Low-cost interference lithography

The authors report demonstration of a low-cost ( ∼ 1000 USD) interference lithography system based on a Lloyd’s mirror interferometer that is capable of ∼ 300 nm pitch patterning. The components include only a 405 nm GaN diode-laser module, a machinist’s block, a chrome-coated silicon mirror, substr...

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Bibliographic Details
Main Authors: Fucetola, Corey P., Korre, Hasan, Berggren, Karl K.
Other Authors: Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Format: Article
Language:en_US
Published: American Vacuum Society (AVS) 2012
Online Access:http://hdl.handle.net/1721.1/73454
https://orcid.org/0000-0002-8657-8537
https://orcid.org/0000-0001-7453-9031
Description
Summary:The authors report demonstration of a low-cost ( ∼ 1000 USD) interference lithography system based on a Lloyd’s mirror interferometer that is capable of ∼ 300 nm pitch patterning. The components include only a 405 nm GaN diode-laser module, a machinist’s block, a chrome-coated silicon mirror, substrate, and double-sided carbon scanning electron microscopy (SEM) tape. The laser and the machinist’s block were assembled in a linear configuration, and to complete the system, the mirror and substrate were taped to perpendicular surfaces of the machinist’s block. Approximately 50 silicon substrates were prepared, exposed, and developed, after which some were inspected in a SEM. The associated laser spectrum was also measured, enabling calculation of the laser’s fringe visibility as it varied along the substrate surface. To compare the exposed resist pattern to the fringe visibility, the authors measured the first order diffraction efficiency as a function of position along the grating surface. Their measurements indicated that artifacts seen in both the optical spectrum and resulting grating patterns arose from the laser diode source, thus improving the source characteristics will be the topic of future work.