Safe separation for nano imprinting

1. In a nanoimprint lithography system, a method comprising:

providing a template in contact with a formed patterned layer on a substrate, the template and the substrate having lateral strains d t and d b associated therewith, respectively, when subjected to a separation force;

determining the difference between the lateral strains d t and d b by either (i) measuring the lateral strain values during an initial separation, or (ii) modeling the lateral strain values during a theoretical separation to determine the difference between the d t and d b values;

based on the determined differences, determining the back pressure values which may be applied to the template, the substrate, or both such that the lateral strains d t and d b are brought into a matching condition;

adjusting the lateral strain of the template (d t ) or the substrate (d b ) or both, while the template remains in contact with the formed patterned layer on the substrate, by applying the determined back pressure or pressures to the template or to the substrate or to both such that the lateral strains d t and d b are matched when the template and substrate are subjected to the separation force; and

applying the separation force to separate the template from the substrate while the determined back pressure or back pressures are applied to the template or to the substrate or both.

2. The method of claim 1 wherein the back pressure is applied prior to applying the separation force.

3. The method of claim 1 wherein the back pressure is applied concurrently with applying the separation force.

4. The method of claim 1 wherein the back pressure is only applied to the template.

5. The method of claim 1 wherein the back pressure is only applied to the substrate.

6. The method of claim 1 wherein the applied back pressure is positive pressure.

7. The method of claim 1 wherein the applied back pressure is negative pressure.

8. The method of claim 1 wherein positive back pressure is applied to the template and negative back pressure is applied to the substrate.

9. The method of claim 1 wherein negative back pressure is applied to the template and positive back pressure is applied to the substrate.

10. An imprint lithography method for separating an imprint lithography template from a patterned layer formed by contacting the imprint lithography template with a formable material deposited on a substrate and solidifying the formable material to form the patterned layer such that the template and the substrate have lateral strains d t and d b associated therewith, respectively, when subsequently subjected to a separation force, the method comprising:

determining the differences between lateral strains d t and d b using an analytical model and/or finite element analysis;

based on the determined differences between lateral strains d t and d b , determining the amount of back pressure to apply to the template, the substrate, or both, such that the lateral strains dt and db become matched when subjected to the separation force;

applying the determined amount of back pressure to the template, the substrate, or both while the template remains in contact with the formed patterned layer; and

applying the separation force to separate the template from the formed patterned layer.

11. The method of claim 10 wherein the back pressure is applied prior to applying the separation force.

12. The method of claim 10 wherein the back pressure is applied concurrently with applying the separation force.

13. The method of claim 10 wherein the back pressure is only applied to the template.

14. The method of claim 10 wherein the back pressure is only applied to the substrate.

15. The method of claim 10 wherein the applied back pressure is positive pressure.

16. The method of claim 10 wherein the applied back pressure is negative pressure.

17. The method of claim 10 wherein positive back pressure is applied to the template and negative back pressure is applied to the substrate.

18. The method of claim 10 wherein negative back pressure is applied to the template and positive back pressure is applied to the substrate.

19. An imprint lithography method for separating an imprint lithography template from a patterned layer formed by contacting the imprint lithography template with a formable material deposited on a substrate and solidifying the formable material to form the patterned layer such that the template and the substrate have lateral strains d t and d b associated therewith, respectively, when subsequently subjected to a separation force, the method comprising:

determining the differences between lateral strains d t and d b using an analytical model and/or finite element analysis;

based on the determined differences between lateral strains d t and d b , determining the amount of back pressure to apply to the template, the substrate, or both, such that the ratio of lateral strains (d t /d b ) is approximately 1 when subjected to the separation force;

applying the determined amount of back pressure to the template, the substrate, or both while the template remains in contact with the formed patterned layer; and

applying the separation force to separate the template from the formed patterned layer.

20. The method of claim 19 wherein the back pressure is applied prior to applying the separation force.

21. The method of claim 19 wherein the back pressure is applied concurrently with applying the separation force.

22. The method of claim 19 wherein the back pressure is only applied to the template.

23. The method of claim 19 wherein the back pressure is only applied to the substrate.

24. The method of claim 19 wherein the applied back pressure is positive pressure.

25. The method of claim 19 wherein the applied back pressure is negative pressure.

26. The method of claim 19 wherein positive back pressure is applied to the template and negative back pressure is applied to the substrate.

27. The method of claim 19 wherein negative back pressure is applied to the template and positive back pressure is applied to the substrate.