Won-Jong Kang et al 2006 J. Micromech. Microeng. 16 821 doi:10.1088/0960-1317/16/4/020
Won-Jong Kang, Erik Rabe, Stefan Kopetz and Andreas Neyer
Show affiliationsThick-film photolithography based on SU-8 has gained great interest in the field of microreplication technologies. For replication applications the SU-8 structures themselves or electroplated copies of the resist structures are used as casting or embossing tools. In this paper, a simple estimation model is proposed to predict the sidewall profiles of SU-8. This model is based on the effects of Fresnel diffraction and absorption resulting in useful approximations for the pattern profile of SU-8. Its usefulness is successfully verified by experimental results; the estimated and experimental results show similar trends. In addition, by utilizing this model two exposure methods based on reflection and refraction could be developed which avoid negatively sloped sidewall profiles of SU-8. Using these exposure methods, SU-8 preforms without undercut for the replication of optical waveguides have been achieved.
42.82.Cr Fabrication techniques; lithography, pattern transfer
42.25.Fx Diffraction and scattering
42.82.Ds Interconnects, including holographic interconnects
42.25.Gy Edge and boundary effects; reflection and refraction
Issue 4 (April 2006)
Received 7 November 2005, in final form 21 February 2006
Published 20 March 2006
Won-Jong Kang et al 2006 J. Micromech. Microeng. 16 821
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