A bilayer bottom antireflective coating (BARC) structure composed of tetraethoxysilane (TEOS) oxide and silicon nitride film stacks is demonstrated for F2 excimer laser (157 nm) lithography. The top TEOS oxide film is an NH3 contaminant-free material that can be used as an NH3 capping layer. After an oxygen plasma treatment, the bilayer structure is shown to have high thermal stability by thermal desorption spectrometry. The measured swing effect is significantly reduced by adding the bilayer BARC structure. This BARC structure could also reduce the reflectance of various highly reflective substrates to less than 2% at 157 nm.