Effects of Process Parameters on the Adhesion of Copper Film on Polyethylene Tetrephthalate(Pet) Substrate Prepared by ECRMOCVD Coupled with a Periodic DC Bias

2003 ◽  
Vol 795 ◽  
Author(s):  
Jin Hyun ◽  
Bup Ju Jeon ◽  
Dongjin Byun ◽  
Joong Kee Lee

ABSTRACTCharacteristics of Cu/C:H films on the PET substrate prepared by ECR-MOCVD coupled with a DC bias under Cu(hfac)2-Ar-H2 was investigated with special attention to process parameters. Our results showed that the Cu/C:H film has strongly adhere with the polymer substrate by chemical bonding and exhibited wide range of electrical conductivity that could be controlled by process parameters. The increase in H2/Ar ratio, microwave power and negative DC bias voltage brought on the higher pulling strength between Cu/C:H films and PET substrate. The effects of surface pretreatments of polymer substrate on pulling strength were insignificant in the range of our experimental range.

2002 ◽  
Vol 734 ◽  
Author(s):  
Joong Kee Lee ◽  
Hyungduk Ko ◽  
Jin Hyun ◽  
Dongjin Byun ◽  
Byung Won Cho ◽  
...  

ABSTRACTCu/C films were prepared at room temperature under Cu(hfac)2-Ar-H2 atmosphere in order to obtain metallized polymer by using ECR-MOCVD (Electron Cyclotron Resonance Metal Organic Chemical Vapor Deposition) coupled with periodic DC bias system. Room temperature MOCVD was possible when periodic negative voltage was applied on the polymer substrate. The periodic negative voltage induces ions and radicals to have nucleation reaction on the surface of the substrate. Formation of Cu/C films strongly depends on the periodic negative pattern of DC bias and the electric sheet resistance of the films was controlled from 108 to 100ohm/sq ranges by process parameters such as microwave power and magnet current. The increase in microwave power and magnet current brought on copper-rich film formation with low electric resistance. On the other hand carbon-rich films with high sheet electric resistance were prepared with decreased values for process parameters aforementioned.


2019 ◽  
Vol 45 (9) ◽  
pp. 11989-12000 ◽  
Author(s):  
Y. Slimani ◽  
B. Unal ◽  
E. Hannachi ◽  
A. Selmi ◽  
M.A. Almessiere ◽  
...  

2015 ◽  
Vol 2015 (DPC) ◽  
pp. 002095-002127
Author(s):  
Warda Benhadjala ◽  
Florence Sonnerat ◽  
Jennifer Guillaume ◽  
Christel Dieppedale ◽  
Philippe Renaux ◽  
...  

Modern RF systems have triggered an important and urgent demand for inexpensive voltage controlled capacitors used for a wide range of applications such as tunable antennas or low-noise voltage-controlled oscillators (VCO). Ferroelectric materials have received considerable interest for electrically tunable dielectrics due to their high dielectric constant and large dielectric nonlinearity under dc bias field. Lead zirconate titanate (PZT) ceramics which have been under intense investigation for various industrial domains including micro-electro-mechanical systems (MEMS), non-volatile memories, and high-k capacitors, are especially well-known candidate materials due to their unequalled ferroelectric properties and stability in device operating ranges. However, reported voltage tunability of PZT films is relatively low (~35%@4GHz) and remains insufficient for microwave tunable devices. Therefore, much attention has been focused on the PZT modification by adding a small amount of dopants. Shao et al., studied strontium-doped PZT (PSZT) thin films and achieved a tunability of 48% @1MHz. More recently, Hu et al. reported a tunability of 65%@10kHz for lanthanum-modified PZT (PLZT) films. In the presented study, effect of manganese (Mn) doping on electrical properties of PZT (PMZT) thin films has been investigated. Metal/insulator/metal (MIM) capacitors using PZT-based thin films and ruthenium (Ru) top electrodes were processed on platinized (Pt) silicon wafers by a sol gel method. Dielectric properties of PMZT thin films were studied by varying the dopant amount and compared to those of pure PZT layers. At this end, on-wafer electrical measurements were conducted with a particular attention on leakage current characterization and RF measurements under DC bias voltage. We have shown that leakage current density decreased from 6.5 μA/cm2 to 1 μA/cm2 at 850kV/cm by doping PZT with Mn. Observed conduction mechanisms will be discussed in detail in the full-length paper. Moreover, developed PZT-based thin films exhibit high dielectric strengths achieving 2.1MV/cm and outstanding tunability as high as 85% (~7:1) @1GHz at bias voltage of 20V. Thus, PMZT tunability is among the highest ones reported in the literature for PZT-derived thin films but also for other piezoelectric materials. Indeed, in comparison, the tunability of BST-based materials, typically studied for voltage tunable applications, does not exceed 5:1. These remarkable results indicate that Mn-doped PZT thin films are promising candidates for RF tunable capacitors.


Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 822
Author(s):  
Christine Thanner ◽  
Martin Eibelhuber

Ultraviolet (UV) Nanoimprint Lithography (NIL) is a replication method that is well known for its capability to address a wide range of pattern sizes and shapes. It has proven to be an efficient production method for patterning resist layers with features ranging from a few hundred micrometers and down to the nanometer range. Best results can be achieved if the fundamental behavior of the imprint resist and the pattern filling are considered by the equipment and process parameters. In particular, the material properties and pattern size and shape play a crucial role. For capillary force-driven filling behavior it is important to understand the influencing parameters and respective failure modes in order to optimize the processes for reliable full wafer manufacturing. In this work, the nanoimprint results obtained for different pattern geometries are compared with respect to pattern quality and residual layer thickness: The comprehensive overview of the relevant process parameters is helpful for setting up NIL processes for different nanostructures with minimum layer thickness.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1157
Author(s):  
Danka Labus Zlatanovic ◽  
Sebastian Balos ◽  
Jean Pierre Bergmann ◽  
Stefan Rasche ◽  
Milan Pecanac ◽  
...  

Friction stir spot welding is an emerging spot-welding technology that offers opportunities for joining a wide range of materials with minimum energy consumption. To increase productivity, the present work addresses production challenges and aims to find solutions for the lap-welding of multiple ultrathin sheets with maximum productivity. Two convex tools with different edge radii were used to weld four ultrathin sheets of AA5754-H111 alloy each with 0.3 mm thickness. To understand the influence of tool geometries and process parameters, coefficient of friction (CoF), microstructure and mechanical properties obtained with the Vickers microhardness test and the small punch test were analysed. A scanning acoustic microscope was used to assess weld quality. It was found that the increase of tool radius from 15 to 22.5 mm reduced the dwell time by a factor of three. Samples welded with a specific tool were seen to have no delamination and improved mechanical properties due to longer stirring time. The rotational speed was found to be the most influential parameter in governing the weld shape, CoF, microstructure, microhardness and weld efficiency. Low rotational speeds caused a 14.4% and 12.8% improvement in joint efficiency compared to high rotational speeds for both tools used in this investigation.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jonathan H. Gosling ◽  
Oleg Makarovsky ◽  
Feiran Wang ◽  
Nathan D. Cottam ◽  
Mark T. Greenaway ◽  
...  

AbstractPristine graphene and graphene-based heterostructures can exhibit exceptionally high electron mobility if their surface contains few electron-scattering impurities. Mobility directly influences electrical conductivity and its dependence on the carrier density. But linking these key transport parameters remains a challenging task for both theorists and experimentalists. Here, we report numerical and analytical models of carrier transport in graphene, which reveal a universal connection between graphene’s carrier mobility and the variation of its electrical conductivity with carrier density. Our model of graphene conductivity is based on a convolution of carrier density and its uncertainty, which is verified by numerical solution of the Boltzmann transport equation including the effects of charged impurity scattering and optical phonons on the carrier mobility. This model reproduces, explains, and unifies experimental mobility and conductivity data from a wide range of samples and provides a way to predict a priori all key transport parameters of graphene devices. Our results open a route for controlling the transport properties of graphene by doping and for engineering the properties of 2D materials and heterostructures.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Caroline O’Keeffe ◽  
Laura Rhian Pickard ◽  
Juan Cao ◽  
Giuliano Allegri ◽  
Ivana K. Partridge ◽  
...  

