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Conformal Electroless Copper and Nickel Deposition on Mems Structures

Published online by Cambridge University Press:  10 February 2011

Hercules P. Neves ,
Thomas D. Kudrle ,
Jia-Ming Chen ,
Scott G. Adams ,
Michel Maharbiz ,
Sergey Lopatin  and
N. C. MacDonald
Hercules P. Neves
Affiliation:
School of Electrical Engineering, Phillips Hall, Cornell University, Ithaca NY 14853-5401
Thomas D. Kudrle
Affiliation:
School of Electrical Engineering, Phillips Hall, Cornell University, Ithaca NY 14853-5401
Jia-Ming Chen
Affiliation:
School of Electrical Engineering, Phillips Hall, Cornell University, Ithaca NY 14853-5401
Scott G. Adams
Affiliation:
Kionix Inc., 22 Thornwood Drive, Ithaca NY 14850
Michel Maharbiz
Affiliation:
Berkeley Sensors and Actuators Center, University of California, Berkeley CA 94720-1774
Sergey Lopatin
Affiliation:
AMD Inc., One AMD Place, MS 160, Sunnyvale CA 94088-3453
N. C. MacDonald
Affiliation:
School of Electrical Engineering, Phillips Hall, Cornell University, Ithaca NY 14853-5401
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Abstract

We propose electroless metallization as a method for conformal metal deposition microelectromechanical systems (MEMS). The intrinsically conformal nature of electroless deposition makes it ideal for coating high aspect ratio (greater than 50:1) structures frequently fabricated with micromachining techniques We take advantage of the selective nature of the deposition to obtain self-aligned electrical isolation. We minimize the metal film roughness for potential applications in RF and optics. Given the specific MEMS metallization requirements, we determined the ideal concentrations of additives and surfactants in order to provide good electrical isolation, low roughness and high film reliability. Our depositions were done using seed layers as well as through direct chemical activation of the silicon surface. Characteristics such as resistivity [ 1 ], morphology [ 1 ], microstructure [ 2 ], and electrochemical behavior [ 3 ] have already been reported in the literature; our paper is focused on the specific requirements for MEMS applications.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 546: Symposium AA – Materials Science of Microelectromechanical Systems (MEMS)… , 1998 , 139
Copyright
Copyright © Materials Research Society 1999

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References

[1] Lopatin, S., Shacham, Y., Dubin, V., Vasudev, P. K., Kim, Y., Smy, T., “Characterization of electroless Cu, Co, Ni and their alloys for ULSI metallization,” MRS Conf. Proc. ULSI XIII, p. 437, (1998).Google Scholar
[2] Nucci, J., Neves, H., Shacham, Y., Eisenbraun, E., Zheng, B., Kaloyeros, A., “In-situ analysis of microstructure in thermally treated thin copper films”, Proceedings of the (1993) MRS Spring Meeting.Google Scholar
[3] Paunovic, M.. “Potentiostatic high overpotential studies of copper deposition from electroless copper solutions,” J. Electrochem. Soc., vol.132., no. 5, p. 1155, May (1985).Google Scholar
[4] Brenner, A., “History of the dectroless plating process,” Symp. Electroless Nickel Plating, ASTM Special Technical Publication no. 265, p. 1, (1959).Google Scholar
[5] Ohno, I., Wakabayashi, O., Haruyama, S., “Anodic oxidation of reductants in electroless plating, J. Electrochem. Soc., vol.132, no. 10, p. 2323, October (1985).Google Scholar
[6] Mak, C. Y., “Electroless copper deposition on metals and metal silicides,” MRS Bulletin, p. 55, August (1994).Google Scholar
[7] Mallory, G. O., Hajdu, J. B., Electroless Plating, AESF, Orlando, (1990).Google Scholar
[8] Morishita, H., Kawamoto, M., Wajima, M., Murakami, K., “Electroless copper solution,” U.S. Pat. 4,099,974, July (1978).Google Scholar
[9] MacDonald, N. C., “SCREAM microelectromechanical systems,” Microelectronic Engineering, vol.32, p. 49, (1996).Google Scholar
[10] Laermer, F., Schilp, A., “Method for anisotropically etching silicon, ” U. S. Pat. 5,501,893, March (1996)Google Scholar