Effects of optimized nitrogen tailoring in high-k dielectrics on impurity penetration and stress induced device degradation [MOSFETs]

In this work, we present the effects of nitrogen-incorporation at the top interface of HfSiON gate dielectrics on the dielectric charge trapping and time-dependent threshold voltage instability. The TSN (top silicon/nitrogen) HfSiON structure was found to be useful in confining nitrogen near the top interface, which is effective in blocking metallic impurity penetration from the gate electrode, and in improving the bottom interface layer quality and thickness control.