A method for forming separate narrow lines is described. A target layer is formed over a substrate. Base patterns are formed over the target layer. Target line patterns and connection patterns between the ends of the target line patterns are formed as spacers on the sidewalls of the base patterns. The base patterns are removed. The target line patterns and the connection patterns are transferred to the target layer to form target lines and connection segments between the ends of the target lines. At least a portion of each connection segment is removed to disconnect the target lines while other area of the substrate is subjected to a patterned removal treatment.