Method to arrange features on a substrate to replicate features having minimal dimensional variability
View Patent ↗The present invention is directed to a method of and a mold for arranging features on a substrate to replicate the features with minimal dimensional variability. The method includes arranging features on a layer to minimize thickness variations in the layer that are attributable to density variations of the plurality of features on the layer. The features are transferred into an underlying substrate. It is believed that by forming the features so as to define a uniform fill factor in the layer, the thickness variations may be reduced, if not abrogated. To that end, one method in accordance with the present invention includes forming a flowable material on the substrate. Thereafter, a plurality of features is formed in a region of the flowable material. The plurality of features are arranged to provide a substantially uniform fill factor in the region.
1. A method of arranging features, on a substrate having topological variations, to replicate features having minimal dimensional variability, said method comprising:
forming a volume of flowable material on a region of said substrate, said region having an area associated therewith;
forming, from said volume of flowable material, a plurality of features on said region; and
transferring said plurality of features into said substrate, defining transferred features, with said area of said region being established to maximize a planarity of said region in a first direction to minimize dimensional variations among a subset of said transferred features in a second direction orthogonal to said first direction.
2. The method as recited in claim 1 wherein forming said plurality of features further includes arranging said plurality of features to be periodic over said region, with each of said plurality of features having a geometric pattern selected from a set of patterns consisting essentially of arcuate shapes, L-shapes and linear shapes.
3. The method as recited in claim 2 wherein forming said volume of said flowable material further includes depositing a bead of said flowable material onto said substrate and forming said plurality of features further includes contacting said bead with a mold having a relief structure on a surface thereof to spread said bead over said region, imprinting said plurality of features therein and further including subjecting said flowable material to conditions to polymerize said flowable material, forming a polymerized layer.
4. The method as recited in claim 3 wherein forming said plurality of features further includes forming said plurality of features on said region to have first and second sets of said linear shapes, with said first set intersecting said second set and extending orthogonally thereto to define a matrix pattern.
5. The method as recited in claim 3 wherein forming said plurality of features further includes forming said plurality of features on said region as a plurality of spaced-apart projections having a cross-sectional shape from a set of shapes consisting essentially of polygonal and circular.
6. The method as recited in claim 5 wherein all of said plurality of features have a common shape.
7. The method as recited in claim 1 wherein said substrate includes a lattice structure having crystalline planes with said plurality of features including a sidewall orientated to extend parallel to a subset of said crystalline planes.
8. The method as recited in claim 1 wherein said region includes an edge, wherein forming said plurality of features further includes forming said plurality of features so as to be absent from portions of said region proximate to said edge.
9. A method of arranging features on a substrate to replicate features having minimal dimensional variability, said method comprising:
forming a volume of flowable material on a region of said substrate, said region having an area associated therewith;
forming, from said volume of said flowable material, a plurality of features on said region, said plurality of features comprising first and second subsets having first and second thicknesses, with a magnitude of said volume of said flowable material being defined by said area, said first and second thicknesses, and a fill factor associated with one of said first and second subsets; and
transferring said plurality of features into said substrate, defining transferred features, with said area of said region being established to maximize a planarity of said region to minimize dimensional variations among a subset of said transferred features.
10. The method as recited in claim 9 wherein forming said plurality of features further includes said magnitude of said volume of said flowable material being defined by:
A×[t 2 +( f×t 1 )]
wherein A is said area, t 1 is said first thickness, t 2 is said second thickness, and f is said fill factor.
11. The method as recited in claim 10 wherein forming said plurality of features further includes defining said fill factor to be a percentage of said region comprising said first subset of said plurality of features.
12. The method as recited in claim 1 further includes minimizing thickness variations among a subset of said plurality of features.
13. The method as recited in claim 1 includes minimizing a magnitude of said area.
14. The method as recited in claim 1 wherein forming said volume of said flowable material further includes positioning said region upon said substrate to maximize said planarity of said region.