Patrik Willi Hoffmann

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Thin films of oxide materials are widely used for various types of applications. The selection of an appropriate deposition method depends on the aimed material and application. We review here a high vacuum chemical vapour deposition (HV-CVD) method, which ...

Chemical vapour deposition (CVD) processes depend on the availability of suitable precursors. Precursors that deliver a stable vapour pressure are favourable in classical CVD processes, as they ensure process reproducibility. In high vacuum CVD (HV-CVD) pr ...

A generic method is described for the reversible immobilization of polyhistidine-bearing polypeptides and proteins on attenuated total reflecting (ATR) sensor surfaces for the detection of biomol. interactions by FTIR spectroscopy. Nitrilotriacetic acid (NTA) groups are covalently attached to self-assembled monolayers of either thioalkanes on gold films or mercaptosilanes on silicon dioxide films deposited on germanium internal reflection elements. Complex formation between Ni2+ ions and NTA groups activate

Erbium-doped amorphous aluminum oxide layers deposited on Si or oxidized silicon substrates are promising construction pieces for future monolytic integrated optoelectronics devices. In a novel high-vacuum chemical vapor deposition setup the alumina films ...

Barium titanate (BTO) is a promising perovskite-like material, exhibiting interesting functionalities, such as ferroelectricity, piezoelectricity, high dielectric constant, and electrooptic coefficients. All these properties are closely related to the orie ...

A substrate with transparent electrodes is formed from a transparent material on which is deposited a film of a transparent conducting material with a thickness e 1and a refractive index n 1. A substrate with transparent electrodes is formed from a transparent material on which is deposited a film of a transparent conducting material with a thickness e 1and a refractive index n 1. The film is structured to form an assembly of electrodes of which the contours delimit some insulating spaces. The insulating sp

The development of high-quality copper (Cu) thin films by atomic layer deposition (ALD) remains challenging due to a limited understanding of the reaction mechanisms that govern film growth and composition. To address this gap, in this study, time-of-flight mass spectrometry (TOFMS) was used to perform the first comprehensive in situ investigation of the surface reactions during Cu ALD, using dehydrated Cu(II) hexafluoroacetylacetonate (Cu(hfac) 2) (CAS 14781−45−4) and diethylzinc (DEZ, ZnEt 2) (CAS 557−20−

Metal additive manufacturing is a recent breakthrough technology that promises automated production of complex geometric shapes at low operating costs. However, its potential is not yet fully exploited due to the low reproducibility of quality in mass prod ...

Focused electron beam induced depositions of nickel-containing materials obtained by using bis(methylcyclopentadienyl)nickel(II) Ni(C5H4CH3)(2) and tetrakis(trifluorophosphine)nickel(0) Ni(PF3)(4) as precursors, were compared in terms of chemical composition and electrical resistivity. Ni(PF3)(4) decomposed into higher Ni content materials than that obtained with Ni(C5H4CH3)(2) (typically 40 and 10 at. %, respectively). Attempts of increasing the Ni content by injecting controlled flows of molecular oxygen

In this paper, we present near-field optical images of nanostructures exhibiting an extraordinary transmission. These structures consist of annular aperture arrays engraved in a metallic film: they are quite promising structures for nanophotonics because o ...

Direct writing of metal features narrower than 100 nm is accomplished by scanning a focused ion beam over a substrate covered with a thin solid metalorg. film. A metalorg. cluster coordination compd. [Ir4(CO)11Br] [N(C2H5)4] is spun on an oxidized Si wafer from acetone soln. and the resulting layer is irradiated with a focused 20 keV Ga-ion beam. The partially decompd. irradiated film regions show a marked decrease of soly. in acetone. Developing by dissolving the nonirradiated parts of the surface hence le

We report on the fabrication of two-dimensional arrays of nano-optical apertures in gold layers by electron beam lithography (EBL) on a transparent glass substrate. 30 x 30 μ m(2) large arrays of high aspect ratio sub-wavelength cylinders (400 nm diameter ...

