High‐Entropy Alloy (HEA)‐Coated Nanolattice Structures and Their Mechanical Properties

Nanolattice structure fabricated by two‐photon lithography (TPL) is a coupling of size‐dependent mechanical properties at micro/nano‐scale with structural geometry responses in wide applications of scalable micro/nano‐manufacturing. In this work, three‐dimensional (3D) polymeric nanolattices are initially fabricated using TPL, then conformably coated with an 80 nm thick high‐entropy alloy (HEA) thin film (CoCrFeNiAl_0.3) via physical vapor deposition (PVD). 3D atomic‐probe tomography (APT) reveals the homogeneous element distribution in the synthesized HEA film deposited on the substrate. Mechanical properties of the obtained composite architectures are investigated via in situ scanning electron microscope (SEM) compression test, as well as finite element method (FEM) at the relevant length scales. The presented HEA‐coated nanolattice encouragingly not only exhibits superior compressive specific strength of ≈0.032 MPa kg^?1 m³ with density well below 1000 kg m^?3, but also shows good compression ductility due to its composite nature. This concept of combining HEA with polymer lattice structures demonstrates the potential of fabricating novel architected metamaterials with tunable mechanical properties.

     

Hierarchical CdS Nanorod@SnO2 Nanobowl Arrays for Efficient and Stable Photoelectrochemical Hydrogen Generation

An efficient photoanode based on CdS nanorod@SnO₂ nanobowl (CdS NR@SnO₂ NB) arrays is designed and fabricated by the preparation of SnO₂ nanobowl arrays via nanosphere lithography followed by hydrothermal growth of CdS nanorods on the inner surface of the SnO₂ nanobowls. A photoelectrochemical (PEC) device constructed by using this hierarchical CdS NR@SnO₂ NB photoanode presents significantly enhanced performance with a photocurrent density of 3.8 mA cm^?2 at 1.23 V versus a reversible hydrogen electrode (RHE) under AM1.5G solar light irradiation, which is about 2.5 times higher than that of CdS nanorod arrays. After coating with a thin layer of SiO₂, the photostability of the CdS NR@SnO₂ NB arrays is greatly enhanced, resulting in a stable photoanode with a photocurrent density of 3.0 mA cm^?2 retained at 1.23 V versus the RHE. The much improved performance of the CdS NR@SnO₂ NB arrays toward PEC hydrogen generation can be ascribed to enlarged surface area arising from the hierarchical nanostructures, improved light harvesting owing to the NR@NB architecture containing multiple scattering centers, and enhanced charge separation/collection efficiency due to the favorable CdS–SnO₂ heterojunction.     

Sculpting Extreme Electromagnetic Field Enhancement in Free Space for Molecule Sensing

A strongly confined and enhanced electromagnetic (EM) field due to gap‐plasmon resonance offers a promising pathway for ultrasensitive molecular detections. However, the maximum enhanced portion of the EM field is commonly concentrated within the dielectric gap medium that is inaccessible to external substances, making it extremely challenging for achieving single‐molecular level detection sensitivity. Here, a new family of plasmonic nanostructure created through a unique process using nanoimprint lithography is introduced, which enables the precise tailoring of the gap plasmons to realize the enhanced field spilling to free space. The nanostructure features arrays of physically contacted nanofinger‐pairs with a 2 nm tetrahedral amorphous carbon (ta‐C) film as an ultrasmall dielectric gap. The high tunneling barrier offered by ta‐C film due to its low electron affinity makes an ultranarrow gap and high enhancement factor possible at the same time. Additionally, its high electric permittivity leads to field redistribution and an abrupt increase across the ta‐C/air boundary and thus extensive spill‐out of the coupled EM field from the gap region with field enhancement in free space of over 10³. The multitude of benefits deriving from the unique nanostructure hence allows extremely high detection sensitivity at the single‐molecular level to be realized as demonstrated through bianalyte surface‐enhanced Raman scattering measurement.     

