Patents Assigned to Efficient Power Conversion Corporation
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Patent number: 9214528Abstract: A method for forming an enhancement mode GaN HFET device with an isolation area that is self-aligned to a contact opening or metal mask window. Advantageously, the method does not require a dedicated isolation mask and the associated process steps, thus reducing manufacturing costs. The method includes providing an EPI structure including a substrate, a buffer layer a GaN layer and a barrier layer. A dielectric layer is formed over the barrier layer and openings are formed in the dielectric layer for device contact openings and an isolation contact opening. A metal layer is then formed over the dielectric layer and a photoresist film is deposited above each of the device contact openings. The metal layer is then etched to form a metal mask window above the isolation contact opening and the barrier and GaN layer are etched at the portion that is exposed by the isolation contact opening in the dielectric layer.Type: GrantFiled: July 2, 2014Date of Patent: December 15, 2015Assignee: Efficient Power Conversion CorporationInventors: Chunhua Zhou, Jianjun Cao, Alexander Lidow, Robert Beach, Alana Nakata, Robert Strittmatter, Guangyuan Zhao, Seshadri Kolluri, Yanping Ma, Fang Chang Liu, Ming-Kun Chiang, Jiali Cao
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Patent number: 9171911Abstract: An integrated semiconductor device which includes a substrate layer, a buffer layer formed on the substrate layer, a gallium nitride layer formed on the buffer layer, and a barrier layer formed on the gallium nitride layer. Ohmic contacts for a plurality of transistor devices are formed on the barrier layer. Specifically, a plurality of first ohmic contacts for the first transistor device are formed on a first portion of the surface of the barrier layer, and a plurality of second ohmic contacts for the second transistor device are formed on a second portion of the surface of the barrier layer. In addition, one or more gate structures formed on a third portion of the surface of the barrier between the first and second transistor devices. Preferably, the one or more gate structures and the spaces between the gate structures and the source contacts of the transistor devices collectively form an isolation region that electrically isolates the first transistor device from the second transistor device.Type: GrantFiled: July 2, 2014Date of Patent: October 27, 2015Assignee: Efficient Power Conversion CorporationInventors: Chunhua Zhou, Jianjun Cao, Alexander Lidow, Robert Beach, Alana Nakata, Robert Strittmatter, Guangyuan Zhao, Seshadri Kolluri, Yanping Ma, Fang Chang Liu, Ming-Kun Chiang, Jiali Cao
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Patent number: 9035417Abstract: A highly efficient, single sided circuit board layout design providing magnetic field self-cancellation and reduced parasitic inductance independent of board thickness. The low profile power loop extends through active and passive devices on the top layer of the circuit board, with vias connecting the power loop to a return path in an inner layer of the board. The magnetic effect of the portion of the power loop on the top layer is reduced by locating the inner layer return path directly underneath the power loop path on the top layer.Type: GrantFiled: December 27, 2013Date of Patent: May 19, 2015Assignee: Efficient Power Conversion CorporationInventors: David Reusch, Johan Tjeerd Strydom
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Patent number: 8969918Abstract: An enhancement mode GaN transistor having a gate pGaN structure having a thickness which avoids dielectric failure. In one embodiment, this thickness is in the range of 400 ? to 900 ?. In a preferred embodiment, the thickness is 600 ?.Type: GrantFiled: April 8, 2010Date of Patent: March 3, 2015Assignee: Efficient Power Conversion CorporationInventors: Alexander Lidow, Robert Beach, Alana Nakata, Jianjun Cao, Guang Yuan Zhao
