NOVELTY - A composition (C1) comprises block copolymer including organosilicon block; organic block; and at least one moiety comprising hydrogen bond donor or acceptor; and organic additive including at least one moiety comprising hydrogen bond acceptor or donor, where hydrogen bonds formed between the moieties in block copolymer and moieties in organic additive produce ordered arrangements of atoms in composition (C1).    USE - As mask composition used in lithography system; and to form structures having features of 5-100 nm size (claimed) used in lithographic processes; also in articles of manufacture such as photovoltaic system, photonic crystal system, nano-porous membrane system, nano-lithographic system, battery system, photonics system, artificial membrane system, water purification system, fuel cell system, display system, data storage system, resist system for device patterning, or flexible electronics system; for controlled assembly and for inducing and enhancing order and nanostructures in organosilicon block copolymers compositions which are used e.g. as a mask for lithographic patterning and during stages of semiconductor device fabrication.    ADVANTAGE - The ordered arrangements of atoms in the composition increase the segregation strength of block copolymer; increase the glass transition temperature of block copolymer; and/or inhibit crystallization of block copolymer. The material effectively induces and increases order and nanostructures in polymeric materials, used in three dimensional microfabrication technologies such as nanolithography.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) lithography system comprising substrate comprising layered material; and mask composition (C1) disposed over the substrate; and    (2) method for forming structures having size of 5-100 nm involving (a) forming layer of mask material over substrate comprising several layered materials, where the mask material comprises block copolymer composition (C1); (b) annealing mask material on substrate; (c) exposing mask material to an etching process selected for its ability to selectively etch the organic block and organic additive of block copolymer composition (C1), where the etching process exposes layer of substrate; and (d) exposing substrate material to second etching process selected for its ability to etch the layer of substrate exposed by step (c); so that structures having size of 5-100 nm are formed.