tailieunhanh - Báo cáo "FABRICATION OF HIGH-ASPECT-RATIO MICRO STRUCTURES USING UV-LIGA TECHNOLOGY "

VNU. JOURNAL OF SCIENCE, Mathematics - Physics, , n02, 2005 Nguyen Thi Minh Hanga,b, Chien-Hung Hoc, Vu Ngoc Hungb, Nguyen Phu Thuyb,d a d Center for Micro Electronic and Information Technology (IMET) International Training Institute for Materials Science (ITIMS) c Precision Instrument Development Center (PIDC) College of Technology, Vietnam National University, Hanoi (VNU) b Abstract. Thanks to almost transparent property of SU8 for wavelength of 365400nm, UV-LIGA technology using this photoresist has been applied to fabricate high-aspect-ratio (HAR) microstructures. This allows transferring patterns with vertical sidewall from masks to the photoresist. This paper introduces UV-LIGA and its application in fabricating comb drive structure for an angular. | VNU. JOURNAL OF SCIENCE Mathematics - Physics N02 2005 FABRICATION OF HIGH-ASPECT-RATIO MICRO STRUCTURES USING UV-LIGA TECHNOLOGY Nguyen Thi Minh Hanga b Chien-Hung Hoc Vu Ngoc Hungb Nguyen Phu Thuyb d a Center for Micro Electronic and Information Technology IMET b International Training Institute for Materials Science ITIMS c Precision Instrument Development Center PIDC d College of Technology Vietnam National University Hanoi VNU Abstract. Thanks to almost transparent property of SU8 for wavelength of 365-400nm UV-LIGA technology using this photoresist has been applied to fabricate high-aspect-ratio HAR microstructures. This allows transferring patterns with vertical sidewall from masks to the photoresist. This paper introduces UV-LIGA and its application in fabricating comb drive structure for an angular rate sensor of linewidth and thickness of 50pm and 120pm respectively. Keywords UV-LIGA HAR SU8 comb structure 1. Introduction The LIGA process Lithographie Galvanoformung Abformung that stands for deep-etch X-ray lithography electroplating and molding is a micromachining technology developed in the early 1980 s at the Karlsruhe Nuclear Research Center 1 . Based on this technique it is possible to produce microstructures from a variety of materials metals with very high-aspect-ratio more than 100 very small features in the submicron range and very smooth sidewalls surface roughness less than 50nm due to reduced diffraction low resist absorption and minimal proximity effects. Because the synchrotron for X-ray is very expensive and many structures require very neither HAR nor fine linewidth the UV-LIGA technique with wavelength of 356-405 nm UV is applied instead. The cost for the UV-LIGA process is much cheaper than the LIGA process. In the UV-LIGA approach a proximity UV aligner is used with a thick resist in place of the synchrotron X-ray exposure step. After the lithography process electrodeposition and planarization are used to produce metal microparts