Abstract: Nonvolatile memory devices include a plurality of nonvolatile memory cell transistors having respective channel regions within a semiconductor layer formed of a first semiconductor material and respective source/drain regions formed of a second semiconductor material, which has a smaller bandgap relative to the first semiconductor material. The source/drain regions can form non-rectifying junctions with the channel regions. The source/drain regions may include germanium (e.g., Ge or SiGe regions), the semiconductor layer may be a P-type silicon layer and the source/drain regions of the plurality of nonvolatile memory cell transistors may be P-type germanium or P-type silicon germanium.

Abstract: Provided are a selection transistor and a method of fabricating the same. A selection transistor can be formed on an active region in a semiconductor substrate to include a gate electrode that includes recessed portions of a sidewall of the gate electrode which are recessed inward adjacent lower portions of the gate electrode to define a T-shaped cross section of the gate electrode. A tunnel insulating layer can be located between the gate electrode and the active region.

Abstract: Provided are a selection transistor and a method of fabricating the same. A selection transistor can be formed on an active region in a semiconductor substrate to include a gate electrode that includes recessed portions of a sidewall of the gate electrode which are recessed inward adjacent lower portions of the gate electrode to define a T-shaped cross section of the gate electrode. A tunnel insulating layer can be located between the gate electrode and the active region.

Abstract: A NOR flash memory device includes a substrate having trenches that extend in a first direction and stepped portions that are arranged between the trenches. A bit region having a linear shape extends in a second direction substantially perpendicular to the first direction in the substrate. The bit region is doped with impurities. A first dielectric layer is on the substrate having the trenches. An electric charge trap layer is on the first dielectric layer. A second dielectric layer is on the electric charge trap layer. An upper electrode is on sidewalls of the trenches. The upper electrode has a spacer shape. Related fabrication methods are also described.

Abstract: A method of manufacturing a semiconductor device, including forming a plurality of gate structures on a substrate, the gate structures each including a hard mask pattern stacked on a gate conductive pattern, forming an insulating layer pattern between the gate structures at least partially exposing a top surface of the hard mask pattern, forming a trench that exposes at least a top surface of the gate conductive pattern by selectively removing the hard mask pattern, and forming a silicide layer on the exposed gate conductive pattern.

Abstract: In one embodiment, the semiconductor memory device includes a semiconductor substrate having projecting portions, a tunnel insulation layer formed over at least one of the projecting semiconductor substrate portions, and a floating gate structure disposed over the tunnel insulation layer. An upper portion of the floating gate structure is wider than a lower portion of the floating gate structure, and the lower portion of the floating gate structure has a width less than a width of the tunnel insulating layer. First insulation layer portions are formed in the semiconductor substrate and project from the semiconductor substrate such that the floating gate structure is disposed between the projecting first insulation layer portions. A dielectric layer is formed over the first insulation layer portions and the floating gate structure, and a control gate is formed over the dielectric layer.

Abstract: A NOR flash memory device includes a substrate having trenches that extend in a first direction and stepped portions that are arranged between the trenches. A bit region having a linear shape extends in a second direction substantially perpendicular to the first direction in the substrate. The bit region is doped with impurities. A first dielectric layer is on the substrate having the trenches. An electric charge trap layer is on the first dielectric layer. A second dielectric layer is on the electric charge trap layer. An upper electrode is on sidewalls of the trenches. The upper electrode has a spacer shape. Related fabrication methods are also described.