Patents by Inventor Kamal Raj Varadarajan
Kamal Raj Varadarajan 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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Publication number: 20240014308Abstract: A die seal ring including a two-dimensional electron gas is presented herein. A semiconductor device comprises an active device region. The active device region comprises a device terminal; and a die seal ring comprising a two dimensional electron gas region surrounds the active device region. By electrically coupling the device terminal to the two dimensional electron gas region, voltages at the semiconductor sidewall may be controlled to substantially equal that of the device terminal.Type: ApplicationFiled: August 27, 2021Publication date: January 11, 2024Applicant: Power Integrations, Inc.Inventors: Kuo-Chang Robert YANG, Alexey KUDYMOV, Kamal Raj VARADARAJAN, Alexei ANKOUDINOV, Sorin S. GEORGESCU
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Patent number: 11824094Abstract: Silicon carbide (SiC) junction field effect transistors (JFETs) are presented herein. A deep implant (e.g., a deep p-type implant) forms a JFET gate (106). MET gate and MET source (108) may be implemented with heavily doped n-type (N+) and heavily doped p-type (P+) implants, respectively. Termination regions may be implemented by using equipotential rings formed by deep implants (e.g., deep p-type implants).Type: GrantFiled: March 25, 2021Date of Patent: November 21, 2023Assignee: POWER INTEGRATIONS, INC.Inventors: Kuo-Chang Robert Yang, Kamal Raj Varadarajan, Sorin S. Georgescu
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Publication number: 20230147746Abstract: Silicon carbide (SiC) junction field effect transistors (JFETs) are presented herein. A deep implant (e.g., a deep p-type implant) forms a JFET gate (106). MET gate and MET source (108) may be implemented with heavily doped n-type (N+) and heavily doped p-type (P+) implants, respectively. Termination regions may be implemented by using equipotential rings formed by deep implants (e.g., deep p-type implants).Type: ApplicationFiled: March 25, 2021Publication date: May 11, 2023Applicant: Power Integrations, Inc.Inventors: Kuo-Chang Robert YANG, Kamal Raj VARADARAJAN, Sorin S. GEORGESCU
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Publication number: 20190393314Abstract: A vertical power transistor device includes a semiconductor layer of a first conductivity type, with a plurality of dielectric regions disposed in the semiconductor layer. The dielectric regions extend in a vertical direction from a top surface of the semiconductor layer downward. Each dielectric region has a rounded-square cross-section in a horizontal plane perpendicular to the vertical direction. Adjacent ones of the dielectric regions are laterally separated by a narrow region of the semiconductor layer. Each dielectric region has a cylindrical field plate member centrally disposed therein. The cylindrical field plate member extends in the vertical direction from the top surface downward to near a bottom of the dielectric region. The dielectric region laterally separates the cylindrical field plate member from the narrow region. A source region is disposed at the top surface, and a drain region is disposed at the bottom, of the semiconductor layer.Type: ApplicationFiled: May 13, 2019Publication date: December 26, 2019Applicant: Power Integrations, Inc.Inventors: Sorin Stefan Georgescu, Kamal Raj Varadarajan, Alexei Ankoudinov
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Patent number: 10325988Abstract: A vertical power transistor device includes a semiconductor layer of a first conductivity type, with a plurality of dielectric regions disposed in the semiconductor layer. The dielectric regions extend in a vertical direction from a top surface of the semiconductor layer downward. Each dielectric region has a rounded-square cross-section in a horizontal plane perpendicular to the vertical direction. Adjacent ones of the dielectric regions are laterally separated by a narrow region of the semiconductor layer. Each dielectric region has a cylindrical field plate member centrally disposed therein. The cylindrical field plate member extends in the vertical direction from the top surface downward to near a bottom of the dielectric region. The dielectric region laterally separates the cylindrical field plate member from the narrow region. A source region is disposed at the top surface, and a drain region is disposed at the bottom, of the semiconductor layer.Type: GrantFiled: December 13, 2016Date of Patent: June 18, 2019Assignee: Power Integrations, Inc.Inventors: Sorin Stefan Georgescu, Kamal Raj Varadarajan, Alexei Ankoudinov
