Rapid formation of ultra-thin dielectrics by Si surface modification using a large area low energy electron beam

Rapid formation of ultra-thin dielectrics by Si surface modification (oxidation/renitridation/reoxidized nitrided oxides) using a low energy (<3.0 keV, dose range 0.75-3.0 C cm-2) large area e-beam, which is based on cold cathode glow discharge of secondary emission, has been performed. Ultra-thin dielectric films over a range up to 200 A were grown rapidly. Higher oxidation rate (∼ 625 A2 s-1) and renitridation for shorter irradiation time (≤ 120 s) were obtained at lower substrate temperature (∼ 7400C) in N2, O2-He gas. AES and XPS demonstrated an electron-stimulated process on Si. Identifications of AES and C-V measurement for renitrided/reoxidized nitrided oxide films have shown that during a short processing of the e-beam (60-120 s) in N2-He gas, nitrogen atoms can be incorporated in SiO2 bulk besides nitrogen being piled up at SiO2-Si interface, the shifts of C-V curves for the grown films have been also discussed. This e-beam as an alternative for rapid modification may be used to grow ultra-thin dielectric films on Si surfaces. (author)