Fabrication of Nano-Electromechanical Structures Down to 20 nm by Spacer Technology

2007 ◽  
Author(s):  
Xiang Han ◽  
Ling Xia ◽  
Wengang Wu ◽  
Guizhen Yan ◽  
Jun Xu ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Mechanical Vibration ◽  
Cantilever Beams ◽  
Fabrication Method ◽  
Feature Size ◽  
Plasma Damage ◽  
Nano Fabrication ◽  
Nano Structures ◽  
20 Nm ◽  
Deposited Film

Spacer technology has been developed to fabricate nano-structures for NEMS application. It provides a parallel nano-fabrication method with double or quadplex device density at a certain lithography node. By controlling the deposited film thickness, the feature size of the SiO2 spacer hard mask is reduced down to 35 nm. After the spacer pattern is transferred to Si, a precise thermal oxidation is performed to improve the profile and reduce the plasma damage. Finally, sublimation or HF vapor phase etching is introduced to release the nano-structures according to different structure dimensions. As a result, with better surface morphology, suspended Si nano-beams with a width of 20 nm are obtained. Actuated by mechanical vibration and electrostatic forces, vibrations of the obtained cantilever beams and fixed-fixed beams are observed in SEM. In addition, a metallic nano-nozzle with a diameter of 140 nm is established by electroless plating around the suspended Si nano-beam served as a mold. As a development of the spacer technology, nano-needle array is demonstrated at the cross points of crossed SiO2 spacers by anisotropic etching. The diameters of the hybridized nano-needles are 300 nm so far and can be further reduced by smaller spacer dimension.

Bubble Based Micro/Nano Fabrication Method

2007 ◽  
Author(s):  
Xiao-Dan Bai ◽  
Jing Liu
Keyword(s):  
Chemical Reaction ◽  
Large Scale ◽  
Large Diameter ◽  
Building Blocks ◽  
Membrane Thickness ◽  
Fabrication Method ◽  
Specific Chemical ◽  
Soap Bubbles ◽  
Nano Fabrication ◽  
Nano Structures

Micro/nano structures, especially those in one dimensional, such as nano wires, are commonly used building blocks for the bottom-up assembly of electronic, photonic or mechanical devices. However, their fabrications are generally limited to the expensive equipments and methods capable of only working in an extremely small space. A big challenge facing the current scientific society is to overcome this barrier and build up a bridge between the macroscopic manipulation/observation and the fabrication in small world. Here, we proposed a new conceptual fabrication method, which can easily be implemented to synthesize, etch and construct micro or nano structures through manipulating the large scale bubbles composed of specific chemical compounds. The core of the method lies in the chemical reaction occurring at the interfaces between two or more soap bubbles. A surprisingly unique virtue of the bubble is that it can have a rather large diameter however an extremely small membrane thickness, whose smallest size even reaches nano scale. Therefore, the chemical reaction and synthesis occurred in the common boundary of such contacting bubbles would lead to products with very small size. Most important of all, all these were achieved via a much easy and straightforward way. To better understand the physical picture of the new method, the principle and mechanism for the bubble based fabrication process were interpreted. Several fundamental equations for characterizing the bubbles were proposed and preliminarily discussed. As the first trial to demonstrate the new concept, several typical micro structures were successfully fabricated in our lab. Particularly, a micro wire which can be used as tiny temperature sensor was made and tested. Being flexible, easily controllable and observable, environmentally friend and extremely low in cost, the present method is expected to be a significant technical route for making micro/nano structures in the near future. It also indicated for the first time that blowing soap bubbles means not just funny but also opens a new world for micro/nano fabrication.

scholarly journals Two-photon polymerization nanolithography technology for fabrication of stimulus-responsive micro/nano-structures for biomedical applications

2020 ◽  
Vol 9 (1) ◽  
pp. 1118-1136
Author(s):  
Zhenjia Huang ◽  
Gary Chi-Pong Tsui ◽  
Yu Deng ◽  
Chak-Yin Tang
Keyword(s):  
Biomedical Applications ◽  
Three Dimensional ◽  
Water Soluble ◽  
Fabrication Technology ◽  
Nano Fabrication ◽  
Two Photon ◽  
Nano Structures ◽  
Wide Range ◽  
Stimulus Responsive ◽  
Two Photon Polymerization

AbstractMicro/nano-fabrication technology via two-photon polymerization (TPP) nanolithography is a powerful and useful manufacturing tool that is capable of generating two dimensional (2D) to three dimensional (3D) arbitrary micro/nano-structures of various materials with a high spatial resolution. This technology has received tremendous interest in cell and tissue engineering and medical microdevices because of its remarkable fabrication capability for sophisticated structures from macro- to nano-scale, which are difficult to be achieved by traditional methods with limited microarchitecture controllability. To fabricate precisely designed 3D micro/nano-structures for biomedical applications via TPP nanolithography, the use of photoinitiators (PIs) and photoresists needs to be considered comprehensively and systematically. In this review, widely used commercially available PIs are first discussed, followed by elucidating synthesis strategies of water-soluble initiators for biomedical applications. In addition to the conventional photoresists, the distinctive properties of customized stimulus-responsive photoresists are discussed. Finally, current limitations and challenges in the material and fabrication aspects and an outlook for future prospects of TPP for biomedical applications based on different biocompatible photosensitive composites are discussed comprehensively. In all, this review provides a basic understanding of TPP technology and important roles of PIs and photoresists for fabricating high-precision stimulus-responsive micro/nano-structures for a wide range of biomedical applications.

