A comparative study of the oxide breakdown in short-channel nMOSFETs and pMOSFETs stressed in inversion and in accumulation regimes

A comparative study of oxide breakdown in short-channel nMOSFETs and pMOSFETs stressed at high voltages in inversion and in accumulation regimes is reported. We show that in all cases the breakdown location is uniformly distributed along the total channel length, indicating a uniform breakdown process independent of the dopant type in the electrodes. At low stress voltages (i.e., at operating conditions) we expect the breakdown locations to be still uniformly distributed in devices operated in inversion, while occurring preferentially in the source and drain extensions in devices operated in accumulation. Furthermore, we find that the hard oxide breakdown occurs in; the case of nMOSFETs stressed in inversion, while in all the other cases almost all the breakdowns are soft.