Abstract: A method of manufacturing a High Electron Mobility Transistor (HEMT) may include forming first and second material layers having different lattice constants on a substrate, forming a source, a drain, and a gate on the second material layer, and changing the second material layer between the gate and the drain into a different material layer, or changing a thickness of the second material layer, or forming a p-type semiconductor layer on the second material layer. The change in the second material layer may occur in an entire region of the second material layer between the gate and the drain, or only in a partial region of the second material layer adjacent to the gate. The p-type semiconductor layer may be formed on an entire top surface of the second material layer between the gate and the drain, or only on a partial region of the top surface adjacent to the gate.

Abstract: Provided is a chemical sensor that may include a first electrode on a substrate, a sensing member covering the first electrode on the substrate, and a plurality of second electrodes on a surface of the sensing member exposing the surface of the sensing member. The chemical sensor may be configured to measure the change in electrical characteristics when a compound to be sensed is adsorbed on the sensing member. Provided also is a chemical sensor array including an array of chemical sensors.

Abstract: Provided is a method of reliably operating a highly integratable nonvolatile memory device. The nonvolatile memory device may include a string selection transistor, a plurality of memory transistors, and a ground selection transistor between a bit line and a common source line. In the nonvolatile memory device, data may be erased from the memory transistors by applying an erasing voltage to the bit line or the common source line.

Abstract: Provided are a capacitorless DRAM and methods of manufacturing the same. The capacitorless DRAM may include a substrate including a source, a drain and a channel, a gate on the channel of the substrate, and a hole reserving unit below the channel.

Abstract: A quantum interference transistor may include a source; a drain; N channels (N?2), between the source and the drain, and having N?1 path differences between the source and the drain; and at least one gate disposed at one or more of the N channels. One or more of the N channels may be formed in a graphene sheet. A method of manufacturing the quantum interference transistor may include forming one or more of the N channels using a graphene sheet. A method of operating the quantum interference transistor may include applying a voltage to the at least one gate. The voltage may shift a phase of a wave of electrons passing through a channel at which the at least one gate is disposed.

Abstract: Provided is a chemical sensor that may include a first electrode on a substrate, a sensing member covering the first electrode on the substrate, and a plurality of second electrodes on a surface of the sensing member exposing the surface of the sensing member. The chemical sensor may be configured to measure the change in electrical characteristics when a compound to be sensed is adsorbed on the sensing member. Provided also is a chemical sensor array including an array of chemical sensors.

Abstract: A nonvolatile memory cell may include a bidirectional switch having a first threshold voltage when a forward current is applied to the bidirectional switch and a second threshold voltage when a reverse current is applied to the bidirectional switch; and a variable resistor connected to the bidirectional switch in series. A state of resistance of the variable resistor may be controlled according to voltage applied to the variable resistor. A sum of a magnitude of the first threshold voltage and a magnitude of the second threshold voltage may be greater than a write voltage that is used to perform a write operation on the variable resistor.

Abstract: Example embodiments include nonvolatile memory devices that have good operation performance and may be made in a highly integrated structure, and methods of operating the same. Example embodiments of the nonvolatile memory devices include a substrate electrode, and a semiconductor channel layer on the substrate electrode, a floating gate electrode on the substrate electrode, wherein a portion of the floating gate electrode faces the semiconductor channel layer, a control gate electrode on the floating gate electrode, and wherein a distance between a portion of the floating gate electrode and the substrate electrode is smaller than a distance between the semiconductor channel layer and the substrate electrode wherein charge tunneling occurs.

Abstract: A spin field effect transistor may include at least one gate electrode, a channel layer, a first stack and a second stack separate from each other on a substrate, wherein the channel layer is formed of a half metal. The half metal may be at least one material selected from the group consisting of chrome oxide (CrO2), magnetite (Fe3O4), a double perovskite structure material, a Heusler alloy, NiMnSb, La(1-x)AxMnO3 (A=Ca, Ba, Sr, x˜0.3), and GaN doped with Cu, and the double perovskite structure material is expressed as a chemical composition of A2BB?O6, and a material corresponding to A is Ca, Sr, or Ba, a material corresponding to B is a 3d orbital transition metal, and a material corresponding to B? is a 4d orbital transition metal. The 3d orbital transition metal may be Fe or Co, and the 4d orbital transition metal is Mo or Re.

