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Fracture Strength of Polycrystalline Silicon

Published online by Cambridge University Press:  10 February 2011

P.T. Jonestt ,
G.C. Johnsontt  and
R.T. Howe
P.T. Jonestt
Affiliation:
Berkeley Sensor & Actuator Center, University of California, Berkeley, CA 94720 Department of Mechanical Engineering, University of California, Berkeley, CA 94720
G.C. Johnsontt
Affiliation:
Berkeley Sensor & Actuator Center, University of California, Berkeley, CA 94720 Department of Mechanical Engineering, University of California, Berkeley, CA 94720
R.T. Howe
Affiliation:
Berkeley Sensor & Actuator Center, University of California, Berkeley, CA 94720 Department of Mechanical Engineering, University of California, Berkeley, CA 94720 Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA 94720
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Abstract

A structure has been developed to measure the fracture strength of thin films that allows for a large amount of statistical data to be generated from a single die. The strength of a material is determined by measuring the displacement at fracture of cantilever beams bending in-plane. This device has been used to measure the fracture strain of three different polysilicon materials: polysilicon from two different MCNC MUMPS runs and a polysilicon fabricated at the Microfabrication Laboratory at the University of California at Berkeley. The strain at fracture of the MUMPS polysilicon was measured to be 1.5% ± 0.2% for both MCNC MUMPS runs. The Berkeley polysilicon exhibited a fracture strength of 1.2% ± 0.1%, a difference from the MUMPS result that is statistically significant. Also, no statistical difference in fracture strength was measured on specimens that were super-critically carbon dioxide dried as opposed to furnace dried. In a separate experiment, the Young's modulus of the MCNC MUMPS polysilicon was found to be 173 ± 20 GPa.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 518: Symposium N – Microelectromechanical Structures for Materials Research , 1998 , 197
Copyright
Copyright © Materials Research Society 1998

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References

[1] Tai, Y.C., Muller, R.S., “Fracture strain of LPCVD polysilicon,” 1988 Solid State Sensor and Actuator Workshop. Technical Digest (Cat. No.88TH0215-4), Hilton Head Island, SC, USA, 6-9 June 1988. p. 88–91 Google Scholar
[2] Fan, L.-S., Howe, R.T., Muller, R.S., “Microstructures for fracture toughness characterization of brittle thin films,” Proceedings: IEEE Micro Electro Mechanical Systems. An Investigation of Micro Structures, Sensors, Actuators, Machines and Robots (IEEE Cat. No.89TH0249-3), Salt Lake City, UT, USA, 20-22 Feb. 1989. p. 40–1Google Scholar
[3] Fan, L.S., Howe, R.T., Muller, R.S., “Fracture toughness characterization of brittle thin films,” (5th International Conference on Solid-State Sensors and Actuators and Eurosensors III, Montreux, Switzerland, 25-30 June 1989). Sensors and Actuators A (Physical), April 1990, vol.A23, (no. 1-3):872–4Google Scholar
[4] Tsuchiya, T., Tabata, O., Sakata, J., Taga, Y., “Specimen Size Effect on Tensile Strength of Surface-micromachined Polycrystalline Silicon Thin Films,” Journal of Microelectromechanical Systerms, March 1998, vol. 7 (no. 1):106–13Google Scholar
[5] Sharpe, W.N., Yuan, B., Vaidyanathan, R., Edwards, R.L., “New Test Structures and Techniques for Measurement of Mechanical Properties of MEMS Materials,” Proceeding of the SPIE – The International Society for Optical Engineering 1996, vol. 2880:78–91 Google Scholar
[6] Jones, P.T., Johnson, G.C., “Micromechanical Structures for Fracture Testing of Brittle Thin Films,” ASME International Mechanical Engineering Congress and Exposition Micro-Electro-Mechanical Systems (MEMS) 1996, DSC-Vol. 59, p. 325–330 Google Scholar
[7] Brown, S., Johnson, G., Knauss, W., Sharpe, W., “Round-Robin Tests of Modulus and Strength of Polysilicon,” 1998 Spring Meeting of the Materials Research SocietyGoogle Scholar
[8] MCNC Electronic Technologies Div., 3021 Cornwallis Road, Research Triangle Park, North Carolina 27709, USAGoogle Scholar
[9] Mulhem, G.T, Soane, D.S, and Howe, R.T., “Supercritical Carbon Dioxide Drying of Microstructures,” Transducers '93, p. 296–299 Google Scholar
[10] Tai, Y.C., “IC-Processed Polysilicon Micromechanics: Technology, Material, and Devices,” Dissertation – University of California at Berkeley (1989)Google Scholar
[11] Keller, C.G., Howe, R.T., “Hexsil tweezers for teleoperated micro-assembly,” Proceedings IEEE. The Tenth Annual International Workshop on Micro Electro Mechanical Systems. An Investigation of Micro Structures, Sensors, Actuators, Machines and Robots, Nagoya, Japan, 26-30 Jan. 1997). New York, NY, USA: IEEE, 1997. p. 72–7Google Scholar