Abstract: A semiconductor device including a group III-V barrier and a method of manufacturing the semiconductor device, the semiconductor device including: a substrate, insulation layers formed to be spaced apart on the substrate, a group III-V material layer for filling the space between the insulation layers and having a portion protruding higher than the insulation layers, a barrier layer for covering the side and upper surfaces of the protruding portion of the group III-V material layer and having a bandgap larger than that of the group III-V material layer, a gate insulation film for covering the surface of the barrier layer, a gate electrode formed on the gate insulation film, and source and drain electrodes formed apart from the gate electrode. The overall composition of the group III-V material layer is uniform. The barrier layer may include a group III-V material for forming a quantum well.

Abstract: A semiconductor device including a group III-V barrier and a method of manufacturing the semiconductor device, the semiconductor device including: a substrate, insulation layers formed to be spaced apart on the substrate, a group III-V material layer for filling the space between the insulation layers and having a portion protruding higher than the insulation layers, a barrier layer for covering the side and upper surfaces of the protruding portion of the group III-V material layer and having a bandgap larger than that of the group III-V material layer, a gate insulation film for covering the surface of the barrier layer, a gate electrode formed on the gate insulation film, and source and drain electrodes formed apart from the gate electrode. The overall composition of the group III-V material layer is uniform. The barrier layer may include a group III-V material for forming a quantum well.

Abstract: A High electron mobility transistor (HEMT) includes a source electrode, a gate electrode, a drain electrode, a channel forming layer in which a two-dimensional electron gas (2DEG) channel is induced, and a channel supplying layer for inducing the 2DEG channel in the channel forming layer. The source electrode and the drain electrode are located on the channel supplying layer. A channel increase layer is between the channel supplying layer and the source and drain electrodes. A thickness of the channel supplying layer is less than about 15 nm.

Abstract: According to example embodiments, a substrate structure may include a GaN-based third material layer, a GaN-based second material layer, a GaN-based first material layer, and a buffer layer on a non-GaN-based substrate. The GaN-based first material layer may be doped with a first conductive type impurity. The GaN-based second material layer may be doped with a second conductive type impurity at a density that is less than a density of the first conductive type impurity in the first GaN-based material layer. The GaN-based third material layer may be doped with a first conductive type impurity at a density that is less than the density of the first conductive type impurity of the GaN-based first material layer. After a second substrate is attached onto the substrate structure, the non-GaN-based substrate may be removed and a GaN-based vertical type semiconductor device may be fabricated on the second substrate.

Abstract: A High electron mobility transistor (HEMT) includes a source electrode, a gate electrode, a drain electrode, a channel forming layer in which a two-dimensional electron gas (2DEG) channel is induced, and a channel supplying layer for inducing the 2DEG channel in the channel forming layer. The source electrode and the drain electrode are located on the channel supplying layer. A channel increase layer is between the channel supplying layer and the source and drain electrodes. A thickness of the channel supplying layer is less than about 15 nm.

Abstract: According to an example embodiment, a power electronic device includes a first semiconductor layer, a second semiconductor layer on a first surface of the first semiconductor layer, and a source, a drain, and a gate on the second semiconductor layer. The source, drain and gate are separate from one another. The power electronic device further includes a 2-dimensional electron gas (2DEG) region at an interface between the first semiconductor layer and the second semiconductor layer, a first insulating layer on the gate and a second insulating layer adjacent to the first insulating layer. The first insulating layer has a first dielectric constant and the second insulating layer has a second dielectric constant less than the first dielectric constant.

Abstract: According to an example embodiment, a high electron mobility transistor (HEMT) includes a substrate, a buffer layer on the substrate, a channel layer on the buffer layer, and a barrier structure on the channel layer. The buffer layer includes a 2-dimensional electron gas (2DEG). A polarization of the barrier structure varies in a region corresponding to a gate electrode. The HEMT further includes and the gate electrode, a source electrode, and a drain electrode on the barrier structure.

