Potentialities of a new positive photoresist for the realization of thick moulds

The fabrication of MEMS by using the technique of electrodeposition inside resist moulds has known a large development in recent years. Recently, Clariant has produced a new positive photoresist, AZ 9260(R) (500 cps), aimed at the realization of such thick moulds. In this paper, we describe the excellent characteristics of this product through the use of our original method to control technological parameters. The most important feature of AZ 9260(R) photoresist is its good transparency. Current results, using a standard mask aligner, give a good aspect ratio (height-width) of up to 15 easily for 100 mu m thick moulds and up 20 occasionally and our measurement method of transparency predicts the potential realization of mould thickness up to 150 mu m in one UV exposure.