Method of forming patterns on substrate by double nanoimprint lithography

A method of forming patterns on a substrate by double nanoimprint processes, comprising:

• providing a first replicate mold and a second replicate mold, wherein the first replicate mold is defined into a first region and a second region, the first replicate mold comprises a plurality of first patterns disposed within the first region and the second region, a density of distribution of the plurality of first patterns within the first region is the same as a density of distribution of the plurality of first patterns within the second region, the second replicate mold comprises at least one second pattern, and the second pattern corresponds to at least one of the plurality of first patterns;
• providing a first substrate, and a first polymeric compound layer being coated on the first substrate;
• performing a first nanoimprint process to nanoimprint the plurality of first patterns into the first polymeric compound layer;
• after the first nanoimprint process, performing a first etching process to etch the first substrate to form a plurality of protruding features by taking the first polymeric compound layer as a first mask;
• after the first etching process, completely removing the first polymeric compound layer before forming a second polymeric compound layer coated on the first substrate;
• performing a second nanoimprint process to nanoimprint the second pattern into the second polymeric compound layer;
• and
• after the second nanoimprint process, performing a second etching process to completely remove at least one of the plurality of protruding features by taking the second polymeric compound layer as a second mask, wherein during the second etching process at least another one of the plurality of protruding features is not etched.