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: The present invention relates to a video decoding system having a compensation function, the video decoding system comprising: one AD converter; a synchronized signal level detector for detecting a synchronized signal level using a digital signal output from the AD converter; a color burst level detector for detecting a color burst level using the digital signal output from the AD converter; a compensation apparatus for compensating the video level and the high frequency components of an analog signal by using information detected by the synchronized signal level detector and the color burst level detector, and for compensating and transmitting a synchronized signal level to the AD converter; and a decoding apparatus for outputting a digital component image signal (YCrCb) using the digital signal output from the AD converter.

Abstract: High electron mobility transistors (HEMT) exhibiting dual depletion and methods of manufacturing the same. The HEMT includes a source electrode, a gate electrode and a drain electrode disposed on a plurality of semiconductor layers having different polarities. A dual depletion region exists between the source electrode and the drain electrode. The plurality of semiconductor layers includes an upper material layer, an intermediate material layer and a lower material layer, and a polarity of the intermediate material layer is different from polarities of the upper material layer and the lower material layer.

Abstract: The present invention relates to an image quality adaptive video security system, a security camera generating an original video signal from a camera sensor, inserting an image quality discrimination signal including image quality information for video to the original video signal and generating a video signal. A DVR system determines whether a video signal from a security camera is transmitted in an analog transmission scheme or in a digital transmission scheme. In the case of the analog transmission scheme, the DVR system decodes the analog video signal to a first digital component video signal and detects image quality information. In a case of the digital transmission scheme, the DVR system converts the digital video signal to a digital second component video signal and detects image quality information.

Abstract: According to example embodiments, a high electron mobility transistor (HEMT) includes: stack including a buffer layer, a channel layer containing a two dimensional electron gas (2DEG) channel, and a channel supply layer sequentially stacked on each other, the stack defining a first hole and a second hole that are spaced apart from each other. A first electrode, a second electrode, and third electrode are spaced apart from each other along a first surface of the channel supply layer. A first pad is on the buffer layer and extends through the first hole of the stack to the first electrode. A second pad is on the buffer layer and extends through the second hole of the stack to the second electrode. A third pad is under the stack and electrically connected to the third electrode.

Abstract: According to example embodiments a transistor includes a channel layer on a substrate, a first channel supply layer on the channel, a depletion layer, a second channel supply layer, source and drain electrodes on the first channel supply layer, and a gate electrode on the depletion layer. The channel includes a 2DEG channel configured to generate a two-dimensional electron gas and a depletion area. The first channel supply layer corresponds to the 2DEG channel and defines an opening that exposes the depletion area. The depletion layer is on the depletion area of the channel layer. The second channel supply layer is between the depletion layer and the depletion area.

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: High electron mobility transistors (HEMTs) including lightly doped drain (LDD) regions and methods of manufacturing the same. A HEMT includes a source, a drain, a gate, a channel supplying layer for forming at least a 2-dimensional electron gas (2DEG) channel, and a channel formation layer in which at least the 2DEG channel is formed. The channel supplying layer includes a plurality of semiconductor layers having different polarizabilities. A portion of the channel supplying layer is recessed. One of the plurality of semiconductor layers, which is positioned below an uppermost layer is an etching buffer layer, as well as a channel supplying layer.

Abstract: According to example embodiments, a method of operating a power device includes applying a control voltage to a control electrode of the power device, where the control electrode is electrically separated from a source electrode, a drain electrode, and a gate electrode of the power device. The control voltage is separately applied to the control electrode. The method may include applying a negative control voltage to the control electrode prior to applying a gate voltage to the gate electrode.

Abstract: The methods may include forming a first material layer on a substrate, increasing electric resistance of the first material layer, and forming a source pattern and a drain pattern, which are spaced apart from each other, on the first material layer, a band gap of the source and drain patterns greater than a band gap of a first material layer.

Abstract: Provided are a high electron mobility transistor (HEMT) and a method of manufacturing the HEMT. The HEMT includes: a channel layer comprising a first semiconductor material; a channel supply layer comprising a second semiconductor material and generating two-dimensional electron gas (2DEG) in the channel layer; a source electrode and a drain electrode separated from each other in the channel supply layer; at least one depletion forming unit that is formed on the channel supply layer and forms a depletion region in the 2DEG; at least one gate electrode that is formed on the at least one depletion forming unit; at least one bridge that connects the at least one depletion forming unit and the source electrode; and a contact portion that extends from the at least one bridge under the source electrode.

