Abstract: A process for forming a detailed image having a high sensitivity to far-UV light and capable of giving a positive type image with a high precision is provided, which process comprises applying onto a base a resist solution comprising an organic solution, of a homopolymer of methyl vinyl ketone or a copolymer thereof with a comonomer of the formula R.sup.1 R.sup.2 C.dbd.CH.sub.2 wherein R.sup.1 is H or --CH.sub.3 and R.sup.2 is acetoxy, nitrile, unsubstituted or substituted aryl or ##STR1## wherein R.sup.3 is alkyl, to form a coating on the base; irradiating far-UV light; developing the coating with a developer composed mainly of a cellosolve compound; and rinsing or/and washing the resulting material.

Abstract: A silicon-containing step ladder polymer comprising a unit represented by the following general formula (I): ##STR1## a unit represented by the following general formula (II): ##STR2## and a unit represented by the following general formula (III): ##STR3## where R.sup.1 represents a hydrocarbon or fluorine-substituted hydrocarbon group, R.sup.2 represents hydrogen or a trialkyl siloxy group, and R.sup.3 and R.sup.4 which may be identical or different with each other represent individually hydrocarbon or fluorine-substituted hydrocarbon groups, the molar ratio of the unit (I) to the unit (II) is between 5:1-100:1 and the molar ratio of the unit (III) to the total amount of the unit (I)+unit (II) is between 1:5-1:100, as well as a process for producing such polymer.

Abstract: A silicon-containing step ladder polymer comprising a unit represented by the following general formula (I): ##STR1## a unit represented by the following general formula (II): ##STR2## and a unit represented by the following general formula (III): ##STR3## where R.sup.1 represents a hydrocarbon or fluorine-substituted hydrocarbon group, R.sup.2 represents hydrogen or a trialkyl siloxy group, and R.sup.3 and R.sup.4 which may be identical or different with each other represent individually hydrocarbon or fluorine-substituted hydrocarbon groups, the molar ratio of the unit (I) to the unit (II) is between 5:1-100:1 and the molar ratio of the unit (III) to the total amount of the unit (I)+unit (II) is between 1:5-1:100, as well as a process for producing such polymer.