Search

Abstract Multi-element nitride films of AlCrNbSiTiV high-entropy alloy (HEAs) are deposited on a cermet cutter (T1200A) and glass substrates using reactive direct current magnetron sputtering (DCMS) and high power impulse magnetron sputtering (HIPIMS) with a single equimolar AlCrNbSiTiV HEA target. This study determines the effect of the ratio of the nitrogen flow (varying from 0 to 40%) on the chemical composition, microstructure, mechanical properties and cutting tool performance of the (AlCrNbSiTiV)N film. The films are found to have increased hardness and elastic recovery when the nitrogen flow ratio is increased. The (AlCrNbSiTiV)N film adheres well to the substrate and the Rockwell indentation results are HF1. (AlCrNbSiTiV)N films that are grown using DCMS and HIPIMS feature only a simple face-center-cubic structure. The samples that are deposited using HIPIMS exhibit a higher film density, a smoother surface and excellent hardness and elastic recovery, compared to coatings that are deposited using DCMS. The (AlCrNbSiTiV)N films are coated onto cutters for the dry turning of a SCM440 steel work-piece. The machining surface of a coated tool that is deposited using a HIPIMS system exhibits fewer surface defects and the tool flank wear is decreased. Highlights • TEM pattern of (AlCrNbSiTiV)N film shows a simple NaCl-type FCC phase. • Nitride films shows good adhesion strength to the substrate be classified as HF1. • The distribution of elements is homogeneous through the depth of the nitride film. • The films deposited with the HIPIMS are smoother, better crystallized and good mechanical property. [ABSTRACT FROM AUTHOR]

This study employed the four-point bending test (4-PBT) to measure the interfacial strength of pressure-sensitive adhesive (PSA)/SiN passivation stacked thin films. Finite element analysis (FEA) is combined with the J integral approach and the modified virtual crack closure technique to validate the results of 4-PBT. The FEA simulation results verify the measurement results. The stress status and energy release rate of the delaminated tip are also determined at different elevations of stacked thin films of 4-PBT specimens adjacent to the PSA/SiN interface. The crack in the PSA parallel to the foregoing interface with a slight span occurs on the fractured interface. This behavior is confirmed by observing the scanning electron micrographs of the specimens after 4-PBT. [ABSTRACT FROM AUTHOR]

Abstract: The integration of thin film technology into the fabrication of semiconductor transistors has given rise to significant challenges in the design of multi-level back-end-of-line interconnects. The interfacial adhesion between Al metal and TiN barrier is one of the major factors that affect interconnect reliability. Analyzing the effect of the interconnect structures of Al/TiN barriers on interfacial cracking energy under flexural loading is an interesting research direction. This work proposes a robust estimation of interfacial cracks by simulation-based methods to satisfy the mechanical design requirements for multi-level interconnect systems. A constant bending moment can be generated with the framework of the four-point bending test (4-PBT). A 4-PBT simulation model can be used in finite element analysis, combined with the J-integral method and the modified virtual crack closure technique, to accurately predict the interfacial fracture energy of Al/TiN films. Preliminary results indicate a considerable increase in energy release rate. Energy is released as a crack along the interface of the Al/TiN films passes through the region above the parallel metal lines of patterned interconnects, especially for a Cu/SiLK material system. The results also show that dielectrics can serve as stress buffer layers that inhibit crack growth. [Copyright &y& Elsevier]

Abstract: Organic electronic devices with multi-stacked thin films based on polymeric substrates are proposed for use in mainstream flexible organic light-emitting diode displays. To achieve the above-mentioned requirements, indium tin oxide (ITO) thin film, a brittle, inorganic material, is necessary to be utilized as a transparent electrode in flexible electronics. The failure rate of ITO films is of concern when introducing harsh flexural load in terms of reliability. This study utilizes a simulation-based factorial-design approach to determine a suitable combination of mechanical characteristics of ITO film stacked with other films to reduce the neutral plane (NP) impact of stacked films. The results indicate that both Young's modulus and cover plate thickness are major factors that alter the stress magnitude of ITO films. Moreover, the simulated results for stacked structures reveal that the distance between the ITO film and NP is significantly reduced when polyimide materials, rather than steel metal, are used for the cover plate. In the meanwhile, ITO film stress drops in virtue of lower mechanical stiffness and lesser thickness direction between the NP and ITO films in a multi-stacked film structure. [Copyright &y& Elsevier]

Abstract: Formation and composition analyses of titanium oxinitride nanocrystals (NCs) fabricated via treating a magnetron co-sputtered thin film of titanium and silicon dioxide with a rapid thermal annealing in nitrogen ambient were demonstrated for nonvolatile memory applications. Phase separation characteristics with different annealing conditions were examined by transmission electron microscopy and chemical bonding characteristics were confirmed by X-ray photon emission spectra. It was observed that a blanket layer composed mainly of titanium oxide was still present as annealing temperature was increased to 700°C, associated with the thermodynamically stable phase of titanium oxide. Furthermore, a higher thermal treatment of 900°C induced formation of a well-separated NC structure and caused simultaneously partial nitridation of the titanium oxide, thereby forming titanium oxinitride NCs. A significant capacitance–voltage hysteresis in threshold voltage shift at 1V was easily achieved under a small sweeping voltage range of +2V/−2V, and a memory window retention of 2.2V was obtained after 107 s by extrapolation under a 1s initial-program/erase condition of +5V/−5V, respectively. [Copyright &y& Elsevier]

Based on wavelet transforms extracting characteristic features from experimental data, the wavelet neural network (WNN) is used as an elementary model to study the characteristics of field emission from thin films. The WNN model is trained with learning samples of thin film thickness. The function mappings that the trained WNN model contains are the very ones that thin film thickness varies with characteristic parameters of field emission. A predicting model on thin film thickness of field emission is obtained. The data of thickness of diamond thin films is used to test this model. The results show that the absolute value of the relative error is within 2.98%, and the well-trained WNN model possesses good forecasting characteristics. [Copyright &y& Elsevier]

Abstract: Polycrystalline silicon thin film transistors (poly-Si TFTs) with the ion implantation of fluorine elements were investigated in this study. The electrical performance and reliability were reported comprehensively. Experimental work has shown the electrical characteristics of excimer laser crystallized F-ions-implanted poly-Si TFTs are improved effectively, especially for field effect mobility. It is also found that the fluorine piled up at the poly-Si interface during thermal annealing, for the TFT fabricated without a prior deposition of pad oxide. The stronger Si–F bonds replace the Si–Si/Si–H, leading to the superior electrical reliability. However, the dose of F ions is critical in poly-Si, or the electrical characteristics of TFT devices will be degraded. [Copyright &y& Elsevier]