Abstract: According to example embodiments, a high electron mobility transistor (HEMT) includes a channel layer having a 2-dimensional electron gas (2DEG), a channel supply layer on the channel layer, a source electrode and a drain electrode spaced apart from each other on one of the channel layer and the channel supply layer, at least one channel depletion layer on the channel supply layer; a gate electrode on at least a part of the channel depletion layer, and at least one bridge connecting the channel depletion layer and the source electrode. The channel depletion layer is configured to form a depletion region in the 2DEG. The HEMT has a ratio of a first impedance to a second impedance that is a uniform value. The first impedance is between the gate electrode and the channel depletion layer. The second impedance is between the source electrode and the channel depletion layer.

Abstract: According to example embodiments, a high electron mobility transistor (HEMT) includes a channel layer; a channel supply layer on the channel layer; a source electrode and a drain electrode spaced apart from each other on one of the channel layer and the channel supply layer; a gate electrode on a part of the channel supply layer between the source electrode and the drain electrode; a first depletion-forming layer between the gate electrode and the channel supply layer; and a at least one second depletion-forming layer on the channel supply layer between the gate electrode and the drain electrode. The at least one second depletion-forming layer is electrically connected to the source electrode.

Abstract: High electron mobility transistors (HEMTs) including a cavity below a drain and methods of manufacturing HEMTS including removing a portion of a substrate below a drain.

Abstract: A high electron mobility transistor (HEMT) according to example embodiments includes a channel layer, a channel supply layer on the channel layer, a source electrode and a drain electrode on at least one of the channel layer and the channel supply layer, a gate electrode between the source electrode and the drain electrode, and a Schottky electrode forming a Schottky contact with the channel supply layer. An upper surface of the channel supply layer may define a Schottky electrode accommodation unit. At least part of the Schottky electrode may be in the Schottky electrode accommodation unit. The Schottky electrode is electrically connected to the source electrode.

Abstract: According to example embodiments, a power device chip includes a plurality of unit power devices classified into a plurality of sectors, a first pad and a second pad. At least one of the first and second pads is divided into a number of pad parts equal to a number of the plurality of sectors. The first pad is connected to first electrodes of the plurality of unit power devices, and the second pad is connected to second electrodes of the plurality of unit power devices. The unit power devices may be diodes. The power device chip may further include third electrodes in the plurality of unit power devices, and a third pad may be connected to the third electrodes. In this case, the unit power devices may be high electron mobility transistors (HEMTs). Pad parts connected to defective sectors may be excluded from bonding.

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 HEMT includes a channel supply layer on a channel layer, a p-type semiconductor structure on the channel supply layer, a gate electrode on the p-type semiconductor structure, and source and drain electrodes spaced apart from two sides of the gate electrode respectively. The channel supply layer may have a higher energy bandgap than the channel layer. The p-type semiconductor structure may have an energy bandgap that is different than the channel supply layer. The p-type semiconductor structure may include a hole injection layer (HIL) on the channel supply layer and be configured to inject holes into at least one of the channel layer and the channel supply in an on state. The p-type semiconductor structure may include a depletion forming layer on part of the HIL. The depletion forming layer may have a dopant concentration that is different than the dopant concentration of the HIL.

Abstract: High electron mobility transistors (HEMTs) including a substrate and a HEMT stack on the substrate, the HEMT stack including a compound semiconductor layer that includes a 2-dimensional electron gas (2DEG), an upper compound semiconductor layer that has a polarization index higher than a polarization index of the compound semiconductor layer, and a source electrode, a drain electrode, and a gate that are disposed on the upper compound semiconductor layer. The substrate may be a nitride substrate that has a dielectric constant and a thermal conductivity higher than a dielectric constant and a thermal conductivity of a silicon substrate. The substrate may include an insulating layer that has a dielectric constant and a thermal conductivity higher than a dielectric constant and a thermal conductivity of the silicon substrate, a metal layer that is deposited on the insulating layer, and a plate that is attached to the metal layer.

Abstract: The methods may include forming a first material layer on a substrate, increasing electric resistance of the first material layer, and forming a source pattern and a drain pattern, which are spaced apart from each other, on the first material layer, a band gap of the source and drain patterns greater than a band gap of a first material layer.