Devices and methods for pattern generation by ink lithography

Abstract

The present invention provides methods, devices and device components for fabricating patterns on substrate surfaces, particularly patterns comprising structures having microsized and / or nanosized features of selected lengths in one, two or three dimensions and including relief and recess features with variable height, depth or height and depth. Composite patterning devices comprising a plurality of polymer layers each having selected mechanical and thermal properties and physical dimensions provide high resolution patterning on a variety of substrate surfaces and surface morphologies. Gray-scale ink lithography photomasks for gray-scale pattern generation or molds for generating embossed relief features on a substrate surface are provided. The particular shape of the fabricated patterned can be manipulated by varying the three-dimensional recess pattern on an elastomeric patterning device which is brought into conformal contact with a substrate to localize patterning agent to the recess portion of the pattern.

Description

[0001] Cross References to Related Applications [0002] This application claims the benefit of US Provisional Patent Application 60 / 863,248, filed October 27, 2006, and US Nonprovisional Patent Application 11 / 675,659, filed February 16, 2007, both of which are incorporated herein by reference in their entirety. Background of the invention [0003] The design and fabrication of micron-scale structures and devices has enormous implications for a variety of important technologies, including microelectronics, optoelectronics, microfluidics, and microsensing. For example, the ability to fabricate micron-sized electronic devices has revolutionized the field of electronics, resulting in faster and higher performing electronic components with significantly less energy requirements. As these technologies continue to advance at a rapid pace, it has become increasingly apparent that further gains will be realized by developing the ability to manipulate and organize matter at the nanosca...

AI Technical Summary

Problems solved by technology

While nanolithography offers viable methods for fabricating nanoscale structures and devices, these methods have certain limitations that prevent their practical integration into commercial methods that can provide low-cost, high-volume processing of nanomaterials

First, nanolithography methods require elaborate and expensive steppers or writing tools to direct light, electrons and / or ions onto the photoresist surface

Second, these methods are limited to patterning a very narrow range of specialized materials and are not suitable for introducing specific chemical functionalities into nanostructures

Third, conventional nanolithography is limited to the fabrication of nanoscale features on small areas of ultra-flat rigid surfaces, making them less suitable for patterning glass, carbon, and plastic surfaces

[0013] While the use of conventional composite templates and molds has somewhat improved the performance of soft lithography methods for generating features with dimensions in the sub-100nm range, these techniques are still susceptible to several issues that prevent their Efficient commercial application for high-throughput fabrication of microscale and nanoscale devices

First, some conventional template and mold designs have limited flexibility such that good conformal contact with distorted or rough surfaces is not possible

Second, the relief pattern of conventional multi-material PDMS templates is susceptible to unwanted shrinkage during thermal or UV curing, which distorts the relief pattern on the transfer surface of this template

Third, the use of conventional composite templates comprising multiple layers with different coefficients of thermal expansion can lead to distortion of the relief pattern and curvature of the transfer surface of the template due to temperature changes

Fourth, the use of hard and / or brittle backing layers, such as glass and certain metal layers, makes conventional composite stencils difficult to incorporate into existing commercial printing configurations, such as roll and flexo press configurations

Especially after complex processes on plastic substrates, unexpected misfits due to thermal expansion or residual tension make precise alignment impossible

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