The elastic property of a copper (Cu) thin film was investigated using the surface acoustic wave (SAW) measurement technique. The Cu film was deposited on a quartz substrate using a direct current magnetron sputter and its surface morphology was inspected using atomic force microscopy. Time-domain waveforms of the SAW on the film were acquired at different propagation distances to estimate the Young’s modulus of Cu such that the experimentally-obtained dispersion curve can be compared to the analytical result calculated using the Transfer Matrix method for curve-fitting. Results showed that the film’s elastic property value decreased by 18.5% compared to that of the bulk state, and the scale effect was not significant in the thickness range of 150-300 nm, showing good agreement with those by the nanoindentation technique. The property, however, increased by 15.5% with the grain coarsening.
This study investigated the Laser-Induced Plasma Backward Deposition (LIPBD) process for transparent glass-copper composite film production. LIPBD was compared with Laser-Induced Backward Transfer (LIBT). Controlling laser parameters and the z-axis position of Depth of focus (DOF) resulted in various post-deposition outcomes. The optimal deposition depth was 10 μm to 90 μm, ensuring good glass-copper adhesion. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) mapping confirmed copper and copper oxide (CuO) particles. X-ray diffraction confirmed Cu and CuO peaks. The adhesive test showed a strong binding between glass and deposition, but the parts of the cracks caused by heat accumulation were delaminated during the test. LIPBD offers controlled deposition potential for glass-copper composites. Optimizing laser parameters leads to high-quality films. This study provides valuable insights into nanotechnology and the semiconductor industry, with potential applications across diverse fields.
In the Jet-Circulating electrodeposition, selective electrodeposition is done using the local circulation of the electrolyte. The Scale of fabricated patterns using the Jet-Circulating electrodeposition is dependent on the contact area between the nozzle and the workpiece surface through the electrolyte circulation. The shape of the electrolyte meniscus determines the contact area. The factors that influence the shape of the meniscus include the electrolyte jetting parameter and the characteristics of the workpiece surface. The jet distances are analyzed based on the shape of the electrolyte meniscus and contact area which is dependent on the jetting pressure and the suction pressure. In order to investigate the effect of contact area on the workpiece surface, the surface is treated using Hexamethyldisilazane spin coating, self-assembled monolayer formation, and Neverwet ® spray coating. The contact angle and the contact area based on the surface treatment methods are analyzed. The width of the copper patterns fabricated through Jet-Circulating electrodeposition are compared. The copper pattern width of the self-assembled monolayer formation surface had reduction of 30% in comparison to the untreated surface.
Silicon nitride/cobalt tungsten boride (SiN/CoWB) passivation layer improves mass transport rate at copper thin film layers of semiconductor wafers after chemical mechanical polishing process. This study evaluates mass transport at the interface between copper and passivation layers by stress relaxation method, followed by deduction of interface diffusivity via a kinetic model. For comparison, SiN/CoWB, SiN, silicon carbon nitride (SiCN) and silicon carbide (SiC) passivation layers are introduced. A thin layer of SiN/CoWB demonstrates an outstanding performance as diffusion retarding material, especially at high temperature. The order of stress relaxation in terms of passivation layers is SiN/CoWB < SiN < SiCN < SiC, implying the order of mass transport at the interface. Using the kinetic model, the diffusivities and activation energies regarding passivation layers are calculated and reveal a good agreement with experimental results.
There are two well-known synthetic approaches for copper nanowires (CuNWs): ethylenediamine (EDA)-mediated synthesis and alkylamine-mediated synthesis. The alkylamine-mediated synthesis produces very high aspect ratio nanowires but requires an autoclave for high-pressure environments, and a long reaction time, which normally is above 12 hours. The EDA-mediated synthesis can be carried out under normal conditions and requires 30 min. The CuNWs produced by this method have an average aspect ratio lower than 1000 and are produced in a lower yield. In this paper, the researchers present a modified EDA-mediated synthesis to improve the yield and reduce the synthesis time. When NaOH and Cu(NO3)2 were replaced with KOH and CuCl2, respectively and the reaction temperature was kept at room temperature, the synthesis time was shortened to 15 min. Moreover, the aspect ratio of the as-synthesized Cu NWs increased to 650 and the synthesis yields raised from 17.73% to 80.16%.
A study of super-hydrophobic surface originated from the analysis of lotus leaf in the nature and fabrication method of super-hydrophobic surface on copper substrate has been researched for, showed functional surfaces with anti-corrosion. However, since copper nanowires decomposed during thiol coating, it is necessary to reseach on the relation with morphology of copper nanowires and thiol coating time. In this study, the research is all about the effect of thiol coating time on wettability of copper nanowires surface. Copper hydroxide nanowires were made up by oxidation using dipping method and a polymer layer was formed on nanowires using thiol coating. Surface characteristics were assessed using scanning electron microscopy and liquid contact angles. The conclusion showed relation for wettability of thiol coated copper hydroxide nanowires with thiol coating time and proposed method would be favorable for anti-corrosion functional surface.
This paper introduces a facile method to enhance the functionality of a patterned metallic transparent conductor through selective laser ablation of the metal nanowire percolation network. By scanning focused nanosecond pulsed laser a on copper nanowire percolation network, the copper nanowires are selectively ablated and patterned without resorting to any conventional chemical etching or photolithography steps. Several arbitrary patterns of copper nanowire transparent conductors are readily created on the percolation network by changing various laser parameters, such as repetition rate and power. Finally, in a few seconds, the copper nanowire electrode is continuously ablated to a 1 × 1 mm square area. This research thereby proves the advantage of the laser fabrication method.