Fabrication of Porous Gold Film Using Graphene Oxide as a Sacrificial Layer

An original and simple fabrication process to produce thin porous metal films on selected substrates is reported. The fabrication process includes the deposition of a thin layer of gold on a substrate, spin coating of a graphene oxide dispersion, etching the gold film through the graphene oxide layer, and removing the graphene oxide layer. The porosity of the thin gold film is controlled by varying the etching time, the thickness of the gold film, and the concentration of the graphene oxide dispersion. Images by scanning electron and metallurgical microscopes show a continuous gold film with random porosity formed on the substrate with a porosity size ranging between hundreds of nanometers to tens of micrometers. This general approach enables the fabrication of porous metal films using conventional microfabrication techniques. The proposed process is implemented to fabricate electrodes with patterned porosity that are used in a microfluidic system to manipulate living cells under dielectrophoresis. Porous electrodes are found to enhance the magnitude and spatial distribution of the dielectrophoretic force.

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Surface Acoustic Wave Biosensor with Laser-Deposited Gold Layer Having Controlled Porosity

Chemosensors ◽

10.3390/chemosensors9070173 ◽

2021 ◽

Vol 9 (7) ◽

pp. 173

Author(s):

Dana Miu ◽

Izabela Constantinoiu ◽

Valentina Dinca ◽

Cristian Viespe

Keyword(s):

Acoustic Wave ◽

Surface Acoustic Wave ◽

Gold Film ◽

Good Control ◽

Gold Layer ◽

Porous Gold ◽

Deposition Parameters ◽

Acoustic Wave Sensors ◽

Controlled Porosity ◽

Wave Sensors

Laser-deposited gold immobilization layers having different porosities were incorporated into love wave surface acoustic wave sensors (LW-SAWs). Variation of pulsed laser deposition parameters allows good control of the gold film morphology. Biosensors with various gold film porosities were tested using the biotin–avidin reaction. Control of the Au layer morphology is important since the biotin and avidin layer morphologies closely follow that of the gold. The response of the sensors to biotin/avidin, which is a good indicator of biosensor performance, is improved when the gold layer has increased porosity. Given the sizes of the proteins, the laser-deposited porous gold interfaces have optimal pore dimensions to ensure protein stability.

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Graphene oxide dispersion state in polystyrene-based composites below percolation threshold via linear melt rheology

Rheologica Acta ◽

10.1007/s00397-021-01263-7 ◽

2021 ◽

Vol 60 (4) ◽

pp. 209-218

Author(s):

Claudia Dessi ◽

Leice G. Amurin ◽

Pablo A. R. Muñoz ◽

Yuri D. C. de Oliveira ◽

Guilhermino J. M. Fechine ◽

...

Keyword(s):

Graphene Oxide ◽

Percolation Threshold ◽

Oxide Dispersion ◽

Melt Rheology ◽

Dispersion State

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Interaction Between Low Temperatures Spacers and Source Drain Extensions and Pockets for Both NMOS and PMOS of the 65 nm Node Technology

MRS Proceedings ◽

10.1557/proc-0912-c02-06 ◽

2006 ◽

Vol 912 ◽

Author(s):

Nathalie Cagnat ◽

Cyrille Laviron ◽

Daniel Mathiot ◽

Pierre Morin ◽

Frédéric Salvetti ◽

...

Keyword(s):

Oxide Layer ◽

Hydrogen Content ◽

Low Temperatures ◽

Direct Contact ◽

Fabrication Process ◽

Experimental Results ◽

The Other ◽

Mos Transistors ◽

Phosphorus Source ◽

Activation Annealing

AbstractDuring the MOS transistors fabrication process, the source-drain extension areas are directly in contact with the oxide liner of the spacers stack. In previous works [1, 2, 3] it has been established that boron can diffuse from the source-drain extensions into the spacer oxide liner during the subsequent annealing steps, and that the amount of boron loss depends on the hydrogen content in the oxide, because it enhances B diffusivity in SiO2.In order to characterize and quantify the above phenomena, we performed test experiments on full sheet samples, which mimic either BF2 source-drain extensions over arsenic pockets implants, or BF2 pockets under arsenic or phosphorus source-drain extensions implants. Following the corresponding implants, the wafers were covered with different spacer stacks (oxide + nitride) deposited either by LPCVD, or PECVD. After appropriate activation annealing steps, SIMS measurements were used to characterize the profiles of the various dopants, and the corresponding dose loss was evaluated for each species.Our experimental results clearly evidence that LPCVD or PECVD spacer stacks have no influence on the arsenic profiles. On the other hand, phosphorus and boron profiles are affected. For boron profiles, each spacer type has a different influence. It is also shown that boron out-diffuses not only from the B doped source-drain extension in direct contact with the oxide layer, but also from the "buried" B pockets lying under n-doped source drain extension areas. All these results are discussed in term of the possible relevant mechanism.

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