A method for preparing a patterned directed self-assembly layer for reducing directed self-assembly pattern defectivity using direct current superpositioning is provided. A substrate having a block copolymer layer overlying a first intermediate layer, said block copolymer layer comprising a first phase-separated polymer defining a first pattern and a second phase-separated polymer defining a second pattern in said block copolymer layer is provided. A first plasma etching process using plasma formed of a first process composition to remove said second phase-separated polymer while leaving behind said first pattern of said first phase-separated polymer is performed. A second plasma etching process to transfer said first pattern into said first intermediate layer using plasma formed of a second process composition is performed. In an embodiment, said first phase-separated polymer is exposed to an electron beam preceding, during, or following said first plasma etching process, or preceding or during said second plasma etching process.