Pinning at template feature edges for step and flash imprint lithography

We present a theory of the pinning of an air-liquid interface at the feature edge of a template during the imprint step of step and flash imprint lithography (SFIL). Pinning occurs when the pressure at the air-liquid interface reaches the pressure of the bulk liquid. At this condition, there is no pressure gradient or driving force to move the liquid and fill the feature. We examined several parameters, including residual layer thickness, wettability of the feature edge, applied force on the template, and the radius of curvature of the feature edge, to study their effect on pinning. An optimal SFIL process window and template modifications are proposed that minimize the pinning at the feature edge while still preventing any extrusion along the mesa (pattern containing area on the template) edge.