Improved performance of Au nanocrystal nonvolatile memory by N2-plasma treatment on HfO2 blocking layer**Project supported by the High Level Talent Project of Xiamen University of Technology, China (Grant Nos. YKJ16012R and YKJ16016R) and the National Natural Science Foundation of China (Grant No. 51702271).

Abstract

The N2-plasma treatment on a HfO2 blocking layer of Au nanocrystal nonvolatile memory without any post annealing is investigated. The electrical characteristics of the MOS capacitor with structure of Al–TaN/HfO2/SiO2/p-Si are also characterized. After N2-plasma treatment, the nitrogen atoms are incorporated into HfO2 film and may passivate the oxygen vacancy states. The surface roughness of HfO2 film can also be reduced. Those improvements of HfO2 film lead to a smaller hysteresis and lower leakage current density of the MOS capacitor. The N2-plasma is introduced into Au nanocrystal (NC) nonvolatile memory to treat the HfO2 blocking layer. For the N2-plasma treated device, it shows a better retention characteristic and is twice as large in the memory window than that for the no N2-plasma treated device. It can be concluded that the N2-plasma treatment method can be applied to future nonvolatile memory applications.