Observation of selective thermal desorption of electron stimulated SiO2 with a combined scanning reflection electron microscope/scanning tunneling microscope

Selective thermal desorption (STD) of ${\mathrm{SiO}}_{\mathrm{2}}$ film of less than 1 nm thick induced by a focused electron beam has been investigated with a combined apparatus of scanning reflection electron microscope and scanning tunneling microscope. It has been found that clean Si open windows formed in the ${\mathrm{SiO}}_{\mathrm{2}}$ film by STD have atomically flat surface morphology and uniform linewidth. The surface morphology depends on electron dose, oxide film thickness, and desorption temperature. The fabrication process of Si nanowires using the STD technique has been also investigated.