Correlation of electrical properties with interface structures of CVD oxide-based oxynitride tunnel dielectrics

We compare the electrical properties and interface characteristics in terms of nitrogen depth distribution and hydrogen diffusion behavior of two CVD oxide tunnel films that were nitrided by NO and N
₂
O gas, respectively. The N
₂
O-oxynitride shows a stronger resistance against the approach of the SiO
₂
/Si interface by diffusing hydrogen in nuclear reaction analysis. This H diffusion behavior correlates with a characteristic N distribution in the tunnel oxide. The superior electrical quality of N
₂
O-oxynitride over the NO-oxynitride is attributed to the existence of a N-rich H-diffusion barrier layer in the front of the oxynitride/Si interface.