Fabrication of Large-Area Imprint Mold with High-Aspect-Ratio Nanotip Arrays of Sub-Micron Diameter

2007 ◽  
Vol 364-366 ◽  
pp. 607-612 ◽  
Author(s):  
Chia Jen Ting ◽  
Hung Yin Tsai ◽  
Chang Pin Chou
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Electron Cyclotron Resonance ◽  
Plasma Process ◽  
Large Area ◽  
Ecr Plasma ◽  
Aspect Ratios ◽  
Electroforming Process ◽  
Micron Diameter ◽  
Short Time

Many research works have been focusing on nanoimprint technology due to the recent potential mass production for the nanostructure applications. For optical or display application, a nanoimprint mold of large area becomes one of the thorniest techniques since it takes much time to fabricate the whole mold with nanostructure and it may make the beginning nanostructures inconsistent with the final ones. In order to fabricate the nanostructure mold of large area in a short time, the plasma process forming nanostructures on silicon substrate and the electroforming process are explored in the current study. Well-aligned nanotip arrays of 4 inch silicon were fabricated by electron cyclotron resonance (ECR) plasma process using gas mixtures of silane, methane, argon, and hydrogen. The resultant tips have nano-scale apexes, approximately ~1 nm, with high aspect ratios, nearly ~15, which were achieved by simultaneous SiC nano-mask formation and dry etching during ECR plasma process. Next, the nickel mold of nanostructures is made from silicon nanostructures through the electroforming process by using Nickel Sulfamate. The total thickness of the nickel mold is 120 μm after a 10-hour-long electroforming process. The nanostructures of 100 nm diameter holes are successfully obtained. Nanoimprint process is proceeded by the nickel mold and the reflectance of the PMMA after imprinting at 160 °C has the lowest value, 0.2 %, compared with the other results for the incident optical wavelength of 550 nm. The large-area imprint mold with high-aspect-ratio nanotip arrays of sub-micron diameter is fabricated and is proofed by the optical application.

Large Area, High Aspect Ratio Microelectrode Arrays

2003 ◽  
Vol 773 ◽  
Author(s):  
Charles D. Merritt ◽  
Paul L. Falkenstein ◽  
Brian L. Justus
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Glass Matrix ◽  
Microelectrode Arrays ◽  
Electrode Array ◽  
Electrode Spacing ◽  
Electrode Arrays ◽  
Large Area ◽  
Aspect Ratios ◽  
Highly Uniform

AbstractA method is described for the fabrication of arrays of conducting, high aspect-ratio microwires for use as electrodes. The electrode arrays are fabricated by electrochemical deposition of metals, including Ni, Pt, Ag, Au and Rh, in channel glass templates having parallel, uniform, hollow channels with diameters that range from sub-micrometer to over 100 micrometers. The metals completely fill the hollow channels, yielding highly uniform electrodes with aspect ratios on the order of 1000 or more. The glass template electrically insulates the electrodes from one another. The electrode array wafers are cut and polished to a thickness ranging from about 100 to 2000 micrometers. The overall surface area is as large as 1 square centimeter. Alternatively, the wafers can be partially etched with acid to remove some of the glass matrix surrounding the electrodes, exposing an array of bare, solid wire stubs. The high aspect ratio microelectrode arrays were initially fabricated in order to provide the electrical interface for an intraocular retinal prosthesis, but have additional applications including biological and chemical sensing. Arrays with different channel sizes, different electrode spacing (with pitch from approximately 3R to 20R, where R is the electrode radius), and different geometrical arrangement are presented.

