Gold Micro Research Articles

An in vitro comparative evaluation of efficiency of three rotary nickel-titanium file systems in terms of remaining dentin thickness using cone-beam computed tomography.

The objective of the present research was to assess and compare the residual dentin thickness after biomechanical preparation of teeth using three distinct rotary nickel-titanium (Ni-Ti) file systems. In the current experimental study, a total of 45 single-rooted teeth were selected for the analysis. The cementoenamel junction of each tooth was decoronated using a diamond disc. The teeth were randomly allocated to three groups, with each group representing a different rotary file system: Group 1: Hero GOLD (Micro Mega), Group 2: One Curve (Micro Mega), and Group 3: HyFlex electro-discharge machining (EDM) (Coltene-Whaledent, Altstatten, Switzerland). To evaluate the initial condition of the teeth, cone-beam computed tomography (CBCT) scans were conducted before the biomechanical preparation. The teeth were positioned on a modeling wax sheet, and the CBCT scans provided baseline measurements. The biomechanical preparation of the root canals followed the manufacturer's recommended guidelines for each file system. After the completion of the canal preparation, follow-up CBCT scans were conducted. The postprocedure CBCT scans were then compared with the initial scans to assess any changes in the residual thickness of dentin in the teeth. Post hoc Tukey analysis of variance tests was utilized to examine differences between the groups. A statistically significant result was defined as P = 0.05 or less for every test. The comparison of preinstrumentation and postinstrumentation CBCT images showed that the HyFlex EDM group removed less dentin clinically compared to the other two groups, i.e., Hero GOLD and One Curve. No significant statistical difference was found between Hero GOLD versus One Curve, One Curve versus HyFlex EDM, and Hero GOLD versus HyFlex EDM. Based on the results of this study, the HyFlex EDM file system exhibited superior cutting efficiency at various levels. Nonetheless, additional investigations are required to comprehensively assess the influence of Ni-Ti rotary file systems on the remaining dentin thickness.

(Invited) Direct Laser Induced Gold Wiring of 2D Materials with Sub-Μm Resolution

One of the most influential technologies of our modern world are integrated electronics. Almost all parts of our daily life include some bearing with any kind of electrical technologies. The fabrication methods itself, for integrated miniatured electrical devices have had not much innovation in terms of production. Several processing steps still mainly consist of different kinds of lithography. This situation may change with new challenges on the production of smaller quantities with specialized functions, or the use of temperature critical or atomically thin surfaces, where the thermal evaporation of metals damages the sample.For some decades now, printing of all types of electronics have gained great attraction. While lithography is a time-consuming multi-step process (including resist preparation, illuminating, developing, evaporation and lift-off) with expensive and harmful photoresists and harsh environmental conditions (high-vacuum and thermal treatments), ink printing allows for direct and simple application of the desired structures [1]. Two main types of inks are typically applied: colloidal solutions of metal nanoparticles [2, 3] or metal-organic precursor solutions [4]. In both cases, thermal curing after deposition is required to achieve metallic conduction. To this end, laser writing is often advantageous over thermal sintering due to the overall lower thermal stress applied to the material, particularly on flexible, thermally sensitive substrates [5] whereas metal nanoparticles suffer from a relatively high photothermal stability and the need for a large laser power to achieve sufficient sintering [3]. In contrast, metal-organic precursor solutions feature a relatively low metal content (≤34 wt-%)10, and undergo large volume contractions during laser writing. These challenges have so far prevented the definition of metallic gold contacts with diffraction-limited feature sizes by ink printing and laser writing.Here, we introduce atomically-precise, metalloid Au32(nBuP12Cl8) nanoclusters (Au32NCs) [6] as an ink for resistless, direct laser writing of metallic gold micro- and nanostructures. The unique advantages of this ink over Au nanoparticles or typical metal-organic Au precursors are their high photosensitivity in combination with a large gold content of 70 wt-%. This allows for writing gold structures with feature sizes of 250 nm and line spacings < 200 nm using 1.86 mW laser power at 488 nm with a scan speed of 0.1 mm/s. We apply this method on a wide range of substrates, including flexible polymer membranes, find metallic conductance with conductivities ~ 1 × 106 S/m and demonstrate that defining such Au contacts on two-dimensional semiconductors results in fully functional optical switches and field effect transistors made out from 2D materials.[1] Raut NC. et al., Jour. Mat. Chem. C 2018, 6(7): 1618-1641.[2] Ko E. et al., Nanotechnology 2007, 18(34): 345202.[3] Hong S. et al., ACS Nano 2013, 7(6): 5024-5031.[4] Schoner C et al., Thin Solid Films 2013, 531: 147-151.[5] Skylar-Scott MA et al., PNAS 2016, 113(22): 6137-6142.[6] Kenzler S et al., Angew. Chem. Int. Ed. 2019, 58(18): 5902-5905. Figure 1

