Patents by Inventor Scott T. Allen
Scott T. Allen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9142636Abstract: A III-Nitride field-effect transistor, specifically a HEMT, comprises a channel layer, a barrier layer on the channel layer, an etch stop layer on the cap layer, a dielectric layer on the etch stop layer, a gate recess that extends to the barrier layer, and a gate contact in the gate recess. The etch stop layer may reduce damage associated with forming the recessed gate by not exposing the barrier layer to dry etching. The etch stop layer in the recess is removed and the remaining etch stop layer serves as a passivation layer.Type: GrantFiled: May 13, 2013Date of Patent: September 22, 2015Assignee: Cree, Inc.Inventors: Scott T. Sheppard, Andrew K. Mackenzie, Scott T. Allen, Richard P. Smith
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Patent number: 8907366Abstract: Semiconductor light emitting devices, such as light emitting diodes, include a substrate, an epitaxial region on the substrate that includes a light emitting region such as a light emitting diode region, and a multilayer conductive stack including a current spreading layer, on the epitaxial region. A barrier layer is provided on the current spreading layer and extending on a sidewall of the current spreading layer. The multilayer conductive stack can also include an ohmic layer between the reflector and the epitaxial region. The barrier layer further extends on a sidewall of the ohmic layer. The barrier layer can also extend onto the epitaxial region outside the multilayer conductive stack. The barrier layer can be fabricated as a series of alternating first and second sublayers.Type: GrantFiled: October 30, 2013Date of Patent: December 9, 2014Assignee: Cree, Inc.Inventors: David B. Slater, Jr., Bradley E. Williams, Peter S. Andrews, John A. Edmond, Scott T. Allen
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Publication number: 20140048822Abstract: Semiconductor light emitting devices, such as light emitting diodes, include a substrate, an epitaxial region on the substrate that includes a light emitting region such as a light emitting diode region, and a multilayer conductive stack including a current spreading layer, on the epitaxial region. A barrier layer is provided on the current spreading layer and extending on a sidewall of the current spreading layer. The multilayer conductive stack can also include an ohmic layer between the reflector and the epitaxial region. The barrier layer further extends on a sidewall of the ohmic layer. The barrier layer can also extend onto the epitaxial region outside the multilayer conductive stack. The barrier layer can be fabricated as a series of alternating first and second sublayers.Type: ApplicationFiled: October 30, 2013Publication date: February 20, 2014Applicant: Cree, Inc.Inventors: David B. Slater, JR., Bradley E. Williams, Peter S. Andrews, John A. Edmond, Scott T. Allen
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Patent number: 8604502Abstract: Semiconductor light emitting devices, such as light emitting diodes, include a substrate, an epitaxial region on the substrate that includes a light emitting region such as a light emitting diode region, and a multilayer conductive stack including a reflector layer, on the epitaxial region. A barrier layer is provided on the reflector layer and extending on a sidewall of the reflector layer. The multilayer conductive stack can also include an ohmic layer between the reflector and the epitaxial region. The barrier layer further extends on a sidewall of the ohmic layer. The barrier layer can also extend onto the epitaxial region outside the multilayer conductive stack. The barrier layer can be fabricated as a series of alternating first and second sublayers.Type: GrantFiled: August 15, 2012Date of Patent: December 10, 2013Assignee: Cree, Inc.Inventors: David B. Slater, Jr., Bradley E. Williams, Peter S. Andrews, John A. Edmond, Scott T. Allen
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Publication number: 20130252386Abstract: A III-Nitride field-effect transistor, specifically a HEMT, comprises a channel layer, a barrier layer on the channel layer, an etch stop layer on the cap layer, a dielectric layer on the etch stop layer, a gate recess that extends to the barrier layer, and a gate contact in the gate recess. The etch stop layer may reduce damage associated with forming the recessed gate by not exposing the barrier layer to dry etching. The etch stop layer in the recess is removed and the remaining etch stop layer serves as a passivation layer.Type: ApplicationFiled: May 13, 2013Publication date: September 26, 2013Applicant: Cree, Inc.Inventors: Scott T. Sheppard, Andrew K. Mackenzie, Scott T. Allen, Richard P. Smith
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Publication number: 20120305939Abstract: Semiconductor light emitting devices, such as light emitting diodes, include a substrate, an epitaxial region on the substrate that includes a light emitting region such as a light emitting diode region, and a multilayer conductive stack including a reflector layer, on the epitaxial region. A barrier layer is provided on the reflector layer and extending on a sidewall of the reflector layer. The multilayer conductive stack can also include an ohmic layer between the reflector and the epitaxial region. The barrier layer further extends on a sidewall of the ohmic layer. The barrier layer can also extend onto the epitaxial region outside the multilayer conductive stack. The barrier layer can be fabricated as a series of alternating first and second sublayers.Type: ApplicationFiled: August 15, 2012Publication date: December 6, 2012Inventors: David B. Slater, JR., Bradley E. Williams, Peter S. Andrews, John A. Edmond, Scott T. Allen
