Abstract: Provided are a nonvolatile memory device and a method of manufacturing the same. A floating gate electrode of the nonvolatile memory device may have a cross-shaped section as taken along a direction extending along a control gate electrode. The floating gate electrode may have an inverse T-shaped section as taken along a direction extending along an active region perpendicular to the control gate electrode. The floating gate electrode may include a lower gate pattern, a middle gate pattern and an upper gate pattern sequentially disposed on a gate insulation layer, in which the middle gate pattern is larger in width than the lower gate pattern and the upper gate pattern. A boundary between the middle gate pattern and the upper gate pattern may have a rounded corner.

Abstract: A semiconductor memory device can include select transistors and cell transistors on a semiconductor substrate. An insulation layer covers the select transistors and the cell transistors. The bit lines are in the insulation layer and are electrically connected to respective ones of the select transistors. The bit lines are arranged along at least two different parallel planes having different heights relative to the semiconductor substrate.

Abstract: Example embodiments relate to methods of fabricating a non-volatile memory device. According to example embodiments, a method of fabricating a non-volatile memory device may include forming at least one gate structure on an upper face of a substrate. The at least one gate structure may include a tunnel insulation layer pattern, a charge storing layer pattern, a dielectric layer pattern and a control gate. According to example embodiments, a method of fabricating a non-volatile memory device may also include forming a silicon nitride layer on the upper face of the substrate to cover the at least one gate structure, forming an insulating interlayer on the silicon nitride layer on the upper face of the substrate, and providing an annealing gas toward the upper face of the substrate and a lower face of the substrate to cure defects of the tunnel insulation layer pattern.

Abstract: A flash memory device includes a cell string having a plurality of cell transistors connected in series, and a string selection transistor and a ground selection transistor connected to both ends of the cell string, respectively, wherein the cell transistor has a channel impurity concentration higher than a channel impurity concentration of at least one of the string selection transistor and the ground selection transistor.

Abstract: A nonvolatile memory device includes a string selection gate and a ground selection gate on a semiconductor substrate, and a plurality of memory cell gates on the substrate between the string selection gate and the ground selection gate. First impurity regions extend into the substrate to a first depth between ones of the plurality of memory cell gates. Second impurity regions extend into the substrate to a second depth that is greater than the first depth between the string selection gate and a first one of the plurality of memory cell gates immediately adjacent thereto, and between the ground selection gate and a last one of the plurality of memory cell gates immediately adjacent thereto. Related fabrication methods are also discussed.

Abstract: A semiconductor memory device can include select transistors and cell transistors on a semiconductor substrate. An insulation layer covers the select transistors and the cell transistors. The bit lines are in the insulation layer and are electrically connected to respective ones of the select transistors. The bit lines are arranged along at least two different parallel planes having different heights relative to the semiconductor substrate.

Abstract: A flash memory device includes a cell string having a plurality of cell transistors connected in series, and a string selection transistor and a ground selection transistor connected to both ends of the cell string, respectively, wherein the cell transistor has a channel impurity concentration higher than a channel impurity concentration of at least one of the string selection transistor and the ground selection transistor.

Abstract: A method of fabricating a flash memory device using a process for forming a self-aligned floating gate is provided. The method comprises forming mask patterns on a substrate, etching the substrate using the mask patterns as an etch mask to form a plurality of trenches, and filling the trenches with a first insulating layer, wherein sidewalls of the mask patterns remain exposed after filling the trenches with the first insulating layer. The method further comprises forming spacers on the exposed sidewalls of the mask patterns, filling upper insulating spaces with a second insulating layer thereby defining isolation layers, and removing the mask patterns and the spacers.

Abstract: A NAND type flash memory device includes a semiconductor substrate, word lines, first and second selection lines, tunnel insulation layers, and selection gate insulation layers. The semiconductor substrate includes a memory transistor region and a selection transistor region. The word lines are arranged in the memory transistor region of the semiconductor substrate, and the selection lines are arranged in the selection transistor region of the semiconductor substrate. The tunnel insulation layers are interposed between the word lines and the semiconductor substrate, and the selection gate insulation layers are interposed between the selection lines and the semiconductor substrate and have a thinner thickness than the thickness of the tunnel insulation layers. Also, the selection gate insulation layers have a thinner thickness in their center region than in their edge portions.

Abstract: Embodiments of the invention provide a semiconductor device and a related method of fabricating a semiconductor device. In one embodiment, the invention provides a semiconductor device comprising a first gate electrode comprising a lower silicon pattern and an upper silicon pattern and disposed on an active region of a semiconductor substrate, wherein the upper silicon pattern has the same crystal structure as the lower silicon pattern and the active region is defined by a device isolation layer. The semiconductor device further comprises a gate insulating layer disposed between the active region and the first gate electrode.