Abstract: A capacitorless DRAM and methods of manufacturing and operating the same are provided. The capacitorless DRAM includes a source, a drain and a channel layer, formed on a substrate. A charge reserving layer is formed on the channel layer. The capacitorless DRAM includes a gate that contacts the channel layer and the charge reserving layer.

Abstract: The non-volatile memory device may include a substrate, a plurality of first signal lines on the substrate in a vertical direction, a plurality of memory cells having ends connected to the plurality of first signal lines, a plurality of second signal lines perpendicular to the plurality of first signal lines on the substrate and each connected to other ends of the plurality of memory cells, and a plurality of selection elements on the substrate and connected to at least two of the plurality of first signal lines.

Abstract: A ferroelectric memory device having a NAND array of a plurality of ferroelectric memory cells includes: a fully depleted channel layer; a gate electrode layer; and a ferroelectric layer located between the channel layer and the gate electrode layer. The data of the plurality of ferroelectric memory cells is erased by applying a first erase voltage to a bit line and a common source line and applying a second erase voltage to a string selection line and a ground selection line.

Abstract: Power electronic devices including 2-dimensional electron gas (2DEG) channels and methods of manufacturing the same. A power electronic device includes lower and upper material layers for forming a 2DEG channel, and a gate contacting an upper surface of the upper material layer. A region below the gate of the 2DEG channel is an off region where the density of a 2DEG is reduced or zero. The entire upper material layer may be continuous and may have a uniform thickness. A region of the upper material layer under the gate contains an impurity for reducing or eliminating a lattice constant difference between the lower and upper material layers.

Abstract: Field effect semiconductor devices and methods of manufacturing the same are provided, the field effect semiconductor devices include a second semiconductor layer on a first surface of a first semiconductor layer, a first and a second third semiconductor layer respectively on two sides of the second semiconductor layer, a source and a drain respectively on the first and second third semiconductor layer, and a gate electrode on a second surface of the first semiconductor layer.

Abstract: A semiconductor memory device performing an erase operation using an erase gate and a method of manufacturing the same are provided. The memory device may include a charge trap layer storing a first charge transfer medium having a first polarity and at least one erase gate. The at least one erase gate may be formed below the charge trap layer. A second charge transfer medium, which has a second polarity opposite to the first polarity, may be stored in the at least one erase gate. During the erase operation, the second charge transfer medium migrates to the charge trap layer causing the first charge transfer medium to combine with the second charge transfer medium.

Abstract: Provided is a method of reliably operating a highly integratable nonvolatile memory device. The nonvolatile memory device may include a string selection transistor, a plurality of memory transistors, and a ground selection transistor between a bit line and a common source line. In the nonvolatile memory device, data may be erased from the memory transistors by applying an erasing voltage to the bit line or the common source line.

Abstract: A semiconductor memory device performing an erase operation using an erase gate and a method of manufacturing the same are provided. The memory device may include a charge trap layer storing a first charge transfer medium having a first polarity and at least one erase gate. The at least one erase gate may be formed below the charge trap layer. A second charge transfer medium, which has a second polarity opposite to the first polarity, may be stored in the at least one erase gate. During the erase operation, the second charge transfer medium migrates to the charge trap layer causing the first charge transfer medium to combine with the second charge transfer medium.

Abstract: Disclosed are a spin transistor and a method of operating the spin transistor. The disclosed spin transistor includes a channel formed of a magnetic material selectively passing a spin-polarized electron having a specific direction, a source formed of a magnetic material, a drain, and a gate electrode. When a predetermined voltage is applied to the gate electrode, the channel selectively passes a spin-polarized electron having a specific direction and thus, the spin transistor is selectively turned on.

Abstract: Provided is a method of reliably operating a highly integratable nonvolatile memory device. The nonvolatile memory device may include a string selection transistor, a plurality of memory transistors, and a ground selection transistor between a bit line and a common source line. In the nonvolatile memory device, data may be erased from the memory transistors by applying an erasing voltage to the bit line or the common source line.

Abstract: Provided are spin field effect logic devices, the logic devices including: a gate electrode; a channel formed of a magnetic material above the gate electrode to selectively transmit spin-polarized electrons; a source on the channel; and a drain and an output electrode on the channel outputting electrons transmitted from the source. The gate electrode may control a magnetization state of the channel in order to selectively transmit the electrons injected from the source to the channel.