Investigation of hot carrier effects in n-MISFETs with HfSiON gate dielectric

This paper reports the hot carrier reliability of n-MISFET with HfSiON gate dielectrics and n⁺ polysilicon gate electrode. It is found that generation of electron traps is the main cause of device degradation. The worst hot carrier stress condition is found to be V_d=V_g condition rather than the well-known condition of V_g giving maximum substrate current (I_sub^max), which is the worst condition for n-MOSFET with conventional SiO₂. It is revealed that this difference originates from the difference in degradation mechanism.