Impurity analysis of electroplated gold components with multi-layered structures by thermal desorption spectrometry toward application in gold Micro electro mechanical system capacitive accelerometers

Au-based micro-electro-mechanical-system (Au-MEMS) capacitance accelerometers show high sensitivity by suppressing the mechanical noise because of the high mass density of gold (ρ = 19.3 g/cm3). On the other hand, their long-term reliability suffers from drift phenomena induced by the impurities incorporated in the key component during their fabrication process, such as the gold electroplating step. Herein, impurities in electroplated Au-based components for MEMS capacitive accelerometers are evaluated by thermal desorption spectrometry (TDS) measurements. The TDS measurement reveals that dominant desorption gases from the Au-based component are molecular hydrogen (H2) and water (H2O). These desorption gases are derived from impurities in the electroplated Au-based component, and the amount of these gases is significantly suppressed by a thermal treatment step. In conclusion, this study demonstrates that the electroplated Au-based component contains impurities originated from the fabrication process, and these impurities could be removed by a thermal treatment step.

Research on Surface Morphology of Gold Micro Bumps Based on Monte Carlo Method.

In advanced packaging technology, the micro bump has become an important means of chip stacking and wafer interconnection. The reliability of micro bumps, which plays an important role in mechanical support, electrical connection, signal transmission and heat dissipation, determines the quality of chip packaging. Surface morphological defects are one of the main factors affecting the reliability of micro bumps, which are closely related to materials and bonding process parameters. In this paper, the electrodeposition process of preparing gold bumps is simulated at the atomic scale using the Kinetic Monte Carlo method. The differences in surface morphology and roughness of the plated layer are studied from a microscopic perspective under different deposition parameters. The results show that the gold micro bumps prepared by electrodeposition have better surface quality under conditions of lower deposition voltage, lower ion concentration and higher plating temperature, which can provide significant guidance for engineering applications.

Разработка метода и прибора для измерения сил в контактах частиц в условиях флотации микродисперсий золота

Introduction. In flotation of gold-containing ores, metal losses with tailings are mainly related to the fine particle size classes - micro dispersions. Study of the physical nature of the forces in the contacts between the particles, including gold micro dispersions, allows gaining new knowledge associated with the solution of the pressing problem of effective extraction of difficult to extract forms of the precious metal by flotation. Materials and methods. Measurement of the forces in contacts of particles was carried out by sediment volumetric method using the developed device. The method allows to determine the forces in contacts of particles by the volume of their sediment, formed as a result of kinetic destruction of the disperse system. Alluvial gold from the collection formed during the experimental tests of the equipment of separation complexes "Shlich", "Shlich-2", "PGShOK-50-2" was used in the experiments. The results of measuring the forces were supplemented by theoretical studies, which had the aim to estimate the contribution of the fluid volume held by capillary forces in contacts of particles to the volume of sediment. Results. It was found that the volume formed by the kinetic destruction of the disperse system is determined by the force in the contacts of particles, and the volume of capillary held liquid is of subordinate importance. Discussion. It is shown that the results obtained can be explained by involving the notions of boundary layers of fluids with a structure changed under the influence of surface forces. The low-entropic structure of liquid in the boundary layer of hydrophobic surface is caused by forces arising inside liquid itself near weakly interacting surface, and is energetically the least favorable, corresponding to the maximum of free energy. Therefore, the particles behave as if there are hydrophobic attraction forces among them. Conclusion. Uncompensated charges near hydrophilic surface create high-entropic structure of water with normal orientation of its dipoles and increased density, which causes the appearance of structural hydrophilic repulsive forces among particles. Resume. Structural hydrophobic attraction and hydrophilic repulsion are endothermic processes. Their violation will be an exothermic process and its exo-thermicity increases as the temperature rises. The developed method of flotation is based on this property of structural forces: the stability of wetting films in flotation processes of micro-dispersions of minerals is changed by heating water in the boundary layers of air bubbles - hydrophobic cavities in water - due to the condensation heat of hot water vapor. For this purpose, aeration of the flotation system is carried out by a mixture of air and steam. Proposals for practical application and direction of future research. Practical significance of the project is to develop technology for flotation of the most difficult to extract forms of gold. Its essence is based on the effect of preferential adhesion of gold micro-dispersions on its own hydrophobic large particles - a solid wall. Thin plates, flakes and sheets of native gold are used as it. The aggregates formed by the above described mechanisms from poly disperse particles are extracted by flotation. In case of extraction in several steps the rough concentrate can be used as a solid wall (carrier minerals). In further research it is necessary to develop an organizational mechanism of joint processing of ores and gold placers.

