Nanoimprint enhanced resist spacer patterning method

A method of making a device, comprising:

• forming a first hard mask layer over an underlying layer;
• forming a first imprint resist layer over the first hard mask layer;
• forming first features over the first hard mask layer by bringing a first imprint template in contact with the first imprint resist layer;
• forming a first spacer layer over the first features;
• etching the first spacer layer to form a first spacer pattern and to expose top of the first features;
• removing the first features;
• patterning the first hard mask, using the first spacer pattern as a mask, to form first hard mask features;
• removing the first spacer pattern;
• forming a second imprint resist layer over the first hard mask features;
• forming second features over the first hard mask features by bringing a second imprint template in contact with the second imprint resist layer;
• forming a second spacer layer over the second features;
• etching the second spacer layer to form a second spacer pattern and to expose top of the second features;
• removing the second features;
• etching the first hard mask features, using the second spacer pattern as a mask, to form second hard mask features;
• and
• etching at least part of the underlying layer using the second hard mask features as a mask.