Fabrication and Characterization of Graphene Nanofibers by Electrospinning Technique and Its Electrochemical Properties

2020 ◽  
Vol 20 (12) ◽  
pp. 7659-7664
Author(s):  
Senthilkumar Jayanthi ◽  
Thirugnanam Lavanya ◽  
Mrinal Dutta ◽  
Nagarajan Anbil Saradha ◽  
Kaveri Satheesh
Keyword(s):  
Fourier Transform ◽  
Physicochemical Properties ◽  
Fabrication Method ◽  
Electrospinning Technique ◽  
Raman Spectroscopic ◽  
Reduced Graphene ◽  
Electrospinning Method ◽  
Fabrication And Characterization ◽  
20 Nm

Graphene has proved to be superior material for its exceptional physicochemical properties. However engineering graphene macroscopic structures by manipulating microscopic structures has faced a great challenge. Towards this here we report a fabrication method of graphene nanofiber by using simple electrospinning method. Fourier transform infrared and Raman spectroscopic characterizations confirmed the transformation from GO to reduced graphene for the nanofiber material. Estimated surface area of this material is as high as 526 m2g−1 with pores having size around 20 nm. Specific-capacitance of these nanofibers for current-density of 1 Ag−1 is 144.2 Fg−1, which will be useful for the advancement of devices for storing energy.

Review of Fabrication Methods of Nanotube / Nanowire Devices

2011 ◽  
Vol 411 ◽  
pp. 427-431 ◽  
Author(s):  
Miao Miao Tan ◽  
Zi Yi Zhang ◽  
Lin Hui Zhao ◽  
Jian Cheng Zhang
Keyword(s):  
Carbon Nanotube ◽  
High Performance ◽  
Chemical Properties ◽  
Research Field ◽  
Nano Materials ◽  
One Dimensional ◽  
Nano Fabrication ◽  
Nano Structures ◽  
Manufacturing Methods ◽  
And Chemical Properties

With the development of nano materials, a novel research field of NEMS forms by combining nano materials, nano-structures and nano fabrication with MEMS. Carbon nanotube (CNT) is a kind of one-dimensional nano structures which has unique mechanical, electrical and chemical properties. Using CNTs, new nano-devices with new principle or high performance would be developed. This paper reviews the assembly methods of one dimensional nanostructure and analyzes the characteristics of various methods, which provides reference for the device manufacturing methods using nanotubes/nanowires.

Feature Size and Density Effects in Wet Selective Etching of GaAs/AlAs p-HEMT Structures with Organic Acid - Peroxide Solutions.

2003 ◽  
Vol 799 ◽  
Author(s):  
Vinay S. Kulkarni ◽  
Kanti Prasad ◽  
William Quinn ◽  
Frank Spooner ◽  
Changmo Sung
Keyword(s):  
Surface Morphology ◽  
Organic Acid ◽  
Etch Rate ◽  
Low Noise ◽  
Wet Etching ◽  
Low Noise Amplifiers ◽  
Etch Depth ◽  
Feature Size ◽  
Selective Etch ◽  
Etch Stop

ABSTRACTPseudomorphic HEMT (p-HEMT) devices are used in a number of wireless communication applications including power amplifiers in the 17–50 GHz range, low noise amplifiers and switches. Selective wet etching is often used to form the gate regions of these devices to avoid plasma damage associated with dry etching. We have investigated the wet etching of small (8μm to 0.5μm) features with organic acid - hydrogen peroxide solutions. Two acid solutions were used as a selective etchant for GaAs using AlAs etch stop layers in a p-HEMT structure grown by MBE. The etched features were characterized by AFM, SEM, and TEM techniques. The etch depth uniformity and reproducibility were found to depend on a number of factors including feature size, feature density, etching chemistry, agitation and surface tension. When features with a range of size and density were placed in close proximity in a layout we found that the etch rate of the different features was a function of density, size and most importantly the etch chemistry. One etchant solution exhibited a 12% difference in etch rate from the smallest feature to the largest, while another solution exhibited uniform etching of all features regardless of size or density. Both solutions produced specular etched surfaces in GaAs and AlGaAs. However, the AlAs etch stop showed a non-uniform surface morphology after etching. The surface morphology of the AlAs etch stop is one factor that limits the over etch which can be designed into the process. The most important factors to be considered in designing a selective etch process will be presented.