Futures Trading Business Opportunities and Feasibility (Gold Micro Account) at PT. Agrodana Futures as an Alternative Business Opportunity for Small Entrepreneurs

There are many business or business opportunities in Indonesia that are actually attractive, promising and have legality from the government and have legal force based on the law, but many do not know about these business opportunities. One of them is Business in the Field of Trading / Futures Trading or Trading on the Exchange. This business can be an alternative choice for small entrepreneurs. Trading / Futures Trading is growing rapidly in Indonesia. Apart from offering huge profits, technological developments are also very supportive of the booming world of trading. Business people can transact anywhere and anytime. on the condition that it is not too complicated and the capital is not too large. All of that is an extraordinary magnet for anyone who wants to enter the world of trading. Behind all the conveniences and the lure of very attractive profits, lies a very large risk as well. The risk is that the capital can run out in a short time in the Trading Market. This is not caused by ignorance, but is often caused by not wanting to know the risk. Business people focus on thinking about the benefits they get. Another reason for working in this field, business people are obsessed with returning the capital that has been taken by the market. However, actually the Business Opportunity in the field of Trading is very helpful for the community in increasing the income from the capital they have, developing it, meeting operational needs and other needs, certain goals are even inherited. With the right Innovation Strategy, measurable planning and evaluation as well as organized risk management, plus a SWOT model to find out how the opportunities, strengths, threats and weaknesses faced by these small business actors/entrepreneurs at PT. Agrodana Futures and future projections for this business.

Nanostructure, electrochemistry and potential-dependent lubricity of the catanionic surface-active ionic liquid [P6,6,6,14] [AOT

HypothesisA catanionic surface-active ionic liquid (SAIL) trihexyltetradecylphosphonium 1,4-bis(2-ethylhexoxy)-1,4-dioxobutane-2-sulfonate ([P6,6,6,14] [AOT]) is nanostructured in the bulk and at the interface. The interfacial nanostructure and lubricity may be changed by applying a potential. ExperimentsThe bulk structure and viscosity have been investigated using small angle X-ray scattering (SAXS) and rheometry. The interfacial structure and lubricity as a function of potential have been investigated using atomic force microscopy (AFM). The electrochemistry has been investigated using cyclic voltammetry. Findings[P6,6,6,14] [AOT] shows sponge-like bulk nanostructure with distinct interdigitation of cation–anion alkyl chains. Shear-thinning occurs at 293 K and below, but becomes less obvious on heating up to 313 K. Voltammetric analysis reveals that the electrochemical window of [P6,6,6,14] [AOT] on a gold micro disk electrode exceeds the potential range of the AFM experiments and that negligible redox activity occurs in this range. The interfacial layered structure of [P6,6,6,14] [AOT] is weaker than conventional ILs and SAILs, whereas lubricity is better, confirming the inverse correlation between the near-surface structure and lubricity. The adhesive forces of [P6,6,6,14] [AOT] are lower at −1.0 V than at open circuit potential and +1.0 V, likely due to reduced electrostatic interactions caused by shielding of charge centres via long alkyl chains.

Long-term outcome of supraciliary gold micro shunt in refractory glaucoma.

