The constitution of nitrided oxides and reoxidized nitrided oxides on silicon

Chemical analysis has been made of 361-Å thermal oxide films nitrided in ammonia and also subsequently reoxidized in oxygen at 1000 °C, using techniques of ellipsometry and infrared spectrometry. The nitrided film is shown to have a three-layer structure consisting of 22 Å of 48% nitrogen, 334 Å of 17% nitrogen, and 7.4 Å of 100% nitrogen, where the fractions refer to % N/(N+O). After oxidation, the interface layer was unchanged and the surface merged into the bulk, the nitrogen content of which was reduced to 11%. The void content has also been determined.