Challenges and progress in x-ray lithography

Abstract

X-ray lithography ͑XRL͒ is a very promising technique with the potential to be available for integrated circuit manufacturing as early as the 130 nm generation. As a result of many years of development, the technology is relatively mature. Synchrotron sources have demonstrated performance and reliability; preproduction aligners are available from multiple vendors; significant improvements are being made in mask fabrication; and high resolution imaging has been demonstrated at 100 nm and below. Established vendors already have experience with almost all of the tools that are needed, although improved performance is required for most in order to satisfy the error budgets at 130 nm and below. Significant development activities are continuing in both the United States and Japan, and numerous complex integrated circuits have been fabricated using XRL for one or more critical levels. Nonetheless, there are challenges still to be met. Among the most important are the development and commercial availability of an improved e-beam mask writer; the ability to fabricate defect-free masks satisfying the image placement and critical dimension control requirements with good yields; the stability of the masks in usage ͑including the issue of possible radiation damage͒; the ability to correct for magnification errors; and the ability to satisfy the industry's desire for a technology extendible to 70 nm ground rules. These issues are primarily manufacturing issues, as opposed to issues related to demonstrating proof-of-concept or feasibility, although demonstrating extendibility is still needed before the industry can commit to using XRL at 70 nm ground rules. Because of the existing XRL facilities and experience, effective work to address these and other issues can be accomplished in a timely manner.

Nanoscale cues regulate the structure and function of macroscopic cardiac tissue constructs

“…We thus fabricated biocompatible, PEG-based substrata with precisely controlled nanoscale topography, whose overall dimensions extended from the nanometer to centimeter scale, allowing both electrophysiological analysis and biochemical tests (e.g., the immunoblotting assays). We note that compared with other nanolithographic methods, such as electron beam lithography (27), x-ray lithography (28), and scanning probe lithography (29), the advantages of the capillary lithography-based approach used here are in its increased reproducibility, scalability, and cost effectiveness.…”

Surface plasmon polaritons maskless lithography of metal–dielectric multilayers with tunable resolution

“…Kinds of photolithography techniques have been proposed to fabricate patterns with smaller feature size, including immersion photolithography [1], extreme ultraviolet lithography [2], and soft X-ray [3]. However, the above methods are limited by the present liquid crystal materials or costly short-wavelength light sources.…”

<title>Vacuum spark point source for x-ray/EUV lithography</title>

“…1 Synchrotrons have been used as X-ray source in several lithography pilot projects. As high as 12 -16 aligners must be installed on a synchrotron, and each aligner delivers enough X-ray radiation power for lithography use.…”