  We developed a microdisplay-based microscope projection photolithography
(MDMPP) technique in which a liquid crystal (LC) microdisplay is used as a
reconfigurable photomask for a microscope projector. The LC microdisplay
provides a significant advantage in terms of cost and speed since patterns can
be generated through software instead of redesigning and fabricating glass
photomasks. The constructed MDMPP system could produce line patterns as narrow
as 2.4 um, smaller than that specified by the diffraction limit, with the aid
of a 4X objective lens. The achievement of a linewidth smaller than the
theoretical limit may be ascribed to a combination of overexposure and the
underetching effect, in addition to the good optical performance of the system.
In a diffraction experiment performed with fabricated slits, the application of
the MDMPP technique helped provide various patterns of the slits, demonstrating
the potential usefulness of the MDMPP system in undergraduate optics courses.
We expect that MDMPP can contribute to the field of physics education and
various areas of research, such as chemistry and biology, in the future.
