Disclosed is a nonvolatile memory device using a variable resistive element, and a data read circuit for use in variable resistive memory devices. More specifically, embodiments of the invention provide a data read circuit with one or more decoupling units to remove noise from one or more corresponding control signals. For instance, embodiments of the invention remove noise from a clamping control signal, a read bias control signal, and/or precharge signal. The disclosed decoupling units may be used alone or in any combination. Embodiments of the invention are beneficial because they can increase sensing margin and improve the reliability of read operations in memory devices with variable resistive elements.

A phase change memory device includes: a semiconductor substrate having active areas; a pair of word lines formed over the active areas and connected with each other at each end thereof; source areas formed in the respective active areas at both sides of the pair of word lines; drain areas formed in the respective active areas between the word lines of the pair of word lines connected with each other at each end thereof; ground lines and cell selection lines formed so as to make contact with the respective source areas respectively; lower electrodes formed so as to make contact with the drain areas; phase change layers and upper electrodes stacked over the respective lower electrodes; and bit lines formed over upper portion of the active areas so as to make contact to the upper electrodes.

A programmable resistance memory element comprising a dielectric material between a programmable resistance memory material and a threshold switching material.

A circuit for accessing a chalcogenide memory array is disclosed. The chalcogenide memory array includes multiple subarrays with rows and columns formed by chalcogenide storage elements. The chalcogenide memory array is accessed by discrete read and write circuits. Associated with a respective one of the subarrays, each of the write circuits includes an independent write 0 circuit and an independent write 1 circuit. Also associated with a respective one of the subarrays, each of the read circuits includes a sense amplifier circuit. In addition, a voltage level control module is coupled to the read and write circuits to ensure that voltages across the chalcogenide storage elements within the chalcogenide memory array do not exceed a predetermined value during read and write operations.