Abstract: An MRAM device comprises an insulating interlayer comprising a flat first upper surface on a first region and a second region of a substrate. A pattern structure comprising pillar-shaped magnetic tunnel junction (MTJ) structures and a filling layer pattern between the MTJ structures is formed on the insulating interlayer of the first region. The pattern structure comprises a flat second upper surface that is higher than the first upper surface. Bit lines are formed on the pattern structure that contact top surfaces of the MTJ structures. An etch-stop layer is formed on the pattern structure between the bit lines of the first region and the first upper surface of the first insulating interlayer of the second region. A first portion of an upper surface of the etch-stop layer on the first region is higher than a second portion of the upper surface of the etch-stop layer on the second region.

Abstract: A semiconductor device includes a first semiconductor layer extending in a first direction on a substrate, a plurality of second semiconductor layers spaced apart in the first direction on the first semiconductor layer, and an insulation layer structure surrounding side walls of the first semiconductor layer and the plurality of second semiconductor layers. The first semiconductor layer may have a first conductivity type, and the plurality of second semiconductor layers may have a second conductivity type.

Abstract: A semiconductor device with buried word line structures and methods of forming the semiconductor device are provided. The semiconductor device includes a plurality of insulating line patterns extending in a direction in a substrate, a plurality of word lines alternately with ones of the plurality of insulating line patterns, the plurality of word lines extending in the direction and comprising a metal, a plurality of first doped regions on respective ones of the plurality of the word lines and between two adjacent ones of the plurality of insulating line patterns, an interlayer insulating film on the plurality of insulating line patterns and the plurality of first doped regions, the interlayer insulating film including a plurality of openings exposing upper surfaces of ones of the plurality of first doped regions and a plurality of second doped regions contacting respective ones of the plurality of first doped regions within the openings.

Abstract: Provided are a method of forming a contact and a method of manufacturing a phase change memory device using the same. The method of forming a contact includes forming on a substrate an insulating layer pattern having first sidewalls extending in a first direction and second sidewalls extending in a second direction perpendicular to the first direction and which together delimit contact holes, forming semiconductor patterns in lower parts of the contact holes, forming isolation spacers on the semiconductor pattern and side surfaces of the first sidewalls to expose portions of the semiconductor patterns, and etching the exposed portions of the semiconductor patterns using the isolation spacers as a mask to divide the semiconductor patterns into a plurality of finer semiconductor patterns.

Abstract: A semiconductor device includes a first semiconductor layer extending in a first direction on a substrate, a plurality of second semiconductor layers spaced apart in the first direction on the first semiconductor layer, and an insulation layer structure surrounding side walls of the first semiconductor layer and the plurality of second semiconductor layers. The first semiconductor layer may have a first conductivity type, and the plurality of second semiconductor layers may have a second conductivity type.

Abstract: A semiconductor device with buried word line structures and methods of forming the semiconductor device are provided. The semiconductor device includes a plurality of insulating line patterns extending in a direction in a substrate, a plurality of word lines alternately with ones of the plurality of insulating line patterns, the plurality of word lines extending in the direction and comprising a metal, a plurality of first doped regions on respective ones of the plurality of the word lines and between two adjacent ones of the plurality of insulating line patterns, an interlayer insulating film on the plurality of insulating line patterns and the plurality of first doped regions, the interlayer insulating film including a plurality of openings exposing upper surfaces of ones of the plurality of first doped regions and a plurality of second doped regions contacting respective ones of the plurality of first doped regions within the openings.

Abstract: Provided are a method of forming a contact and a method of manufacturing a phase change memory device using the same. The method of forming a contact includes forming on a substrate an insulating layer pattern having first sidewalls extending in a first direction and second sidewalls extending in a second direction perpendicular to the first direction and which together delimit contact holes, forming semiconductor patterns in lower parts of the contact holes, forming isolation spacers on the semiconductor pattern and side surfaces of the first sidewalls to expose portions of the semiconductor patterns, and etching the exposed portions of the semiconductor patterns using the isolation spacers as a mask to divide the semiconductor patterns into a plurality of finer semiconductor patterns.

Abstract: In a method of forming a pattern, a first mask layer and a first sacrificial layer may be sequentially formed on an object layer. The first sacrificial layer may be partially etched to form a first sacrificial layer pattern. A second sacrificial layer pattern may be formed on the first mask layer. The second sacrificial layer pattern may enclose a sidewall of the first sacrificial layer pattern. The first sacrificial layer pattern may then be removed. The first mask layer may be partially etched using the second sacrificial layer pattern as an etching mask to form a first mask layer pattern. The object layer may be partially etched using the first mask layer pattern as an etching mask.

Abstract: A memory device comprises a plurality of memory cells, each memory cell comprising a memory cell material that has an initial resistance that is determined in response to an applied programming current in a programming operation, the resistance of the memory cell varying from the initial resistance over a time period following the programming operation, and each memory cell being connected to a conduction line of the memory device that is used to apply the programming current to program the resistance of the corresponding memory cell in the programming operation and that is used to apply a read current to read the resistance of the corresponding memory cell in a read operation. A modification circuit modifies the resistance of a memory cell of the plurality of memory cells selected for a read operation to return its resistance to near the initial resistance prior to a read operation of the memory cell.

Abstract: A memory device comprises a plurality of memory cells, each memory cell comprising a memory cell material that has an initial resistance that is determined in response to an applied programming current in a programming operation, the resistance of the memory cell varying from the initial resistance over a time period following the programming operation, and each memory cell being connected to a conduction line of the memory device that is used to apply the programming current to program the resistance of the corresponding memory cell in the programming operation and that is used to apply a read current to read the resistance of the corresponding memory cell in a read operation. A modification circuit modifies the resistance of a memory cell of the plurality of memory cells selected for a read operation to return its resistance to near the initial resistance prior to a read operation of the memory cell.

