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Mechanical Property Measurement of 0.5-µm CMOS Microstructures

Published online by Cambridge University Press:  10 February 2011

M. S.-C. Lu
Affiliation:
ECE Department, Carnegie Mellon University, PA 15213, [email protected]
X. Zhu
Affiliation:
ECE Department, Carnegie Mellon University, PA 15213, [email protected]
G. K. Fedder
Affiliation:
ECE Department and the Robotics Institute, Carnegie Mellon University, PA 15213
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Abstract

Measurements are reported on the mechanical properties of high-aspect-ratio micromechanical structures formed using a conventional 0.5-µm CMOS process. Composite structures are etched out of the CMOS dielectric, aluminum, and gate-polysilicon thin films using a post-CMOS CHF3:O2 reactive-ion etch and followed by a SF6 :O2silicon etch for release. Microstructures have a height of 5 µm and beam widths and gaps down to 1.2 µm. Properties are strongly dependent on the relative metal and dielectric content of the beams. Beams with three metal conductors and polysilicon have an effective Young's modulus of 62 GPa, residual stress of -29 MPa, and an average out-of-plane radius of curvature of 1.9 mm. Maximum Young's modulus variation is 3 GPa die-todie, and is 9 GPa between two runs. Die-to-die variation of stress and stress gradient is poor for many beam compositions, however local matching on a die is very good. Cracking is induced in a resonant fatigue structure at 620 MPa of repetitive stress after over 50 million cycles.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

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References

1 Fedder, G. K., Santhanam, S., Reed, M. L., Eagle, S. C., Guillou, D. F., Lu, M. S.-C., and Carley, L. R., Sensors and Actuators A, 57, pp. 103110 (1996).Google Scholar
2 Biebl, M., Scheiter, T., Hierold, C., Philipsborn, H. V. and Klose, H., Sensors and Actuators A, 46–47, pp. 593597 (1995).Google Scholar
3 Seidel, H., Fritsch, U., Gottinger, R., Schalk, J., Walter, J. and Ambaum, K., Tech. Digest, 8th Int. Conf. Solid-State Sensors and Actuators (Transducers '95)/Eurosensors IX, Stockholm, Sweden, Vol. 1, pp. 597600 (1995).Google Scholar
4 Hoffman, E., Wameka, B., Kruglick, E., Weigold, J. and K. Pister, S. J., Proc. IEEE Micro Electro Mech. Syst. Workshop, Amsterdam, Netherlands, pp. 288293 (1995).Google Scholar
5 Parameswaran, M., Baltes, H.P., Ristic, L., Dhaded, A. C. and Robinson, A. M., Sensors and Actuators A, 19, pp. 289307 (1989).Google Scholar
6 Read, B. C. III, Bright, V. M. and Comtois, J. H., Proc. SPIE - Int. Soc. Opt. Eng. (USA), Vol. 2642, pp. 2232 (1995).Google Scholar
7 Paul, O. M., Korvink, J. and Baltes, H., Sensors and Actuators A, 41, pp. 161164 (1994).Google Scholar
8 Bryce, G. R. and Collette, D., Microelectronics Manufacturing and Testing, p.25 (Oct. 1984).Google Scholar
9 Gianchandani, Y. B. and Najafi, K., IEEE J. MEMS, 5, pp. 5258 (1996).Google Scholar
10 MEMCAD 3.2 User Guide, Microcosm Technologies, Inc.Google Scholar
11 Brown, S. B. and Janson, E., Digest. IEEE/LEOS 1996 Summer Topical Meetings, Optical MEMS and their applications, pp. 910.Google Scholar