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LED‐based light sources utilizing novel light‐recycling cavities have been developed that have small output etendue. A portion of the light emitted by the LED source is recycled back to the LEDs to enhance both the average brightness of the source and the brightness of the cavity output. Experimentally, we have achieved brightness enhancement factors of approximately 1.3x–2.0x.

193nm lithography is a promising candidate for the fabrication of microelectronic devices at the l3Onm design rule and below. With smaller feature sizes, below l3Onm, reduced resist thickness is essential because of the pattern collapse issues at high aspect ratios and the limited depth of focus with 193nm lithography tools. However, ArF resists have shown problems with etch selectivity, especially with the thin resist layers necessary. Additionally, pattern slimming during CD-SEM measurement, due to the nature of the resist chemistry, is an issue with feature stability after patterning.At present, many studies have been performed for improving the etch selectivity of resists and addressing line slimming issues. In this study, the electron beam stabilization process has been applied for improving the etch selectivity of resist patterns having an aspect ratio less than 3.0. The electron beam stabilization has been applied to two different ArF resist types; acrylate and cyclic-olefin-maleicanhydride (COMA), which have been evaluated with respect to materials properties, etch selectivity, and line slimming performance as a function of electron beam dose and etch condition.Film shrinkage and the change in index of refraction were monitored as a function of stabilization condition. The chemical properties were characterized before and after electron beam stabilization using FTIR analysis. Blanket resist etch rate studies were performed as a function of stabilization condition for each resist type. Cross-sectional views of resist patterns after etch processing were also investigated to evaluate the improvement in etch resistance provided by the electron beam process. CD SEM measurements were performed to evaluate the impact of the stabilization process on the patterned features. The issue of line slimming has also been evaluated, with and without electron beam stabilization, for the different ArF resist materials considered. The results were compared with a KrF resist currently used in production. Based on the experimental results, the electron beam process provides a method for improving etch selectivity and reducing line slimming issues of ArF resists.

A new large-area electron-beam source which can operate continuously, stably, and indefinitely in a poor vacuum environment is described. This novel electron source produces a near monoenergetic electron beam which can uniformly expose large area substrates (i.e., 200 mm diam wafers and larger flat panel displays). The electron gun incorporates a cold cathode which is impervious to solvents and outgassing from irradiated polymer coatings. Unlike glow discharge electron sources, the accelerating voltage can be controlled independently of the emission current from the electron gun with a small bias voltage to a grid anode. Accelerating voltages of 1–60 keV and higher are possible. The principles of operation and performance characteristics of this new source are described, including its ability to expose insulating samples without requiring a conductive overcoat. This new electron source has enabled a number of new process innovations in photoresist stabilization, interlayer dielectric curing, lift-off processing, and pattern lithography.