Abstract: A phase-change memory device and its firing method are provided. The firing method of the phase-change memory device includes applying a writing current to phase-change memory cells, identifying a state of the phase-change memory cells after applying the writing current, and applying a firing current, in which an additional current is added to the writing current, to the phase-change memory cells in accordance with the state.

Abstract: A phase-change random access memory (PRAM) device capable of reducing a resistance of a word line may include a plurality of main word lines of a semiconductor memory device or PRAM bent n times in a layer different from a layer in which a plurality of sub-word lines are disposed. The semiconductor memory device or PRAM may further include jump contacts for connecting the plurality of cut sub-word lines. In a PRAM device including the plurality of main word lines and the plurality of sub-word lines being in different layers, the number of jump contacts for connecting the plurality of main word lines to a transistor of a sub-word line decoder is the same in each sub-word line or the plurality of main word lines are bent several times so that a parasitic resistance on a word line and power consumption may be reduced, and a sensing margin may be increased.

Abstract: Nonvolatile memory devices include an array of variable-resistance memory cells and a write driver electrically coupled to the array. The write driver is configured to drive a bit line in the array of variable-resistance memory cells with a stair-step sequence of at least two unequal bit line voltages during an operation to program a variable-resistance memory cell in said array. This stair-step sequence of at least two unequal bit line voltages includes a precharge voltage (e.g., Vcc-Vth) at a first step and a higher boosted voltage (e.g., Vpp-Vth) at a second step that follows the first step.

Abstract: A phase-change memory device and its firing method are provided. The firing method of the phase-change memory device includes applying a writing current to phase-change memory cells, identifying a state of the phase-change memory cells after applying the writing current, and applying a firing current, in which an additional current is added to the writing current, to the phase-change memory cells in accordance with the state.

Abstract: A phase-change memory device and its firing method are provided. The firing method of the phase-change memory device includes applying a writing current to phase-change memory cells, identifying a state of the phase-change memory cells after applying the writing current, and applying a firing current, in which an additional current is added to the writing current, to the phase-change memory cells in accordance with the state.

Abstract: Nonvolatile memory devices include an array of variable-resistance memory cells and a write driver electrically coupled to the array. The write driver is configured to drive a bit line in the array of variable-resistance memory cells with a stair-step sequence of at least two unequal bit line voltages during an operation to program a variable-resistance memory cell in said array. This stair-step sequence of at least two unequal bit line voltages includes a precharge voltage (e.g., Vcc-Vth) at a first step and a higher boosted voltage (e.g., Vpp-Vth) at a second step that follows the first step.

Abstract: A phase-change random access memory (PRAM) device capable of reducing a resistance of a word line may include a plurality of main word lines of a semiconductor memory device or PRAM bent n times in a layer different from a layer in which a plurality of sub-word lines are disposed. The semiconductor memory device or PRAM may further include jump contacts for connecting the plurality of cut sub-word lines. In a PRAM device including the plurality of main word lines and the plurality of sub-word lines being in different layers, the number of jump contacts for connecting the plurality of main word lines to a transistor of a sub-word line decoder is the same in each sub-word line or the plurality of main word lines are bent several times so that a parasitic resistance on a word line and power consumption may be reduced, and a sensing margin may be increased.

Abstract: A phase-change memory device and its firing method are provided. The firing method of the phase-change memory device includes applying a writing current to phase-change memory cells, identifying a state of the phase-change memory cells after applying the writing current, and applying a firing current, in which an additional current is added to the writing current, to the phase-change memory cells in accordance with the state.