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Patent number: 8269241Abstract: Semiconductor light emitting devices, such as light emitting diodes, include a substrate, an epitaxial region on the substrate that includes a light emitting region such as a light emitting diode region, and a multilayer conductive stack including a reflector layer, on the epitaxial region. A barrier layer is provided on the reflector layer and extending on a sidewall of the reflector layer. The multilayer conductive stack can also include an ohmic layer between the reflector and the epitaxial region. The barrier layer further extends on a sidewall of the ohmic layer. The barrier layer can also extend onto the epitaxial region outside the multilayer conductive stack. The barrier layer can be fabricated as a series of alternating first and second sublayers.Type: GrantFiled: September 22, 2009Date of Patent: September 18, 2012Assignee: Cree, Inc.Inventors: David B. Slater, Jr., Bradley E. Williams, Peter S. Andrews, John A. Edmond, Scott T. Allen
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Patent number: 7970891Abstract: The present disclosure includes a system and method for tracking links displayed in Web browsers. In some implementations, a method includes receiving a hostname operable to identify an action and an instance of a link displayed through a Web browser. The hostname is unique for a period of time. The one or more actions associated with the displayed link are tracked.Type: GrantFiled: January 17, 2007Date of Patent: June 28, 2011Assignee: Google Inc.Inventors: Leonidas Kontothanssis, Scott T. Allen
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Publication number: 20100006883Abstract: Semiconductor light emitting devices, such as light emitting diodes, include a substrate, an epitaxial region on the substrate that includes a light emitting region such as a light emitting diode region, and a multilayer conductive stack including a reflector layer, on the epitaxial region. A barrier layer is provided on the reflector layer and extending on a sidewall of the reflector layer. The multilayer conductive stack can also include an ohmic layer between the reflector and the epitaxial region. The barrier layer further extends on a sidewall of the ohmic layer. The barrier layer can also extend onto the epitaxial region outside the multilayer conductive stack. The barrier layer can be fabricated as a series of alternating first and second sublayers.Type: ApplicationFiled: September 22, 2009Publication date: January 14, 2010Inventors: David B. Slater, JR., Bradley E. Williams, Peter S. Andrews, John A. Edmond, Scott T. Allen
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Patent number: 7611915Abstract: Semiconductor light emitting devices, such as light emitting diodes, include a substrate, an epitaxial region on the substrate that includes a light emitting region such as a light emitting diode region, and a multilayer conductive stack including a reflector layer, on the epitaxial region. A barrier layer is provided on the reflector layer and extending on a sidewall of the reflector layer. The multilayer conductive stack can also include an ohmic layer between the reflector and the epitaxial region. The barrier layer further extends on a sidewall of the ohmic layer. The barrier layer can also extend onto the epitaxial region outside the multilayer conductive stack. The barrier layer can be fabricated as a series of alternating first and second sublayers.Type: GrantFiled: March 20, 2007Date of Patent: November 3, 2009Assignee: Cree, Inc.Inventors: David B. Slater, Jr., Bradley E. Williams, Peter S. Andrews, John A. Edmond, Scott T. Allen
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Patent number: 7211833Abstract: Semiconductor light emitting devices, such as light emitting diodes, include a substrate, an epitaxial region on the substrate that includes a light emitting region such as a light emitting diode region, and a multilayer conductive stack including a reflector layer, on the epitaxial region. A barrier layer is provided on the reflector layer and extending on a sidewall of the reflector layer. The multilayer conductive stack can also include an ohmic layer between the reflector and the epitaxial region. The barrier layer further extends on a sidewall of the ohmic layer. The barrier layer can also extend onto the epitaxial region outside the multilayer conductive stack. The barrier layer can be fabricated as a series of alternating first and second sublayers.Type: GrantFiled: January 20, 2005Date of Patent: May 1, 2007Assignee: Cree, Inc.Inventors: David B. Slater, Jr., Bradley E. Williams, Peter S. Andrews, John A. Edmond, Scott T. Allen