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Publication number: 20150049528Abstract: A power factor correction (PFC) boost circuit. The PFC boost circuit can include a first switching device, a second switching device, a first gate driver coupled to the first switching device, a second gate driver coupled to the second switching device, and a PFC controller configured to control the first and second gate drivers. The PFC controller will utilize a new technique, referred to herein as “predictive diode emulation” to control the switching devices in a desired manner and to overcome inefficiencies and other problems that might arise using traditional diode emulation. The PFC controller is configured to operate in synchronous and non-synchronous modes.Type: ApplicationFiled: May 30, 2013Publication date: February 19, 2015Applicant: EFFICIENT POWER CONVERSION CORPORATIONInventors: Michael A. De Rooij, Johan Strydom
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Patent number: 8890168Abstract: An enhancement-mode GaN transistor. The enhancement-mode GaN transistor includes a substrate, transition layers, a buffer layer comprised of a III Nitride material, a barrier layer comprised of a III Nitride material, drain and source contacts, a gate III-V compound containing acceptor type dopant elements, and a gate metal, where the gate III-V compound and the gate metal are formed with a single photo mask process to be self-aligned and the bottom of the gate metal and the top of the gate compound have the same dimension. The enhancement mode GaN transistor may also have a field plate made of Ohmic metal, where a drain Ohmic metal, a source Ohmic metal, and the field plate are formed by a single photo mask process.Type: GrantFiled: March 15, 2013Date of Patent: November 18, 2014Assignee: Efficient Power Conversion CorporationInventors: Alexander Lidow, Robert Beach, Alana Nakata, Jianjun Cao, Guang Yuang Zhao
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Patent number: 8853749Abstract: A self-aligned transistor gate structure that includes an ion-implanted portion of gate material surrounded by non-implanted gate material on each side. The gate structure may be formed, for example, by applying a layer of GaN material over an AlGaN barrier layer and implanting a portion of the GaN layer to create the gate structure that is laterally surrounded by the GaN layer.Type: GrantFiled: January 31, 2012Date of Patent: October 7, 2014Assignee: Efficient Power Conversion CorporationInventors: Alexander Lidow, Jianjun Cao, Robert Beach, Robert Strittmatter, Guang Y. Zhao, Alana Nakata
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Patent number: 8823012Abstract: Enhancement-mode GaN devices having a gate spacer, a gate metal material and a gate compound that are self-aligned, and a methods of forming the same. The materials are patterned and etched using a single photo mask, which reduces manufacturing costs. An interface of the gate spacer and the gate compound has lower leakage than the interface of a dielectric film and the gate compound, thereby reducing gate leakage. In addition, an ohmic contact metal layer is used as a field plate to relieve the electric field at a doped III-V gate compound corner towards the drain contact, which leads to lower gate leakage current and improved gate reliability.Type: GrantFiled: February 23, 2012Date of Patent: September 2, 2014Assignee: Efficient Power Conversion CorporationInventors: Alexander Lidow, Robert Beach, Alana Nakata, Jianjun Cao, Guang Yuan Zhao, Robert Strittmatter, Fang Chang Liu
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Patent number: 8785974Abstract: A semiconductor device comprising a silicon substrate, a compound semiconductor material, an insulating material between the silicon substrate and the compound semiconductor material, and a top surface comprising means of electrical connection, and passivation material, where the passivation material is silicon nitride, silicon dioxide, or a combination of both. The present invention eliminates the need for a thick electrical insulator between a heat sink and the back surface of a surface mounted device by the inclusion of an AlN seed layer to electrically isolate the silicon substrate of the device. The sidewalls of the device are also electrically isolated from the active area of the device.Type: GrantFiled: April 8, 2010Date of Patent: July 22, 2014Assignee: Efficient Power Conversion CorporationInventors: Alexander Lidow, Robert Beach, Alana Nakata, Jianjun Cao
