Special reliability features for Hf-based high-/spl kappa/ gate dielectrics

Several special reliability features for Hf-based high-/spl kappa/ gate dielectrics are highlighted, including: 1) trapping-induced threshold voltage (V/sub th/) shift is much more of a concern than TDDB in determining the operating lifetime; 2) n-channel MOSFETs (nMOSFETs) are more vulnerable than p-channel MOSFETs (pMOSFETs); and 3) MOSFETs with polySi gates are more vulnerable than those with metal gates. These will be discussed in the context of existing electron/hole traps and trap generation by high-field stress. A novel technique to probe traps in ultrathin gate dielectrics, inelastic electron tunneling spectroscopy (IETS), will be shown to be capable of revealing the energies and locations of traps in high-/spl kappa/ gate dielectrics.