Patents by Inventor Iftikhar Ahmed
Iftikhar Ahmed 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: 10593767Abstract: A structure and a manufacturing method of a power semiconductor device are provided. A structure of thin semi-insulating field plates (32, 33, 34) located between metal electrodes (21, 22, 23) at the surface of the power semiconductor device is provided. The thin semi-insulating field plates (32, 33, 34) are formed by depositing before metallization and annealing after the metallization. The present invention can be used in lateral power semiconductor devices and vertical power semiconductor devices.Type: GrantFiled: November 26, 2014Date of Patent: March 17, 2020Inventors: Chun Wai Ng, Iftikhar Ahmed, Johnny Kin On Sin
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Patent number: 10570902Abstract: A communication system can include a first subsystem of a well tool that can include a first cylindrically shaped band positioned around the first subsystem. The first cylindrically shaped band can be operable to electromagnetically couple with a second cylindrically shaped band. The communication system can also include a second subsystem of the well tool. The second subsystem can include the second cylindrically shaped band positioned around the second subsystem. The communication system can further include an intermediate subsystem positioned between the first subsystem and the second subsystem. The intermediate subsystem can include an insulator positioned coaxially around the intermediate subsystem.Type: GrantFiled: December 29, 2014Date of Patent: February 25, 2020Assignee: Halliburton Energy ServicesInventors: Jin Ma, Wei Hsuan Huang, Glenn Andrew Wilson, Iftikhar Ahmed
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Patent number: 10422217Abstract: A communication system for use in a wellbore can include a first cylindrically shaped band that can be positioned around a first outer housing of a first subsystem of a well tool. The first cylindrically shaped band can be operable to electromagnetically couple with a second cylindrically shaped band. The second cylindrically shaped band can be positioned around a second outer housing of a second subsystem of the well tool. The first cylindrically shaped band can electromagnetically couple with the second cylindrically shaped band via an electromagnetic field or by transmitting a current to the second cylindrically shaped band through a fluid in the wellbore.Type: GrantFiled: December 29, 2014Date of Patent: September 24, 2019Assignee: Halliburton Energy Services, INC.Inventors: Jin Ma, Glenn Andrew Wilson, Iftikhar Ahmed, Li Pan
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Publication number: 20170342986Abstract: A communication system can include a first subsystem of a well tool that can include a first cylindrically shaped band positioned around the first subsystem. The first cylindrically shaped band can be operable to electromagnetically couple with a second cylindrically shaped band. The communication system can also include a second subsystem of the well tool. The second subsystem can include the second cylindrically shaped band positioned around the second subsystem. The communication system can further include an intermediate subsystem positioned between the first subsystem and the second subsystem. The intermediate subsystem can include an insulator positioned coaxially around the intermediate subsystem.Type: ApplicationFiled: December 29, 2014Publication date: November 30, 2017Inventors: Jin Ma, Wei Hsuan Huang, Glenn Andrew Wilson, Iftikhar Ahmed
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Publication number: 20170298724Abstract: A communication system for use in a wellbore can include a first cylindrically shaped band that can be positioned around a first outer housing of a first subsystem of a well tool. The first cylindrically shaped band can be operable to electromagnetically couple with a second cylindrically shaped band. The second cylindrically shaped band can be positioned around a second outer housing of a second subsystem of the well tool. The first cylindrically shaped band can electromagnetically couple with the second cylindrically shaped band via an electromagnetic field or by transmitting a current to the second cylindrically shaped band through a fluid in the wellbore.Type: ApplicationFiled: December 29, 2014Publication date: October 19, 2017Inventors: Jin MA, Glenn Andrew WILSON, Iftikhar AHMED, Li PAN
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Patent number: 9647077Abstract: A power semiconductor device comprising a first metal electrode and a second metal electrode formed on a first substrate surface of a semiconductor substrate, a semi-insulating field plate interconnecting said first and second metal electrodes, and an insulating oxide layer extending between said first and second metal electrodes and between said field plate and said semiconductor substrate, wherein said semi-insulating field plate is a titanium nitride (TiN) field plate.Type: GrantFiled: December 10, 2014Date of Patent: May 9, 2017Assignee: JSAB TECHNOLOGIES LIMITEDInventors: Johnny Kin-On Sin, Iftikhar Ahmed, Chun-Wai Ng
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Publication number: 20160087050Abstract: A power semiconductor device comprising a first metal electrode and a second metal electrode formed on a first substrate surface of a semiconductor substrate, a semi-insulating field plate interconnecting said first and second metal electrodes, and an insulating oxide layer extending between said first and second metal electrodes and between said field plate and said semiconductor substrate, wherein said semi-insulating field plate is a titanium nitride (TiN) field plate.Type: ApplicationFiled: December 10, 2014Publication date: March 24, 2016Applicant: HKG TECHNOLOGIES LIMITEDInventors: Johnny Kin-On Sin, Iftikhar Ahmed, Chun-Wai Ng
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Publication number: 20160013279Abstract: A structure and a manufacturing method of a power semiconductor device are provided. A structure of thin semi-insulating field plates (32, 33, 34) located between metal electrodes (21, 22, 23) at the surface of the power semiconductor device is provided. The thin semi-insulating field plates (32, 33, 34) are formed by depositing before metallization and annealing after the metallization. The present invention can be used in lateral power semiconductor devices and vertical power semiconductor devices.Type: ApplicationFiled: November 26, 2014Publication date: January 14, 2016Inventors: Chun Wai NG, Iftikhar AHMED, Johnny Kin On SIN
