Impact of process conditions on interface and high-κ trap density studied by variable T_charge-T_discharge charge pumping (VT²CP)

Abstract

In this paper we use an improved way to measure electrical traps in Hf-based dielectrics by using Variable T_charge-T_discharge Charge Pumping (VT²CP). By independently controlling the pulse low and high level timings, we are able to clearly separate the traps in the interfacial SiO₂ from the traps in the High-κ layer, independently of the process conditions and Hf-concentration. The results show that the trap density varies by two orders of magnitude for the samples used in this work, indicating the importance of process optimization.