SEMISOUTH LABORATORIES, INC. Patent applications |
Patent application number | Title | Published |
20140029152 | SOLID-STATE CIRCUIT BREAKERS - A fast acting unidirectional or bidirectional electronic circuit breaker for isolating a load from a power-supply unit is described. The described control method for an electronic circuit breaker is capable of instantaneous trip during a short circuit event by improved means of current sensing. The improved control method eliminates the need for additional series components in the conduction path which can add to the circuit breaker's insertion losses. Also, any delay or bandwidth limitations commonly associated with magnetic or hall-effect current sensing methods are eliminated. Circuit breakers with automatic or manual reset options are also described. | 01-30-2014 |
20130062628 | METHODS FOR THE EPITAXIAL GROWTH OF SILICON CARBIDE - A method for the epitaxial growth of SiC is described which includes contacting a surface of a substrate with hydrogen and HCl, subsequently increasing the temperature of the substrate to at least 1550° C. and epitaxially growing SiC on the surface of the substrate. A method for the epitaxial growth of SiC is also described which includes heating a substrate to a temperature of at least 1550° C., contacting a surface of the substrate with a C containing gas and a Si containing gas at a C/Si ratio of 0.5-0.8 to form a SiC buffer layer and subsequently contacting the surface with a C containing gas and a Si containing gas at a C/Si ratio >0.8 to form a SiC epitaxial layer on the SiC buffer layer. The method results in silicon carbide epitaxial layers with improved surface morphology. | 03-14-2013 |
20120262220 | CASCODE SWITCHES INCLUDING NORMALLY-OFF AND NORMALLY-ON DEVICES AND CIRCUITS COMPRISING THE SWITCHES - Switches comprising a normally-off semiconductor device and a normally-on semiconductor device in cascode arrangement are described. The switches include a capacitor connected between the gate of the normally-on device and the source of the normally-off device. The switches may also include a zener diode connected in parallel with the capacitor between the gate of the normally-on device and the source of the normally-off device. The switches may also include a pair of zener diodes in series opposing arrangement between the gate and source of the normally-off device. Switches comprising multiple normally-on and/or multiple normally-off devices are also described. The normally-on device can be a JFET such as a SiC JFET. The normally-off device can be a MOSFET such as a Si MOSFET. The normally-on device can be a high voltage device and the normally-off device can be a low voltage device. Circuits comprising the switches are also described. | 10-18-2012 |
20120187421 | VERTICAL JUNCTION FIELD EFFECT TRANSISTORS AND DIODES HAVING GRADED DOPED REGIONS AND METHODS OF MAKING - Semiconductor devices and methods of making the devices are described. The devices can be junction field-effect transistors (JFETs) or diodes such as junction barrier Schottky (JBS) diodes or PiN diodes. The devices have graded p-type semiconductor layers and/or regions formed by epitaxial growth. The methods do not require ion implantation. The devices can be made from a wide-bandgap semiconductor material such as silicon carbide (SiC) and can be used in high temperature and high power applications. | 07-26-2012 |
20110291112 | NORMALLY-OFF INTEGRATED JFET POWER SWITCHES IN WIDE BANDGAP SEMICONDUCTORS AND METHODS OF MAKING - Wide bandgap semiconductor devices including normally-off VJFET integrated power switches are described. The power switches can be implemented monolithically or hybridly, and may be integrated with a control circuit built in a single- or multi-chip wide bandgap power semiconductor module. The devices can be used in high-power, temperature-tolerant and radiation-resistant electronics components. Methods of making the devices are also described. | 12-01-2011 |
20110291107 | SELF-ALIGNED SEMICONDUCTOR DEVICES WITH REDUCED GATE-SOURCE LEAKAGE UNDER REVERSE BIAS AND METHODS OF MAKING - A vertical junction field effect transistor (VJFET) having a self-aligned pin, a p+/n/n+ or a p+/p/n+ gate-source junction is described. The device gate can be self-aligned to within 0.5 μm to the source in order to maintain good high voltage performance (i.e. low DIBL) while reducing gate-source junction leakage under reverse bias. The device can be a wide-bandgap semiconductor device such as a SiC vertical channel junction field effect. Methods of making the device are also described. | 12-01-2011 |
