Imprint alignment method, system, and template
View Patent ↗An improved lithographic alignment method, system, and template. The method includes creating, within a lithographic subfield, subsequent-layer features which are intentionally offset from their respective previous-layer features, where the intentional offset may vary in magnitude and direction from one subfield to the next. The system includes an imprint lithographic machine and first and second lithography templates where the templates are adapted to enable the machine to form first and second features, respectively, and where a second feature is configured to be deliberately offset from a corresponding first feature. The template set includes at least two templates, one having features which are deliberately offset from corresponding features of another template. Also, a method of manufacturing such a template set.
1. A method of improving alignment between subsequent imprinted device layers within a subfield to provide at least one functional device within the subfield, the method comprising steps of:
a) establishing an x,y grid such that a centermost point of a subfield arranged within a central region has (x,y) coordinates (0,0);
b) establishing an array comprising N subfields arranged in J rows and K columns, wherein each column has a width ‘w’, and wherein each row has a height ‘h’, and wherein a device is arranged entirely within a single subfield;
c) imprinting a first layer of polymerizable material using a first lithographic template to form at least one feature, wherein the first layer comprises an array of N first-layer geometries, wherein a centermost point of a central first-layer geometry has (x,y) coordinates (0,0), wherein a centermost point of each first-layer geometry is commensurate with a centermost point of its respective subfield, and each centermost point of a first-layer geometry is a spaced distance ‘w’ from a centermost point of an immediately laterally adjacent first-layer geometry, and wherein a each centermost point of a first-layer geometry is a spaced distance ‘h’ from a centermost point of an immediately vertically adjacent first-layer geometry; and
d) imprinting a second successive layer of polymerizable material using a second lithographic template to form at least one feature, where the second layer comprises an array of N second-layer geometries, wherein each second-layer geometry has a corresponding first-layer geometry, wherein a centermost point of a central second-layer geometry has (x,y) coordinates (0,0), wherein each centermost point of a second-layer geometry is a spaced distance ‘w+Δw’ from a centermost point of an immediately laterally adjacent second-layer geometry, and wherein each centermost point of a second-layer geometry is a spaced distance ‘h +Δh’ from a centermost point of an immediately vertically adjacent first-layer geometry, wherein Δw is not equal to zero, and wherein Δh is not equal to zero.
2. The method as recited in claim 1 , wherein Δh equals Δw.
3. The method as recited in claim 1 , wherein ‘h’ equals ‘w’.