Dual zone template chuck
View Patent ↗A template chuck includes multiple zones to provide 1) an imprint bend optimized to provide high curvature and provide contact at middle radius of substrate and/or, 2) separation bend zone with an increased free span zone and high crack angle.
1. A nano-imprint lithography method, comprising:
imprinting polymerizable material positioned on a substrate by contacting the polymerizable material with a template to form a patterned layer on the substrate, the template coupled to a chuck and constrained against first and second template supports of the chuck, the first and second template supports defining an imprint outer bend zone, the first template support provided at a first distance from an edge of the patterned layer, the first distance defining a first free span length along the template;
prior to separating the template from the patterned layer and while the template remains in contact with the patterned layer, adjusting the chuck to constrain the template against the second template support and a third template support of the chuck and releasing the constraint against the first support, the second and third supports defining a separation outer bend zone that cinctures the imprint outer bend zone, with the second template support provided at a second distance from an edge of the patterned layer, the second distance defining a second free span length along the template and wherein the first free span length is less than the second free span length; and
separating the template and the patterned layer.
2. The nano-imprint lithography method of claim 1 , wherein the second free span length is configured to reduce the magnitude of force needed to separate the template from the patterned layer.
3. The nano-imprint lithography method of claim 1 , wherein the chuck includes four zones: the separation outer bend zone, the imprint outer bend zone, a back pressure zone, and an inner bend zone, the separation outer bend zone cincturing the imprint outer bend zone which cinctures the back pressure zone which cinctures the inner bend zone.
4. The nano-imprint lithography method of claim 3 , wherein a pump system controls pressure within each zone during the imprinting step and the separation step.
5. The nano-imprint lithography method of claim 4 , wherein prior to imprinting, the pump system provides the imprint outer bend zone and the inner bend zone in a vacuum state, and the back pressure zone in a pressure state, such that template forms a toroidal imprint shape having the first free span length.
6. The nano-imprint lithography method of claim 5 , wherein the toroidal imprint shape provides deflection of the template symmetric about a middle radius of the substrate during imprinting.
7. The nano-imprint lithography method of claim 5 , wherein the imprint outer bend zone and inner bend zone are configured to provide a radius of curvature at an interface of the substrate and the template that accelerates filling of polymerizable material between the substrate and the template during the imprinting step.
8. The nano-imprint lithography method of claim 5 , wherein prior to imprinting, the separation outer bend zone is deactivated.
9. The nano-imprint lithography method of claim 4 , wherein during separation of the template and the patterned layer, the pump system provides the separation outer bend zone in a vacuum state and the back pressure zone in a pressure state such that the template has the second free span length.
10. The nano-imprint lithography method of claim 9 , wherein during separation of the template and the patterned layer, the imprint outer bend zone and the inner bend zone is deactivated.
11. The nano-imprint lithography method of claim 1 , wherein the substrate is coupled to a substrate chuck, and during the separation step, the substrate chuck is in a vacuum state.