Abstract: A memory device comprises a plurality of memory cells, each memory cell comprising a memory cell material that has an initial resistance that is determined in response to an applied programming current in a programming operation, the resistance of the memory cell varying from the initial resistance over a time period following the programming operation, and each memory cell being connected to a conduction line of the memory device that is used to apply the programming current to program the resistance of the corresponding memory cell in the programming operation and that is used to apply a read current to read the resistance of the corresponding memory cell in a read operation. A modification circuit modifies the resistance of a memory cell of the plurality of memory cells selected for a read operation to return its resistance to near the initial resistance prior to a read operation of the memory cell.

Abstract: A method of forming a phase change memory device includes forming a core pattern on a substrate, conformally forming a heat conductive layer on the substrate including the core pattern, anisotropically etching the heat conductive layer down to a top surface of the core pattern to form a heat electrode surrounding a sidewall of the core pattern, and forming a phase change memory pattern connected to a top surface of the heat electrode.

Abstract: A semiconductor device includes an insulating layer on a substrate, a first electrode in the insulating layer having a first upper surface and a second upper surface, a second electrode in the insulating layer spaced apart from the first electrode by a first distance and having a third upper surface and a fourth upper surface, the third upper surface being disposed at a substantially same level as the first upper surface, and the fourth upper surface being disposed at a substantially same level as the second upper surface, a first phase change material pattern covering a part of the first upper surface of the first electrode, and a second phase change material pattern covering a part of the third upper surface of the second electrode, wherein an interface region between the second phase change pattern and the second electrode is spaced apart from an interface region between the first phase change pattern and the first electrode by a second distance greater than the first distance.

Abstract: In a memory device and in a method of programming the same, a memory device comprises: a plurality of memory cells, each memory cell comprising a resistance-changeable material that has an initial resistance that is determined in response to an applied programming current in a programming operation; and a modification circuit that modifies the resistance of the memory cell following a programming operation of the memory cell to vary the resistance of the memory cell from the initial resistance to a second resistance by applying a saturation current in a saturation operation. Each memory cell is connected to a conduction line of the memory device that is used to apply the programming current to program the resistance of the corresponding memory cell in the programming operation, that is used to apply the saturation current to the corresponding memory cell in the saturation operation and that is used to apply a read current to read the resistance of the corresponding memory cell in a subsequent read operation.

Abstract: In a method of controlling resistance drift in a memory cell of a resistance-changeable material memory device, the resistance changeable material in the memory cell is treated so that a drift parameter for the memory cell is less than about 0.18, wherein a change in resistance of a memory cell over the time period is determined according to the relationship: Rdrift=Rinitial×t?; where Rdrift represents a final resistance of the memory cell following the time period, Rinitial represents the initial resistance of the memory cell following the programming operation, t represents the time period; and ? represents the drift parameter.

Abstract: A semiconductor device includes an insulating layer on a substrate, a first electrode in the insulating layer having a first upper surface and a second upper surface, a second electrode in the insulating layer spaced apart from the first electrode by a first distance and having a third upper surface and a fourth upper surface, the third upper surface being disposed at a substantially same level as the first upper surface, and the fourth upper surface being disposed at a substantially same level as the second upper surface, a first phase change material pattern covering a part of the first upper surface of the first electrode, and a second phase change material pattern covering a part of the third upper surface of the second electrode, wherein an interface region between the second phase change pattern and the second electrode is spaced apart from an interface region between the first phase change pattern and the first electrode by a second distance greater than the first distance.

Abstract: A method of fabricating a semiconductor device includes forming a conductive layer on a semiconductor substrate, forming an insulating layer on the conductive layer, forming a word line and isolation trenches by patterning the insulating layer and the conductive layer, forming an isolation layer that fills the isolation trenches, forming a cell contact hole in the insulating layer such that the cell contact hole is self-aligned with the word line and exposes the word line, and forming a cell diode in the cell contact hole.

Abstract: A method of forming a phase change memory device includes forming a core pattern on a substrate, conformally forming a heat conductive layer on the substrate including the core pattern, anisotropically etching the heat conductive layer down to a top surface of the core pattern to form a heat electrode surrounding a sidewall of the core pattern, and forming a phase change memory pattern connected to a top surface of the heat electrode.

Abstract: In a memory device and in a method of programming the same, a memory device comprises: a plurality of memory cells, each memory cell comprising a resistance-changeable material that has an initial resistance that is determined in response to an applied programming current in a programming operation; and a modification circuit that modifies the resistance of the memory cell following a programming operation of the memory cell to vary the resistance of the memory cell from the initial resistance to a second resistance by applying a saturation current in a saturation operation. Each memory cell is connected to a conduction line of the memory device that is used to apply the programming current to program the resistance of the corresponding memory cell in the programming operation, that is used to apply the saturation current to the corresponding memory cell in the saturation operation and that is used to apply a read current to read the resistance of the corresponding memory cell in a subsequent read operation.

Abstract: In a method of controlling resistance drift in a memory cell of a resistance-changeable material memory device, the resistance changeable material in the memory cell is treated so that a drift parameter for the memory cell is less than about 0.18, wherein a change in resistance of a memory cell over the time period is determined according to the relationship: Rdrift=Rinitial×t?; where Rdrift represents a final resistance of the memory cell following the time period, Rinitial represents the initial resistance of the memory cell following the programming operation, t represents the time period; and ? represents the drift parameter.