Characterization of Threshold Voltage Shift by Negative Bias Temperature Stress in HfSiOx Films

Abstract

Threshold voltage shift by negative stress voltage application in HfSiOx films was investigated. It was found that the threshold voltage shift was summation of the voltage shifts due to interface state generation and generation of traps. It was revealed that the contribution of trap generation, which rapidly increases with small amount of hole injection, was the most influential component in a short term. In a long term, on the other hand, the trap generation which proceeds linearly with the amount of hole injection becomes the dominant component, since it does not saturate for long period.