FABRICATION OF SILICON NANOPILLARS CONTAINING POLYCRYSTALLINE SILICONINSULATOR MULTILAYER STRUCTURES/

A new approach to three-dimensional nanostructures is discussed-with t he goal of-fabricating vertical, ultrasmall tunneling junctions suitab le for single electron devices. Pillars consisting of multiple layers of polycrystalline silicon (polysilicon) (similar to 10 nm thick) and silicon nitride (similar to 2 nm thick) were laterally oxidized. The f abrication of vertically stacked silicon nanoislands, with dimensions on the order of 10 nm in all three directions, connected by thin silic on nitride layers, is demonstrated. The saturation of the polysilicon core diameter during the lateral pillar oxidation process is clearly o bserved, confirming the self-limiting effect for polysilicon pillars. This approach allows the fabrication of three-dimensional nanostructur es using conventional silicon processing equipment. (C) 1997 American Institute of Physics.