Paper
14 June 1988 Practical Technologies For FIB Direct-Writing Applications
K Hosono, H Morimoto, Y Watakabe, T. Kato
Author Affiliations +
Abstract
For practical use of focused-ion-beam technology in the advanced-device fabrication, an alignment technique between an ion beam and a wafer is quite important because it restricts the overlay accuracy of patterns on a substrate. Secondary electrons generated by the ion beam irradiation are detected as a signal for registration. The detector is micro-channel-plate, which has an advantage that detected signal is not affected by the geometrical arrangement of registration marks. The marks and ion beams for the experiments are Au pedestals on the GaAs substrate, and 192keV Be++ and 260keV Si++, respectively. This type of mark can be fabricated as the same process step with the source and drain electrodes of GaAs microwave devices. The detection accuracy of the mark is defined as the distribution (3a) of the measured mark locations for a number of beam scans. The detection accuracy of 0.02μm or less for both ion beams was obtained by suppressing the effect of mark edge roughness using the data averaging of detected edge positions. The overlay accuracy, especially overlay repeatability (3a), were 0.11μm for Be++ and 0.13,μm for Si++. These suggested that this alignment technique is available for mushroom-shaped gate fabrication by a mixed exposure of Be++ and Si++. A GaAs MESFET for microwave applications has been fabricated by the direct-writing process using the mixed exposure of these ion species.
© (1988) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
K Hosono, H Morimoto, Y Watakabe, and T. Kato "Practical Technologies For FIB Direct-Writing Applications", Proc. SPIE 0923, Electron-Beam, X-Ray, and Ion Beam Technology: Submicrometer Lithographies VII, (14 June 1988); https://doi.org/10.1117/12.945635
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Cited by 1 scholarly publication.
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KEYWORDS
Silicon

Signal detection

Beryllium

Gallium arsenide

Ion beams

Overlay metrology

Ions

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