Researchers are conducting a synthetic research program to explore a new synthetic and manufacturing approach for the development of advanced novolak resins for microelectronic, printed circuit board, and LCD applications. They are evaluating scientifically designed novolak resins with superior properties and reproducibility, specifically applicable for use in positive photoresists. These resins are being designed based on recently published work on the hydrogen bonding interactions between novolaks and photosensitive components of the resist. They are also designed to give higher dissolution rates, improved thermal stability, better batch-to-batch reproducibility, and very low metal ion contamination. Investigators are undertaking an experimental program to develop a new synthetic approach, prepare discrete low MW oligomeric components, and convert these oligomers into a series of block copolymer resins to be evaluated for relevant performance. Solid novolak resins With less than 100 ppb metal ion and plus/minus 10 percent batch-to-batch reproducibility, and which are capable of providing resists with better than 0.5 @m resolution, approximately 100 mJ/cml threshold energy, and at least 130'C thermal stability are being developed.The potential commercial application as described by the awardee: New novolak resins specifically designed for positive photoresist applications would have immediate potential application in the formulation of high resolution i-line photoresists. It would also have potential application in other electronic applications by providing a much higher resin selectivity and low metal ion contamination.