Time-dependent dielectric breakdown of HfAlOx/SiON gate dielectric

The breakdown characteristics of HfAlOx/SiON layered gate dielectrics were investigated. In the case of nCap accumulation or pFET inversion, the majority carrier type is hole and the time to breakdown (T/sub BD/) under constant voltage stress (CVS) is determined by the SiON breakdown. In the case of pCap accumulation or nFET inversion, the gate current and breakdown voltage is limited by the SiON, while the T/sub BD/ is determined by the HfAlOx breakdown. The incident electron energy is found to be an important factor on the T/sub BD/ distribution.