a non - photosensitive polymeric resist containing at least two immiscible polymeric block components is deposited on the planar surface . the non - photosensitive polymeric resist is annealed to allow phase separation of immiscible components and developed to remove at least one of the at least two polymeric block components . nanoscale features , i . e ., features of nanometer scale , including at least one recessed region having a nanoscale dimension is formed in the polymeric resist . the top surface of the polymeric resist is modified for enhanced etch resistance by an exposure to an energetic beam , which allows the top surface of the patterned polymeric resist to become more resistant to etching processes and chemistries . the enhanced ratio of etch resistance between the two types of surfaces provides improved image contrast and fidelity between areas having the top surface and the at least one recessed region .