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3-D integrations are unavoidable task for new emerging memories, including resistive switching random-access memory (RRAM), in order to overcome the market-leading nand flash. However, an RRAM crossbar array (CBA) suffers severe read margin degradation due to the sneak current, which becomes even more critical as the memory density increases with the 3-D integration. In this paper, we extend the two-port readout scheme for a 2-D CBA, proposed in our previous work, to the 3-D vertical structure. A closed-form expression of the operating principle is derived, and HSPICE simulation using a $32\times 32\times8$ vertical RRAM CBA considering practical circuit parameters verifies feasibility of the two-port scheme to the 3-D CBA. [ABSTRACT FROM AUTHOR]

A key concern for resistive-switching random access memory (RRAM) is the read noise, due to the structural, chemical, and electrical modifications taking place at the localized current path, or conductive filament (CF). Read noise typically appears as a random telegraph noise (RTN), where the current randomly fluctuates between ON and OFF levels. This paper addresses RTN in RRAM, providing physical interpretations and models for the dependence on the programming and read conditions. First, we explain the RTN dependence on the compliance current during set transition in terms of the size-dependent depletion of carriers within the CF. Then, we discuss the bias dependence of the RTN switching times and amplitude, which can be explained by Joule heating and Poole-Frenkel barrier modifications arising from the electrostatics of the RTN fluctuating center. [ABSTRACT FROM AUTHOR]