High quality ultra-thin (4 nm) gate oxide by UV/O/sub 3/ surface pre-treatment of native oxide

A significant improvement in ultra-thin (4 nm) gate oxide quality has been carried out using UV/O/sub 3/ pre-treatment of native oxide before thermal oxidation. UV/O/sub 3/ pre-treatment makes native oxide dense and close-packed without leaving any residue species. Ultra-thin gate oxide formed by UV/O/sub 3/ pre-treatment and O/sub 3/ oxidation has been found to have excellent behavior, low leakage current, low surface state density, and superior dielectric breakdown characteristics. UV/O/sub 3/ pre-treatment looks promising for using in ultra-thin gate oxidation necessary for 0.1 /spl mu/m ULSI fabrication.