Charge pumping spectroscopy: HfSiON defect study after substrate hot electron injection

Spectroscopic charge pumping (CP) is used to study the evolution of the energy distribution of trapped electrons within HfSiON/SiO2 gate stacks under substrate hot electron injection (SHEI). Base level CP measurements with large pulse amplitude allow an efficient charging/discharging of traps and reaching two defect bands in the HfSiON situated at 0.40 and 0.85 eV above the Si conduction band, respectively. Unlike standard constant voltage stress (CVS), SHEI enables full control of the stress by separately controlling the applied gate field, the injected electron energy, and the fluence. During CVS, HfSiON defects at 0.40 eV are generated. Conversely, during SHEI, either the shallow or the deep defects are preferentially created depending on the gate field as well as electron energy.