Nano-patterning is an essential part of nanotechnology research. However, in order for nano-device and nanostructure fabrication to have significant practical value, a low-cost and high-throughput nano-patterning technique is needed. Among many new emerging lithography techniques that are aimed at addressing this issue, nanoimprinting techniques are regarded as one of the most promising. While this technique has proved to be successful in nano-patterning, it can still benefit from flexibility to produce both large and small features in various combinations and distributions. On the other hand, photolithography is a well-developed process and has been pushed towards its limit to maintain its role in future microelectronic fabrication. In most cases, these next generation photolithography systems are cost-prohibitive, except for large-scale production runs. The present invention combines the processing steps of nanoimprint lithography and photolithography to provide a new technique that provides many new advantages, including the ability to pattern both large-scale and sub-micron size structures in a single step.
University of Michigan researchers developed a method for fabricating a device that consists of imprinting a mold having a protrusion against a substrate having a resist layer such that the protrusion engages the resist layer. The mold further has a mask member positioned generally adjacent the resist layer. Radiation energy is then transmitted through the mold and into the resist layer; however, the mask member substantially prevents transmission of the radiation energy therethrough, thereby defining an unexposed area in the resist layer. Once the mold is removed from the substrate, which consequently forms a first feature from nanoimprinting, the unexposed area of resist layer is removed through dissolving in a developer solution.
Applications and Advantages
- Nano-scale electronic, photonic, and biological devices where patterns of various sizes and densities are needed
- Single step procedure to produce patterns of variety of sizes