A memory cell array includes a first and a second column of memory cells, a first and a second bit line, a source line and a first set of vias. The first or second bit line includes a first conductive line located on a first metal layer, and a second conductive line located on a second metal layer. The first and second conductive lines overlap a source of a transistor of a memory cell of the first column or second column of memory cells. The source line is coupled to the first and second column of memory cells. The first set of vias is electrically coupled to the first and second conductive line. A pair of vias of the first set of vias is located above where the first conductive line overlaps each memory cell of the first or second column of memory cells.

The present disclosure relates to a method and apparatus for performing a read operation of an RRAM cell, which applies a non-zero bias voltage to unselected bit-lines and select-lines to increase a read current window without damaging corresponding access transistors. In some embodiments, the method may be performed by activating a word-line coupled to a row of RRAM cells comprising a selected RRAM device by applying a first read voltage to the word-line. A second read voltage is applied to a bit-line coupled to a first electrode of the selected RRAM device. One or more non-zero bias voltages are applied to bit-lines and select-lines coupled to RRAM cells, within the row of RRAM cells, having unselected RRAM devices.

A memory cell includes a selection transistor having a control gate and a first conduction terminal connected to a variable-resistance element. The memory cell is formed in a wafer comprising a semiconductor substrate covered with a first insulating layer, the insulating layer being covered with an active layer made of a semiconductor. The gate is formed on the active layer and has a lateral flank covered with a second insulating layer. The variable-resistance element includes a first layer covering a lateral flank of the active layer in a trench formed through the active layer along the lateral flank of the gate and reaching the first insulating layer, and a second layer made of a variable-resistance material.

In the present disclosure, a non-volatile memory cell comprises a data storage unit, a selection unit and a switching unit. The data storage unit is configured to store an information bit and has a first end and a second end. The first end is coupled to a bit line. The selection unit is configured to access the data storage unit, and the selection unit has a first end coupled to a select line, a second end coupled to the second end of the data storage unit, and a third end coupled to a source line. The switching unit is configured to perform a formation operation and has a first end coupled to a forming line and a second end coupled to the second end of the data storage unit.

A read method and a write method for a memory circuit are provided, wherein the memory circuit includes a memory cell and a selector electrically coupled to the memory cell. The read method includes applying a first voltage to the selector, wherein a first voltage level of the first voltage is larger than a voltage threshold corresponding to the selector; and applying, after the applying of the first voltage, a second voltage to the selector to sense one or more bit values stored in the memory cell, wherein a second voltage level of the second voltage is constant and smaller than the voltage threshold, wherein a first duration of the applying of the first voltage is smaller than a second duration of the applying of the second voltage, wherein the second voltage is applied following the end of the first duration.

Disclosed is a resistive random access memory (RRAM) circuit and related method to limit current, or ramp voltage, applied to a source line or bitline of an RRAM array. The RRAM array has one or more source lines and one or more bitlines. A control circuit sets an RRAM cell to a low resistance state in a set operation, and resets the RRAM cell to a high resistance state in a reset operation. A voltage applied to a bitline or source line is ramped during a first time interval, held to a maximum voltage value during a second interval, and ceased after the second time interval.

An electronic device is provided to comprise a semiconductor memory unit that comprises: a substrate including active regions, which are extended in a second direction and disposed from each other in a first direction; a plurality of gates extended in the first direction and across with the active regions; a lower contact disposed in both sides of gates and coupling the active regions in the first direction; an upper contact of the lower contact overlapping with the active region out of the active regions in a side of each gate, and overlapping with the active regions in the other side of each gate; and first and second interconnection lines coupled to the upper contact, extended in the second direction, and being alternately disposed from each other in the first direction, wherein the upper contact of a side of the gates has a zigzag shape in a first oblique direction.

As disclosed herein, a memory includes an array of resistive memory cells and a voltage regulator circuit that provides a regulated voltage based on a circuit with a replica resistive storage element. The regulated voltage is applied to a mux transistor of a multiplexer of a column decoder that is used to select a particular column line of a memory array from a set of column lines to provide the proper voltage to the memory cell during a write operation to the memory cell.

According to one embodiment, a semiconductor memory device comprises a memory cell and a first circuit. The first circuit is configured to generate a write pulse based on a write command and supply a write current to the memory cell in accordance with the write pulse. The first circuit generates a first write pulse when the first circuit receives a first write command. The first circuit extends the first write pulse when the first circuit receives a second write command within a first time after reception of the first write command.

An integrated chip has an array of memory cells disposed over a semiconductor substrate and a driver circuit. The driver circuit provides the array with a read voltage that varies in relation to an approximate temperature of the memory array to ameliorate temperature dependencies in read currents. The driver circuit may vary the read voltage in an inverse relationship with temperature. The read voltage may be varied continuous or stepwise and the driver circuit may use a table lookup. Optionally, the driver circuit measures a current and modulates the read voltage until the current is within a target range. The memory cells may be multi-level phase change memory cells that include a plurality phase change element disposed between a bottom electrode and a top electrode. Modulating the read voltage to reduce temperature-dependent current variations is particularly useful for multi-level cells.