General Electric Company

Dale M Brown

Marvin Garfinkel

Bernard Gorowitz

Gerald J Michon

Richard J Saia

Kevin Sean Matocha

Mario Ghezzo

James William Kretchmer

Peter Micah Sandvik

Manjin J Kim

John Adam Edmond

Stephen Daley Arthur

Emily Yixie Shu

John Williams Palmour

Lionel M Levinson

Richard D Baertsch

Roy F Thornton

Vikram Bidare Krishnamurthy

Jeffrey Bernard Fedison

Louis Jacob Petrucco

Simon S Cohen

John A Laurent

Thomas Edward Johnson

Wolfgang Daum

William E Engeler

Charles D Greskovich

Paul Alan McConnelee

James F Gibbons

Dominic A Cusano

Donald Thomas McGrath

Robert J Dunki-Jacobs

Robert Joseph Lyons

Michael Kent Cueman

Ernest Wayne Balch

Philip G Kosky

Zachary Matthew Stum

Gregory Alan Mohr

Ronald H Wilson

Tat-Sing P Chow

Kanin Chu

Thomas L Vogelsong

Paul Andrew Frank

Joseph M Pimbley

Jeffery Allan Lovett

Kirby Gannett Vosburgh

William Gregg Hawkins

Gregory Keith Dudoff

Kenneth J Polasko

Yoav Nissan-Cohen

The present invention provides a method of fabricating a metal oxide semiconductor field effect transistor. The method includes the steps of forming a source region on a silicon carbide layer and annealing the source region. A gate oxide layer is formed on the source region and the silicon carbide layer. The method further includes providing a gate electrode on the gate oxide layer and disposing a dielectric layer on the gate electrode and the gate oxide layer. The method further includes etching a portion of the dielectric layer and a portion of the gate oxide layer to form sidewalls on the gate electrode. A metal layer is disposed on the gate electrode, the sidewalls and the source region. The method further includes forming a gate contact and a source contact by subjecting the metal layer to a temperature of at least about 800&#xb0; C. The gate contact and the source contact comprise a metal silicide. The distance between the gate contact and the source contact is less than about 0.6 &#x3bc;m. A vertical SiC MOSFET is also provided.

SiC MOSFETs and self-aligned fabrication methods thereof

An optical spectrometer for combustion flame temperature determination includes at least two photodetectors positioned for receiving light from a combustion flame, each of the at least two photodetectors having a different, overlapping bandwidth for detecting a respective output signal in an ultraviolet emission band; and a computer for subtracting a respective output signal of a first one of the at least two photodetectors from a respective output signal of a second one of the at least two photodetectors to obtain a segment signal, and using the segment signal to determine the combustion flame temperature.

System and method for optical monitoring of a combustion flame

A detection system for detecting gamma rays including a scintillator crystal for receiving at least one gamma ray and generating at least one ultraviolet ray and an avalanche photodiode for detecting the ultraviolet ray. The avalanche photodiode includes: a substrate having a first dopant; a first layer having a second dopant, positioned on top of the substrate; a passivation layer for providing electrical passivation on a surface of the avalanche photodiode; a phosphorous silicate glass layer for limiting mobile ion transport, positioned above of the first layer; and a pair of metal electrodes for providing an ohmic contact wherein a first electrode is positioned below the substrate and a second electrode is positioned above the first layer. The avalanche photodiode comprises a first sidewall and a second sidewall forming a sloped mesa shape.

Detection system including avalanche photodiode for use in harsh environments

An aspect of the present invention is directed to an avalanche photodiode (APD) device for use in oil well drilling applications in harsh, down-hole environments where shock levels are near 250 gravitational acceleration (G) and/or temperatures approach or exceed 150&#xb0; C. Another aspect of the present invention is directed to an APD device fabricated using SiC materials. Another aspect of the present invention is directed to an APD device fabricated using GaN materials. According to an embodiment of the present invention, an avalanche photodiode for detecting ultraviolet photons comprises a substrate having a first dopant; a first layer having the first dopant, positioned on top of the substrate; a second layer having a second dopant, positioned on top of the first layer; a third layer having a second dopant, positioned on top of the second layer; a passivation layer for providing electrical passivation on a surface of the avalanche photodiode; a phosphorous silicate glass layer for limiting mobile ion transport, positioned on top of the third layer; and a pair of metal electrodes for providing an ohmic contact wherein a first electrode is positioned below the substrate and a second electrode is positioned above the third layer; wherein the avalanche photodiode comprises a first sidewall and a second sidewall forming a sloped mesa shape; and wherein the avalanche photodiode operates in an environment comprising a temperature approximately equal to 150 degrees Celsius.