Repeated shape recovery of clustered nanopillars by mechanical pulling

2016 ◽  
Vol 4 (40) ◽  
pp. 9608-9612 ◽  
Author(s):  
Sang Moon Kim ◽  
Seong Min Kang ◽  
Chanseok Lee ◽  
Segeun Jang ◽  
Junsoo Kim ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Shape Recovery ◽  
Adhesion Force ◽  
Large Area ◽  
Short Time

Clustered high-aspect-ratio nanopillars can be recovered to their original shapes by mechanical pulling during a demolding process to overcome the adhesion force between pillars. The process can be applied repeatedly, offering a simple yet powerful way to recover clustered nanostructures in a short time over a large area.

scholarly journals Strength Analysis of Alternative Airframe Layouts of Regional Aircraft on the Basis of Automated Parametrical Models

Aerospace ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 80
Author(s):  
Dmitry V. Vedernikov ◽  
Alexander N. Shanygin ◽  
Yury S. Mirgorodsky ◽  
Mikhail D. Levchenkov
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
High Performance ◽  
Strength Analysis ◽  
Labor Input ◽  
Aerodynamic Loading ◽  
Aspect Ratios ◽  
Wide Range ◽  
Parametrical Design

This publication presents the results of complex parametrical strength investigations of typical wings for regional aircrafts obtained by means of the new version of the four-level algorithm (FLA) with the modified module responsible for the analysis of aerodynamic loading. This version of FLA, as well as a base one, is focused on significant decreasing time and labor input of a complex strength analysis of airframes by using simultaneously different principles of decomposition. The base version includes four-level decomposition of airframe and decomposition of strength tasks. The new one realizes additional decomposition of alternative variants of load cases during the process of determination of critical load cases. Such an algorithm is very suitable for strength analysis and designing airframes of regional aircrafts having a wide range of aerodynamic concepts. Results of validation of the new version of FLA for a high-aspect-ratio wing obtained in this work confirmed high performance of the algorithm in decreasing time and labor input of strength analysis of airframes at the preliminary stages of designing. During parametrical design investigation, some interesting results for strut-braced wings having high aspect ratios were obtained.

scholarly journals A novel fabrication technique for high-aspect-ratio nanopillar arrays for SERS application

RSC Advances ◽  
2020 ◽  
Vol 10 (73) ◽  
pp. 45037-45041
Author(s):  
Tianli Duan ◽  
Chenjie Gu ◽  
Diing Shenp Ang ◽  
Kang Xu ◽  
Zhihong Liu
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Fabrication Technique ◽  
Novel Technique ◽  
Aspect Ratios ◽  
Nanopillar Arrays

A novel technique is demonstrated for the fabrication of silicon nanopillar arrays with high aspect ratios.

Highly ordered nanoscale phosphomolybdate-grafted polyaniline/metal hybrid layered structures prepared via secondary sputtering phenomenon as high-performance pseudocapacitor electrodes

2021 ◽  
Author(s):  
Eun Seop Yoon ◽  
Bong Gill Choi ◽  
Hwan-Jin Jeon
Keyword(s):  
Electron Transfer ◽  
Aspect Ratio ◽  
Electrochemical Performance ◽  
High Aspect Ratio ◽  
High Performance ◽  
Electrode Materials ◽  
Rate Capability ◽  
High Specific Capacitance ◽  
High Rate ◽  
Large Area

Abstract The development of energy storage electrode materials is important for enhancing the electrochemical performance of supercapacitors. Despite extensive research on improving electrochemical performance with polymer-based materials, electrode materials with micro/nanostructures are needed for fast and efficient ion and electron transfer. In this work, highly ordered phosphomolybdate (PMoO)-grafted polyaniline (PMoO-PAI) deposited onto Au hole-cylinder nanopillar arrays is developed for high-performance pseudocapacitors. The three-dimensional nanostructured arrays are easily fabricated by secondary sputtering lithography, which has recently gained attention and features a high resolution of 10 nm, a high aspect ratio greater than 20, excellent uniformity/accuracy/precision, and compatibility with large area substrates. These 10nm scale Au nanostructures with a high aspect ratio of ~30 on Au substrates facilitate efficient ion and electron transfer. The resultant PMoO-PAI electrode exhibits outstanding electrochemical performance, including a high specific capacitance of 114 mF/cm2, a high-rate capability of 88%, and excellent long-term stability.

scholarly journals Saturation Profile Based Conformality Analysis for Atomic Layer Deposition: Aluminum Oxide in Lateral High-Aspect-Ratio Channels

