Step-and-flash imprint lithography (S-FIL) is a leading candidate as the next-generation lithographic technique for replicating sub-10-nm features. The success of this technique is largely connected to the proper control of the interface formation and separation during the imprinting process. In particular, the release process of the imprinted layer from the master template is not straightforward. During release, the path of interface separation must follow precisely the complex topography of geometric features on the sub-100-nm length scale. While the issue of release is currently being addressed, more work is required to understand the underlying mechanisms in controlling release to increase the robustness of this technique in order to make it industrially. viable. In this article, the authors describe a metrology for quantifying release in S-FIL. They show that the surface property and the elastic modulus of the template material control the release characteristics. They demonstrate that substituting the rigid template with a soft, elastomeric template can drastically lower the separation force necessary for release. (c) 2006 American Vacuum Society.