20110217829 | SEMICONDUCTOR DEVICES WITH NON-PUNCH-THROUGH SEMICONDUCTOR CHANNELS HAVING ENHANCED CONDUCTION AND METHODS OF MAKING - Semiconductor devices are described wherein current flow in the device is confined between the rectifying junctions (e.g., p-n junctions or metal-semiconductor junctions). The device provides non-punch-through behavior and enhanced current conduction capability. The devices can be power semiconductor devices as such as Junction Field-Effect Transistors (VJFETs), Static Induction Transistors (SITs), Junction Field Effect Thyristors, or JFET current limiters. The devices can be made in wide bandgap semiconductors such as silicon carbide (SiC). According to some embodiments, the device can be a normally-off SiC vertical junction field effect transistor. Methods of making the devices and circuits comprising the devices are also described. | 09-08-2011 |
20110210340 | HIGH TEMPERATURE GATE DRIVERS FOR WIDE BANDGAP SEMICONDUCTOR POWER JFETS AND INTEGRATED CIRCUITS INCLUDING THE SAME - Gate drivers for wide bandgap (e.g., >2 eV) semiconductor junction field effect transistors (JFETs) capable of operating in high ambient temperature environments are described. The wide bandgap (WBG) semiconductor devices include silicon carbide (SiC) and gallium nitride (GaN) devices. The driver can be a non-inverting gate driver which has an input, an output, a first reference line for receiving a first supply voltage, a second reference line for receiving a second supply voltage, a ground terminal, and six Junction Field-Effect Transistors (JFETs) wherein the first JFET and the second JFET form a first inverting buffer, the third JFET and the fourth JFET form a second inverting buffer, and the fifth JFET and the sixth JFET form a totem pole which can be used to drive a high temperature power SiC JFET. An inverting gate driver is also described. | 09-01-2011 |
20110133212 | METHODS OF MAKING SEMICONDUCTOR DEVICES HAVING IMPLANTED SIDEWALLS AND DEVICES MADE THEREBY - Semiconductor devices and methods of making the devices are described. The devices can be junction field-effect transistors (JFETs) or diodes such as junction barrier Schottky (JBS) diodes or PiN diodes. The devices are made using selective ion implantation using an implantation mask. The devices have implanted sidewalls formed by scattering of normal or near normal incident ions from the implantation mask. Vertical junction field-effect transistors with long channel length are also described. The devices can be made from a wide-bandgap semiconductor material such as silicon carbide (SiC) and can be used in high temperature and high power applications. | 06-09-2011 |
20110121884 | HALF-BRIDGE CIRCUITS EMPLOYING NORMALLY ON SWITCHES AND METHODS OF PREVENTING UNINTENDED CURRENT FLOW THEREIN - A method for rendering a half-bridge circuit containing normally on switches such as junction field effect transistors (JFETs) inherently safe from uncontrolled current flow is described. The switches can be made from silicon carbide or from silicon. The methods described herein allow for the use of better performing normally on switches in place of normally off switches in integrated power modules thereby improving the efficiency, size, weight, and cost of the integrated power modules. As described herein, a power supply can be added to the gate driver circuitry. The power supply can be self starting and self oscillating while being capable of deriving all of its source energy from the terminals supplying electrical potential to the normally on switch through the gate driver. The terminal characteristics of the normally on switch can then be coordinated to the input-to-output characteristics of the power supply. | 05-26-2011 |
20110020991 | VERTICAL JUNCTION FIELD EFFECT TRANSISTORS HAVING SLOPED SIDEWALLS AND METHODS OF MAKING - Semiconductor devices and methods of making the devices are described. The devices can be junction field-effect transistors (JFETs). The devices have raised regions with sloped sidewalls which taper inward. The sidewalls can form an angle of 5° or more from vertical to the substrate surface. The devices can have dual-sloped sidewalls in which a lower portion of the sidewalls forms an angle of 5° or more from vertical and an upper portion of the sidewalls forms an angle of <5° from vertical. The devices can be made using normal (i.e., 0°) or near normal incident ion implantation. The devices have relatively uniform sidewall doping and can be made without angled implantation. | 01-27-2011 |
