FIELD OF ART

The disclosure generally relates to the field of nanoimprint lithography (NIL), and specifically to NIL processes for switching mechanical properties of imprint materials.

BACKGROUND

Nano-imprint lithography (NIL) is a process whereby nanometer scale patterns are imprinted, using mechanical processes, on an imprint material. These patterns may be three dimensional in shape (i.e., vary along three different axes). Such patterned materials may have many applications (e.g., for use to channel fluids, act as waveguides, be used for circuit patterns), and in some cases, are manufactured at a cost that is lower than optical lithography. Commonly, these patterns may be created by imprinting the NIL material with a negative mask, i.e., a mold that has an inverse pattern of the desired pattern. After imprinting the NIL material with the mask, the pattern is formed on the NIL material, and the NIL material may then be cured and passed through additional processing steps.

Ideally, when applying the mask, an NIL material with higher flexibility (i.e., lower Young's modulus) is used, so that the application of the mask does not cause the NIL material to fracture or break, especially when the mask is removed from the NIL material. However, such a flexible material is not ideal during later processing steps. For these later processing steps, an NIL material with a high strength, and low flexibility, is desired instead. These materials may be more resilient during subsequent steps, such as curing.

Therefore, a problem exists in NIL with existing NIL material. The existing NIL material has a fixed modulus. However, during the NIL process, it is desirable to have NIL material with low modulus during the initial imprint process, but with high modulus during later post-processing steps.

SUMMARY

Embodiments relate to modifying the mechanical properties of NIL materials. An imprint mask is applied to a nano-imprint lithography (NIL) material layer to create an imprinted NIL material layer, with the NIL material layer comprised of a NIL material. The imprinted NIL material layer is detached from the imprint mask, with the modulus level of the NIL material below a flexibility threshold to cause a shape of the imprinted NIL material layer to remain unchanged after detachment. The modulus level of the NIL material of the imprinted NIL material layer is increased beyond a strength threshold to create a first imprint layer, with the imprint layer having a structure that remains unaffected by a subsequent process to form a second imprint layer matching a master mold pattern.

