Towards in-situ device fabrication : electrostatic lithography and nanowire field effect devices

Abstract

Electron beams were used to deposit fine line-width charge in electret materials. The electrets were exposed to charged or polarizable nanoparticle precursors. These nanoparticles decorate the charge pattern. Electret materials including Mylar, Polyamide and Teflon were used for this process. Nanoparticles used ranged from carbon black, gold, silver, iron oxide, aluminum oxide and silicon oxide. Multiple nanoparticle delivery methods were employed including immersion in a nanoparticle solution, exposure to a nanoparticle aerosol, electrosprayed nanoparticles and in-situ delivery of nanoparticles. The technique was adapted to produce the fastest known electron beam resist with exposure dosage as low as 10 nC/cm2. We have termed the new resist an electrostatic resist and the technique electrostatic lithography. A novel technique to fabricate logic elements from semiconducting nanowires grown using vapor-liquid-solid mechanism was also developed. The technique involves source, drain, gate-oxide and gate material fabrication using electron beam induced chemical vapor deposition. Field effect transistor and ring oscillator architectures were fabricated using this process. Nanowires were characterized using scanning electron microscopy and transmission electron microscopy. Current-voltage measurements were performed on the nanowire field effect transistors.