Electron-Beam-Induced Selective Thermal Decomposition of Ultrathin SiO₂ Layers Used in Nanofabrication

We used ultrathin SiO 2 layers less than 1 nm thick for nanofabrication. In this method, nanometer-scale patterning onto the oxide layers was achieved by electron-beam (EB)-irradiation and subsequent thermal heating (EB-induced selective thermal decomposition). We examined the delineation mechanism by using scanning reflection electron microscopy (SREM), and Auger electron and X-ray photoelectron spectroscopy (AES and XPS). We found that the change in the oxide layer composition caused by electron-stimulated oxygen desorption (ESD) from the oxide layers accounted for the selective thermal decomposition, by which nanometer-scale voids were densely generated.