P.J. Renstrom’s research while affiliated with University of Minnesota, Duluth and other places

Nanoimprint lithography, a high‐throughput, low‐cost, nonconventional lithographic method proposed and demonstrated recently, has been developed and investigated further. Nanoimprint lithography has demonstrated 25 nm feature size, 70 nm pitch, vertical and smooth sidewalls, and nearly 90° corners. Further experimental study indicates that the ultimate resolution of nanoimprint lithography could be sub‐10 nm, the imprint process is repeatable, and the mold is durable. In addition, uniformity over a 15 mm by 18 mm area was demonstrated and the uniformity area can be much larger if a better designed press is used. Nanoimprint lithography over a nonflat surface has also been achieved. Finally, nanoimprint lithography has been successfully used for fabricating nanoscale photodetectors, silicon quantum‐dot, quantum‐wire, and ring transistors. © 1996 American Vacuum Society

Nanoimprint lithography, a high-throughput, low-cost, nonconventional lithographic method proposed and demonstrated recently, has been developed and investigated further. Nanoimprint lithography has demonstrated 25 nm feature size, 70 nm pitch, vertical and smooth sidewalls, and nearly 90° corners: Further experimental study indicates that the ultimate resolution of nanoimprint lithography could be sub-10 nm, the imprint process is repeatable, and the mold is durable. In addition, uniformity over a 15 mm by 18 mm area was demonstrated and the uniformity area can be much larger if a better designed press is used. Nanoimprint lithography over a nonflat surface has also been achieved. Finally, nanoimprint lithography has been successfully used for fabricating nanoscale photodetectors, silicon quantum-dot, quantum-wire, and ring transistors.

The key obstacle that prevents many nanostructures and nanodevices from becoming economically viable is the lack of a high-throughput and low-cost nanolithography method. Recently, a high-throughput and low-cost nanolithography method, imprint lithography, has been proposed and demonstrated. Here, we report new progress in imprint lithography and the first fabrication of nanodevices (such as MSM photodetectors and Si quantum wire transistors) using imprint lithography. In imprint lithography a mold with nanoscale features is first pressed into a resist film cast on a substrate to create a thickness contrast pattern in the resist. After removing the mold, an anisotropic etching process is used to transfer the pattern through the entire resist thickness by removing the remaining resist in the compressed areas

A high-throughput lithographic method with 25-nanometer resolution and smooth vertical sidewalls is proposed and demonstrated. The technique uses compression molding to create a thickness contrast pattern in a thin resist film carried on a substrate, followed by anisotropic etching to transfer the pattern through the entire resist thickness. Metal patterns with a feature size of 25 nanometers and a period of 70 nanometers were fabricated with the use of resist templates created by imprint lithography in combination with a lift-off process. With further development, imprint lithography should allow fabrication of sub-10-nanometer structures and may become a commercially viable technique for manufacturing integrated circuits and other nanodevices.

A nanoimprint process that presses a mold into a thin thermoplastic polymer film on a substrate to create vias and trenches with a minimum size of 25 nm and a depth of 100 nm in the polymer has been demonstrated. Furthermore, the imprint process has been used as a lithography process to fabricate sub‐25 nm diameter metal dot arrays of a 100 nm period in a lift‐off process. It was found that the nanostructures imprinted in the polymers conform completely with the geometry of the mold. At present, the imprinted size is limited by the size of the mold being used; with a suitable mold, the imprint process should mold sub‐10 nm structures with a high aspect ratio in polymers. The nanoimprint process offers a low cost method for mass producing sub‐25 nm structures and has the potential to become a key nanolithography method for future manufacturing of integrated circuits and integrated optics. © 1995 American Institute of Physics.