Recherche

Afficher tous les résultats pour

Accueil

Personne

Patrik Willi Hoffmann

Cette personne a quitté l’EPFL

À propos
Confidentialité
Mentions légales

Graph Chatbot

Publications associées (42)

Page 1 sur 3

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

Patrik Willi Hoffmann, Ali Dabirian, Yury Kuzminykh, Michael Oliver Reinke

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 ...

Elsevier2013

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

Patrik Willi Hoffmann, Ali Dabirian, Giacomo Benvenuti, Estelle Wagner, Yury Kuzminykh

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 ...

Elsevier2014

A Snake-Based Approach to Accurate Determination of Both Contact Points and Contact Angles

Patrik Willi Hoffmann, Daniel Sage, Laura Barbieri, Gerit Kulik

We present a new method based on B-spline snakes (active contours) for measuring high-accuracy contact angles. In this approach, we avoid making physical assumptions by defining the contour of the drop as a versatile B-spline curve. When useful, we extend ...

Elsevier2006

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

Patrik Willi Hoffmann, Xavier Multone

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 ...

2008

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

Patrik Willi Hoffmann, Wojciech Bozydar Szmyt

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 ...

2020

Nanosecond pulsed laser-processing of CVD diamond

Patrik Willi Hoffmann, Marco Cantoni, Sébastien Equis

This work considers the resulting material structural effects of laser-processing chemical vapor deposited (CVD) diamond. The utilized 532 nm wavelength laser had a pulse duration of 40 ns together with a spot diameter of ca. 40 mu m. The effect of cutting ...

ELSEVIER SCI LTD2020

Precursor adsorption efficiency of titanium tetra isopropoxide in the presence of a barium beta-diketonate precursor

Patrik Willi Hoffmann, Yury Kuzminykh, Michael Oliver Reinke

Barium titanate is a promising candidate for integrated photonic application due to its high electro-optic coefficient; therefore the need arises for a suitable deposition technique which provides high film quality at low temperatures (below 500 degrees C) ...

Elsevier Science Sa2013

Surface 3D Micro Free Forms: Multifunctional Microstructured Mesoporous alpha-Alumina by in Situ Slip Casting Using Excimer Laser Ablated Polycarbonate Molds

Patrik Willi Hoffmann, Paul Bowen, Sriharitha Rowthu

Ceramic surface microstructuring is a rapidly growing field with a variety of applications in tribology, wetting, biology, and so on. However, there are limitations to large-area microstructuring and fabrication of three-dimensional (3D) micro free forms. ...

Amer Chemical Soc2015

Microfabrication of curved sidewall grooves using scanning nanosecond excimer laser ablation

Patrik Willi Hoffmann, Josef Andreas Schuler, Georgios Violakis, André Gabriel Kostro, Jing Gong

Novel glazing with embedded micro-mirrors can significantly reduce the energy consumption due to cooling and lighting in buildings. Especially promising are large arrays of periodic micro compound-parabolic-concentrators (CPCs) with angular-selected transm ...

SPIE2018

Limitations of patterning thin films by shadow mask high vacuum chemical vapor deposition

Patrik Willi Hoffmann, Yury Kuzminykh, Michael Oliver Reinke

A key factor in engineering integrated devices such as electro-optic switches or waveguides is the patterning of high quality crystalline thin films into specific geometries. In this contribution high vacuum chemical vapor deposition (HV-CVD) was employed ...

Elsevier2014

Unsupervised quality monitoring of metal additive manufacturing using Bayesian adaptive resonance

Patrik Willi Hoffmann

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 ...

CELL PRESS2024

Combinatorial HV-CVD survey of barium triisopropyl cyclopentadienyl and titanium tetraisopropoxide for the deposition of BaTiO3

Patrik Willi Hoffmann, Yury Kuzminykh, Michael Oliver Reinke

Barium titanate is a very promising material for the integration of optical communication into electronic integrated circuits. For a successful integration into CMOS compatible technology, a growth process has to be found which allows forming crystalline B ...

Wiley-VCH Verlag2015

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

Patrik Willi Hoffmann, Christian Santschi

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 ...

2008

Selective Growth of Titanium Dioxide by Low-Temperature Chemical Vapor Deposition

Patrik Willi Hoffmann, Yury Kuzminykh, Michael Oliver Reinke

A key factor in engineering integrated optical devices such as electro-optic switches or waveguides is the patterning of thin films into specific geometries. In particular for functional oxides, etching processes are usually developed to a much lower exten ...

Amer Chemical Soc2015

Low Temperature Chemical Vapor Deposition Using Atomic Layer Deposition Chemistry

Patrik Willi Hoffmann, Yury Kuzminykh, Michael Oliver Reinke

Chemical vapor deposition (CVD) techniques rely on high temperatures to activate the chemical decomposition of precursors on the substrate surface. Lower temperatures are applied in atomic layer deposition (ALD), where deliberate pyrolysis of the precursor ...

American Chemical Society2015

Microstructure and ferroelectricity of BaTiO3 thin films on Si for integrated photonics

Patrik Willi Hoffmann, Michael Oliver Reinke

Significant progress has been made in integrating novel materials into silicon photonic structures in order to extend the functionality of photonic circuits. One of these promising optical materials is BaTiO3 or barium titanate (BTO) that exhibits a very l ...

Institute of Physics2017

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

Theo Lasser, Benjamin Dwir, Patrik Willi Hoffmann, Marcel Leutenegger, Ivo Utke, Alexandre Perentes

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 ...

2005

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

Jürgen Brugger, Niels Quack, Giovanni Boero, Patrik Willi Hoffmann, Radivoje Popovic, Pavel Kejik, Schahrazede-Lila Mouaziz, Tristan Bret

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 ...

American Institute of Physics2005

Gas-assisted focused electron beam and ion beam processing and fabrication

Patrik Willi Hoffmann, Ivo Utke

Beams of electrons and ions are now fairly routinely focused to dimensions in the nanometer range. Since the beams can be used to locally alter material at the point where they are incident on a surface, they represent direct nanofabrication tools. The aut ...

2008

Impact of oxygen content in powders on the morphology of the laser molten tracks in preparation for additive manufacturing of silicon

Patrik Willi Hoffmann, Lucas Güniat

Powder additive pulsed Nd:YAG laser (wavelength 1064 nm), with the aim of preparing AM of such material. The influence of oxygen content in the initial silicon powders on the continuous tracks morphology was investigated. It was found that the initial oxyg ...

ELSEVIER2020