LIGA Lithography By Bitew Dinke Hugo Ferrer Enee416 Dr Ghodssi Definition of LIGA LIGA is a German acronym that stands for Lithographie Galvanoformung and Abformung When translated it means lithography electroplating and molding Background LIGA is a three stage micromachining technology used to manufacture high aspect ratio microstructures Originally LIGA technology was researched in Germany in order to be used for the separation of uranium isotopes Henry Guckel of the University of Wisconsin brought LIGA technology to the USA Background Two main types of LIGA Technology X ray LIGA and Extreme Ultraviolet EUV LIGA X ray LIGA can fabricate with great precision high aspect ratio microstructures EUV LIGA can fabricate lower quality microstructures LIGA Process LIGA is a hybrid fabrication technique The LIGA Process Lithography Electron beam lithography Focused ion beam lithography Optical and exciter laser lithography Deep X ray lithography using synchrotron radiation Electroplating metalized layer seed layer Molding Machining process to remove overplated metal region Function of LIGA To produce high aspect ratio To manufacture 3 D microstructures from a wide variety of materials Figure1 3 D microstructure Lithography Deep X ray lithography Historically chosen as a source for LIGA process superior to optical lithography Utilize short wavelength very large depth of focus Synchrotron Light Source maintains energy anywhere from 106to 109 eV Figure2 Synchrotron Light Source setup Deep X ray Lithography techniques Step 1 Deposition of Adhesion Seed layer Step 2 resist coating Step 3 expose the PMMA resist Step 4 development of the exposed resist Electroplating and Micro molding techniques Electroplating is a process to fill in the voids between the polymeric features Step 5 metal plating Molding is process of machining the overplated region filling the microstructure Step 7 filling and ejection the microstructure Step 6 removal of the remaining resist MORE about LIGA Technology Fig Outline of the LIGA technology a Photoresist patterning b electroplating of metal c resist removal and d molded plastic components Advantages Disadvantage Large structural height and sidewall properties Thickness ranging from 100 1000 m Spatial resolution High aspect ratios EUV LIGA is a cheaper alternative X ray LIGA is expensive due to the equipment required Slow process Complicated process Difficulty transitioning from research to production Applications MEMS Components Sensors Actuators Trajectory Sensing Devices Mass Spectrometers Microoptical Components Questions References C K Malek V Saile 2004 Applications of LIGA Technology to Precision Manufacturing of High aspect ratio Micro components and systems a Review Microelectronics Journal Online Available http www sciencedirect com science ob MiamiImageURL cid 271437 user 9 61305 pii S0026269203002957 check y origin coverDate 29 Feb2004 view c wchp dGLbVlkzSkWz valck 1 md5 82bfcbfb24453b7ea7383a12725e6a32 ie sdarticle J Zhang 2002 December LIGA MOLD INSERT FABRICATION USING SU 8 PHOTORESIST etd lsu edu Online Available http etd lsu edu docs available etd 1108102 101121 unrestricted Zhang thesis pdf O O Sandoval Gonzalez A Fabrication Technology for High Aspect Ratio Microstructures Sandoval Gonzalez Online Available http www sandoval gonzalez com 10 liga pdf V Saile 2009 Introduction LIGA and Its Application Verlag GmbH Co Online Available http www wiley vch de books sample 3527316981 c01 pdf
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