Tunneling current characteristics and oxide breakdown in P+ poly gate PFET capacitors

Abstract

In this work, we investigate both tunneling current and oxide breakdown characteristics for lightly and heavily doped p+ polysilicon gates of PFET capacitors in inversion mode. It was found that tunneling currents show significantly different magnitude for the two doping conditions over the same applied gate voltages. We present experimental evidence that strongly supports electron energy, as set by the gate voltage, and electron fluence, measured as charge-to-breakdown, Q/sub BD/, as being the physical parameters that control the breakdown process, rather than oxide field and time-to-breakdown, T/sub BD/, as suggested by the thermo-chemical model.