Abstract: A method of planarizing topographical features on a substrate for subsequent coating of a radiation sensitive composition thereon comprising:(1) applying thereover a coating of a planarizing coating layer comprising a planarization layer of novolak resin made by the condensation reaction of an aldehyde source with a phenolic monomeric source comprising at least 25 mole percent of ortho-secondary butyl phenol and a suitable solvent; and(2) heating said coated substrate to remove essentially all of said solvent therefrom and cause said coating to reflow, thereby planarizing the topographical features.

Abstract: The process of developing an image-wise exposed positive-working photoresist-coated substrate comprising the steps of:(1) coating said substrate with a radiation-sensitive composition useful as a photoresist; said composition comprising an admixture of:(a) at least one alkali-soluble binder resin;(b) at least one photoactive compound; and(c) a sufficient amount of at least one solvent to dissolve (a) and (b); subject to the proviso that said photoactive compound (b) is a mixture of fully and partially esterified o-naphthoquinone diazide esters of a polyhydroxyaromatic compound having at least four hydroxyl groups capable of being esterified by said diazide groups.