Investigation of random telegraph noise characteristics of Hf-based MONOS nonvolatile memory devices with HfO2 and HfON tunneling layers

Abstract

Abstract This paper investigates the low-frequency noise (LFN) utilizing 1/f noise and random telegraph noise (RTN) characteristics of Hf-based metal/oxide/nitride/oxide/silicon (MONOS) nonvolatile memory devices with HfO2 and HfON tunneling layers (TLs). The LFN spectral density (S I D ) was investigated to evaluate the interface characteristics before and after programming/erasing cycles of 104. The devices show similar slopes of ∼1/f in all frequency regions. Although the HfON TL shows high S I D compared to the HfO2 TL, the increased ratio is 10 which is low compared to the HfO2 TL ratio of 32. As the channel length is decreased from 10 to 2 μm, the HfON TL shows a low increased ratio of S I D . Due to the nitrided characteristics, the HfON TL suppresses the degradation of the interface. Finally, it was found that the trap sites of the HfO2 TL are located near the interface by RTN measurement with the capture (τ C) and emission (τ E) time constants.