Abstract:
A semiconductor structure is provided. The semiconductor structure includes a substrate, a channel layer, a barrier layer, a compound semiconductor layer, a gate electrode, and a stack of dielectric layers. The channel layer is disposed on the substrate. The barrier layer is disposed on the channel layer. The compound semiconductor layer is disposed on the barrier layer. The gate electrode is disposed on the compound semiconductor layer. The stack of dielectric layers is disposed on the gate electrode. The stack of dielectric layers includes layers having different etching rates.
Abstract:
A semiconductor structure includes a substrate, a gate structure on the substrate, and a source structure and a drain structure on opposite sides of the gate structure. The gate structure includes a gate electrode on the substrate and a gate metal layer on the gate electrode. The gate metal layer has at least one notch, which exposes the gate electrode below. The electric potential of the source structure is different from that of the gate structure.
Abstract:
A high electron mobility transistor includes a buffer layer, a threshold voltage adjustment layer, a band adjustment layer, a first enhancement layer, a gate electrode, and source/drain electrodes. The threshold voltage adjustment layer is disposed on the buffer layer. A channel region is disposed in the buffer layer adjacent to an interface between the buffer layer and the threshold voltage adjustment layer. The band adjustment layer is disposed on the threshold voltage adjustment layer. The first enhancement layer is conformally covering the threshold voltage adjustment layer and the band adjustment layer. The gate electrode is disposed on the first enhancement layer. The source/drain electrodes are disposed on the buffer layer through the threshold voltage adjustment layer and the first enhancement layer on opposite sides of the gate electrode respectively. The threshold voltage adjustment layer and the first enhancement layer are III-V semiconductors.
Abstract:
A switch-mode converter includes a high-side driver, a high-side transistor, a low-side driver, a low-side transistor, a capacitor, and an active diode. The high-side driver is supplied by the bootstrap voltage of the bootstrap node and a floating reference voltage of a floating reference node, and generates the high-side output signal. The high-side transistor provides an input voltage to the floating reference node according to the high-side output signal. The low-side driver generates the low-side output signal. The low-side transistor couples the floating reference node to a ground according to the low-side output signal. The capacitor is coupled between the bootstrap node and the floating reference node. The active diode provides the supply voltage to the bootstrap node. When the bootstrap voltage exceeds the supply voltage, the active diode isolates the supply voltage from the bootstrap node.
Abstract:
A semiconductor device includes a first gallium nitride layer disposed on a semiconductor substrate, wherein the first gallium nitride layer has a first conductivity type. The semiconductor device also includes a second gallium nitride layer disposed on the first gallium nitride layer, wherein the second gallium nitride layer has the first conductivity type, and the first gallium nitride layer has a dopant concentration which is greater than that of the second gallium nitride layer. The semiconductor device further includes an anode electrode disposed on the second gallium nitride layer, a cathode electrode disposed on and in direct contact with the first gallium nitride layer, and an insulating region disposed on and in direct contact with the first gallium nitride layer, wherein the insulating region is located between the cathode electrode and the second gallium nitride layer.
Abstract:
A semiconductor device includes a semiconductor substrate having a first conductivity type, and a first well region disposed in the semiconductor substrate, wherein the first well region has a second conductivity type opposite to the first conductivity type. The semiconductor device also includes a buried layer disposed in the semiconductor substrate and under the first well region, wherein the buried layer has the first conductivity type and is in contact with the first well region. The semiconductor device further includes a source electrode, a drain electrode and a gate structure disposed on the semiconductor substrate, wherein the gate structure is located between the source electrode and the drain electrode.
Abstract:
An ultra-high voltage device is provided. The ultra-high voltage device includes a substrate, a first well zone formed in the substrate, a second well zone formed in the substrate adjacent to the first well zone, a gate oxide layer formed on the first well zone and the second well zone, a gate formed on the gate oxide layer, an insulation region formed on the surface of the second well zone, a first implant region formed in the second well zone underneath the insulation region, a second implant region formed below the first implant region, and a junction formed between the first implant region and the second implant region. At least one of the first implant region and the second implant region includes at least two sub-implant regions having different implant concentrations. The sub-implant region having the higher implant concentration is adjacent to the junction.
Abstract:
A high-side circuit, adapted for a switched-mode converter, includes a level shifter, a high-side driver, a high-side transistor, a capacitor, and an active diode. The level shifter receives a first signal to generate a set signal. The high-side driver is supplied by a bootstrap voltage of a bootstrap node and a floating reference voltage of a floating reference node, which controls the high-side transistor to provide an input voltage to the floating reference node according to the set signal. The capacitor is coupled between the bootstrap node and the floating reference node. The active diode provides a supply voltage to the bootstrap node. When the bootstrap voltage exceeds the supply voltage, the active diode isolates the supply voltage from the bootstrap node according to a control voltage. The active diode includes a first-type well coupled to the bootstrap node, where the high-side driver is disposed.
Abstract:
A semiconductor device is provided. The device includes a semiconductor substrate and a gate structure thereon. A well region is formed in the semiconductor substrate. A drain region and a source region are respectively formed in the semiconductor substrate inside and outside of the well region. At least one set of the first and second heavily doped regions is formed in the well region between the drain region and the source region, wherein the first and second heavily doped regions are stacked vertically from bottom to top and have a doping concentration which is larger than that of the well region. The semiconductor substrate and the first heavily doped region have a first conductivity type and the well region and the second heavily doped region have a second conductivity type. A method for fabricating a semiconductor device is also disclosed.
Abstract:
A semiconductor structure is provided. The semiconductor structure includes a substrate, a buffer layer, a barrier layer, a dielectric layer, a source structure, and a drain structure. The buffer layer is disposed on the substrate. The barrier layer is disposed on the buffer layer. The dielectric layer is disposed on the barrier layer. The passivation layer is disposed on the dielectric layer. The source structure and the drain structure are disposed on the passivation layer.