Substrate pretreatment for reducing fill time in nanoimprint lithography
A nanoimprint lithography method includes disposing a pretreatment composition on a substrate to form a pretreatment coating. The pretreatment composition includes a polymerizable component. Discrete imprint resist portions are disposed on the pretreatment coating, with each discrete portion of the imprint resist covering a target area of the substrate. A composite polymerizable coating is formed on the substrate as each discrete portion of the imprint resist spreads beyond its target area. The composite polymerizable coating includes a mixture of the pretreatment composition and the imprint resist. The composite polymerizable coating is contacted with a template, and is polymerized to yield a composite polymeric layer on the substrate. The interfacial surface energy between the pretreatment composition and air exceeds the interfacial surface energy between the imprint resist and air or between at least a component of the imprint resist and air.
1. A system comprising:
a substrate;
a liquid pretreatment composition for forming a liquid pretreatment layer on the substrate; and
a liquid imprint resist for disposing discrete portions of the liquid imprint resist on the liquid pretreatment layer;
wherein the liquid pretreatment composition comprises a polymerizable component, the liquid imprint resist is a polymerizable composition, and the interfacial surface energy between the liquid pretreatment composition and air exceeds the interfacial surface energy between the liquid imprint resist and air, and
wherein the imprint resist disposed in discrete portions on the liquid pretreatment layer spreads more rapidly than the same imprint resist disposed on the same substrate in the absence of the liquid pretreatment layer.
2. The system of claim 1 , wherein the interfacial surface energy between the liquid imprint resist and air is in a range of 20 mN/m to 60 mN/m.
3. The system of claim 1 , wherein the interfacial surface energy between the liquid pretreatment composition and air is in a range of 30 mN/m to 45 mN/m.
4. The system of claim 1 , wherein drops of the liquid imprint resist, when disposed on a layer of the liquid pretreatment composition, achieve complete spreading on the layer of the liquid pretreatment composition.
5. The system of claim 1 , wherein a drop diameter ratio of a drop diameter of the liquid imprint resist when disposed on the layer formed of the liquid pretreatment composition on the substrate to a drop diameter of the same imprint resist disposed on the same substrate in the absence of the pretreatment composition is at least 1.59, the drop diameter being measured at a time of 500 ms after disposing the imprint resist portions on the respective layer.