A method for forming a tunneling layer of a nonvolatile trapped-charge memory device and the article made thereby. The method includes multiple oxidation and nitridation operations to provide a dielectric constant higher than that of a pure silicon dioxide tunneling layer but with a fewer hydrogen and nitrogen traps than a tunneling layer having nitrogen at the substrate interface. The method provides for an improved memory window in a SONOS-type device. In one embodiment, the method includes an oxidation, a nitridation, a reoxidation and a renitridation. In one implementation, the first oxidation is performed with O2 and the reoxidation is performed with NO.