PurposeTo evaluate the 10‐year follow‐up efficacy and safety of gold micro shunt (GMS) in patients with refractory glaucoma, and the potential risk factors for failure.MethodsRetrospective data analyses based on medical records from 55 patients who underwent GMS implant for refractory glaucoma between March 2007 and April 2008. The primary outcome measure was the cumulative probability of success defined as intraocular pressure (IOP) below 21 mmHg together with a 33% lowering of the baseline IOP with (qualified) or without (complete) topical medications, no reoperation for glaucoma or loss of light perception.ResultsMean IOP 10 years after the GMS implantation was 21.6 ± 5.1 mmHg with 2.7 ± 0.7 drugs. Qualified success was achieved in 8/55 patients (14.5%) with a mean of 2.9 ± 0.8 drugs at 5 years and in 2/55 patients (3.6%) with a mean of 2.7 ± 1.0 drugs at 10 years. None of the patients reached complete success at five years from surgery. The cumulative probability of complete success was 14%, 9% and 0% at 1, 2 and 5 years, respectively, and 72%, 67%, 36% and 3.6% at 1, 2, 5 and 10 years, respectively, for qualified success criterion. Baseline IOP for complete success, number of baseline medication for qualified success and age at the time of GMS implantation for both criteria were risk factors significantly associated with failure.ConclusionA very low long‐term survival rate of GMS in refractory glaucoma was found. Most patients did not reach the IOP success criteria of the study, even with the re‐introduction of medications, leading to the need for further surgical procedures.

Mineralization and Self‐assembly of Gold Nanoparticles using Sulfur Amino Acid Modified Hierarchically Porous Metal‐Organic Frameworks

AbstractIn this work, we modified the hierarchically porous metal‐organic frameworks (HP‐MOFs) HP‐UiO‐66 with sulfur‐containing amino acid cysteine and methionine, respectively. The cysteine or methionine modified HP‐MOFs, HP‐UiO‐66‐C and HP‐UiO‐66‐M, can be used for the adsorption and mineralization of Gold nanoparticles. Au nanoparticles will form in HP‐MOFs when the concentration of chloroauric acid is relatively low. Intriguingly, when the concentration of the chloroauric acid solution was increased to 5 mg ml−1, hexagonal gold micro flakes appeared in the system after adsorption by the HP‐UiO‐66‐C and HP‐UiO‐66‐M. Transmission electron microscope revealed that the hexagonal gold micro flakes are formed by the ordered self‐assembly of gold nanoparticles induced by the HP‐UiO‐66‐C and HP‐UiO‐66‐M. The obtained AuNP@HP‐UiO‐66‐C and AuNP@HP‐UiO‐66‐M can catalyze the reduction of 4‐NP. The apparent reaction rates constant of unit mass catalyst kcat are 0.0356 mg−1 min−1 and 0.0265 mg−1 min−1, respectively.

Current Biomedical and Diagnostic Applications of Gold Micro and Nanoparticles.

Production of particles and their adaptation in the pharmacology became an object of interest, and they are the currently introduced therapies based on the use of micro and nanoparticles. The use of gold particles is not an exception. This review has focused on the application of gold micro and nanoparticles in pharmacology and biomedicine. The particles can be used for diagnosis respective theranostic of cancer, rheumatoid arthritis and as antimicrobial means. Besides these applications, specifications of gold, gold particles, and colloidal gold manufacturing and their comparison with the solid gold, are described as well. This review is based on a survey of actual scientific literature.

Sulfur Dioxide (SO2) Detection Using Composite of Nickel Benzene Carboxylic (Ni3BTC2) and OH-Functionalized Single Walled Carbon Nanotubes (OH-SWNTs)

In the present investigation, composite of ‘nickel benzene carboxylic (Ni3BTC2)’ and ‘OH-functionalized single walled carbon nanotubes (OH-SWNTs)’ was synthesized by solvothermal method. The synthesized Ni3BTC2/OH-SWNTs were drop casted on gold micro electrode tip on Si/SiO2 substrate. The synthesized composite materials were characterized by X-ray diffraction (XRD) for structural analysis, electrical analysis using current-voltage (I/V) characteristics, Field emission scanning electron microscopy (FESEM) for surface morphology, Field effect transistor (FET) by using transfer and output characteristics and spectroscopic analysis using Fourier-transform infrared spectroscopy (FTIR). This composite was used for detection of SO2. The proper incorporated OH-SWNTs in Ni3BTC2 MOF exhibits increase in conductivity and sensing performance (better response and recovery time, repeatability). This work reveals that the composite of Ni3BTC2/OH-SWNTs can be used for reversible sensing of SO2 gas in ChemFET modality at room temp.

