Integrating process and novel sacrificial layer fabricating technique based on diluted SU-8 resist

Although there are many types of commercially available SU-8 photoresist, all of them contain the same concentration of photo acid generator (PAG). This directly produces the restriction that the upper layer of the resist structure has to be smaller than or of the same size as the lower one when we fabricate multilayer SU-8 resist structure by an integrating process. In this paper we introduce a method to fabricate SU-8 resist with varying concentration of PAG – diluted SU-8 resist. The PAG concentration of this diluted resist can easily be changed. On the basis of the research of optical performance and proper utilization of the diluted SU-8 resist series, the existing restriction is successfully removed and the application scope of integrating process is expanded. A new sacrificial layer fabricating technique based on the diluted SU-8 resist is also introduced in this paper.

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