Papers by Keyword: Lithography

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Authors: Q. Humayun, U. Hashim
Abstract: Fabrication techniques for Metal-molecule-metal junction electrodes suitable to study electron tunneling through metal junctions are reviewed. The applications of current technologies such as mechanical break junction, electromigration, shadow mask lithography, focused ion beam deposition, chemical and electrochemical plating, electron-beam lithography, in fabricating vacant junction electrodes are briefly described. For biomolecular sensing applications, the size of the junction electrodes must be small enough to allow the biomolecule inserted into the junction space to connect both leads to keep the molecules in a relaxed and undistorted state. A significant advantage of using Metal-molecule-metal junction electrodes devices is that the junction can be characterized with and without the molecule in place. Any electrical artifacts introduced by the electrode fabrication process are more easily deconvoluted from the intrinsic properties of the molecule.
Authors: Huan Liu, Wei Guo Liu, Chang Long Cai, Shun Zhou
Abstract: A novel method for fabrication of self-supporting microbridge based on a-si films with tilted support legs for bolometer is studied in this paper. Based on the research of diffractive characteristics when the light passing through the mask in proximity lithography, we found if the distance of mask and photoresist is suitable, the intensity distribution curve of Fraunhofer diffraction (far field diffraction) at the border of contacthole is suitable to fabricate microbridge with tilted legs. By use of the method, the constant change of photoresist thickness around the contacthole can be realized using the far field diffraction proximity lithography. Then transfer the outline of photoresist to the sacrificial layer by plasma etching. Thus the fabrication of microbridge with tilted support legs was carried out easily, and this method has the advantages of low cost, simple and feasible.
Authors: Qing Hua Lin, Jin Yun Zhou, Wen Jing Li
Abstract: For the 1:1 laser projection lithography system used to achieve large-area patterning with higher resolutions as well as higher throughput, the key parameters such as the laser beam geometry, the numerical aperture of projection lens, the laser source power and the pulse repetition rate are theoretically analyzed. It is expounded the process of uniform exposure in hexagonal beam shape, the advantages and limitations of 1:1 projection owing to numerical apertures deciding the resolution, as well as the cause of choosing larger laser power and pulse repetition rate. Meanwhile, the projection lens for a unit-magnification, refractive imaging system is tentatively simulationdesigned using ZEMAX optical design software. The optimized three-dimensional layout is plotted. For the designed results, the maximum optical path difference is smaller thanλ /4 within entire visual field. The resolution for feature sizes 10μm can be achieved within depth of focus 400μm by evaluating MTF. The maximum field curvature is within 10μm and the maximum distortion is small than 0.000007%. This fulfills the demands in technical specifications.
Authors: Vytautas Ostaševičius, Vytautas Bagdonas, Sigitas Tamulevičius, V. Grigaliūnas
Abstract: An electrostatic motor is a very complex dynamical system whose performance critically depends on the shape of the rotor and stator, number of poles, clearances between axis and rotor, friction, rotor vibrations, and levitation, etc. There are many possible micromotor constructions depending on the required accuracy, the speed of rotation and power of the motor. This work shows the technology required to build a micromotor using UV lithography. Studies of vibration characteristics using ANSYS and MATLAB modeling software and an experimental analysis to optimize the dynamical properties of the system and to improve its manufacturing process are also shown.
Authors: Jeong Woo Park, Nam Hun Kim
Abstract: Micro/Nanofabrication of silicon substrate based on the atomic force microscope (AFM) followed by wet chemical etching was demonstrated. A specially designed cantilever with a diamond tip, allowing the formation of damaged layer on silicon substrate by a simple scratching process, has been applied instead of conventional Si or Si3N4-based micro cantilever for scanning. A thin damaged layer forms in the substrate at the diamond tip-sample junction along scanning path of the tip, which was found to be a low crystallized amorphous silicon layer. Hence these sequential processes, called tribo nanolithography, TNL, can fabricate 2D or 3D micro structures in nanometer range. The developed TNL tools show outstanding machinability against single crystal silicon wafer. Hence, they are expected to have a possibility for industrial applications as a micro-to-nano machining tool. According to our results, it has been clearly known that the damaged layer withstands against aqueous potassium hydroxide solution, while it dissolves in diluted hydro fluoric (DHF) solution.
