed by electrical, photoluminescence and Raman spectroscopy measurements. We explain the opening of a bandgap in graphene in terms of functionalization of its pristine lattice with oxygen atoms. Ab initio calculations show more details about the interaction between carbon and oxygen atoms and the consequences on the optoelectronic properties, that is, on the extent of the bandgap opening upon increased functionalisation density.

Within this paper, the authors propose a refined high vacuum scanning spreading resistance microscopy (HV-SSRM) electromechanical nanocontact model based on experimental results as well as molecular dynamics (MD) simulation results. The formation under the tip of a nanometer-sized pocket of β-tin, a metastable metalliclike phase of silicon (also named Si-II), acting as a virtual probe is demonstrated. This gives a reasonable explanation for the superior SSRM spatial resolution as well as for the electrical properties at the Schottky-like SSRM contact. Moreover, the impact of the doping concentration on the plastic deformation of silicon for different species using micro-Raman combined with indentation experiments is studied. In order to elucidate the superior results of SSRM measurements when performed under high vacuum conditions, the impact of humidity on the mechanical deformation and Si-II formation is also analyzed using MD and SSRM experimental results.

The incorporation of hydrogen during deposition of amorphous germanium can influence solid phase epitaxy in many ways. We show that Ge–H bonds are not important during the crystallization process. However, atomic hydrogen is important during deposition to obtain a highly disordered layer. We have found that highly disordered layers can also be obtained when using a beam of inert gas species during ultrahigh vacuum deposition. These inert species effectively increase the disorder of the layer by limiting the surface mobility of adsorbed germanium atoms. In this way subsequent solid phase epitaxy can be improved significantly.

The effects of thermal annealing in inert Ar gas atmosphere of SiO2-supported, exfoliated single-layer graphene are investigated in this work. A systematic, reproducible change in the electronic pr...

We report on the growth of surface-bound, vertically oriented 1-D III/V nanostructures, specifically GaAs and InAs nanowires, on lattice-matched and -mismatched substrates by selective-area vapour phase epitaxy. Control of nanowire features and growth directions is achieved by tuning of the growth conditions. Grown nanostructures are characterised by scanning and transmission electron microscopy, X-ray diffraction and Raman spectroscopy.

We report on the optical and electrical characterization of graphene supported on various dielectric substrates. Graphene single- and bilayer flakes were successfully isolated and Raman spectroscopy was performed to assess their crystalline quality. Temperaturedependent electrical characterization of graphene devices supported on SiO2 and Si3N4 films show the onset of scattering by interfacial phonons and limiting graphene mobility above 200 K.

The elemental and structural changes of 248nm DUV photoresist induced by arsenic implantation with high dose and different acceleration energies were studied. For this purpose different analytical techniques were combined. An investigation of the capabilities of the Micro Raman Spectroscopy for analysis of ion implanted photoresist (II-PR) revealed that the method is unreliable for the characterization of II-PR since it induces a modification of the top crust layer. Moreover, alternative methods were used for characterization of the crust. The crust structure was indentified as cross-linked PR by Solid State Nuclear Magnetic Resonance. No experimental evidence for presence of amorphous carbon was found. Furthermore, the elemental composition and mechanical properties of the crust as a function of the implant energy were discussed as a measure for the cross-linking density. Finally, the dopant role in the cross-link process was considered.

We here present the controlled synthesis of ultra-small diameter nanotubes in well-defined subnanometer sized confined space within zeolites. A critical view on the zeolite occluded nanotube growth is presented. Thermogravimetric analysis and optical techniques are evaluated for nanotube characterization. The introduction of Bro̸nsted acid sites in the zeolite framework leads to optimized yields. As temperatures below 500{degree sign}C are envisioned for nanotube synthesis, zeolite occluded nanotubes are compatible with current CMOS technology platform, in densities in accordance with ITRS standards for future interconnects, making zeolites a viable pathway for integration of SWCNTs in the chip of the future.

Heiß oder kalt: Die hohe Lokalisierung in SERS-Hotspots lässt sich direkt anhand der selektiven Ablagerung von Raman-Analyten innerhalb und außerhalb von Regionen mit verstärktem Feld in einem Spalt zeigen (siehe Bild). Dies bestätigen Messungen der absoluten SERS-Intensitäten ebenso wie kinetische Studien zum lichtinduzierten Abbau an unterschiedlichen Stellen.

The investigation of the optical properties of porous silica samples is presented. Optical spectroscopy measurements, including Raman scattering, steady state and time resolved photoluminescence, optical absorption and excitation of photoluminescence are reported. The chapter reviews the results of the research we carried out upon the emission features of porous silica in the ultraviolet and visible wavelength range and the characterization of the emission properties of dye-doped sol-gel synthesized silica samples. In particular, the study of the emission band recorded at about 3.7 eV and its correlation with the chemical and physical conditions of the surface is discussed. As regards dye-doped silica samples, the analysis of the spectroscopic features of pre- and post-doped hybrid samples is presented and their potential feasibility as solid state dye laser is proposed.

As CMOS is approaching the 22nm node, the importance of high-mobility materials such as Ge and GaAs is rapidly increasing. For the timely development of these new technologies accurate dopant and carrier-profiling solutions for source-drain extensions with these materials are required. Identical n-type-doped (Si, Se) layers on same and opposite type medium-doped layers on S.I. GaAs substrates will be investigated, with layer thicknesses ranging from 200 down to 50nm and doping concentration levels up to 1e20at/cm3. In this work, secondary ion mass spectrometry will be used for dopant profiling. For GaAs carrier profiling, conventional spreading resistance probe, as commonly used in Si-CMOS, fails. Hence, reliable alternatives need to be found for characterizing these high–low structures. Techniques to be discussed range from the more conventional approaches such as Hall or electrochemical capacitance–voltage (performed by different laboratories), over micro-Raman spectroscopy and photo-luminescence along a beveled surface, up to more advanced approaches using scanning spreading resistance microscopy.