Adjacent assembly of self-assembled monolayers for the construction of selective bio-platforms

Selective patterning of bio-substances onto solid platforms is of increasing importance in many areas and widely used for various applications ranging from bio-sensing to cell and tissue engineering. In this study, a new fabrication scheme for the construction of highly selective bio-platforms is presented. The method is based on a direct patterning of poly(ethyleneglycol) (PEG) bio-inert layers on a conducting indium tin oxide (ITO) substrate using electron beam lithography and subsequent assembly of modified amine reactive layers onto the exposed areas. The process is found to create very high “surface contrast” between adhesive and repulsive regions onto the substrate. The platforms are shown to be enable efficient for selective adsorption of a variety of bio-substances including protein arrays, latex beads, and single cells. The high resolution of the technique makes it also applicable for the construction and deposition of bio-structures at the sub-micron scale. The reported technique employs standard lithography and surface chemistry processes, which makes it useful and easy to adopt for a variety of applications and other conductive substrates.     

Recent developments in large‐area photomasks for display applications

One of the most critical areas in the manufacturing process for FPD panels or shadow masks for CRTs is lithography. Most existing lithography technologies require high‐quality large‐area photomasks. The requirements on these photomasks include positioning accuracy (registration) and repeatability (overlay), systematic image quality errors (“mura” or display quality), and resolution (minimum feature size). The general trend toward higher resolution and improved performance, e.g., for TFT desktop monitors, has put a strong focus on the specifications for large‐area‐display photomasks. This article intends to give an overview of the dominant issues for large‐area‐display photomasks, and illustrates differences compared with other applications. The article will also present state‐of‐the‐art methods and trends. In particular, the aspects of positioning accuracy over large areas and systematic image‐quality errors will be described. New qualitative and objective methods have been developed as means to capture systematic image‐quality errors. Results indicating that errors below 25 nm can be found early in the manufacturing process is presented, thus allowing inspection for visual effects before the actual display is completed. Positioning accuracy below 400 nm (3 sigma) over 720 × 560 mm have been achieved. These results will in the future be extended up toward 1 × 1 m for generation 4 in TFT‐LCD production.     

Ion-beam processing of single crystal diamond using SOG mask

Various ion-beam etching characteristics of diamond and selectivity between diamond and spin-on-glass (SOG) were examined. The maximum selectivity of diamond and SOG was 12.7 in oxygen reactive ion-beam etching process at 100 V acceleration voltage. Using this etching condition and dot-shaped SOG mask, conical diamond field electron emitter arrays with 30 nm curvature radius, 2.58 μm base radius and 5.86 μm height were fabricated.     

Preparation of patterned SiC and SiCN microstructures

With the development of modern science and technology, the importance of small structures or microstructures (such as the fluidic nanostructure or microreactor[1], the in- tegrate circuit in microelectronics[2], the factory in a chip[3,4], etc.) has been incarnated day by day in the fields of microelectronics, micro-optical systems, microanalytical sys- tems, microelectromechanical systems and cytobiology. And the fabrication technique (microfabrication) of the small structures has become the h…     

193nm浸液式光刻技术现状

概述了193nm浸液式光刻技术发展现状及技术路线,结合国际半导体技术发展指南(ITRS)和各公司在SPIE微光刻研讨会上宣布的最新研究成果,探讨了193nm浸液式光刻技术的发展趋势。     

用于100nm节点ArF准分子激光光刻的相移掩模技术

用于100nm节点ArF准分子激光光刻的相移掩模(PSM)技术主要有无铬相移掩模(CPM),交替相移掩模(APSM)、衰减相移掩模(AttPSM)和混合相移掩模技术。对这些掩模的基本原理、制作方法及性能比较进行了分析研究。研究表明,无铬相位光刻(CPL)PSM和高透AttPSM 相结合构成的混合掩模最适合用于193nmArF光刻,以产生100nm节点抗蚀剂图形。     

An electron beam lithography and digital image acquisition system for scanning electron microscopes

A low‐cost microcontroller based control and data acquisition unit for digital image recording of scanning electron microscope (SEM) images and scanning electron microscope based electron beam lithography (EBL) is described. The developed microcontroller low‐level embedded software incorporates major time critical functions for image acquisition and electron beam lithography and makes the unit an intelligent module which communicates via USB with the main computer. The system allows recording of images with up to 4096 × 4096 pixel size, different scan modes, controllable dwell time, synchronization with main power frequency, and other user controllable functions. The electron beam can be arbitrary positioned with 12‐bit precision in both dimensions and this is used to extend the scanning electron microscope capabilities for electron beam lithography. Hardware and software details of the system are given to allow its easy duplication. Performance of the system is discussed and exemplary results are presented.