Electron field emission from SiC/Si heterostructures synthesized by carbon implantation using a MEVVA ion source

摘要

Planar SiC/Si heterostructures were formed by high dose carbon implantation using a metal vapor vacuum arc ion source. The variations of the field emission properties with the implant dose and annealing conditions were studied. A remarkably low turn-on field of 1 V//spl mu/m was observed from a sample implanted at 35 keV to a dose of 1.0/spl times/10/sup 18/ cm/sup -2/ with subsequent annealing in nitrogen at 1200/spl deg/C for 2 h. The chemical composition depth profiles were determined from X-ray photoelectron spectroscopy and the surface morphology was observed by atomic force microscopy. The formation of a thin surface stoichiometric SiC layer and the formation of densely distributed small protrusions on the surface are believed to be the two factors responsible for the efficient electron field emission.