Extraction of the Si-SiO2 interface trap layer parameters in MOS transistors using a new charge pumping analysis

Using an in-depth approach for the Si-SiO₂ interface in metal-oxide-semiconductor (MOS) transistors, the parameters of the Si-SiO₂ interface trap layer can be measured. Trap depth concentration profiles are found of the form N_t(x)=N_ts exp(-x/d)+N_to. The first term corresponds to the Si-SiO ₂ interface traps and the second to the trap density in the oxide strained layer. In state-of-the-art MOS transistors, N_ts/N_to≈100 while d≈1 Å. This is achieved using a new charge pumping (CP) analysis based on the evolution of the CP current with the gate signal frequency. The distortions introduced to the profiles by the near source and drain regions of the devices, where the doping concentration is lower than in the channel, are studied. The case of RTCVD oxynitrides as gate films is also considered