Microsystem Technologies

, Volume 19, Issue 3, pp 425–431 | Cite as

High aspect ratio metal micro and nano pillars for minimal footprint MEMS suspension

  • Felix GreinerEmail author
  • Helmut F. Schlaak
Technical Paper


Vertical nano and micro pillars perpendicularly rising from a substrate offer two lateral translatory–rotatory degrees of freedom. Electroforming allows their production as small footprint integrated suspension elements of micro to nano scale. This paper demonstrates the design of a novel inertial sensor concept with acceleration sensor and gyroscope function using only one inertial mass. Experimental results using UV Direct LIGA with AZ 125 nXT show the feasibility of a technology demonstrator with a copper micro pillar of 400 μm length and 40 μm diameter. Further work using x-ray Direct LIGA is scheduled for the production of the pillar with a length of 100 μm and a diameter of 3–6 μm. Fabrication concepts and pilot tests show promising possibilities for miniaturization towards nano scale pillars for minimal footprint suspension in MEMS.


Inertial Sensor Acceleration Sensor Through Silicon Vias Film Photoresist Movable Object 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



This work was supported in part by the German Federal Ministry of Education and Research (BMBF) under the grants 16SV5053. The X-ray lithography part of this work will be carried out with the support of the Karlsruhe Nano Micro Facility (KNMF 2010-004-000365,, a Helmholtz Research Infrastructure at Karlsruhe Institute of Technology (KIT, The support of Technische Universität Darmstadt EMK clean room staff Bernhard Jochem and Darina Riemer is acknowledged. Valuable technical discussions with Wolfgang Ensinger, and Markus Rauber of TUD Material Science, Christina Trautmann of GSI Helmholtz Centre for Heavy Ion Research, Robert Preisser and Xihai Kang of Atotech are greatly appreciated.