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Patent number: 7067361Abstract: SiC MESFETs are disclosed which utilize a semi-insulating SiC substrate which substantially free of deep-level dopants. Utilization of the semi-insulating substrate may reduce back-gating effects in the MESFETs. Also provided are SiC MESFETs with a two recess gate structure. MESFETS with a selectively doped p-type buffer layer are also provided. Utilization of such a buffer layer may reduce output conductance by a factor of 3 and produce a 3 db increase in power gain over SiC MESFETs with conventional p-type buffer layers. A ground contact may also be provided to the p-type buffer layer and the p-type buffer layer may be made of two p-type layers with the layer formed on the substrate having a higher dopant concentration. SiC MESFETs according to embodiments of the present invention may also utilize chromium as a Schottky gate material. Furthermore, an oxide-nitride-oxide (ONO) passivation layer may be utilized to reduce surface effects in SiC MESFETs.Type: GrantFiled: November 12, 2003Date of Patent: June 27, 2006Assignee: Cree, Inc.Inventors: Scott T. Allen, John W. Palmour, Terrence S. Alcorn
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Publication number: 20040159865Abstract: SiC MESFETs are disclosed which utilize a semi-insulating SiC substrate which substantially free of deep-level dopants. Utilization of the semi-insulating substrate may reduce back-gating effects in the MESFETs. Also provided are SiC MESFETs with a two recess gate structure. MESFETS with a selectively doped p-type buffer layer are also provided. Utilization of such a buffer layer may reduce output conductance by a factor of 3 and produce a 3 db increase in power gain over SiC MESFETs with conventional p-type buffer layers. A ground contact may also be provided to the p-type buffer layer and the p-type buffer layer may be made of two p-type layers with the layer formed on the substrate having a higher dopant concentration. SiC MESFETs according to embodiments of the present invention may also utilize chromium as a Schottky gate material. Furthermore, an oxide-nitride-oxide (ONO) passivation layer may be utilized to reduce surface effects in SiC MESFETs.Type: ApplicationFiled: November 12, 2003Publication date: August 19, 2004Inventors: Scott T. Allen, John W. Palmour, Terrence S. Alcorn
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Patent number: 6686616Abstract: SiC MESFETs are disclosed which utilize a semi-insulating SiC substrate which substantially free of deep-level dopants. Utilization of the semi-insulating substrate may reduce back-gating effects in the MESFETs. Also provided are SiC MESFETs with a two recess gate structure. MESFETS with a selectively doped p-type buffer layer are also provided. Utilization of such a buffer layer may reduce output conductance by a factor of 3 and produce a 3 db increase in power gain over SiC MESFETs with conventional p-type buffer layers. A ground contact may also be provided to the p-type buffer layer and the p-type buffer layer may be made of two p-type layers with the layer formed on the substrate having a higher dopant concentration. SiC MESFETs according to embodiments of the present invention may also utilize chromium as a Schottky gate material. Furthermore, an oxide-nitride-oxide (ONO) passivation layer may be utilized to reduce surface effects in SiC MESFETs.Type: GrantFiled: May 10, 2000Date of Patent: February 3, 2004Assignee: Cree, Inc.Inventors: Scott T. Allen, John W. Palmour, Terrence S. Alcorn
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Patent number: 5945879Abstract: A microwave power amplifier is comprised of a plurality of series connected amplifier stages. Each stage is provided with a local negative feedback. The addition of the local voltage feedback distribution networks provide correct voltage distribution and equal current distribution for all transistors, such that the peak-to-peak voltage and current swings of each transistor can be set simultaneously to the values required for efficient amplifier operation. The method applies to both FETs and bipolar transistors. The series connected microwave power amplifier is thus characterized as a stack with local voltage feedback networks which provide an equal distribution of voltage across the transistors in the stack. The amplifier stages can be biased and tuned to collectively operate either as a class A or B amplifier.Type: GrantFiled: February 5, 1998Date of Patent: August 31, 1999Assignee: The Regents of the University of CaliforniaInventors: Mark Rodwell, Shrinivasan Jaganathan, Scott T. Allen
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Patent number: 5686737Abstract: A metal-semiconductor field-effect-transistor (MESFET) is disclosed that exhibits reduced source resistance and higher operating frequencies. The MESFET comprises an epitaxial layer of silicon carbide, and a gate trench in the epitaxial layer that exposes a silicon carbide gate surface between two respective trench edges. A gate contact is made to the gate surface, and with the trench further defines the source and drain regions of the transistor. Respective ohmic metal layers form ohmic contacts on the source and drain regions of the epitaxial layer, and the edges of the metal layers at the trench are specifically aligned with the edges of the epitaxial layer at the trench.Type: GrantFiled: September 16, 1994Date of Patent: November 11, 1997Assignee: Cree Research, Inc.Inventor: Scott T. Allen