2020 ◽  
Author(s):  
Jihong Yim ◽  
Oili Ylivaara ◽  
Markku Ylilammi ◽  
Virpi Korpelainen ◽  
Eero Haimi ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Atomic Layer Deposition ◽  
High Aspect Ratio ◽  
Atomic Layer ◽  
Profile Measurement ◽  
Aspect Ratios ◽  
New Information ◽  
Layer Deposition ◽  
Rectangular Channels ◽  
Saturation Profile

<p>ABSTRACT: Atomic layer deposition (ALD) raises global interest through its unparalleled conformality. This work describes new microscopic lateral high-aspect-ratio (LHAR) test structures for conformality analysis of ALD. The LHAR structures are made of silicon and consist of rectangular channels supported by pillars. Extreme aspect ratios even beyond 10 000:1 enable investigations where the adsorption front does not penetrate to the end of the channel, thus exposing the saturation profile for detailed analysis. We use the archetypical trimethylaluminum (TMA)-water ALD process to grow alumina as a test vehicle to demonstrate the applicability, repeatability and reproducibility of the saturation profile measurement and to provide a benchmark for future saturation profile studies. Through varying the TMA reaction and purge times, we obtained new information on the surface chemistry characteristics and the chemisorption kinetics of this widely studied ALD process. We propose new saturation profile related classifications and terminology. </p>

Focused Ion Beam: Advanced Technique for Device Modification

1994 ◽  
Vol 337 ◽  
Author(s):  
Marsha Abramo ◽  
Loren Hahn
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Semiconductor Materials ◽  
Advanced Technique ◽  
Aspect Ratios ◽  
Chip Technology ◽  
Design Changes ◽  
Critical Feedback

ABSTRACTFocused ion beam (FIB) technology is used to modify circuits for early-product design debug; it also has the capability to create probe points to underlying metallurgy, allowing device characterization while maintaining full functionality. These techniques provide critical feedback to designers for rapid verification of proposed design changes.Current FIB technology has its limitations because of redeposition of sputtered material; this phenomena may induce vertical electrical shorts and limit the achievable aspect ratio of a milled via to 6:1. Therefore, innovative enhancements are required to provide modification capability on planar chip technology which may utilize up to five levels of metallurgy. The ability to achieve high-aspect-ratio milling is required to access underlying circuitry. Vias with aspect ratios of 10:1 are necessary in some cases.This paper reviews a gas-assisted etching (GAE) process that enhances FIB milling by volatilizing the sputtered material, examines the results obtained from utilizing the GAE process for high-aspect-ratio milling, and discusses selectivity of semiconductor materials (silicon, aluminum, tungsten and silicon dioxide).

High-Aspect-Ratio Electroplated Structures With 2μm Beamwidth

1999 ◽  
Author(s):  
Xiaobin Li ◽  
Siddharth Kiyawat ◽  
Hector J. De Los Santos ◽  
Chang-Jin “CJ” Kim
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Stress Gradient ◽  
Optimization Method ◽  
Nickel Layer ◽  
Driving Voltage ◽  
Aspect Ratios ◽  
Nickel Electroplating ◽  
Electroplating Process ◽  
Micro Structures

Abstract Narrow beamwidth is highly desirable for many micromechanical elements moving parallel to the substrate. A good example is the electrostatically driven flexure structure, whose driving voltage is determined by the width of the beam. This paper presents the process flow and the result of a high-aspect-ratio electroplating process using photoresist (PR) molds. Following a systematic optimization method, PR molds with aspect ratios up to 4.0 were fabricated with a beamwidth of only 2.1μm. Higher aspect ratios, up to 6.8, were achieved using PR double coating technique, with a beamwidth of 2.6μm. Using a Cr/Cu seed layer, nickel electroplating was successfully carried out to translate the PR molds into nickel micro-structures. We observed bend-down of the fully released nickel cantilevers that are over 8μm thick. Further investigation suggested a combined effect of residual stress gradient in the electroplated nickel layer and in-use stiction of the cantilever beams.

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