PREVAIL-EPL alpha tool: Early results

Abstract

The IBM/Nikon alliance is developing an EPL stepper alpha tool based on the PREVAIL technology. This article provides a status report on the alliance activity with particular focus on the electron optical subsystem developed at IBM. We have previously described design features of the PREVAIL Alpha system. The state-of-the-art e-beam lithography concepts have since been reduced to practice and turned into functional building blocks of a production level lithography tool. The electron optical subsystem has been designed, built, assembled, and tested at IBM’s Semiconductor Research and Development Center (SRDC) in East Fishkill, NY. After demonstrating subsystem functionality, the column, an interim mechanical system and all associated control electronics hardware and software have been shipped during January 2001 to Nikon’s facility in Kumagaya, Japan, for integration into the Nikon commercial e-beam stepper Alpha tool. Postshipment activity has been directed primarily toward demonstrating subfield stitching, a task which exercises system architecture, calibration, stability, and noise performance.

Neutral particle lithography: a simple solution to charge-related artefacts in ion beam proximity printing

“…The Fresnel number of a mask feature, defined as F = a 2 /λg, where a is the feature size, λ is the wavelength of the exposing radiation and g is the mask-to-wafer proximity gap, provides a qualitative means for comparing diffraction conditions in different proximity lithography tools. The resolution limit is usually taken to be F = k 2 1 , where k 1 ranges from 0.6 for isolated features to 0.8 for dense line-space patterns [23]. A recent paper provides an informative example of diffraction in optical proximity lithography [24].…”

“…This has been accomplished by relentlessly shrinking the wavelength of the exposing radiation from visible light in the early years to the deep ultra-violet photons of today. This paradigm of reducing wavelength may continue with electrons [2], light ions [3] and extreme ultraviolet [4] or it may shift to imprinting techniques [5][6][7][8]. Beyond the semiconductor roadmap [9] is the domain of nanoscale integrated systems, based perhaps on magnetic, quantum-dot, nanotube or molecular devices [10][11][12][13], that could support a new generation of information processing systems, and the expansion of global productivity [14], far beyond the semiconductor era.…”