Submicrometer-gate MOSFET's by the use of focused-ion-beam exposure and a dry development technique

Resist patterns as small as 0.1 µm were fabricated by the irradiation of a gallium focused ion beam followed by an oxygen plasma development. The measured width of the patterns fabricated by this technique was in good agreement with the designed linewidth in the sub-half-micrometer region, n-channel Si MOSFET's with 0.3-0.8-µm gates were fabricated by the use of this technique. These results, accompanied by the fabricated and demonstrated performance of a ring oscillator, showed the feasibility of focused-ion-beam lithography.