Abstract
An efficient method is presented to determine the mechanical properties of thick metal layers using the pull-in voltage of electrostatically actuated structures. To fabricate these high aspect ratio beams without severe deformations, additional features were added, which made existing pull-in voltage equations inaccurate and therefore corrections were necessary. ANSYS Multiphysics was used to analyze the differences between ideal beams and the fabricated beams. To demonstrate the proposed approach, both nickel and gold devices were fabricated. To extract the material property values, a sum of least squares fitting scheme was used. A Young’s modulus of 186.2 and 60.8 GPa was obtained for nickel and gold structures respectively. Both values are significantly smaller than values reported for bulk material, but fall within the range of values reported in the literature.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Achenbach S, Klymyshyn D, Haluzan D, Mappes T, Wells G, Mohr J (2006) Fabrication of RF MEMS variable capacitors by deep X-ray lithography and electroplating. Microsyst Technol 13:343–347
Baek CW, Kim YK, Ahn Y, Kim YH (2005) Measurement of the mechanical properties of electroplated gold thin films using micromachined beam structures. Sens Actuators A 117:17–27
Becker EW, Ehrfeld W, Hagmann P, Maner A, Münchmeyer D (1986) Fabrication of microstructures with high aspect ratios and great structural heights by synchrotron radiation lithography, galvanoforming, and plastic moulding (LIGA process). Microelectron Eng 4:35–56
Buchheit TE, Christenson TR, Schmale DT, LaVan DA (1998) Understanding and tailoring the mechanical properties of LIGA fabricated materials. Proc MRS Symp 546:121–126
Chowdhury S, Ahmadi M, Miller WC (2005) A closed-form model for the pull-in voltage of electrostatically actuated cantilever beams. J Micromech Microeng 15:756–763
Chowdhury S, Ahmadi M, Miller WC (2006) Pull-in voltage study of electrostatically actuated fixed–fixed beams using a VLSI on-chip interconnect capacitance model. J Microelectromech Syst 15:639–651
Christenson TR, Buchheit TE, Schmale DT, Boucier R (1998) Mechanical and metallographic characterization of LIGA fabricated nickel and 80% Ni–20% Fe permalloy. Proc MRS Symp 518:185–190
Davis JR (1998) Metals handbook: desk edition, 2nd ed. ASM International, Materials Park, OH
Greek S, Ericson F (1998) Young’s modulus, yield strength and fracture strength of microelements determined by tensile testing. Proc MRS Symp 518:51–56
Klymyshyn DM, Haluzan DT, Börner M, Achenbach S, Mohr J, Mappes T (2007) High aspect ratio vertical cantilever RF-MEMS variable capacitor. IEEE Microwave Wirel Compon Lett 17:127–129
Majjad H, Basrour S, Delobelle P, Schmidt M (1999) Dynamic determination of Young’s modulus of electroplated nickel used in LIGA technique. Sens Actuators A 74:148–151
Mazza E, Abel S, Duel J (1996) Experimental determination of mechanical properties of Ni and Ni-Fe microbars. Microsyst Technol 2:197–202
Menz W, Mohr J, Paul O (2001) Microsyst Technol. Wiley,
Osterberg PM (1995) Electrostatically actuated microelectromechanical test structures for material property measurements. PhD Dissertation, Massachusetts Institute of Technology, MA
Osterberg PM, Senturia SD (1997) M-TEST: a test chip for MEMS material property measurement using electrostatically actuated test structures. J Microelectromech Syst 6:107–118
Robert L (1997) Structural and mechanical properties of electroplated nickel used in LIGA technique. PhD Dissertation, Universite de Franche-Comte
Ruther P, Bacher W, Feit K, Maas D, Menz W (1997) Prototype of a microtesting system made by the LIGA process to measure the Young’s modulus in cantilever microbeams. ASME J Dyn Syst Meas Contr 119:57–60
Sadeghian H, Rezazadeh G, Osterberg PM (2007) Application of the generalized differential quadrature method to the study of pull-in phenomena of MEMS switches. J Microelectromech Syst 16:1334–1340
Sharpe WN Jr, LaVan DA, McAleavey A (1997) Mechanical testing of thicker MEMS materials. ASME DSC Microelectron mech Syst 62:93–97
Stephens LS, Kelly KW, Simhadri S, McCandless AB, Meletis EI (2001) Mechanical property evaluation and failure analysis of cantilevered LIGA nickel microposts. J Microelectron mech Syst 10:347–359
Tang J, Wang H, Guo X, Liu R, Dai X, Ding G, Yang C (2010) An investigation of microstructure and mechanical properties of UV-LIGA nickel thin films electroplated in different electrolytes. J Micromech Microeng 20:025033
Xie ZL, Pan D, Last H, Hemker KJ (2000) Effect of as-processed and annealed microstructures on the mechanical properties of LIGA Ni MEMS. Proc MRS Symp 605:197–202
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Haluzan, D.T., Klymyshyn, D.M., Achenbach, S. et al. VM-TEST: Mechanical property measurement using electrostatically actuated vertical MEMS test structures fabricated in thick metal layers. Microsyst Technol 18, 443–452 (2012). https://doi.org/10.1007/s00542-011-1408-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00542-011-1408-6