Avalanche photodiode for use in harsh environments

A photodiode device includes a silicon carbide photodiode including a second semiconductor layer on a first semiconductor layer and an integral aluminum gallium nitride filter on the second semiconductor layer. A method for fabricating a photodiode device for combustion flame temperature determination includes fabricating an integral filter over a silicon carbide photodiode. Examples of various filter fabrication techniques include growing an aluminum gallium nitride filter, fabricating a silicon oxynitride filter, and alternating thin film layers of silicon oxide and silicon nitride.

Photodiode device and method for fabrication

A flame sensor for combustion flame temperature determination comprises elongated extensions that are positioned with parallel interdigitated longitudinal axis with respect to one another. An optical spectrometer comprises the sensor and a system comprises the sensor. A method for combustion flame temperature determination comprises obtaining a first photodiode signal and a second photodiode signal by using photodiode devices comprising photodiodes with elongated extending interdigitated digits. A method of fabricating a flame sensor for combustion flame temperature determination, comprises forming first and second photodiodes with elongated extending interdigitated digits.

Interdigitated flame sensor, system and method

A radiation detector includes: a scintillator which produces UV photons in response to receiving radiation from a radiation producing source; and, a wide bandgap semiconductor device sensitive to the UV photons produced by the scintillator. The semiconductor device produces an electric signal as a function of the amount of UV photons incident thereon. Preferably, the electric signal is then measure, recorded and/or otherwise analyzed.

SiC photodiode detectors for radiation detection applications

A solid state optical spectrometer for combustion flame temperature determination comprises: a first photodiode device for obtaining a first photodiode signal, the first photodiode device comprising a silicon carbide photodiode and having a range of optical responsivity within an OH band; a second photodiode device for obtaining a second photodiode signal, the second photodiode device comprising a silicon carbide photodiode and a filter, the second photodiode device having a range of optical responsivity in a different and overlapping portion of the OH band than the first photodiode device; and a computer for obtaining a ratio using the first and second photodiode signals and using the ratio to determine the combustion flame temperature.

Optical spectrometer and method for combustion flame temperature determination

An apparatus for detecting flashback occurrences in a premixed combustor system having at least one fuel nozzle includes at least one photodetector and at least one fiber optic element coupled between the at least one photodetector and a test region of the combustor system wherein a respective flame of the fuel nozzle is not present under normal operating conditions. A signal processor monitors a signal of the photodetector. The fiber optic element can include at least one optical fiber positioned within a protective tube. The fiber optic element can include two fiber optic elements coupled to the test region. The optical fiber and the protective tube can have lengths sufficient to situate the photodetector outside of an engine compartment. A plurality of fuel nozzles and a plurality of fiber optic elements can be used with the fiber optic elements being coupled to respective fuel nozzles and either to the photodetector or, wherein a plurality of photodetectors are used, to respective ones of the plurality of photodetectors. The signal processor can include a digital signal processor.

Fiber optic sensors for gas turbine control

An optical spectrometer for combustion flame temperature determination includes at least two photodetectors positioned for receiving light from a combustion flame and having different overlapping optical bandwidths for producing respective output signals; and a computer for obtaining a difference between a first respective output signal of a first one of the at least two photodetectors with and a second respective output signal of a second one of the at least two photodetectors, dividing the difference by one of the first and second respective output signals to obtain a normalized output signal, and using the normalized output signal to determine the combustion flame temperature.

