Thin stacked SiO2/Si3N4/SiO2 (ONO) films have been fabricated for the first time using in situ multiple step rapid thermal processing chemical vapor deposition (RTP‐CVD). Stacked Si3N4/SiO2 (NO) layers were deposited in situ by RTP‐CVD. Some samples received an in situ rapid thermal oxidation immediately after stacked layer deposition to form oxide/nitride/oxide stacked layers. These films were characterized by ellipsometry, Fourier transform infrared spectroscopy, x‐ray photoelectron spectroscopy, and Auger electron spectroscopy. Results show that well‐defined Si3N4/SiO2 and Six Ny Oz /Si3N4/SiO2 stacked layers have been formed.