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Publication number: 20190006475Abstract: A vertical power transistor device includes a semiconductor layer of a first conductivity type, with a plurality of dielectric regions disposed in the semiconductor layer. The dielectric regions extend in a vertical direction from a top surface of the semiconductor layer downward. Each dielectric region has a rounded-square cross-section in a horizontal plane perpendicular to the vertical direction. Adjacent ones of the dielectric regions are laterally separated by a narrow region of the semiconductor layer. Each dielectric region has a cylindrical field plate member centrally disposed therein. The cylindrical field plate member extends in the vertical direction from the top surface downward to near a bottom of the dielectric region. The dielectric region laterally separates the cylindrical field plate member from the narrow region. A source region is disposed at the top surface, and a drain region is disposed at the bottom, of the semiconductor layer.Type: ApplicationFiled: December 13, 2016Publication date: January 3, 2019Inventors: Sorin Stefan Georgescu, Kamal Raj Varadarajan, Alexei Ankoudinov
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Patent number: 9973183Abstract: A lateral semiconductor field-effect transistor (FET) device fabricated on a substrate includes a high-voltage main FET having interdigitated, elongated source and drain electrode fingers each of which is electrically connected to a respective interdigitated, elongated source and drain region disposed in the substrate. The FET device further includes first and second sense FETs each having a drain region in common with the high-voltage main FET. The sense FETS also include respective first and second elongated source electrode fingers each of which is electrically connected to respective first and second elongated source regions of the first and second sense FETs, respectively. The first and second elongated source electrode fingers are disposed length-wise adjacent to one of the elongated drain electrode fingers. The first elongated source finger has a first length, and the second elongated source finger has a second length, the second length being less than the first length.Type: GrantFiled: September 28, 2015Date of Patent: May 15, 2018Assignee: Power Integrations, Inc.Inventors: Lin Zhu, Kamal Raj Varadarajan, Yury Gaknoki
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Publication number: 20180069087Abstract: A vertical power transistor device includes a semiconductor layer of a first conductivity type, with a plurality of dielectric regions disposed in the semiconductor layer. The dielectric regions extend in a vertical direction from a top surface of the semiconductor layer downward. Each dielectric region has a rounded-square cross-section in a horizontal plane perpendicular to the vertical direction. Adjacent ones of the dielectric regions are laterally separated by a narrow region of the semiconductor layer. Each dielectric region has a cylindrical field plate member centrally disposed therein. The cylindrical field plate member extends in the vertical direction from the top surface downward to near a bottom of the dielectric region. The dielectric region laterally separates the cylindrical field plate member from the narrow region. A source region is disposed at the top surface, and a drain region is disposed at the bottom, of the semiconductor layer.Type: ApplicationFiled: December 13, 2016Publication date: March 8, 2018Inventors: Sorin Stefan Georgescu, Kamal Raj Varadarajan, Alexei Ankoudinov
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Patent number: 9768274Abstract: A method includes defining, on a surface of a material, a plurality of discrete portions of a surface as surface elements having at least one of a laterally-varying size, a laterally-varying shape, and a laterally-varying spacing. A plurality of portions of the material beneath the surface elements are doped with a single quantity of dopant material per element area. The dopant material within the material beneath the surface elements expands to provide a lateral gradient of dopant material in the material beneath the surface elements.Type: GrantFiled: April 13, 2015Date of Patent: September 19, 2017Assignee: Power Integrations, Inc.Inventors: Wayne B. Grabowski, Kuo-Chang Yang, Kamal Raj Varadarajan, Sujit Banerjee, Vijay Parthasarathy
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Publication number: 20170093387Abstract: A lateral semiconductor field-effect transistor (FET) device fabricated on a substrate includes a high-voltage main FET having interdigitated, elongated source and drain electrode fingers each of which is electrically connected to a respective interdigitated, elongated source and drain region disposed in the substrate. The FET device further includes first and second sense FETs each having a drain region in common with the high-voltage main FET. The sense FETS also include respective first and second elongated source electrode fingers each of which is electrically connected to respective first and second elongated source regions of the first and second sense FETs, respectively. The first and second elongated source electrode fingers are disposed length-wise adjacent to one of the elongated drain electrode fingers. The first elongated source finger has a first length, and the second elongated source finger has a second length, the second length being less than the first length.Type: ApplicationFiled: September 28, 2015Publication date: March 30, 2017Inventors: Lin Zhu, Kamal Raj Varadarajan, Yury Gaknoki