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Publication number: 20140183550Abstract: A highly efficient, single sided circuit board layout design providing magnetic field self-cancellation and reduced parasitic inductance independent of board thickness. The low profile power loop extends through active and passive devices on the top layer of the circuit board, with vias connecting the power loop to a return path in an inner layer of the board. The magnetic effect of the portion of the power loop on the top layer is reduced by locating the inner layer return path directly underneath the power loop path on the top layer.Type: ApplicationFiled: December 27, 2013Publication date: July 3, 2014Applicant: Efficient Power Conversion CorporationInventors: David Reusch, Johan Tjeerd Strydom
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Publication number: 20130234153Abstract: An enhancement-mode GaN transistor. The enhancement-mode GaN transistor includes a substrate, transition layers, a buffer layer comprised of a III Nitride material, a barrier layer comprised of a III Nitride material, drain and source contacts, a gate III-V compound containing acceptor type dopant elements, and a gate metal, where the gate III-V compound and the gate metal are formed with a single photo mask process to be self-aligned and the bottom of the gate metal and the top of the gate compound have the same dimension. The enhancement mode GaN transistor may also have a field plate made of Ohmic metal, where a drain Ohmic metal, a source Ohmic metal, and the field plate are formed by a single photo mask process.Type: ApplicationFiled: March 15, 2013Publication date: September 12, 2013Applicant: Efficient Power Conversion CorporationInventors: Alexander Lidow, Robert Beach, Alana Nakata, Jianjun Cao, Guang Yuang Zhao
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Patent number: 8436398Abstract: An enhancement-mode GaN transistor, the transistor having a substrate, transition layers, a buffer layer comprised of a III Nitride material, a barrier layer comprised of a III Nitride material, drain and source contacts, a gate containing acceptor type dopant elements, and a diffusion barrier comprised of a III Nitride material between the gate and the buffer layer.Type: GrantFiled: April 7, 2010Date of Patent: May 7, 2013Assignee: Efficient Power Conversion CorporationInventors: Alexander Lidow, Robert Beach, Guang Y. Zhao, Jianjun Cao
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Patent number: 8431960Abstract: An enhancement mode gallium nitride (GaN) transistor with a Mg doped layer and a Mg growth interruption (diffusion barrier) layer to trap excess or residual Mg dopant. The Mg growth interruption (diffusion barrier) layer is formed by growing GaN, stopping the supply of gallium while maintaining a supply of ammonia or other nitrogen containing source to form a layer of magnesium nitride (MgN), and then resuming the flow of gallium to form a GaN layer to seal in the layer of MgN.Type: GrantFiled: April 7, 2010Date of Patent: April 30, 2013Assignee: Efficient Power Conversion CorporationInventors: Robert Beach, Guang Yuan Zhao
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Patent number: 8404508Abstract: An enhancement-mode GaN transistor and a method of forming it. The enhancement-mode GaN transistor includes a substrate, transition layers, a buffer layer comprised of a III Nitride material, a barrier layer comprised of a III Nitride material, drain and source contacts, a gate III-V compound containing acceptor type dopant elements, and a gate metal, where the gate III-V compound and the gate metal are formed with a single photo mask process to be self-aligned and the bottom of the gate metal and the top of the gate compound have the same dimension. The enhancement mode GaN transistor may also have a field plate made of Ohmic metal, where a drain Ohmic metal, a source Ohmic metal, and the field plate are formed by a single photo mask process.Type: GrantFiled: April 8, 2010Date of Patent: March 26, 2013Assignee: Efficient Power Conversion CorporationInventors: Alexander Lidow, Robert Beach, Alana Nakata, Jianjun Cao, Guang Yuan Zhao
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Patent number: 8350294Abstract: A MISFET, such as a GaN transistor, with low gate leakage. In one embodiment, the gate leakage is reduced with a compensated GaN layer below the gate contact and above the barrier layer. In another embodiment, the gate leakage is reduced by employing a semi-insulating layer below the gate contact and above the barrier layer.Type: GrantFiled: April 8, 2010Date of Patent: January 8, 2013Assignee: Efficient Power Conversion CorporationInventors: Alexander Lidow, Robert Beach, Jianjun Cao, Alana Nakata, Guang Yuan Zhao