Turnaround of hysterisis for capacitance–voltage characteristics of hafnium oxynitride dielectrics

The capacitance–voltage (C–V) characteristics of hafnium oxynitride gate dielectrics for silicon metal-oxide-semiconductor (MOS) capacitors with different sweep voltage were investigated. It was found that, for the p-type substrate MOS capacitor, the C–V hysterisis has a turnaround characteristic as the applied voltage exceeds −3.0 V. The phenomenon is explained by electron trappings at the low electric field and hole trappings, which resulted from the impact ionization, at the high electric field in the dielectrics.