AbstractConventional carbon fibre laminates are known to be moderately electrically conductive in-plane, but have a poor through-thickness conductivity. This poses a problem for functionality aspects that are of increasing importance to industry, such as sensing, current collection, inductive/resistive heating, electromagnetic interference (EMI) shielding, etc. This restriction is of course more pronounced for non-conductive composite reinforcements such as glass, organic or natural fibres. Among various solutions to boost through-thickness electrical conductivity, tufting with hybrid micro-braided metal-carbon fibre yarns is one of the most promising. As a well-characterised method of through thickness reinforcement, tufting is easily implementable in a manufacturing environment. The hybridisation of materials in the braid promotes the resilience and integrity of yarns, while integrating metal wires opens up a wide range of multifunctional applications. Many configurations can be produced by varying braid patterns and the constituting yarns/wires. A predictive design tool is therefore necessary to select the right material configuration for the desired functional and structural performance. This paper suggests a fast and robust method for generating finite-element models of the braids, validates the prediction of micro-architecture and electrical conductivity, and demonstrates successful manufacturing of composites enhanced with braided tufts.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 638
Author(s):  
Sanam SaeidNahaei ◽  
Hyun-Jun Jo ◽  
Sang Jo Lee ◽  
Jong Su Kim ◽  
Sang Jun Lee ◽  
...  

For examining the carrier movements through tunnel junction, electrically and optically-biased photoreflectance spectroscopy (EBPR and OBPR) were used to investigate the internal electric field in the InGaP/GaAs dual junction solar cell at room temperature. At InGaP and GaAs, the strength of p-n junction electric fields (Fpn) was perturbed by the external DC bias voltage and CW light intensity for EBPR and OBPR experiments, respectively. Moreover, the Fpn was evaluated using the Fast Fourier Transform (FFT) of the Franz—Keldysh oscillation from PR spectra. In the EBPR, the electric field decreased by increasing the DC bias voltage, which also decreased the potential barrier. In OBPR, when incident CW light is absorbed by the top cell, the decrement of the Fpn in the GaAs cell indicates that the photogenerated carriers are accumulated near the p-n junction. Photogenerated carriers in InGaP can pass through the tunnel junction, and the PR results show the contribution of the modification of the electric field by the photogenerated carriers in each cell. We suggest that PR spectroscopy with optical-bias and electrical-bias could be analyzed using the information of the photogenerated carrier passed through the tunnel junction.


2001 ◽  
Vol 1 ◽  
pp. 767-776 ◽  
Author(s):  
E.D. Lund ◽  
M.C. Wolcott ◽  
G.P. Hanson

Soil texture varies significantly within many agricultural fields. The physical properties of soil, such as soil texture, have a direct effect on water holding capacity, cation exchange capacity, crop yield, production capability, and nitrogen (N) loss variations within a field. In short, mobile nutrients are used, lost, and stored differently as soil textures vary. A uniform application of N to varying soils results in a wide range of N availability to the crop. N applied in excess of crop usage results in a waste of the grower’s input expense, a potential negative effect on the environment, and in some crops a reduction of crop quality, yield, and harvestability. Inadequate N levels represent a lost opportunity for crop yield and profit. The global positioning system (GPS)-referenced mapping of bulk soil electrical conductivity (EC) has been shown to serve as an effective proxy for soil texture and other soil properties. Soils with a high clay content conduct more electricity than coarser textured soils, which results in higher EC values. This paper will describe the EC mapping process and provide case studies of site-specific N applications based on EC maps. Results of these case studies suggest that N can be managed site-specifically using a variety of management practices, including soil sampling, variable yield goals, and cropping history.


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