Realizing high aspect ratio silver micro and nanostructures by microcontact printing of alkyl thiol self-assembled monolayers

ABSTRACTThe patterning of gold and silver micro and nanostructures on rigid and flexible substrates is investigated by microcontact printed thiol based self-assembled monolayers. The aspect ratio of the noble metal micro and nanostructures is determined by interaction of the -SH head group of the CH3(CH2)19SH molecules and the surface of the noble metal. Silver micro and nanostructures with &gt;10 times higher aspect ratios can be realized in comparison to commonly realized gold micro and nanostructures. The printing process is described, and the etching process is characterized in terms of etching window and etching selectivity. Potential electronic and photonic applications of the micro and nanostructures are discussed taking the boundary conditions of the printing process and the selected material system into consideration.

Transition from two-photon absorption to saturable absorption in gold patterned ruby thin film

Nonlinear behaviour of gold micro disks patterned Ruby film has been investigated via Z-scan technique. Open Z-scan was performed for Ruby and Ruby/gold thin film using 532 nm Laser source. Two-photon absorption (TPA) and Saturable absorption (SA) have been observed in pure Ruby and Ruby/gold thin film respectively. The expression for normalized transmittance in open Z-scan was obtained by Gaussian decomposition method for fitting. The values for nonlinear absorption coefficient (β) for Ruby/gold (7.41×10-7m/W) was two orders of magnitude higher than that of Ruby (1.41×10-9m/W). Further, TPA and SA were confirmed by open Z-scan on these films, performed using 633 nm Laser source.

Nanomole Silver Detection in Chloride-Free Phosphate Buffer Using Platinum and Gold Micro- and Nanoelectrodes

The electrochemical determination of ultra-low concentrations of silver requires reliable, reproducible measurements using sensitive analytical techniques. To date, the electrochemical determination of silver in biological buffers and pH neutral media has not been successful in terms of reproducibility. In this work, we report on the determination of ultra-low concentrations of silver in chloride-free phosphate buffer solution (PB, pH 7.4). Detection was conducted at gold and platinum micro and nanoelectrodes using anodic stripping voltammetry (ASV). The micro and nanoelectrodes were fabricated using a Sutter P-2000 laser puller, with physical and electrochemical characterization revealing flat disk-shaped working surfaces of 10–15 μm (microelectrode) and 10–100 nm (nanoelectrodes) in radius. These dimensions were calculated from steady-state limiting currents and confirmed using FE-SEM. The laser pulled electrodes exhibit excellent electrochemical activity when characterized using ferrocene, without the addition of supporting electrolyte, and reproducible stripping voltammetric profiles for the determination of silver, with a LoD of 1.3 pM (1.8%) were obtained in 0.1 M chloride-free phosphate at platinum nanoelectrode. Determination of ultra-low concentrations of silver in chloride-free PB provides the scope to explore the mechanism of action of bioinorganic silver-based anti-bacterial, anti-fungal and anti-cancer drugs in cell media for in vitro and, potentially, in vivo analysis.

A highly sensitive glucose biosensor based on a micro disk array electrode design modified with carbon quantum dots and gold nanoparticles

A miniaturised biosensor for glucose was prepared by immobilizing glucose oxidase (GOx) onto a carbon quantum dots (CQDs)-gold nanoparticles (AuNPs) nanohybrid material which was in turn attached to gold micro disk array electrodes. The gold micro disk array electrodes (GDAE) were microfabricated on Si substrate using electronics-standard lithography, deposition and etching techniques. Each microelectrode consisted of 85 gold disk electrodes with 20 μm diameter and 200 μm inter-electrode distance and were located hexagonally. The electrodes were studied by scanning electron microscopy (SEM), atomic force microscopy (AFM) and cyclic voltammetry (CV). CV of the bare electrodes showed a symmetrical sigmoidal voltammogram arising from their radial diffusion profile. The electrodes developed were used to fabricate a miniaturised glucose biosensor. The resulting biosensor exhibited a high sensitivity of 626.06 μA mM−1 cm−2 towards glucose detection with excellent reproducibility and reusability. The superior performance of the biosensor is discussed in relation to the use of the micron-sized low density disk array electrodes.

Nanoantenna structures for the detection of phonons in nanocrystals.