Abstract: Provided are a nonvolatile memory device and a method of manufacturing the same. A floating gate electrode of the nonvolatile memory device may have a cross-shaped section as taken along a direction extending along a control gate electrode. The floating gate electrode may have an inverse T-shaped section as taken along a direction extending along an active region perpendicular to the control gate electrode. The floating gate electrode may include a lower gate pattern, a middle gate pattern and an upper gate pattern sequentially disposed on a gate insulation layer, in which the middle gate pattern is larger in width than the lower gate pattern and the upper gate pattern. A boundary between the middle gate pattern and the upper gate pattern may have a rounded corner.

Abstract: Non-volatile memory devices include memory cells therein with reduced cell-to-cell coupling capacitance. These memory cells include floating gate electrodes with open-ended wraparound shapes that operate to reduce the cell-to-cell coupling capacitance in a bit line direction, while still maintaining a high coupling ratio between control and floating gate electrodes within each memory cell.

Abstract: A method of fabricating a flash memory device using a process for forming a self-aligned floating gate is provided. The method comprises forming mask patterns on a substrate, etching the substrate using the mask patterns as an etch mask to form a plurality of trenches, and filling the trenches with a first insulating layer, wherein sidewalls of the mask patterns remain exposed after filling the trenches with the first insulating layer. The method further comprises forming spacers on the exposed sidewalls of the mask patterns, filling upper insulating spaces with a second insulating layer thereby defining isolation layers, and removing the mask patterns and the spacers.

Abstract: A non-volatile memory device comprises a floating gate formed across an active region of a semiconductor substrate, and a control gate electrode formed over the floating gate. An insulation pattern is formed between the floating gate and the active region such that the insulation pattern makes contact with a bottom edge and a sidewall of the floating gate.

Abstract: A NAND type flash memory device includes a semiconductor substrate, word lines, first and second selection lines, tunnel insulation layers, and selection gate insulation layers. The semiconductor substrate includes a memory transistor region and a selection transistor region. The word lines are arranged in the memory transistor region of the semiconductor substrate, and the selection lines are arranged in the selection transistor region of the semiconductor substrate. The tunnel insulation layers are interposed between the word lines and the semiconductor substrate, and the selection gate insulation layers are interposed between the selection lines and the semiconductor substrate and have a thinner thickness than the thickness of the tunnel insulation layers. Also, the selection gate insulation layers have a thinner thickness in their center region than in their edge portions.

Abstract: Non-volatile memory devices include a floating gate having a lower portion and a pair of walls extending upward from opposite edges of the lower portion to define a void. An overlap area between adjacent floating gates is decreased by a side area of the void defined by the lower portion and the walls, so that a parasitic electrostatic capacitance can be reduced.

Abstract: A nonvolatile memory device includes a device isolating layer disposed at a substrate to define an active region and a floating gate disposed on the active region. The floating gate includes a flat portion and a pair of wall portions. The pair of wall portions extend upward from both edges of the flat portion adjacent to the device isolating layer and face each other. The nonvolatile memory device further includes a tunnel insulating layer interposed between the floating gate and the active region. Moreover, the wall portions and the flat portion are formed of a single layer, and the thickness of the flat portion is larger than a width of the wall portions.

Abstract: There are provided a memory transistor having a select transistor with asymmetric gate electrode structure and an inverted T-shaped floating gates and a method for forming the same. A gate electrode of the select transistor adjacent to a memory transistor has substantially an inverted T-shaped figure, whereas the gate electrode of the select transistor opposite to the memory transistor has nearly a box-shaped figure. In order to form the floating gate of the memory transistor in shape of the inverted T, a region for the select transistor is closed when opening a region for the memory transistor.

Abstract: A DRAM device having a triple well structure and a manufacturing method of the device are disclosed. The DRAM device includes first and second well regions of a first conductivity type formed in a semiconductor substrate of the first conductivity type. The first and second well regions are spaced apart from each other. The DRAM device also includes a third well region of a second conductivity type formed in the semiconductor substrate to encapsulate one of the first and second well regions for electrically isolating the encapsulated region from the semiconductor substrate. At least one first MOS transistor and at least one memory cell are formed in one of the first and second well regions. At least one second MOS transistor is formed in the other of the first and second well regions. In the present invention, one of the first and second MOS transistors has a gate length less than the gate length of the other.