Asymmetric templates for forming non-periodic patterns using directes self-assembly materials

A method, comprising:

• forming a first template having a first plurality of elements above a process layer, wherein portions of the process layer are exposed between adjacent elements of the first template;
• forming a first directed self-assembly layer over the exposed portions, the first directed self-assembly layer having alternating etchable components and etch-resistant components;
• removing the etchable components of the first directed self-assembly layer;
• patterning the process layer using the first template and the etch-resistant components of the first directed self-assembly layer, wherein a first plurality of periodic elements are defined in the process layer by the etch-resistant components of the first directed self-assembly layer;
• forming a second template having a second plurality of elements above the process layer, wherein portions of the process layer are exposed between adjacent elements of the second template;
• forming a second directed self-assembly layer over the exposed portions, the second directed self-assembly layer having alternating etchable components and etch-resistant components;
• removing the etchable components of the second directed self-assembly layer;
• and
• patterning the process layer using the second template and the etch-resistant components of the second directed self-assembly layer, wherein a second plurality of periodic elements are defined in the process layer by the etch-resistant components of the second directed self-assembly layer and non-periodic elements are defined in the process later in regions covered by both the first and second templates during the patterning of the process layer.