Two classes of siloxane polymers applicable as resist materials are being described. In the first series of materials acid-sensitive substituents as t-butoxycarbonyloxy, or t-butoxy are linked to a polysiloxane backbone. Preparation of these polymers occurs via hydrosilylation of polymethylhydrosiloxane with suitable olefins. The second class concerns graftcopolymers and/or tercopolymers in which acid-sensitive groups are attached to a carbon backbone in combination with grafted polysiloxane chains. These polymers are synthesized by free radical polymerization of olefins and silicon macromers. In microlithographic experiments two-layer resist systems have been irradiated with e-beam or DUV, the top layer being a silicon-containing polymer in combination with a catalytic amount of a photoacid generator. In general a high sensitivity was observed combined with a high oxygen RIE resistance.