Nanostructure fabrication using electron beam and its application to nanometer devices

Nanofabrication developed by using electron beam (EB) are described. Ten-nm structures of organic positive and negative resist patterns have been achieved by using a commercially available EB lithography system with energy of 30-50 keV. The self-developing properties of an AlF₃-doped LiF inorganic resist have been studied for sub-10-nm lithography. By optimizing the inorganic resist film quality, 5-nm linewidth patterns with 60-nm periodicity were directly delineated under a 30-keV EB. Moreover, EB-induced deposition is described as an interesting method for nanofabrication. An novel approach for nanolithography using de Broglie wave has been developed. Line and dot patterns with 100-nm periodicity were exposed on a PMMA resist by EB holography with a thermal field-emitter gun and an electron biprism. This technique allows us to produce nanoscale periodic patterns simultaneously. Furthermore, the possibility of nanostructure fabrication by atomic-beam holography has been demonstrated by using a laser-trap technique and a computer-generated hologram made by EB lithography. As applications of EB nanolithography to nanodevices, a 40-nm-gate NMOS Si device and a high-temperature-operation single-electron transistor (SET) are described