[KSCI] Korea Science Citation Index Service

http://dx.doi.org/10.4313/TEEM.2005.6.4.135

Characterization of Low-temperature SU-8 Negative Photoresist Processing for MEMS Applications

May Gary S. (School of Electrical and Computer Engineering, Georgia Institute of Technology)
Han, Seung-Soo (Department of Information Engineering, Myongji University)
Hong, Sang-Jeen (Department of Electronic Engineering and Nano-Bio Research Center, Myongji University)

Publication Information

Transactions on Electrical and Electronic Materials / v.6, no.4, 2005 , pp. 135-139 More about this Journal

Abstract

In this paper, negative SU-8 photoresist processed at low temperature is characterized in terms of delamination. Based on a $3^3$ factorial designed experiment, 27 samples are fabricated, and the degree of delamination is measured for each. In addition, nine samples are fabricated for the purpose of verification. Employing the. neural network modeling technique, a process model is established, and response surfaces are generated to investigate degree of delamination associated with three process parameters: post exposure bake (PEB) temperature, PEB time, and exposure energy. From the response surfaces generated, two significant parameters associated with delamination are identified, and their effects on delamination are analyzed. Higher PEB temperature at a fixed PEB time results in a greater degree of delamination. In addition, a higher dose of exposure energy lowers the temperature at which the delamination begins and also results in a larger degree of delamination. These results identify acceptable ranges of the three process variables to avoid delamination of SU-8 film, which in turn might lead to potential defects in MEMS device fabrication.

Keywords

MEMS; SU-8; Design of experiment; Neural networks; CTE mismatch;

Citations & Related Records

Reference

1	G. Voskerician, M. Shive, R. Shawgo, H. Recum, J. Anderson, M. Cima, and R. Langer, 'Biocompatibility and biofouling of MEMS drug delivery devices', Biomaterials, Vol. 24, p. 1959, 2003 DOI ScienceOn
2	M. Brunet, T. O'Donnell, J. O'Brien, P. McCloskey, and S. Mathuna, 'Thick photoresist development for the fabrication of high aspect ratio magnetic coils', J. Micromech. Microeng., Vol. 12, p. 444, 2002
3	J. Zhang, K. L. Tan, and H. Q. Gong, 'Characterization of the polymerization of SU-8 photoresist and its applications in micro-electro-mechanical systems', Polymer Testing, Vol. 20, p. 693, 2001
4	B. Eyre, J. Blosiu, and D. Wiberg, 'Taguchi optimization for the processing of Epon SU-8 resist', in Proc. IEEE, The eleventh Annual International Workshop on Micro Eelectro Mechanical Systems, p. 25, 1998
5	G. Box, W. Hunter, and J. Hunter, 'Statistics for Experimenters', New York: Wiley, 1978
6	A. Wong and D. Linton, 'Application of SU-8 in flip chip bump micro machining for millimeter wave applications', in Proceedings of 3rd Electronics Packaging Technology Conference (EPTC 2000),p.204, 2000
7	S. Hong, G. May, and D. Park, 'Neural network modeling of reactive ion etch using optical emission spectroscopy data', IEEE Trans. Semi. Manufac., Vol. 16, No.4, p. 1, 2003
8	C. Davis, S. Hong, R. Setia, R. Pratap, T. Brown, B. Ku, G. Triplett, and G. May, 'A java_based objected-oriented neural network simulator for semiconductor manufacturing applications', submitted to the 8th World Multi-conference on Systemics, Cybernetics and Informatics, Orlando, FL,2004
9	H. Khoo, K. Liu, and F. Tseng, 'Mechanical strength and interfacial failure analysis of cantilevered SU-8 microposts', J. Micromech. Microeng., Vol. 13, p. 822, 2003 DOI ScienceOn
10	M. Despont, H. Lorenz, N. Fahrni, J. Brugger, P. Renaud, and P. Vettiger, 'High-aspect ratio ultrathick, negative tone near-UV photoresist for MSMS applications', in Proc. IEEE, Tenth Anuual Internaltional Workshop in Micro Eletro Mechanical Systems, Nagoya, Japan, p. 518, 1997