摘要:
In a silicon carbide semiconductor device such as a trench gate type power MOSFET, the film thickness and the impurity concentration of a thin film silicon carbide semiconductor layer formed on a trench side face to constitute an accumulation-type channel-forming region and enable the device to operate with a low gate voltage, low on-resistance and low power loss are set so that on impression of a reverse bias voltage a pn junction between a P-type epitaxial layer and an n.sup.- -type epitaxial layer undergoes avalanche breakdown before the thin film silicon carbide semiconductor layer undergoes punch-through. By this means it is possible to obtain a target high source-drain withstand voltage.
摘要:
A semiconductor device comprises a semiconductor substrate including a first conductivity type first semiconductor layer and a second conductivity type second semiconductor layer formed on the first semiconductor layer. A unit cell for controlling current flowing between a source electrode and a drain electrode is formed in the semiconductor substrate. A trench is formed in a peripheral region of the unit cell to form mesa structure. A field relaxing layer is formed between an insulating film on a side face of the second trench and both the first semiconductor layer and the second semiconductor layer in order to relax concentration of an electric field in the insulating film.
摘要:
A semiconductor device includes a vertical field-effect transistor having a substrate of first conduction type in a substrate base, a drain electrode formed on a first surface of the substrate, an epitaxial layer of first conduction type formed on a second surface of the substrate, a source region of first conduction type formed on the semiconductor base, a source ohmic contact metal film in ohmic contact with the source region, trenches formed from the second surface of the semiconductor base, and a gate region of second conduction type formed along the trenches. The semiconductor device further includes a gate rise metal film in ohmic contact with the draw-out layer of the gate region on the bottom of the trenches and rising to the second surface of the semiconductor base, and a gate draw-out metal film connected to the gate rise metal film from the second surface of the semiconductor base.
摘要:
A SiC semiconductor device includes: a SiC substrate having a drain layer, a drift layer and a source layer stacked in this order; multiple trenches penetrating the source layer and reaching the drift layer; a gate layer on a sidewall of each trench; an insulation film on the sidewall of each trench covering the gate layer; a source electrode on the source layer; and a diode portion in or under the trench contacting the drift layer to provide a diode. The drift layer between the gate layer on the sidewalls of adjacent two trenches provides a channel region. The diode portion is coupled with the source electrode, and insulated from the gate layer with the insulation film.
摘要:
A semiconductor device includes a vertical field-effect transistor having a substrate of first conduction type in a substrate base, a drain electrode formed on a first surface of the substrate, an epitaxial layer of first conduction type formed on a second surface of the substrate, a source region of first conduction type formed on the semiconductor base, a source ohmic contact metal film in ohmic contact with the source region, trenches formed from the second surface of the semiconductor base, and a gate region of second conduction type formed along the trenches. The semiconductor device further includes a gate rise metal film in ohmic contact with the draw-out layer of the gate region on the bottom of the trenches and rising to the second surface of the semiconductor base, and a gate draw-out metal film connected to the gate rise metal film from the second surface of the semiconductor base.
摘要:
A semiconductor device includes (a) a vertical field effect transistor, the vertical field effect transistor including a drain electrode formed on a first surface of a first conductivity type of a semiconductor, a pair of first trenches formed from a second surface of the semiconductor, control regions of a second conductivity type formed respectively along the first trenches, a source region of the first conductivity type formed along the second surface of the semiconductor between the first trenches, a source electrode joined to the source region, and a gate electrode adjacent to the control regions, (b) a pair of second trenches formed from the second surface of the semiconductor independently of the field effect transistor, (c) control regions of the second conductivity type formed along the second trenches, and (d) a diode having a junction formed on the second surface between the second trenches.
摘要:
A SiC semiconductor device includes: a SiC substrate having a drain layer, a drift layer and a source layer stacked in this order; multiple trenches penetrating the source layer and reaching the drift layer; a gate layer on a sidewall of each trench; an insulation film on the sidewall of each trench covering the gate layer; a source electrode on the source layer; and a diode portion in or under the trench contacting the drift layer to provide a diode. The drift layer between the gate layer on the sidewalls of adjacent two trenches provides a channel region. The diode portion is coupled with the source electrode, and insulated from the gate layer with the insulation film.
摘要:
In a BRE300, an RF interface for transmitting and receiving an RF signal is used for communication with a MDE 200 and a digital signal interface for transmitting and receiving a digital signal in accordance with CPRI is used for communication with BDE 300. The BRE 300 includes a monitoring signal interface configured to notify the MDE 200 of a monitoring signal indicating a state of the radio unit 50. The signal transmitted and received through the monitoring signal interface is a ground signal and is of type different from types of signals transmitted and received by the RF interface and the digital signal interface.
摘要:
A wavelength selective switch for suppressing degradation of pass band characteristics when the temperature rises. The wavelength selective switch includes a spectroscopic element for separating input light and providing angular dispersion depending on wavelengths, a collective lens for gathering light output from the spectroscopic element, and a movable reflection block which includes a plurality of mirrors arranged in the direction of angular dispersion made by the spectroscopic element, changes the angles of the mirrors in a direction differing from the direction of angular dispersion, and reflects the light coming from the collective lens. The collective lens is fixed at one end with respect to the direction of angular dispersion, expands with heat in a direction in which it is not fixed when the temperature rises, and outputs the light in a direction opposite to the direction in which the angle of light output from the spectroscopic element changes.
摘要:
An active layer having a p-type quantum dot structure is disposed over a lower cladding layer made of semiconductor material of a first conductivity type. An upper cladding layer is disposed over the active layer. The upper cladding layer is made of semiconductor material, and includes a ridge portion and a cover portion. The ridge portion extends in one direction, and the cover portion covers the surface on both sides of the ridge portion. A capacitance reducing region is disposed on both sides of the ridge portion and reaching at least the lower surface of the cover portion. The capacitance reducing region has the first conductivity type or a higher resistivity than that of the ridge portion, and the ridge portion has a second conductivity type. If the lower cladding layer is an n-type, the capacitance reducing region reaches at least the upper surface of the lower cladding layer.