A Comparison Of The Dissolution Behavior Of Poly(P-Hydroxystyrene) With Novolac

An examination of the literature revealed that aqueous-processable positive-working photoresists based on novolac resins have been frequently reported, while analogous resists employing poly(p-hydroxystyrene) as the binder have not. In a functional resist formulation, poly(p-hydroxystyrene) would be expected to be similar to novolac in its development characteristics; however, this is not true. The dissolution properties of these two types of binders have been examined in order to identify the crucial differences. This paper presents the determination of the dissolution kinetic expression for both polymers. Additionally, the dissolution behavior of these materials in a resist-like environment is also discussed. From the results of our study, it can be concluded that poly(p-hydroxystyrene) does not exhibit as high a discrimination between exposed and unex-posed dissolution rates as does novolac.