20110003456 | SILICON CARBIDE AND RELATED WIDE-BANDGAP TRANSISTORS ON SEMI INSULATING EPITAXY - A method of making a semi-insulating epitaxial layer includes implanting a substrate or a first epitaxial layer formed on the substrate with boron ions to form a boron implanted region on a surface of the substrate or on a surface of the first epitaxial layer, and growing a second epitaxial layer on the boron implanted region of the substrate or on the boron implanted region of the first epitaxial layer to form a semi-insulating epitaxial layer. | 01-06-2011 |
20100320530 | METHODS OF MAKING VERTICAL JUNCTION FIELD EFFECT TRANSISTORS AND BIPOLAR JUNCTION TRANSISTORS WITHOUT ION IMPLANTATION AND DEVICES MADE THEREWITH - Methods of making semiconductor devices such as vertical junction field effect transistors (VJFETs) or bipolar junction transistors (BJTs) are described. The methods do not require ion implantation. The VJFET device has an epitaxially regrown n-type channel layer and an epitaxially regrown p-type gate layer as well as an epitaxially grown buried gate layer. Devices made by the methods are also described. | 12-23-2010 |
20100320476 | VERTICAL JUNCTION FIELD EFFECT TRANSISTORS AND DIODES HAVING GRADED DOPED REGIONS AND METHODS OF MAKING - Semiconductor devices and methods of making the devices are described. The devices can be junction field-effect transistors (JFETs) or diodes such as junction barrier Schottky (JBS) diodes or PiN diodes. The devices have graded p-type semiconductor layers and/or regions formed by epitaxial growth. The methods do not require ion implantation. The devices can be made from a wide-bandgap semiconductor material such as silicon carbide (SiC) and can be used in high temperature and high power applications. | 12-23-2010 |
20100295102 | NORMALLY-OFF INTEGRATED JFET POWER SWITCHES IN WIDE BANDGAP SEMICONDUCTORS AND METHODS OF MAKING - Wide bandgap semiconductor devices including normally-off VJFET integrated power switches are described. The power switches can be implemented monolithically or hybridly, and may be integrated with a control circuit built in a single- or multi-chip wide bandgap power semiconductor module. The devices can be used in high-power, temperature-tolerant and radiation-resistant electronics components. Methods of making the devices are also described. | 11-25-2010 |
20100283515 | GATE DRIVER FOR ENHANCEMENT-MODE AND DEPLETION-MODE WIDE BANDGAP SEMICONDUCTOR JFETS - A DC-coupled two-stage gate driver circuit for driving a junction field effect transistor (JFET) is provided. The JFET can be a wide bandgap junction field effect transistor (JFET) such as a SiC JFET. The driver includes a first turn-on circuit, a second turn-on circuit and a pull-down circuit. The driver is configured to accept an input pulse-width modulation (PWM) control signal and generate an output driver signal for driving the gate of the JFET. | 11-11-2010 |
20100283061 | HIGH TEMPERATURE GATE DRIVERS FOR WIDE BANDGAP SEMICONDUCTOR POWER JFETS AND INTEGRATED CIRCUITS INCLUDING THE SAME - Gate drivers for wide bandgap (e.g., >2 eV) semiconductor junction field effect transistors (JFETs) capable of operating in high ambient temperature environments are described. The wide bandgap (WBG) semiconductor devices include silicon carbide (SiC) and gallium nitride (GaN) devices. The driver can be a non-inverting gate driver which has an input, an output, a first reference line for receiving a first supply voltage, a second reference line for receiving a second supply voltage, a ground terminal, and six Junction Field-Effect Transistors (JFETs) wherein the first JFET and the second JFET form a first inverting buffer, the third JFET and the fourth JFET form a second inverting buffer, and the fifth JFET and the sixth JFET form a totem pole which can be used to drive a high temperature power SiC JFET. An inverting gate driver is also described. | 11-11-2010 |