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Publication number: 20120323747Abstract: A system for reconciling financial data is configured to retrieve first and second financial data from respective data sources. The first and second financial data each contains one or more respective records, each containing a respective name, date, and monetary amount. The system attempts to match one of the first records with one of the second records, initially based on general equivalence of the names, dates, and the first and second monetary amounts. If any of the records remain unmatched, the system is configured to attempt to match two or more of the second records with one of the first records, utilizing the sum of the second monetary amounts, and attempt to match two or more of the first records with one of the second records based on the sum of the first monetary amounts.Type: ApplicationFiled: June 17, 2011Publication date: December 20, 2012Applicant: THE BANK OF NEW YORK MELLONInventors: Tohm Lim KANTIKOVIT, Zeeshan Iftikhar AHMED, Neil Gavin MOORE, Rajendra DABBIRU
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Patent number: 6699775Abstract: A termination structure and reduced mask process for its manufacture for either a FRED device or any power semiconductor device comprises at least two concentric diffusion guard rings and two spaced silicon dioxide rings used in the definition of the two guard rings. A first metal ring overlies and contacts the outermost diffusion. A second metal ring which acts as a field plate contacts the second diffusion and overlaps the outermost oxide ring. A third metal ring, which acts as a field plate, is a continuous portion of the active area top contact and overlaps the second oxide ring. The termination is useful for high voltage (of the order of 1200 volt) devices. The rings are segments of a common aluminum or Palladium contact layer.Type: GrantFiled: August 30, 2002Date of Patent: March 2, 2004Assignee: International Rectifier CorporationInventors: Igor Bol, Iftikhar Ahmed
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Patent number: 6525389Abstract: A termination structure and reduced mask process for its manufacture for either a FRED device or any power semiconductor device comprises at least two concentric diffusion guard rings and two spaced silicon dioxide rings used in the definition of the two guard rings in an implant and drive system. A first metal ring overlies and contacts the outermost diffusion. A second metal ring which acts as a field plate contacts the second diffusion and overlaps the outermost oxide ring. A third metal ring, which acts as a field plate, is a continuous portion of the active area top contact and overlaps the second oxide ring. The termination is useful for high voltage (of the order of 1200 volt) devices. The rings are segments of a common aluminum or palladium contact layer. A thin high resistivity layer of amorphous silicon is deposited over the full upper surface of the wafer and is disposed between the wafer upper surface and all of the metal rings.Type: GrantFiled: February 22, 2000Date of Patent: February 25, 2003Assignee: International Rectifier CorporationInventor: Iftikhar Ahmed
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Publication number: 20030006425Abstract: A termination structure and reduced mask process for its manufacture for either a FRED device or any power semiconductor device comprises at least two concentric diffusion guard rings and two spaced silicon dioxide rings used in the definition of the two guard rings. A first metal ring overlies and contacts the outermost diffusion. A second metal ring which acts as a field plate contacts the second diffusion and overlaps the outermost oxide ring. A third metal ring, which acts as a field plate, is a continuous portion of the active area top contact and overlaps the second oxide ring. The termination is useful for high voltage (of the order of 1200 volt) devices. The rings are segments of a common aluminum or Palladium contact layer.Type: ApplicationFiled: August 30, 2002Publication date: January 9, 2003Applicant: International Rectifier CorporationInventors: Igor Bol, Iftikhar Ahmed
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Patent number: 6486524Abstract: A FRED device having an ultralow Irr employs a contact layer which contacts spaced P diffusions in an N type silicon substrate and also contacts the silicon surface spanning between the P diffusions. The contact layer is formed of a contact having a lower barrier height than the conventional aluminum, and is palladium silicide with a top contact layer of aluminum.Type: GrantFiled: February 22, 2000Date of Patent: November 26, 2002Assignee: International Rectifier CorporationInventor: Iftikhar Ahmed
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Patent number: 6417554Abstract: A three layer IGBT which cannot latch on is provided with a trench gate and a Schottky contact to the depletion region surrounding the trench gate. An emitter contact is connected to base diffusion regions which are diffused into the depletion region. The depletion region is formed atop an emitter region which emits carriers into the depletion region in response to the turn on of the gate and the injection of carriers from the Schottky gate.Type: GrantFiled: April 27, 2000Date of Patent: July 9, 2002Assignee: International Rectifier CorporationInventor: Iftikhar Ahmed
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Patent number: 6294445Abstract: A single mask process for manufacture of a FRED employs a thick oxide layer over an N type silicon surface and a thin nitride layer over the oxide. A single mask defines FRED device spaced P diffusions. The oxide spanning the P diffusions is laterally etched away, under the nitride layer to expose the surface of adjacent P diffusions and the spanning N type silicon surface. All nitride is then removed and a top contact layer of aluminum is applied atop the silicon surface, contacting a P guard ring diffusion; the surface of the P diffusions defining PN junctions; and the top of the N silicon to define a Schottky diode contact.Type: GrantFiled: February 22, 2000Date of Patent: September 25, 2001Assignee: International Rectifier Corp.Inventors: Igor Bol, Iftikhar Ahmed
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Patent number: 5614771Abstract: A high voltage switch in which an extended SCR is built in an insulated polysilicon layer for providing a single structure high voltage switch. The high voltage SCR is built by building unit SCRs comprising a cathode, a gate, an anode and a voltage sustaining area. The unit SCRs are built as horizontal linear devices. The unit SCRs can then be combined to form a large SCR by building each unit SCR so that the anode of one SCR is at least partially contiguous with the cathode of the next unit SCR.Type: GrantFiled: December 27, 1995Date of Patent: March 25, 1997Assignee: Xerox CorporationInventors: Iftikhar Ahmed, Steven A. Buhler