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Patent number: 9543396Abstract: A vertical power transistor device includes a semiconductor layer of a first conductivity type, with a plurality of cylindrically-shaped dielectric regions disposed in the semiconductor layer. The cylindrically-shaped dielectric regions extend in a vertical direction from a top surface of the semiconductor layer downward. Adjacent ones of the cylindrically-shaped dielectric regions being laterally separated along a common diametrical axis by a narrow region of the semiconductor layer having a first width. Each dielectric region has a cylindrically-shaped, conductive field plate member centrally disposed therein. The cylindrically-shaped, conductive field plate member extends in the vertical direction from the top surface downward to near a bottom of the dielectric region. The dielectric region laterally separates the cylindrically-shaped, conductive field plate member from the narrow region.Type: GrantFiled: October 22, 2014Date of Patent: January 10, 2017Assignee: Power Integrations, Inc.Inventors: Sorin Stefan Georgescu, Wayne Byran Grabowski, Kamal Raj Varadarajan, Lin Zhu, Kuo-Chang Robert Yang
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Publication number: 20160149018Abstract: A method includes defining, on a surface of a material, a plurality of discrete portions of a surface as surface elements having at least one of a laterally-varying size, a laterally-varying shape, and a laterally-varying spacing. A plurality of portions of the material beneath the surface elements are doped with a single quantity of dopant material per element area. The dopant material within the material beneath the surface elements expands to provide a lateral gradient of dopant material in the material beneath the surface elements.Type: ApplicationFiled: April 13, 2015Publication date: May 26, 2016Inventors: Wayne B. Grabowski, Kuo-Chang Yang, Kamal Raj Varadarajan, Sujit Banerjee, Vijay Parthasarathy
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Publication number: 20150171174Abstract: A vertical power transistor device includes a semiconductor layer of a first conductivity type, with a plurality of cylindrically-shaped dielectric regions disposed in the semiconductor layer. The cylindrically-shaped dielectric regions extend in a vertical direction from a top surface of the semiconductor layer downward. Adjacent ones of the cylindrically-shaped dielectric regions being laterally separated along a common diametrical axis by a narrow region of the semiconductor layer having a first width. Each dielectric region has a cylindrically-shaped, conductive field plate member centrally disposed therein. The cylindrically-shaped, conductive field plate member extends in the vertical direction from the top surface downward to near a bottom of the dielectric region. The dielectric region laterally separates the cylindrically-shaped, conductive field plate member from the narrow region.Type: ApplicationFiled: October 22, 2014Publication date: June 18, 2015Inventors: Sorin Stefan Georgescu, Wayne Byran Grabowski, Kamal Raj Varadarajan, Lin Zhu, Kuo-Chang Robert Yang
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Patent number: 8159024Abstract: In one aspect, a lateral MOS device is provided. The lateral MOS device includes a gate electrode disposed at least partially in a gate trench to apply a voltage to a channel region, and a drain electrode spaced from the gate electrode, and in electrical communication with a drift region having a boundary with a lower end of the channel region. The device includes a gate dielectric layer in contact with the gate electrode, and disposed between the gate electrode and the drain electrode. The channel region is adjacent to a substantially vertical wall of the gate trench. The device includes a field plate contacting the gate electrode and configured to increase a breakdown voltage of the device.Type: GrantFiled: April 20, 2008Date of Patent: April 17, 2012Assignee: Rensselaer Polytechnic InstituteInventors: Tat-sing Paul Chow, Kamal Raj Varadarajan
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Publication number: 20100163988Abstract: In one aspect, a lateral MOS device is provided. The lateral MOS device includes a gate electrode disposed at least partially in a gate trench to apply a voltage to a channel region, and a drain electrode spaced from the gate electrode, and in electrical communication with a drift region having a boundary with a lower end of the channel region. The device includes a gate dielectric layer in contact with the gate electrode, and disposed between the gate electrode and the drain electrode. The channel region is adjacent to a substantially vertical wall of the gate trench. The device includes a field plate contacting the gate electrode and configured to increase a breakdown voltage of the device.Type: ApplicationFiled: April 20, 2008Publication date: July 1, 2010Applicant: Rensselaer Polytechnic InstituteInventors: Tat-sing Paul Chow, Kamal Raj Varadarajan