20100148186 | VERTICAL JUNCTION FIELD EFFECT TRANSISTORS HAVING SLOPED SIDEWALLS AND METHODS OF MAKING - Semiconductor devices and methods of making the devices are described. The devices can be junction field-effect transistors (JFETs). The devices have raised regions with sloped sidewalls which taper inward. The sidewalls can form an angle of 5° or more from vertical to the substrate surface. The devices can have dual-sloped sidewalls in which a lower portion of the sidewalls forms an angle of 5° or more from vertical and an upper portion of the sidewalls forms an angle of <5° from vertical. The devices can be made using normal (i.e., 0°) or near normal incident ion implantation. The devices have relatively uniform sidewall doping and can be made without angled implantation. | 06-17-2010 |
20100026370 | HALF-BRIDGE CIRCUITS EMPLOYING NORMALLY ON SWITCHES AND METHODS OF PREVENTING UNINTENDED CURRENT FLOW THEREIN - A method for rendering a half-bridge circuit containing normally on switches such as junction field effect transistors (JFETS) inherently safe from uncontrolled current flow is described. The switches can be made from silicon carbide or from silicon. The methods described herein allow for the use of better performing normally on switches in place of normally off switches in integrated power modules thereby improving the efficiency, size, weight, and cost of the integrated power modules. As described herein, a power supply can be added to the gate driver circuitry. The power supply can be self starting and self oscillating while being capable of deriving all of its source energy from the terminals supplying electrical potential to the normally on switch through the gate driver. The terminal characteristics of the normally on switch can then be coordinated to the input-to-output characteristics of the power supply. | 02-04-2010 |
20090278177 | SEMICONDUCTOR DEVICES WITH NON-PUNCH-THROUGH SEMICONDUCTOR CHANNELS HAVING ENHANCED CONDUCTION AND METHODS OF MAKING - Semiconductor devices are described wherein current flow in the device is confined between the rectifying junctions (e.g., p-n junctions or metal-semiconductor junctions). The device provides non-punch-through behavior and enhanced current conduction capability. The devices can be power semiconductor devices as such as Junction Field-Effect Transistors (VJFETs), Static Induction Transistors (SITs), Junction Field Effect Thyristors, or JFET current limiters. The devices can be made in wide bandgap semiconductors such as silicon carbide (SiC). According to some embodiments, the device can be a normally-off SiC vertical junction field effect transistor. Methods of making the devices and circuits comprising the devices are also described. | 11-12-2009 |
20090278137 | SEMICONDUCTOR DEVICES WITH NON-PUNCH-THROUGH SEMICONDUCTOR CHANNELS HAVING ENHANCED CONDUCTION AND METHODS OF MAKING - Semiconductor devices are described wherein current flow in the device is confined between the rectifying junctions (e.g., p-n junctions or metal-semiconductor junctions). The device provides non-punch-through behavior and enhanced current conduction capability. The devices can be power semiconductor devices as such as Junction Field-Effect Transistors (VJFETs), Static Induction Transistors (SITs), Junction Field Effect Thyristors, or JFET current limiters. The devices can be made in wide bandgap semiconductors such as silicon carbide (SiC). According to some embodiments, the device can be a normally-off SiC vertical junction field effect transistor. Methods of making the devices and circuits comprising the devices are also described. | 11-12-2009 |
20090242899 | Epitaxial Growth on Low Degree Off-Axis SiC Substrates and Semiconductor Devices Made Thereby - A method of epitaxially growing a SiC layer on a single crystal SiC substrate is described. The method includes heating a single-crystal SiC substrate to a first temperature of at least 1400° C. in a chamber, introducing a carrier gas, a silicon containing gas and carbon containing gas into the chamber; and epitaxially growing a layer of SiC on a surface of the SiC substrate. The SiC substrate is heated to the first temperature at a rate of at least | 10-01-2009 |
20080251793 | JUNCTION BARRIER SCHOTTKY RECTIFIERS HAVING EPITAXIALLY GROWN P+-N JUNCTIONS AND METHODS OF MAKING - A junction barrier Schottky (JBS) rectifier device and a method of making the device are described. The device comprises an epitaxially grown first n-type drift layer and p-type regions forming p | 10-16-2008 |