ELECTRICAL-PROPERTIES OF ULTRATHIN RTCVD OXINITRIDE FILMS IN N-CHANNEL AND P-CHANNEL MOSFETS

n and p-channel MOS transistors using ultrathin (approximate to 60 Ang strom) oxinitrides as gate dielectrics are studied. The threshold volt age, the interface trap density and the slow insulator trap densities are investigated as a function of the nitrogen concentration in the in sulator. The positive charge in the insulating layers as well as the i nterface trap density are found to increase with the nitrogen concentr ation for both device types, in agreement with the results obtained us ing other nitridation methods. The in-depth study of the oxinitride-se miconductor interface traps carried out using charge pumping measureme nts reveals that the trap profiles have the same shape as that in stat e-of-the-art MOS transistors. These profiles evidence the increase of the trap concentration in the oxinitrides, emphasizing the correlation between the interface trap density, the oxinitride positive charge an d the oxinitride trap density. The results also show that the trap den sity increases more rapidly with the nitrogen concentration in the nit rided layers than at the insulator-semiconductor interface. Finally, t he comparison with noise measurements reveals that the oxinitride trap concentrations obtained using the CP method are lower than those extr acted from noise measurements.