Fabrication of nanometer Schottky-tunneling MOSFETs by a novel silicide nanopatterning method

Nanometer Schottky-Tunneling MOSFETs which use Schottky contacts at both the source and the drain were fabricated by a novel epitaxial CoSi2 silicide nanopatterning method. The nanopatterning process which is based on local oxidation of silicide layers, involves two key steps. First, a conventional oxidation mask of 20 nm SiO2 and 300 nm Si3N4 was deposited by plasma enhanced chemical vapor deposition on CoSi2/Si(100) and patterned by optical lithography and dry etching. Second, rapid thermal oxidation (RTO) was performed in dry oxygen. During RTO, the originally continuous silicide layer is separated near the edge of the nitride mask. Oxide formed on top of the gap and on the surface of the uncovered CoSi2. Highly uniform gaps as narrow as 50nm between the masked and the unprotected regions of the silicide layer have been fabricated for 20nm thick CoSi2 layers. N-channel Schottky-Tunneling MOSFETs with epitaxial CoSi2 Schottky contacts at source and drain were fabricated using this nanopatterning method to make the 100nm gate. The devices show good I-V characteristics at 300K.