A new degradation scheme for direct-tunneling ultrathin gate dielectric

A new degradation scheme for ultrathin gate dielectric is presented on the basis of gate current. By using Drain Avalanche Hot Carrier (DAHC) injection, we demonstrate for the first time that the hot-carrier induced trapping enhances the direct-tunneling gate leakage current of MOSFETs. We also show that oxynitrided dielectric exhibits a higher resistance against hot-carrier injection. Moreover, an anomalous increase was found without affecting Gm degradation trends under hot-carrier stressing. Therefore, gate current is a very important parameter in the reliability of ultrathin gate dielectric.