SELECTIVE-AREA GROWTH OF SI ON THIN INSULATING LAYERS FOR NANOSTRUCTURE FABRICATION

A new method of fabricating Si microstructures on thin insulating film s is described. It combines selective-area growth of Si with electron- beam direct patterning of a SiO2/SiNx bilayer mask. The chemical compo sition of the top SiO2 layer of the mask can be modified locally by el ectron-beam irradiation. The different chemical properties between irr adiated and nonirradiated surfaces make it possible to deposit Si only on the irradiated surface. The bottom SiNx layer is stable against el ectron-beam irradiation, and thus insulates electrically the deposited Si microstructure from the Si substrate. Selective-area growth of Si was performed by ultrahigh-vacuum chemical vapor deposition (UHVCVD).