An optical spectrometer for combustion flame temperature determination includes at least two photodetectors positioned for receiving light from a combustion flame, each of the at least two photodetectors having a different, overlapping bandwidth for detecting a respective output signal in an OH emission band; and a computer for subtracting a respective output signal of a first one of the at least two photodetectors from a respective output signal of a second one of the at least two photodetectors to obtain a segment signal, and using the segment signal to determine the combustion flame temperature.

Solid state optical spectrometer for combustion flame temperature measurement

A depletion mode MOSFET and resistor are fabricated as a silicon carbide (SiC) integrated circuit (IC). The SiC IC includes a first SiC layer doped to a first conductivity type and a second SiC layer overlaid on the first SiC layer and doped to a second conductivity type. The second SiC layer includes at least four more heavily doped regions of the second conductivity type, with two of such regions comprising MOSFET source and drain electrodes and two other of such regions comprising resistor electrodes. The second SiC layer includes an isolation trench between the MOSFET electrodes and the resistor electrodes. At least two electrically conductive contacts are provided as MOSFET electrode contacts, each being positioned over at least a portion of a respective MOSFET electrode and two other electrically conductive contacts are provided as resistor electrode contacts, each being positioned over at least a portion of a respective resistor electrode. An oxide layer extends over the second SiC layer with at least a portion of the oxide layer positioned between the MOSFET electrode contacts. A MOSFET gate electrode is positioned over the oxide layer, and coupling means are provided for electrically coupling one of the source, drain, and gate electrodes to one of the resistor electrodes.

Silicon carbide integrated circuits

A SiC MOSFET having a self-aligned gate structure is fabricated upon a monocrystalline substrate layer, such as a p type conductivity .alpha.6H silicon carbide (SiC) substrate. An SiC n+ type conductivity layer is epitaxially grown on the substrate layer. A steep-walled groove is etched through the n+ SiC layer and partially into the p SiC layer at a location on the substrate where a MOSFET gate structure is desired. Subsequently, a thin layer of silicon dioxide and a layer of gate metal are successively deposited over the entire structure. The gate metal layer is deposited with sufficient thickness to substantially fill the groove. A layer of photoresist is applied to the entire surface of the gate metal layer. The photoresist and the underlying gate metal are then reactive ion etched down to the oxide layer, leaving gate metal remaining only in the groove. The gate metal and oxide layer form the self-aligned gate structure wherein the walls of the groove are automatically aligned with the edges of drain and source regions that are formed on either side of the groove.

Silicon carbide MOSFET having self-aligned gate structure and method of

A SiC MOSFET having a self-aligned gate structure is fabricated upon a monocrystalline substrate layer, such as a p type conductivity .alpha.6H silicon carbide (SiC) substrate. An SiC n+ type conductivity layer, epitaxially grown on the substrate layer, includes a steep-walled groove etched through the n+ SiC layer and partially into the p SiC layer. The groove is lined with a thin layer of silicon dioxide which extends onto the n+ type conductivity layer. A filling of gate metal over the layer of silicon dioxide is contained entirely in the groove. The silicon dioxide layer includes a first window extending to the filling of gate metal in the groove, and second and third windows extending to the n+ type conductivity layer on either side of the groove, respectively. A gate contact extends through the first window to the filling of gate metal in the groove while drain and source contacts extend through the second and third window, respectively, to make contact with the n+ type conductivity layer in drain and source regions on either side of the groove.

Silicon carbide MOSFET having self-aligned gate structure

A MOSFET includes a first SiC semiconductor contact layer, a SiC semiconductor channel layer supported by the first SiC contact layer, and a second SiC semiconductor contact layer supported by the channel layer. The second contact and channel layers are patterned to form a plurality of gate region grooves therethrough. Each of the gate region grooves includes a base surface and side surfaces which are covered with groove oxide material. A plurality of metal gate layers are provided, each being supported in a respective one of the plurality of grooves. A plurality of deposited oxide layers are provided, each in a respective one of the grooves so as to be supported by a respective one of the plurality of metal gate layers. A first metal contact layer is applied to the surface of the first SiC contact layer, and a second metal contact layer is applied to a portion of the surface of the second SiC contact layer.

Vertical channel silicon carbide metal-oxide-semiconductor field effect

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Schenectady, NY, United States of America

Dale M Brown