Authors: Bin Miao, Xiao Wei Wei, Dong Min Wu, Jia Dong Li
Abstract: A novel micro spring with steel structures is described here. It can be fit into a specially designed microtensile apparatus, which is capable of carrying out a series of tests on micron scale freestanding thin films. This method is suitable for thin metal films or polymer layers with large strain and can be applied to samples with different thicknesses. The novel fabrication method uses the conventional lithography and electrochemical metal etching techniques. A single photomask is used to define the whole structure, resulting in a simple and inexpensive fabrication process. The method proposed here is promising for the low cost fabrication of micro spring based on steel. A micro spring of 100μm wide, 100μm thick, with 200μm diametric of the semicircle and 6 turns was prepared by this method; the elasticity of the spring is 147.3N / m. A gold wire was measured by this micro spring. The young's modulus and ultimate tensile strength of the gold wire were 30Gpa and 120Mpa, respectively.
Authors: Zhi Pen Wu, Xing Lin Chen
Abstract: In order to achieve high position precision and synchronization between the wafer stage and the reticle stage, a cross-coupled sliding mode control scheme for a coarse-fine combined synchronization servo system of lithography is proposed. To accomplish high bandwidth and high tracking precision, a conventional linear motor is combined with a voice coil motor as a coarse-fine dual-stage control system. A cross-coupled structure is presented to decrease the synchronization error during scanning operation. Sliding mode control law is designed based on the control error and the synchronization error. Simulation results show that the synchronization error and the control error have the same order of magnitude, and the dynamic performance of the control system satisfies the design requirement.
Authors: Liang Lei, Xin Liu, Lang Lin Li, Jin Yun Zhou
Abstract: Double fold reduction projection lithography objective lens with bi-telecentric configuration, consists of 6 lenses and the number aperture , is designed based on the optical design software Zemax. It uses the 405nm laser diode (LD) as light source. The spatial resolving capacity approaches to 5um. In a field of view of , its wave-front aberration is less than a quarter of wave-length and the distortion ratio is not more than. The imaging performance, in particular, the accurate modulation transfer function (MTF) value of the projection objective lens being fabricated by experiments is determined in this paper. Through analyzing the noise disturbance law in MTF tests, the result show that the projection objective lens has sub ten micrometer resolving ability.
Authors: Raphaël Moulart, René Rotinat, Fabrice Pierron, Gilles Lérondel
Abstract: This work deals with the development of a full-field extensometric method at a micrometric scale in order to precisely identify the local features of a metallic alloy at the scale of the grains. The full-field method that has been chosen is the grid method that applies a spatial phase-shifting algorithm to a periodic pattern. To mark the sample, direct interferometric photolithography was used. The paper presents the basic features of the technique and first mechanical test results are commented.
Authors: Robert J. Hocken, R. Fesperman, J. Overcash, O. Ozturk, C. Stroup
Abstract: Nanotechnology can be defined as “the study, development and processing of materials, devices, and systems in which structure on a dimension of less than 100 nm is essential to obtain the required functional performance.” There are currently two very different approaches to nanotechnology, the first and more classical approach is commonly called engineering nanotechnology. This approach involves using classical deterministic mechanical and electrical engineering principles to build structures with tolerances at levels approaching a nanometer. The other approach, sometimes called molecular nanotechnology, is concerned with self-assembled machines and the like and is far more speculative. At UNC Charlotte’s Center for Precision Metrology we have been working in engineering nanotechnology for more than a decade. We started with molecular manipulation with scanning probe microscopes in the late 1980s [1] and have continued to develop new measurement systems [2], nano-machining systems [3,4], and nano-positioning devices. One of the largest challenges is precision motion control of macroscopic stages. Currently we have three stages under development or modification. The first is the Sub Atomic Measuring Machine (SAMM) [5] which is being modified to provide picometer resolution; the second is the Multi-Scale Alignment and Positioning System (MAPS) initially to be used for nanoimprinting; the third is an Ultra-Precision Vacuum Stage [6], which is the subject of another paper in this conference. This paper will discuss the first two systems.
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