Miniature low-voltage electron beam columns are well suited for low cost imaging and high throughput direct-write lithography applications. Previous generations of miniature columns have demonstrated high-resolution imaging and proof-of-concept lithography. However, those columns suffered from difficult fabrication techniques and costly assembly, making them impractical for broad application. A new type of miniature electron beam column has been developed with the goal of manufacturability using bonded stacks of batch fabricated silicon lenses and glass insulators. Bulk micromachining and integrated chip fabrication techniques facilitate the fabrication of columns with precise aperture-to-aperture alignment and high aperture circularity. The lens stacks are bonded to a multilayer ceramic package with embedded interconnects. This approach enables a small package that can include buried internal and external passive and active devices, ground planes, and controlled impedance-matched lines. The package is fully scalable for continued miniaturization, and can be easily designed to accommodate 1×4 or larger modules of individually correctable columns for arrayed operation. This article presents the first lithography results with these miniature columns over a beam energy range of 0.5–2keV. Patterns were written into ∼45nm ZEP-520A resist using a raster-scan writing strategy. A nominal dose of 7μC∕cm2 yielded 90nm isolated and 180nm line-space patterns. High-resolution images resolved <35nm features.

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Silicon photodiode (SPD) detectors can be used for secondary electron detection in miniature electron beam columns, where small apertures, tight lens spacings, and short working distances make traditional detectors impractical. Monte Carlo simulations presented in this article suggest that in these configurations, SPDs have an advantage over traditional secondary electron detectors due to their potentially higher collection efficiency. Responsivity results presented here for SPDs with 40 and 60Å passivation layers show measurable responsivity for electron energies down to 80eV. High contrast images obtained using a SPD mounted with the Novelx miniature electron beam column and biased with a floating voltage to accelerate low-energy electrons demonstrate the effectiveness of SPDs for secondary electron detection. Based on these simulations and results, it is believed that SPDs present a reliable, inexpensive solution for secondary electron detection in miniature electron beam columns, as well as a robust mechanism for system calibration in column arrays for lithography.

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