An In Situ Fabrication of CuGa2 Film on Copper Surface With Improved Tribological Properties

2020 ◽  
Vol 143 (7) ◽  
Author(s):  
Xing Li ◽  
Chao Yan ◽  
Qi Liu ◽  
Guangneng Dong
Keyword(s):  
Chemical Composition ◽  
Liquid Metal ◽  
Surface Morphology ◽  
Tribological Properties ◽  
Copper Surface ◽  
Fabrication Method ◽  
In Situ Fabrication ◽  
Electrochemical Fabrication ◽  
Lubrication Mechanisms

Abstract Interface interaction between gallium-based liquid metal and copper-based materials results in the formation of intermetallic CuGa2 grains. In particular, CuGa2 grains are able to produce a uniform film and the newly formed CuGa2 film holds peculiar characteristics, which have not been fully explored up to now. In this study, we present an electrochemical fabrication method of an in situ CuGa2 film on copper surface. Surface morphology and chemical composition of this film are confirmed. Tribological experiments demonstrate that the CuGa2 film enables good antifriction and antiwear abilities. Furthermore, the lubrication mechanisms of the CuGa2 film are revealed.

Effect of Fabrication Method on Tensile Behaviour of Polysiloxane (POS) Filled Rice Husk Silica (RHA SiO2) Composites

2021 ◽  
Vol 317 ◽  
pp. 320-326
Author(s):  
Mohd Azham Azmi ◽  
Sufian Mohamad Yahya ◽  
Sufizar Ahmad ◽  
Shahruddin Mahzan ◽  
Hamimah Abdul Rahman ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Surface Morphology ◽  
Rice Husk ◽  
Tensile Testing ◽  
Tensile Behaviour ◽  
Vibration Absorber ◽  
Fabrication Method ◽  
Comparison Study ◽  
The Difference ◽  
Filler Distribution

The effect of fabrication methods on polysiloxane (POS) composites were studied by analysing both method of casting (CA) and compression (CO). The POS composites were reinforced with 2-12 wt% of natural derived silica from rice husk (RHA SiO2) as a filler which incinerated at 700°C. The composites behaviour were analysed through tensile testing (ASTM D412). Through comparison study on both CA and CO composites’s tensile behaviour it shows that both composites strength keep increasing with 2wt% - 10wt% RHA SiO2 addition but strength decreased at 12wt% due to agglomeration of RHA SiO2. Moreover, it was found that the tensile strength of CO composites had offer 23.56% higher compared to CA composites. The difference were influenced by the distribution of RHA SiO2 as filler. The surface morphology of CO composites had showed that the most of RHA SiO2 were embedded and less agglomeration, compared to CA composites that had lots of agglomeration which lead to higher tendency of crack propagation. The arrangement of filler due to the CO method that helps RHA SiO2 to distributed homogenously and embedded in a matrix of POS to avoid agglomeration and lead better adhesion respectively. Thus, CO method had potential to offer in enhancing tensile behaviour compared to CA method by influencing filler distribution arrangement for vibration absorber application.

Effect of the Surface Nanomorphology on the Growth of Al Whiskers Formed by Glancing Angle Deposition on a High Temperature Substrate

2007 ◽  
Vol 1059 ◽  
Author(s):  
Kenji Hamachi ◽  
Motofumi Suzuki ◽  
Kaoru Nakajima ◽  
Kenji Kimura
Keyword(s):  
High Temperature ◽  
Surface Morphology ◽  
Substrate Surface ◽  
Side Surface ◽  
Glancing Angle Deposition ◽  
Transport Processes ◽  
The Other ◽  
Glancing Angle ◽  
20 Nm ◽  
Angle Deposition

ABSTRACTWe have investigated the effect of the substrate-surface morphology on the growth of Al whiskers grown by high temperature glancing angle deposition (HT-GLAD). Before the HT-GLAD of Al at 390 °C, the morphology of the substrate was systematically modified by depositing nanocolumnar SiO2 layer of thickness between 0 and 100 nm on the flat SiO2 layer. Aluminum whiskers with the width of ≈100 nm and the length ≤ μm are found on all the samples. The number of short whiskers, which can be grown from very small nuclei, depends strongly on the thickness of the SiO2 nanocolumnar layer and shows the maximum at SiO2 thickness of 20 nm. On the other hand, the number of long whiskers, which requires extraordinary amount of Al than that deposited on the side surface of the whikers, is almost independent of SiO2 thickness. These facts suggest that the surface roughness of the substrate plays an important role in the nucleation of the whiskers and that there are some transport processes of Al, which are insensitive to the surface morphology.

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