Step and flash imprint lithography: A low-pressure, room-temperature nanoimprint lithography

S&barbelow;tep and F&barbelow;lash I&barbelow;mprint L&barbelow;ithography (SFIL) is a technique that has the potential to replace photolithography for patterning resist with sub-100 nm features. SFIL is a bilayer lithographic scheme that utilizes the in situ photopolymerization of a low viscosity organosilicon monomeric fluid to replicate the topography of a template on an organic-coated substrate. The silylated relief structure is then etch transferred through the organic layer, which then can be used for subsequent processing such as additive metalization or device etch.; Several key aspects of the SFIL process have been investigated. Several means of fluid delivery have been evaluated and compression of multiple droplets has been determined to be the most consistent with high volume manufacturing requirements. The surface energies of the SFIL materials have been tailored to allow for preferential separation at the template-photopolymer interface. The mechanical properties and densification induced by photopolymerization have been studied as a function of photopolymer composition. The current photopolymer shrinks 9.3% (v/v) and has an elastic modulus of 4.2 MPa. Based on these experimentally determined properties and finite element simulation, the in-plane motion of replicated patterns was determined to be insignificant and that the effect of the densification manifests itself mainly in the direction normal to the substrate surface.; The photopolymer has been tailored to provide an O₂ reactive ion etch selectivity greater than 10:1 with respect to an underlying organic film. Exploiting this selectivity, features with an aspect ratio of 14:1 were produced and high aspect ratio features have been printed over non-flat surfaces. The SFIL process has been successfully applied to optoelectronic structures such as micropolarizer arrays, and its resolution appears to be limited only by the size of the structures that can be created on the template. The Step and Flash Imprint Lithography process has been proven to be a high-resolution technique capable of patterning a wide variety of substrate at room temperature under low applied pressure in a fashion consistent with high volume manufacturing requirements.