Abstract: A semiconductor device may include a semiconductor buffer layer having a first conductivity type and a semiconductor mesa having the first conductivity type on a surface of the buffer layer. In addition, a current shifting region having a second conductivity type may be provided adjacent a corner between the semiconductor mesa and the semiconductor buffer layer, and the first and second conductivity types may be different conductivity types. Related methods are also discussed.

Abstract: A semiconductor device includes a semiconductor layer having a first conductivity type, a metal contact on the semiconductor layer and forming a Schottky junction with the semiconductor layer, and a semiconductor region in the semiconductor layer. The semiconductor region and the semiconductor layer form a first p-n junction in parallel with the Schottky junction. The first p-n junction is configured to generate a depletion region in the semiconductor layer adjacent the Schottky junction when the Schottky junction is reversed biased to thereby limit reverse leakage current through the Schottky junction. The first p-n junction is further configured such that punch-through of the first p-n junction occurs at a lower voltage than a breakdown voltage of the Schottky junction when the Schottky junction is reverse biased.

Abstract: A semiconductor device includes a drift layer of a first conductivity type having a doping concentration and a conduction layer also of the first conductivity type on the drift layer that has a doping concentration greater than the doping concentration of the drift layer. The device also includes a pair of trench structures, each including a trench contact at one end and a region of a second conductivity type opposite the first conductivity type, at another end. Each trench structure extends into and terminates within the conduction layer such that the second-conductivity-type region is within the conduction layer. A first contact structure is on the drift layer opposite the conduction layer while a second contact structure is on the conduction layer.

Abstract: Insulated gate bipolar conduction transistors (IBCTs) are provided. The IBCT includes a drift layer having a first conductivity type. An emitter well region is provided in the drift layer and has a second conductivity type opposite the first conductivity type. A well region is provided in the drift layer and has the second conductivity type. The well region is spaced apart from the emitter well region. A space between the emitter well region and the well region defines a JFET region of the IBCT. An emitter region is provided in the well region and has the first conductivity type and a buried channel layer is provided on the emitter well region, the well region and the JFET region and has the first conductivity type. Related methods of fabrication are also provided.

Abstract: An electronic device includes a drift layer having a first conductivity type, a buffer layer having a second conductivity type, opposite the first conductivity type, on the drift layer and forming a P—N junction with the drift layer, and a junction termination extension region having the second conductivity type in the drift layer adjacent the P—N junction. The buffer layer includes a step portion that extends over a buried portion of the junction termination extension. Related methods are also disclosed.

Abstract: A semiconductor device according to some embodiments includes a semiconductor layer having a first conductivity type and a surface in which an active region of the semiconductor device is defined. A plurality of spaced apart first doped regions are arranged within the active region. The plurality of first doped regions have a second conductivity type that is opposite the first conductivity type, have a first dopant concentration, and define a plurality of exposed portions of the semiconductor layer within the active region. The plurality of first doped regions are arranged as islands in the semiconductor layer. A second doped region in the semiconductor layer has the second conductivity type and has a second dopant concentration that is greater than the first dopant concentration.

Abstract: An electronic device includes a silicon carbide drift region having a first conductivity type, a Schottky contact on the drift region, and a plurality of junction barrier Schottky (JBS) regions at a surface of the drift region adjacent the Schottky contact. The JBS regions have a second conductivity type opposite the first conductivity type and have a first spacing between adjacent ones of the JBS regions. The device further includes a plurality of surge protection subregions having the second conductivity type. Each of the surge protection subregions has a second spacing between adjacent ones of the surge protection subregions that is less than the first spacing.

Abstract: In accordance with an embodiment of the present invention, a gate structure for a U-shape Metal-Oxide-Semiconductor (UMOS) device includes a dielectric layer formed into a U-shape having side walls and a floor to form a trench surrounding a dielectric layer interior region, a doped poly-silicon layer deposited adjacent to the dielectric layer within the dielectric layer interior region where the doped poly-silicon layer has side walls and a floor surrounding a doped poly-silicon layer interior region, a first metal layer deposited on the doped poly-silicon layer on a side opposite from the dielectric layer where the first metal layer has side walls and a floor surrounding a first metal layer interior region, and an undoped poly-silicon layer deposited to fill the first metal layer interior region.

Abstract: Edge termination structures for semiconductor devices are provided including a plurality of spaced apart concentric floating guard rings in a semiconductor layer that at least partially surround a semiconductor junction. The spaced apart concentric floating guard rings have a highly doped portion and a lightly doped portion. Related methods of fabricating devices are also provided herein.

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: 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: 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: Insulated gate bipolar conduction transistors (IBCTs) are provided. The IBCT includes a drift layer having a first conductivity type. An emitter well region is provided in the drift layer and has a second conductivity type opposite the first conductivity type. A well region is provided in the drift layer and has the second conductivity type. The well region is spaced apart from the emitter well region. A space between the emitter well region and the well region defines a JFET region of the IBCT. An emitter region is provided in the well region and has the first conductivity type and a buried channel layer is provided on the emitter well region, the well region and the JFET region and has the first conductivity type. Related methods of fabrication are also provided.