  1. Bernstein J, Cho S, King A, Kourepenis A, Maciel P, Weinberg M (1993) A micromachined comb-drive tuning fork rate gyroscope. In: Proceedings of the IEEE micro electro mechanical systems, Fort Lauderdale, FL, USA, pp 143–148. doi: 10.1109/MEMSYS.1993.296932
  2. Brophy CP, Fu XR, Lambert DW, Merchant PP (2001) MEMS mirror and method of fabrication. US Patent App. 09/919,325Google Scholar
  3. Cornelius T, Ensinger W, Neumann R, Rauber M (2009) Nanowire structural element. US Patent App. 12/933,184Google Scholar
  4. Dixit P, Tan CW, Xu L, Lin N, Miao J, Pang JH, Backus P, Preisser R (2007) Fabrication and characterization of fine pitch on-chip copper interconnects for advanced wafer level packaging by a high aspect ratio through AZ9260 resist electroplating. J Micromech Microeng 17(5):1078G1086CrossRefGoogle Scholar
  5. Ekinci KL (2004) Ultimate limits to inertial mass sensing based upon nanoelectromechanical systems. J Appl Phys 95(5):2682. doi: 10.1063/1.1642738 CrossRefGoogle Scholar
  6. Engelke R, Mathuni J, Ahrens G, Gruetzner G, Bednarzik M, Schondelmaier D, Loechel B (2008) Investigations of SU-8 removal from metallic high aspect ratio microstructures with a novel plasma technique. Microsyst Technol 14(9):1607G1612CrossRefGoogle Scholar
  7. Greiner PF, Schlaak HF (2011) High aspect ratio metal nano and micro pillars as suspension elements in MEMS. In: Proceedings of the 9th International Workshop on high aspect ratio micro structure technology, HsinChu, TaiwanGoogle Scholar
  8. Greiner PF, Eberhardt J, Schlaak HF (2010) Metallic micro nails MAde by direct LiG process G MiNiMAL. In: Proceedings of the KNMF User Meeting, KarlsruheGoogle Scholar
  9. Greiner F, Eberhardt J, Schlaak HF (2011a) Vertical high aspect ratio nano and micro wires as novel suspension elements in MEMS. In: Proceedings of the Mikro System Technik Kongress 2001, VDE VERLAG GMBH, Berlin-OffenbachGoogle Scholar
  10. Greiner F, Schlaak HF, Quednau S, Staab M (2011b) Mikrospiegelbauteil, Mikrospiegelvorrichtung mit wenigstens einem Mikrospiegelbauteil sowie Verfahren zur Herstellung eines Mikrospiegelbauteils. DE Patent App. 10 2011 104 843.3Google Scholar
  11. Johnson D, Goettert J, Singh V, Yemane D (2011) SUEX-Dry laminate resist - opportunities for MEMS applications. In: Proceedings of the 9th International Workshop on high aspect ratio micro structure technology, HsinChu, TaiwanGoogle Scholar
  12. Lindeberg M, Hjort K (2003) Interconnected nanowire clusters in polyimide for flexible circuits and magnetic sensing applications. Sens Actuators A Phys 105(2):150–161. doi: 10.1016/S0924-4247(03)00088-8
  13. Lisinenkova M, Hahn L, Schulz B, Bade K (2007) Megasonic Supported Mass Transport in LIGA-Microstructures. No. 7378 in Wissenschaftliche Berichte FZKA, KarlsruheGoogle Scholar
  14. Liu G, Huang X, Xiong Y, Tian Y (2008) Fabricating HARMS by using megasonic assisted electroforming. Microsyst Technol 14(9):1223–1226. doi: 10.1007/s00542-007-0556-1 CrossRefGoogle Scholar
  15. Makarova OV, Mancini DC, Moldovan N, Divan R, Tang CM, Ryding DG, Lee RH (2003) Microfabrication of freestanding metal structures using graphite substrate. Sens Actuators A Phys 103(1-2):182G186CrossRefGoogle Scholar
  16. Quednau S, Greiner F, Schlaak HF, Rauber M, Neumann R, Ensinger W (2010) Integration von nanodrahtarrays in mikrosysteme fr die gasflusssensorik. In: 2. GMM-Workshop 3.-4. Mrz 2010 in Erfurt - GMM Fachbericht 63 "Mikro-Nano-Integration", ISBN 978-3-8007-3216-6, Berlin, Offenbach, pp 159–164Google Scholar
  17. Rao CNR, Deepak FL, Gundiah G, Govindaraj A (2003) Inorganic nanowires. Prog Solid State Chem 31(1-2):5G147CrossRefGoogle Scholar
  18. Reznikova EF, Mohr J, Hein H (2005) Deep photo-lithography characterization of SU-8 resist layers. Microsyst Technol 11(4):282G91CrossRefGoogle Scholar
  19. Staab M, Greiner F, Schlosser M, Schlaak HF (2011) Applications of novel High-Aspect-Ratio ultrathick UV photoresist for microelectroplating. J Microelectromech Syst 20(4):794–796. doi: 10.1109/JMEMS.2011.2159098 CrossRefGoogle Scholar
  20. Timoshenko S, Goodier J (1951) Theory of elasticity, 3rd edn, Mc Graw-Hill, NYGoogle Scholar
  21. Xu L, Dixit P, Pang JH, Miao J, Zhang X, Tu K, Preisser R (2007) Characterization of nano-grained high aspect ratio through-wafer copper interconnect column. In: Proceedings of the 57th Electronic Components and Technology Conference 2007, Sparks, NV, USA, pp 2011–2016. doi: 10.1109/ECTC.2007.374078
  22. Xu W, Wong J, Cheng C, Johnson R, Scherer A (1995) Fabrication of ultrasmall magnets by electroplating. J Vac Sci Technol Sect B Microelectron Nanometer Structur 13(6):2372–2375CrossRefGoogle Scholar
  23. Yang R, Jiang J, Meng WJJ, Wang W (2006) Numerical simulation and fabrication of microscale, multilevel, tapered mold inserts using UV-Lithographie, galvanoformung, abformung (LIGA) technology. Microsyst Technol 12(6):545–553. doi: 10.1007/s00542-005-0073-z CrossRefGoogle Scholar
  24. Yazdi N, Ayazi F, Najafi K (1998) Micromachined inertial sensors. Proc IEEE 86(8):1640–1659CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  1. 1.Microtechnology and Electromechanical Systems Laboratory (M+EMS), Institute of Electromechanical DesignTechnische Universität DarmstadtDarmstadtGermany

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