| abstract |
A heat resistant positive-working photosensitive composition that has a polybenzoxazole precursor bearing acid labile functional groups, a photoacid generator, a photosensitizer, and a solvent. The polybenzoxazole precursor bearing acid labile functional groups, has the structure: ##STR1## wherein k 1 is an integer of 1 or 2, k 2 is an interger of 0 or 1, and the sum of k 1 and k 2 is 2; Ar 1 is a tetravalent aromatic, aliphatic, or heterocyclic group, or mixtures thereof; Ar 2 is a divalent aromatic, aliphatic, or heterocyclic group or siloxane group; D is a monovalent acid labile group; and n is an integer from 20 to 200. A portion of Ar 1 can be a divalent aromatic, aliphatic, or heterocyclic diamine moiety such that the fraction of diamine compound is 0-60 mole percent and the sum of diamine and diamino dihydroxy compound is 100%. n Preparation of chemical amplification based positive-working, aqueous base developable photosensitive polybenzoxazole (PBO) precursors, the formulation of the resin composition, and the process for preparing heat-resistant relief structures from this resin composition. The positive photosensitive resin compositions are suitable especially for applications in microelectronics. |