Abstract: An electronic device includes a silicon carbide layer including an n-type drift region therein, a contact forming a junction, such as a Schottky junction, with the drift region, and a p-type junction barrier region on the silicon carbide layer. The p-type junction barrier region includes a p-type polysilicon region forming a P-N heterojunction with the drift region, and the p-type junction barrier region is electrically connected to the contact. Related methods are also disclosed.

Abstract: A transistor structure optimizes current along the A-face of a silicon carbide body to form an AMOSFET that minimizes the JFET effect in the drift region during forward conduction in the on-state. The AMOSFET further shows high voltage blocking ability due to the addition of a highly doped well region that protects the gate corner region in a trench-gated device. The AMOSFET uses the A-face conduction along a trench sidewall in addition to a buried channel layer extending across portions of the semiconductor mesas defining the trench. A doped well extends from at least one of the mesas to a depth within the current spreading layer that is greater than the depth of the trench. A current spreading layer extends between the semiconductor mesas beneath the bottom of the trench to reduce junction resistance in the on-state. A buffer layer between the trench and the deep well further provides protection from field crowding at the trench corner.

Abstract: Methods of forming a p-channel MOS device in silicon carbide include forming an n-type well in a silicon carbide layer, and implanting p-type dopant ions to form a p-type region in the n-type well at a surface of the silicon carbide layer and at least partially defining a channel region in the n-type well adjacent the p-type region. A threshold adjustment region is formed in the channel region. The implanted ions are annealed in an inert atmosphere at a temperature greater than 1650° C. A gate oxide layer is formed on the channel region, and a gate is formed on the gate oxide layer. A silicon carbide-based transistor includes a silicon carbide layer, an n-type well in the silicon carbide layer, and a p-type region in the n-type well at a surface of the silicon carbide layer and at least partially defining a channel region in the n-type well adjacent the p-type region.

Abstract: Semiconductor switching devices include a wide band-gap drift layer having a first conductivity type (e.g., n-type), and first and second wide band-gap well regions having a second conductivity type (e.g., p-type) on the wide band-gap drift layer. First and second wide band-gap source/drain regions of the first conductivity type are on the first and second wide band-gap well regions, respectively. A wide band-gap JFET region having the first conductivity type is provided between the first and second well regions. This JFET region includes a first local JFET region that is adjacent a side surface of the first well region and a second local JFET region that is adjacent a side surface of the second well region. The local JFET regions have doping concentrations that exceed a doping concentration of a central portion of the JFET region that is between the first and second local JFET regions of the JFET region.

Abstract: Metal oxide semiconductor (MOS) power devices are provided including a MOS channel including a semiconductor material having high electron mobility on a silicon carbide (SiC) layer. Related methods are also provided herein.

Abstract: A transistor may include a semiconductor drift layer of a first semiconductor material and a semiconductor channel layer on the semiconductor drift layer. The semiconductor channel layer may include a second semiconductor material different than the first semiconductor material. A semiconductor interconnection layer may be electrically coupled between the semiconductor drift layer and the semiconductor channel layer, and the semiconductor interconnection layer may include a third semiconductor material different than the first and second semiconductor materials. In addition, a control electrode may be provided on the semiconductor channel layer.

Abstract: Provided is a semiconductor bistable switching device that includes a thyristor portion including an anode layer, a drift layer, a gate layer and a cathode layer, the gate layer operable to receive a gate trigger current that, when the anode layer is positively biased relative to the cathode layer, causes the thyristor portion to latch into a conducting mode between the anode and the cathode. The device also includes a transistor portion formed on the thyristor portion, the transistor portion including a source, a drain and a transistor gate, the drain coupled to the cathode of the thyristor portion.

Abstract: Methods of forming a p-channel MOS device in silicon carbide include forming an n-type well in a silicon carbide layer, and implanting p-type dopant ions to form a p-type region in the n-type well at a surface of the silicon carbide layer and at least partially defining a channel region in the n-type well adjacent the p-type region. A threshold adjustment region is formed in the channel region. The implanted ions are annealed in an inert atmosphere at a temperature greater than 1650° C. A gate oxide layer is formed on the channel region, and a gate is formed on the gate oxide layer. A silicon carbide-based transistor includes a silicon carbide layer, an n-type well in the silicon carbide layer, and a p-type region in the n-type well at a surface of the silicon carbide layer and at least partially defining a channel region in the n-type well adjacent the p-type region.

Abstract: High power wide band-gap MOSFET-gated bipolar junction transistors (“MGT”) are provided that include a first wide band-gap bipolar junction transistor (“BJT”) having a first collector, a first emitter and a first base, a wide band-gap MOSFET having a source region that is configured to provide a current to the base of the first wide band-gap BJT and a second wide band-gap BJT having a second collector that is electrically connected to the first collector, a second emitter that is electrically connected to the first emitter, and a second base that is electrically connected to the first base.

Abstract: A packaged power electronic device includes a wide bandgap bipolar driver transistor having a base, a collector, and an emitter terminal, and a wide bandgap bipolar output transistor having a base, a collector, and an emitter terminal. The collector terminal of the output transistor is coupled to the collector terminal of the driver transistor, and the base terminal of the output transistor is coupled to the emitter terminal of the driver transistor to provide a Darlington pair. An area of the output transistor is at least 3 times greater than an area of the driver transistor in plan view. For example, an area ratio of the output transistor to the driver transistor may be between about 3:1 to about 5:1. Related devices and methods of fabrication are also discussed.

