A composition comprising components a), b) and c) wherein a) is a block
copolymer component or a blend of at least two block copolymers, b) is at least one low Tg
oligomer polystyrene additive, and c) is an organic
spin casting organic solvent. Component b) (if more than one, alone) has a Tg in the range of about 68.0 DEG C to about 90.0 DEG C, a Mw in the range of about 2,500 g / mol to about 8,000 g / mol, a polydispersity in the range of about 1.20 to about 1.80, and is further selected from the group consisting of
styrene homopolymers prepared by free
radical polymerization,
styrene random copolymers prepared by free
radical polymerization,
styrene random copolymers prepared by free
radical polymerization, styrene random copolymers prepared by free radical
polymerization, styrene random copolymers prepared by free radical
polymerization, styrene random copolymers prepared by free radical
polymerization, and styrene random copolymers prepared by free radical polymerization. The repeating units consist solely of styrene repeating units and wherein at least two styrene repeating units are present, and a mixture of the styrene homopolymer and at least one styrene random
copolymer. A DSA treatment process using the composition is also described.