Abstract: Polymers having a molecular weight (weight average) M.sub.w from 10.sup.3 to 10.sup.6, comprising recurring structural units of the formulae (I), (IIa) and (IIb) ##STR1## in which R.sub.1 is hydrogen or methyl, Y is a direct bond or a divalent radical of the formula (III) ##STR2## in which Z is a C.sub.1 -C.sub.6 alkylene group bound to the phenyl nucleus,OR.sub.2 is an acid-cleavable radical,in which R.sub.2 is C.sub.4 -C.sub.10 tert-alkyl, allyl, cyclohex-2-enyl, C.sub.6 -C.sub.14 aryl or C.sub.7 -C.sub.16 aralkyl which are unsubstituted or mono- or poly-substituted by C.sub.1 -C.sub.6 alkyl groups, C.sub.1 -C.sub.6 alkoxy groups or halogen atoms, trialkylsilyl or a group of the formulae (IV)-(VII) ##STR3## in which R.sub.8 is C.sub.1 -C.sub.6 alkyl, or C.sub.6 -C.sub.14 aryl or C.sub.7 -C.sub.16 aralkyl which are unsubstituted or mono- or poly-substituted by C.sub.1 -C.sub.6 alkyl groups, C.sub.1 -C.sub.6 alkoxy groups or halogen atoms,R.sub.3 and R.sub.4 independently of one another are hydrogen, C.sub.

Abstract: Positive photoresist compositions comprising, in an organic solvent, at leasta) one alkali-soluble resin,b) one photosensitive quinone diazide,c) one aromatic hydroxy compound of formula I ##STR1## wherein each R is --H, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, --OCH.sub.2 C.sub.6 H.sub.5, --OC.sub.6 H.sub.5 or --COOC.sub.1 -C.sub.4 alkyl, and R.sub.1 and R.sub.2 are each independently of the other H, C.sub.1 -C.sub.4 alkyl, --C.sub.6 H.sub.5 or a cycloaliphatic 5- or 6-membered ring, a is an integer from 0 to 4, and m and n are each independently of the other 0, 1 or 2, which compound enhances the photosensitivity and/or the rate of development, and optionallyd) additional customary modifiers,are eminently suitable for making relief structures.