Characterization and comparison of the charge trapping in HfSiON and HfO/sub 2/ gate dielectrics

Charge trapping in HfSiON and HfO/sub 2/ gate dielectrics was studied using both DC and pulsed I/sub D/-V/sub G/ characterization techniques. The data shows a significant amount of hysteresis in HfO/sub 2/ but negligible instability in HfSiON. Constant voltage stress measurements of HfO/sub 2/ and HfSiON films show that the threshold voltage shift in HfO/sub 2/ films is as much as 10 times higher than that of HfSiON. Further, modeling of the time dependence of the threshold voltage shows that the trap capture cross section responsible for the instability of HfO/sub 2/ films is 10 times higher than the trap capture cross section of HfSiON. Our data indicate that amorphous HfSiON has better electrical stability than HfO/sub 2/.