Abstract: Hybrid semiconductor devices including a PIN diode portion and a Schottky diode portion are provided. The PIN diode portion is provided on a semiconductor substrate and has an anode contact on a first surface of the semiconductor substrate. The Schottky diode portion is also provided on the semiconductor substrate and includes a polysilicon layer on the semiconductor substrate and a ohmic contact on the polysilicon layer. Related Schottky diodes are also provided herein.

Abstract: Semiconductor switching devices include a wide band-gap power transistor, a wide band-gap surge current transistor that coupled in parallel to the power transistor, and a wide hand-gap driver transistor that is configured to drive the surge current transistor. Substantially all of the on-state output current of the semiconductor switching device flows through the channel of the power transistor when a drain-source voltage of the power transistor is within a first voltage range, which range may correspond, for example, to the drain-source voltages expected during normal operation. In contrast, the semiconductor switching device is further configured so that in the on-state the output current flows through both the surge current transistor and the channel of the power transistor when the drain-source voltage of the power transistor is within a second, higher voltage range.

Abstract: High power insulated gate bipolar junction transistors are provided that include a wide band gap semiconductor bipolar junction transistor (“BJT”) and a wide band gap semiconductor MOSFET that is configured to provide a current to the base of the BJT. These devices further include a minority carrier diversion semiconductor layer on the base of the BJT and coupled to the emitter of the BJT, the minority carrier diversion semiconductor layer having a conductivity type opposite the conductivity type of the base of the BJT and forming a heterojunction with the base of the BJT.

Abstract: A bipolar junction transistor includes a collector having a first conductivity type, a drift layer having the first conductivity type on the collector, a base layer on the drift layer and having a second conductivity type opposite the first conductivity type, a lightly doped buffer layer having the first conductivity type on the base layer and forming a p-n junction with the base layer, and an emitter mesa having the first conductivity type on the buffer layer and having a sidewall. The buffer layer includes a mesa step adjacent to and spaced laterally apart from the sidewall of the emitter mesa, and a first thickness of the buffer layer beneath the emitter mesa is greater than a second thickness of the buffer layer outside the mesa step.

Abstract: An electronic device includes a silicon carbide layer having a first conductivity type and a main junction adjacent a surface of the silicon carbide layer, and a junction termination region at the surface of the silicon carbide layer adjacent the main junction. Charge in the junction termination region decreases with lateral distance from the main junction, and a maximum charge in the junction termination region may be less than about 2×1014 cm?2.

Abstract: An electronic device includes a wide bandgap thyristor having an anode, a cathode, and a gate terminal, and a wide bandgap bipolar transistor having a base, a collector, and an emitter terminal. The emitter terminal of the bipolar transistor is directly coupled to the anode terminal of the thyristor such that the bipolar transistor and the thyristor are connected in series. The bipolar transistor and the thyristor define a wide bandgap bipolar power switching device that is configured to switch between a nonconducting state and a conducting state that allows current flow between a first main terminal corresponding to the collector terminal of the bipolar transistor and a second main terminal corresponding to the cathode terminal of the thyristor responsive to application of a first control signal to the base terminal of the bipolar transistor and responsive to application of a second control signal to the gate terminal of the thyristor. Related control circuits are also discussed.

Abstract: A method of forming a semiconductor device may include forming a terminal region of a first conductivity type within a semiconductor layer of the first conductivity type. A well region of a second conductivity type may be formed within the semiconductor layer wherein the well region is adjacent at least portions of the terminal region within the semiconductor layer, a depth of the well region into the semiconductor layer may be greater than a depth of the terminal region into the semiconductor layer, and the first and second conductivity types may be different. An epitaxial semiconductor layer may be formed on the semiconductor layer, and a terminal contact region of the first conductivity type may be formed in the epitaxial semiconductor layer with the terminal contact region providing electrical contact with the terminal region. In addition, an ohmic contact may be formed on the terminal contact region. Related structures are also discussed.

Abstract: The invention is a device for controlling conduction across a semiconductor body with a P type channel layer between active semiconductor regions of the device and the controlling gate contact. The device, often a MOSFET or an IGBT, includes at least one source, well, and drift region. The P type channel layer may be divided into sections, or divided regions, that have been doped to exhibit N type conductivity. By dividing the channel layer into regions of different conductivity, the channel layer allows better control over the threshold voltage that regulates current through the device. Accordingly, one of the divided regions in the channel layer is a threshold voltage regulating region. The threshold-voltage regulating region maintains its original P type conductivity and is available in the transistor for a gate voltage to invert a conductive zone therein. The conductive zone becomes the voltage regulated conductive channel within the device.

Abstract: An insulated gate bipolar transistor (IGBT) includes a first conductivity type substrate and a second conductivity type drift layer on the substrate. The second conductivity type is opposite the first conductivity type. The IGBT further includes a current suppressing layer on the drift layer. The current suppressing layer has the second conductivity type and has a doping concentration that is larger than a doping concentration of the drift layer. A first conductivity type well region is in the current suppressing layer. The well region has a junction depth that is less than a thickness of the current suppressing layer, and the current suppressing layer extends laterally beneath the well region. A second conductivity type emitter region is in the well region.

Abstract: A silicon carbide-based power device includes a silicon carbide drift layer having a planar surface that forms an off-axis angle with a <0001> direction of less than 8°.