Hall devices having an active area of about (500 nm)(2) are fabricated by focused electron-beam-induced deposition. The deposited material consists of cobalt nanoparticles in a carbonaceous matrix. The realized devices have, at room temperature, a current ...

In this paper we describe the fabrication of a two-dimensional photonic band gap structure by focused electron beam induced deposition. Structure geometry is computed in order to create a light-trapping effect at 632 nm wavelength. Deposits produced using tetraethyl orthosilicate (SiO4C8H20) as precursor were studied to determine their chemical composition and geometrical dimensions. The deposited material has a refractive index ~n ¼ 1:85 þ i3:9 � 10�4 at 632 nm. Transmission electron microscopy revealed

High temperature and prolonged thermal annealing for the crystallization of cathode in thin-film batteries (TFBs) restricts the choice of current collector and substrates and causes lithium loss in the cathode. This work explores photonic-based alternative ...

A laser or electron beam assisted deposition in HV-CVD conditions was used in order to achieve structured amorphous alumina (Al2O3) deposits. Selective deposition of Al2O3 in the irradiated regions has been demonstrated. We investigate the influence of irr ...

The invention relates to an effusing source for film deposition made of a reservoir comprising one hole characterized by the fact that the hole diameter is less than one order of magnitude than the mean free path of the molecules determined by the pressure and its thickness is at least one order of magnitude smaller than the diameter. Preferably the source has several holes.

Gas-assisted focused electron beam-induced deposition (FEBID) as a direct, minimally invasive 3D nanopatterning tool offers many advantages in making nanostructures with complex shapes and novel compositions for evolving nanotechnological applications. In ...

We report a simple and versatile self-assembly method for controlling the placement of functional gold nanoparticles on silicon substrates using micellar templates. The hierarchical positioning of gold nanoparticles is achieved in one-step during the spont ...

Laser-assisted deposition: The discovery of chemical vapor deposition (CVD) conditions under which the growth rate is a decreasing function of the precursor flux has the potential to boost the resolution of laser-assisted CVD processes whereas flux- and de ...

Patrik Willi Hoffmann

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High vacuum chemical vapour deposition of oxides: A review of technique development and precursor selection

Evaluation of niobium dimethylamino-ethoxide for chemical vapour deposition of niobium oxide thin films

Reversible immobilization of peptides: Surface modification and in situ detection by attenuated total reflection FTIR spectroscopy

Er-doped Al2O3 thin films deposited by high-vacuum chemical vapor deposition (HV-CVD)

Length Microstructure analysis of epitaxial BaTiO3 thin films on SrTiO3-buffered Si: Strain and dislocation density quantification using HRXRD methods

Substrate with transparent electrodes manufactured by ultraviolet irradiation through a single mask, for applications in visible light wavelengths such as tactile display screens

Reaction Mechanisms in Copper Atomic Layer Deposition Using Copper(II) Hexafluoroacetylacetonate and Diethylzinc via In Situ Time-of-Flight Mass Spectrometry

Unsupervised quality monitoring of metal additive manufacturing using Bayesian adaptive resonance

Focused electron beam induced deposition of nickel

Near-field optical images of subwavelength annular aperture arrays exhibiting an extraordinary transmission

Direct writing of iridium lines with a focused ion beam

Fabrication of arrays of sub-wavelength nano-apertures in an optically thick gold layer on glass slides for optical studies

Submicrometer Hall devices fabricated by focused electron-beam-induced deposition

Focused electron beam induced deposition of a periodic transparent nano-optic pattern

Photonic methods for rapid crystallization of LiMn2O4 cathodes for solid-state thin-film batteries

Combination of Electron or Laser Beam Irradiation with High Vacuum Chemical Vapor Deposition (HV-CVD) of Al2O3 for in-situ Local Structuring on Wafer Scale Substrate

Effusing source for film deposition of reservoir, comprises hole having hole diameter less than one order of magnitude than mean free path of molecules

Electron beam-based direct writing of nanostructures using a palladium β-ketoesterate complex

Hierarchical positioning of gold nanoparticles into periodic arrays using block copolymer nanoring templates

Chemical Vapor Deposition Kinetics and Localized Growth Regimes in Combinatorial Experiments