Abstract: A U-shape Metal-Oxide-Semiconductor (UMOS) device comprises a P-base layer, an N+ source region disposed in the P-base layer where the source region has a first surface coplanar with a first surface of the P-base layer, a dielectric layer extending through the P-base layer and forming a U-shape trench having side walls and floor enclosing a trench interior region, a conducting gate material filling the trench interior region, a first accumulation channel layer disposed along a first side wall of the U-shape trench and in contact with the source region and a first side wall of the U-shape trench, a P-junction gate disposed adjacent to the dielectric layer floor and in proximity to the first accumulation channel layer, and an N-drift region where the P-junction gate is disposed between the dielectric layer and the N-drift region.

Abstract: A silicon carbide power device is fabricated by forming a p-type silicon carbide epitaxial layer on an n-type silicon carbide substrate, and forming a silicon carbide power device structure on the p-type silicon carbide epitaxial layer. The n-type silicon carbide substrate is at least partially removed, so as to expose the p-type silicon carbide epitaxial layer. An ohmic contact is formed on at least some of the p-type silicon carbide epitaxial layer that is exposed. By at least partially removing the n-type silicon carbide substrate and forming an ohmic contact on the p-type silicon carbide epitaxial layer, the disadvantages of using a p-type substrate may be reduced or eliminated. Related structures are also described.

Abstract: A power diode having a silicon mesa atop the drift region includes a first contact positioned on the silicon mesa. The silicon mesa is highly doped p-type or n-type, and the anode may be formed on the mesa. The mesa may include two separate silicon layers, one of which is a Schottky barrier height layer. Under a forward bias, the silicon mesa provides carriers to achieve desirable forward current characteristics. The substrate has a significantly reduced thickness. The diode achieves reverse voltage blocking capability by implanting junction barrier Schottky wells within the body of the diode. The diode utilizes a deeper portion of the drift region to support the reverse bias. The method of forming the diode with a silicon mesa includes forming the mesa within a window on the diode or by thermally or mechanically bonding the silicon layer to the drift region.

Abstract: An insulated gate bipolar transistor (IGBT) includes a substrate having a first conductivity type, a drift layer having a second conductivity type opposite the first conductivity type, and a well region in the drift layer and having the first conductivity type. An epitaxial channel adjustment layer is on the drift layer and has the second conductivity type. An emitter region extends from a surface of the epitaxial channel adjustment layer through the epitaxial channel adjustment layer and into the well region. The emitter region has the second conductivity type and at least partially defines a channel region in the well region adjacent to the emitter region. A gate oxide layer is on the channel region, and a gate is on the gate oxide layer. Related methods are also disclosed.

Abstract: In accordance with an embodiment of the present invention, a gate structure for a U-shape Metal-Oxide-Semiconductor (UMOS) device includes a dielectric layer formed into a U-shape having side walls and a floor to form a trench surrounding a dielectric layer interior region, a doped poly-silicon layer deposited adjacent to the dielectric layer within the dielectric layer interior region where the doped poly-silicon layer has side walls and a floor surrounding a doped poly-silicon layer interior region, a first metal layer deposited on the doped poly-silicon layer on a side opposite from the dielectric layer where the first metal layer has side walls and a floor surrounding a first metal layer interior region, and an undoped poly-silicon layer deposited to fill the first metal layer interior region.

Abstract: A U-shape Metal-Oxide-Semiconductor (UMOS) device comprises a P-base layer, an N+ source region disposed in the P-base layer where the source region has a first surface coplanar with a first surface of the P-base layer, a dielectric layer extending through the P-base layer and forming a U-shape trench having side walls and floor enclosing a trench interior region, a conducting gate material filling the trench interior region, a first accumulation channel layer disposed along a first side wall of the U-shape trench and in contact with the source region and a first side wall of the U-shape trench, a P-junction gate disposed adjacent to the dielectric layer floor and in proximity to the first accumulation channel layer, and an N-drift region where the P-junction gate is disposed between the dielectric layer and the N-drift region.

Abstract: A semiconductor device includes a semiconductor layer having a first conductivity type, a metal contact on the semiconductor layer and forming a Schottky junction with the semiconductor layer, and a semiconductor region in the semiconductor layer. The semiconductor region and the semiconductor layer form a first p-n junction in parallel with the Schottky junction. The first p-n junction is configured to generate a depletion region in the semiconductor layer adjacent the Schottky junction when the Schottky junction is reversed biased to thereby limit reverse leakage current through the Schottky junction. The first p-n junction is further configured such that punch-through of the first p-n junction occurs at a lower voltage than a breakdown voltage of the Schottky junction when the Schottky junction is reverse biased.