Abstract: A power device includes a switching device having a control terminal and an output terminal; and a driving circuit configured to provide a driving voltage to the control terminal such that a voltage between the control terminal and the output terminal remains less than or equal to a critical voltage. A rise time required for the driving voltage to reach a target level is determined according to current-voltage characteristics of the switching device. And, when the voltage between the control terminal and the output terminal exceeds the critical voltage, leakage current is generated between the control terminal and the output terminal.

Abstract: High electron mobility transistors (HEMTs) and methods of manufacturing the same. A HEMT may include a channel layer and a channel supply layer, and the channel supply layer may be a multilayer structure. The channel supply layer may include an etch stop layer and an upper layer on the etch stop layer. A recess region may be in the upper layer. The recess region may be a region recessed to an interface between the upper layer and the etch stop layer. A gate electrode may be on the recess region.

Abstract: Example embodiments relate to a method of forming a core-shell structure. According to a method, a region in which the core-shell structure will be formed is defined on a substrate, and a core and a shell layer may be sequentially stacked in the defined region. A first shell layer may further be formed between the substrate and the core. When the core and the shell layer are sequentially stacked in the core-shell region, the method may further include forming a groove on the substrate, forming the first shell layer covering surfaces of the groove, forming the core in the groove of which surfaces are covered by the first shell layer, and forming a second shell layer covering the core.

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.

Abstract: An Enhancement-mode (E-mode) high electron mobility transistor (HEMT) includes a channel layer with a 2-Dimensional Electron Gas (2DEG), a barrier layer inducing the 2DEG in the channel layer, source and drain electrodes on the barrier layer, a depletion layer on the barrier layer between the source and drain electrodes, and a gate electrode on the depletion layer. The barrier layer is recessed below the gate electrode and the depletion layer covers a surface of the recess and extends onto the barrier layer around the recess.

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.

Abstract: Provided are a light emitting diode (LED) using a Si nanowire as an emission device and a method of fabricating the same. The LED includes: a semiconductor substrate; first and second semiconductor protrusions disposed on the semiconductor substrate to face each other; a semiconductor nanowire suspended between the first and second semiconductor protrusions; and first and second electrodes disposed on the first and second protrusions, respectively.

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: Provided is a semiconductor device that may include a switching device having a negative threshold voltage, and a driving unit between a power terminal and a ground terminal and providing a driving voltage for driving the switching device. The switching device may be connected to a virtual ground node having a virtual ground voltage that is greater than a ground voltage supplied from the ground terminal and may be turned on when a difference between the driving voltage and the virtual ground voltage is greater than the negative threshold voltage.

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.

Abstract: According to example embodiments, a high electron mobility transistor (HEMT) includes a channel supply layer and a channel layer. The channel layer may include an effective channel region and a high resistivity region. The effective channel region may be between the high resistivity region and the channel supply layer. The high resistivity region may be a region into which impurities are ion-implanted. According to example embodiments, a method of forming a HEMT includes forming a device unit, including a channel layer and a channel supply layer, on a first substrate; adhering a second substrate to the device unit; removing the first substrate; and forming a high resistivity region by ion-implanting impurities into at least a portion of the channel layer.

Abstract: According to example embodiments, a substrate structure may include a GaN-based third material layer, a GaN-based second material layer, a GaN-based first material layer, and a buffer layer on a non-GaN-based substrate. The GaN-based first material layer may be doped with a first conductive type impurity. The GaN-based second material layer may be doped with a second conductive type impurity at a density that is less than a density of the first conductive type impurity in the first GaN-based material layer. The GaN-based third material layer may be doped with a first conductive type impurity at a density that is less than the density of the first conductive type impurity of the GaN-based first material layer. After a second substrate is attached onto the substrate structure, the non-GaN-based substrate may be removed and a GaN-based vertical type semiconductor device may be fabricated on the second substrate.

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.