PHOTOPATTERNABLE INSULATING MATERIALS

Present direct photopatternable insulating materials are only availabl e as negative working systems. In connection with the increasing requi rements for resolution capability, higher processing performance and f or environmental reasons, positive working systems offer significant a dvantages for the future. One of the most promising systems is a formu lation composed of a polybenzoxazole (PBO) precursor and a diazoquinon e sensitizer. Compared with the well known novolac-based positive resi sts which are used for fine patterning in IC manufacturing, the anneal ed PBO resist incorporates both resist and dielectric properties. The present paper discusses general aspects of positive and negative mode patterning with the emphasis on positive working PBO precursors which fulfill the most important future requirements.