Masking techniques and templates for dense semiconductor fabrication
A template comprising pitch multiplied and non-pitch multiplied features is configured for use in imprint lithography. On a first substrate, a first pattern is formed using pitch multiplication and a second pattern is formed using photolithography without pitch multiplication. The first pattern and the second pattern are transferred to a template. The template is brought into contact with a transfer layer overlying a series of mask layers overlying a second substrate. The pitch multiplied and non-pitch multiplied patterns on the template are transferred to the transfer layer, forming an imprinted pattern. The imprinted pattern is transferred to the second substrate to form pitch multiplied and non-pitch multiplied features.
1. A method for forming a template for use in imprint lithography, comprising:
forming a first mask with pitch multiplication over a substrate, the first mask defining a first pattern;
separately forming a second mask by photolithography over the substrate, the second mask defining a second pattern;
transferring the first pattern and the second pattern to the substrate; and
transferring the first pattern and the second pattern from the substrate to the template configured for use in imprint lithography.
2. The method of claim 1 , wherein transferring the first pattern and the second pattern from the substrate to the template comprises bringing the substrate in contact with a plate.
3. The method of claim 2 , wherein bringing the substrate in contact with a plate comprises forming an adhesive layer bonded to the substrate and the plate.
4. The method of claim 1 , wherein transferring the first pattern and the second pattern from the substrate to the template comprises forming a substantially planar layer in contact with the substrate.
5. The method of claim 4 , further comprising bonding a plate to the planar layer over the substrate.
6. The method of claim 5 , wherein bonding a plate to the planar layer over the substrate comprises forming an adhesive layer bonded to the planar layer and the plate.
7. The method of claim 5 , further comprising etching the substrate from the substantially planar layer after bonding the plate to the planar layer.
8. The method of claim 1 , wherein forming the first mask with pitch multiplication comprises:
providing a plurality of mandrels on the substrate;
depositing a layer of spacer material over the mandrels on the substrate;
anisotropically etching the spacer material to form spacers; and
selectively removing the mandrels, wherein the spacers correspond to the first pattern.