We report a study of the infrared response by localized surface plasmon resonance (LSPR) modes in gold micro- and nanoantenna arrays with various morphologies and surface-enhanced infrared absorption (SEIRA) by optical phonons of semiconductor nanocrystals (NCs) deposited on the arrays. The arrays of nano- and microantennas fabricated with nano- and photolithography reveal infrared-active LSPR modes of energy ranging from the mid to far-infrared that allow the IR response from very low concentrations of organic and inorganic materials deposited onto the arrays to be analyzed. The Langmuir–Blodgett technology was used for homogeneous deposition of CdSe, CdS, and PbS NC monolayers on the antenna arrays. The structural parameters of the arrays were confirmed by scanning electron microscopy. 3D full-wave electromagnetic simulations of the electromagnetic field distribution around the micro- and nanoantennas were employed to realize the maximal SEIRA enhancement for structural parameters of the arrays whereby the LSPR and the NC optical phonon energies coincide. The SEIRA experiments quantitatively confirmed the computational results. The maximum SEIRA enhancement was observed for linear nanoantennas with optimized structural parameters determined from the electromagnetic simulations. The frequency position of the feature’s absorption seen in the SEIRA response evidences that the NC surface and transverse optical phonons are activated in the infrared spectra.

A novel patient-oriented numerical procedure for glaucoma drainage devices.

The present work analyses the performance of four glaucoma drainage devices, by means of a novel patient-oriented numerical procedure. The procedure is based on the three-dimensional geometry reconstruction from the stacks of tomographic images of a human eye, at different angles, on meshing and on thermo-fluid dynamics modelling activities, carried out on the reconstructed computational domain. The current three-dimensional eye model considers anterior chamber (AC), trabecular meshwork, Schlemm's canal, and collector channels, making use of generalised porous medium approach for modelling ocular porous tissue and cavities. The intraocular pressure (IOP) management inside AC of human eye is analysed, by comparing the results obtained for four drainage devices implanted in a human eye for glaucoma treatment, ie, ExPRESS shunt, iStent inject, SOLX gold micro shunt, and the novel silicon shunt device. The numerical results allow predicting the effects of the installation of these implants on human eyes, in terms of IOP decrease, aqueous humour velocity, pressure, friction coefficient, and local Nusselt number, pointing out the clear distinction between pre-operative and post-operative eye conditions for different glaucoma surgical techniques.

Understanding the influence of thermal annealing of the metal catalyst on the metal assisted chemical etching of silicon

The metal-assisted chemical etching (MACE) is emerging as one of the cost-effective technique for anisotropic etching of silicon (Si) where the metal catalyst plays a key role in the etching process. Although intensive research has been carried out in this field, the effect of thermal annealing of the metal catalyst on MACE is not well understood. Therefore, a systematic study of the thermal annealing effect of the metal catalyst on the MACE of silicon (Si) in conjunction with gold (Au) micro stripes as a catalyst has been carried out in this work. We have demonstrated that the post-deposition thermal annealing of Au micro stripes has a direct relationship to the thickness of the metal catalyst for Si etching. The experimental results indicate that Si etching occurs when an annealed thick (140 nm) and wider (> 3 µm) Au micro stripe is applied as the metal catalyst. However, Si etching does not occur for an annealed thin (50 nm) and wider (> 3 µm) Au micro stripe is used as a metal catalyst. Furthermore, the direct effect of the oxidizing agent on the MACE Si etching by using annealed thick Au micro stripes has also been investigated. We show that a higher concentration of the oxidizing agent only polishes the Si surface with formation of craters in different locations of the Si. Here in this paper, the probable reasons for these results are also discussed.

Study of THz-Plasmon hybridization of a loop Yagi-Uda absorber

In this article we present a three-dimensional loop Yagi-Uda array for efficient, polarization independent and directional absorption of THz radiation over a narrow frequency range (f0 = 0.657 THz & Q factor = 7.5). Unit cell of the array consists of three vertically stacked gold micro rings separated from each other by 30 µm thick SU-8 layers. The proposed array also exhibits a filtering response in its transmittance spectrum. The characteristics are explained by plasmon hybridization method. The transmission, reflection and absorption spectra of the structure are measured and they show a good agreement with corresponding simulated results.

Fabrication of top-down gold nanostructures using a damascene process

In this work, we propose a damascene process to fabricate embedded gold micro- and nano-structures at the same time. We present a systematic study of the material removal rate (MRR) and the selectivity on both gold and silicon dioxide. The embedded microstructures are 2μm wide and 60nm deep, while the nanostructures widths vary from 70nm to 500nm for a 50nm depth. Moreover, we highlight the contribution of the CMP in polishing the surfaces of gold films. Morphological characterizations are performed using mechanical profilometry, Atomic Force Microscopy (AFM), and Scanning Electron Microscopy (SEM). MRR and selectivity are evaluated as a function of time, applied pressure, platen rotation speed, and slurry flow.