The quantum point contact (QPC) model for dielectric breakdown is used to explain the electron transport mechanism in HfO2-based resistive random access memories (ReRAM) with TiN(30 nm)\HfO2(5 nm)\Hf(10 nm)\TiN(30 nm) stacks. Based on experimental I-V characteristics of bipolar HfO2-based ReRAM, we extracted QPC model parameters related to the conduction mechanism in several devices in order to make a statistical study. In addition, we investigated the temperature effect on the conduction mechanism and compared it with the QPC model. Based on these experimental results, we show that the QPC model agrees well with the conduction behavior of HfO2-based ReRAM memory cells.

ABSTRACT:We investigate the structural and electronic properties of pure and Zr-doped PbTiO 3 crystals. The nature of atomic relaxation around the Zr impurity is studied through quantum-chemical simulations based on the Hartree-Fock theory and a periodic large unit cell model adopted within the so-called intermediate neglect of differential overlap approximation. The most stable defect configurations are predicted for different impurity concentrations. The results obtained are compared with those from other theoretical studies and a number of experimental measurements carried out on this technologically important perovskite-type crystal.

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