Papers by Keyword: Nonvolatile Memory

Abstract: In this paper, we have investigated the threshold voltage (V_TH) control of metal-oxide-nitride-oxide-Si (MONOS) nonvolatile memory (NVM) with high-k HfN/HfO₂ stacked layers for analog memory application. The Si surface atomically flattening was found to significantly improve the V_TH controllability of the MONOS NVM with high-k HfN/HfO₂ stacked layers. The multi-level-cell (MLC) operation by controlling the program voltage at the source and drain was demonstrated utilizing MONOS NVM with high-k HfN/HfO₂ stacked layers.

Abstract: In this work, we study the resistive switching behavior of a new model metal/insulator/metal (MIM) junction. The MIM junction consists of titanium front electrode, zinc oxide insulation layer and molybdenum back electrode. The Ti/ZnO/Mo structure was prepared on 3x3 cm² soda lime glass substrates using dc magnetron sputtering for metal electrodes and rf magnetron sputtering for ZnO layer. The thicknesses of Ti, ZnO and Mo films were controlled at 200nm, 50nm and 500nm, respectively. The crystalline structure and microstructure of the films were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM). The current-voltage (I-V) characteristics of the device cells were obtained by using dc voltage sweep mode. The XRD spectra of the devices show Mo(100) and ZnO(002) preferred orientations. The Mo and ZnO film surfaces exhibit dense crystallized grains with the root mean square roughness (RMS) of 1.0 and 1.4 nm, respectively. The device cells behave unipolar resistive switching characteristics with reversible, controllable and reliability within 150 cycles. The difference between high resistive state (HRS) and low resistive state (LRS) is about 10³ times. A low operating voltage range of 0.50-0.60V is obtained for switching from HRS to LRS at a current compliance of 10mA. The new MIM structure was demonstrated and suggested a potential to use as nonvolatile memory application.