News-Archiv 2011

12th Trends in Nanotechnology International Conference

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21.-25.11.2011, Tenerife, Canary Islands, Spain

U. Schwalke, P.J. Wessely, F. Wessely, E. Birinci,
M. Keyn, L. Rispal
In-Situ CCVD Growth of Hexagonal Carbon for CMOS-Compatible Nanoelectronics: From Nanotube Field-Effect Devices to Graphene Transistors

Abstract – In this work, the in-situ growth of carbon nanotubes (CNTs) and graphene films directly on oxidized silicon wafers by means of catalytic chemical vapor deposition (CCVD) is demonstrated. In-situ means that the carbon structures are directly grown in their final position for device applications so that tedious transfer and alignment procedures are obsolete.

220th Meeting of the Electrochemical Society

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09.-14.10.2011, Boston, MA, USA

P.J. Wessely, F. Wessely, E. Birinci, U. Schwalke
In-Situ CCVD Grown Bilayer Graphene Transistor

Abstract – Graphene was first synthesized in 2004 by A. Geim and K. Novoselov. This two dimensional material consists of a monolayer of carbon atoms which are arranged in a hexagonal honeycomb lattice structure. Graphene itself is a non-bandgap material – a monolayer of graphene is always metallic. For a bilayer or a trilayer graphene a bandgap can be achieved while applying an electrical field perpendicular to the layer. The bandgap depends on the number of graphene layers, the intensity of the electric field, the substrate and the doping. Monolayer, bilayer, trilayer and fewlayer graphene is produced by many different approaches. They all have in common that the transfer of the graphene layer to a suitable substrate after synthesis must be performed. In contrast to this we produce bilayer graphene using an appropriate catalyst on silicon-dioxide (SiO2) substrate achieving in-situ grown bilayer graphene by means of catalytic chemical vapor deposition (CCVD) with a methane feedstock.

Session Chair: Prof. Dr. U. Schwalke
(Session H1 on October 12th, 2011 – „Carbon Nanotubes and Nanostructures: From Fundamental Properties and Processes to Applications and Devices“)

41th European Solid-State Device Research Conference

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12.-16.09.2011, Helsinki, Finland

F. Wessely, T. Krauss, U. Schwalke
CMOS without doping: midgap Schottky-barrier nanowire field-effect-transistors for high-temperature applications

Abstract – In this paper we report on a newly developed nanowire based field-effect device-architecture (NWFET) that can be used in high temperature environments. Our devices posess both high temperature stability and low OFF-state current. By changes in source/drain bias-polarity the electrical properties of the NW-devices can be tuned, whether the lowest possible leakage current, or maximum output current is desirable in a specific application.

Halbleitertechnik: Tradition und Forschungskultur

Profilbild Strack

Festkolloquium anlässlich des 80. Geburtstags
von Herrn Professor Dr. rer. nat. Hans Strack

Montag, 04. Juli 2011, ab 15:00
im Mollerhaus (am Staatstheater), Sandstraße 10, 64283 Darmstadt

Download: Einladung / Programm

ImageNano 2011

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11.-14.04.2011, Bilbao, Spain

P.J. Ginsel, F. Wessely, E. Birinci, U. Schwalke
Production of Graphene Layers by Means of CVD for Field Effect Device Fabrication

Abstract – In this paper we report on the fabrication and characterization of graphene layers for graphene field effect devices. This is a modified and advanced approach already developed at the ISTN for the in-situ fabrication of single walled carbon nanotubes (SWCNTs). The graphene layers are grown by means of catalytic chemical vapor deposition (CCVD) using a methane feedstock. The band-gap is engineered by constricting the lateral dimensions of graphene obtaining graphene nanoribbons. The graphene nanoribbons (GNRs) are contacted with selected metals to form field-effect devices for various investigations.

Design & Technology of Integrated Systems 2011

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06.-08.04.2011, Athens, Greece

P.J. Ginsel, F. Wessely, E. Birinci, U. Schwalke
CVD Assisted Fabrication of Graphene Layers for Field Effect Device Fabrication

Abstract – In this paper, we report on the fabrication and characterization of graphene layers for graphene field effect devices. After the graphene layers are generated by means of chemical vapor deposition using a methane feedstock, the band gab is engineered constricting the lateral dimensions of graphene obtaining graphene nano ribbons. Contacting graphene nano ribbons with selected metallic materials performs field effect devices with various applications.

Member of the Programm Committe: Prof. Dr. U. Schwalke

Einladung zum Nanoelektronischen Frühjahrskolloquium

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Dienstag, 15.03.2011, 14:00 Uhr ct, Ort: S2|17 103
zum Thema „Vom Material zum nanoelektronischen Bauelement“

mit Gastvortrag

von Prof. Frank Schwierz (TU Ilmenau)
zum Thema „Graphene Transistors 2011 – Prospects and Problems“

Download: Einladung, Programm

EuroSOI 2011

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17.-19.01.2011, Granada, Spain

F. Wessely, T. Krauss, U. Schwalke
Multi-Gate Voltage Selectable Silicon-Nanowire-FETs

Abstract – In this paper, we report on the fabrication and characterization of voltage-selectable (VS) nanowire (NW) field-effect-transistor (FET) devices suitable to broaden the flexibility in logic circuit design. Silicon NW-structures with mid-gap Schottky S/D junctions on silicon-on-insulator (SOI) substrate were fabricated as unipolar MOSFETs. The versatility of our approach is demonstrated experimentally using a VS-NW-CMOS inverter circuit on a multi-SOI like set-up.