Abstract: Microbridge formation in chemically amplified negative tone photoresists based on poly(hydroxystyrene) (PHS) is avoided when the PHS is blended together with a co-polymer of PHS and an acrylic polymer such as poly(methyl methacrylate) (PMMA). The blend should include at least 10% by weight of the co-polymer. In operation, hydrogen bonding between the hydroxystyrene sub-units and the methacrylate sub-units decreases the availability of sites for crosslinking, and this reduction in crosslinking sites makes the blend less susceptible to formation of polymer resist microbridges. The invention is practicable with a polymers having a wide range of molecular weights (2000-50000 daltons), and development can be achieved using the industry standard 2.38 wt % trimethylammonium hydroxide (TMAH) developer without any adverse impact on the photoresist.