Role of annealing temperature on charge storage characteristics of Au nanocrystals with HfO2 tunneling and blocking layers

In this paper, we demonstrate the fabrication and charge storage characteristics of Au nanocrystals located between two hafnium oxide films acting as the tunneling and blocking layers serving as nonvolatile memory structure. The structure, composition and electrical properties of the device are drastically affected by annealing temperature. The inter-diffusion and stoichiometric changes of various layers are investigated using X-ray Photoelectron Spectroscopy and Rutherford Backscattering Spectroscopy. Electrical measurements show an improvement in leakage characteristics with annealing. The C-V hysteresis loop with and without Au nanocrystals are compared to understand charge storage behavior of the device structures. The occurrence of well-defined hysteresis loop with Au nanocrystals indicates significant role of Au nanocrystals in charge storage characteristics of the device.