Patents by Inventor Dumitru Sdrulla
Dumitru Sdrulla 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: 11158703Abstract: A high-voltage termination for a semiconductor device includes a substrate of a first conductivity type, an implanted device region of a second conductivity type of the semiconductor device, a shallow trench disposed in the substrate adjacent to the implanted device region, a doped extension region of the second conductivity type extending between the implanted device region and a first edge of the shallow trench adjacent to the implanted device region, a junction termination extension region of the second conductivity type formed in the shallow trench contacting the extension region and extending past a second edge of the shallow trench opposite the implanted device region, an insulating layer formed over at least a portion of the extension region and over the junction termination extension region, and a metal layer formed over the insulating layer extending into at least a portion of the shallow trench and electrically connected to the extension region.Type: GrantFiled: June 19, 2019Date of Patent: October 26, 2021Assignee: Microchip Technology Inc.Inventors: Amaury Gendron-Hansen, Dumitru Sdrulla
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Publication number: 20200388670Abstract: A high-voltage termination for a semiconductor device includes a substrate of a first conductivity type, an implanted device region of a second conductivity type of the semiconductor device, a shallow trench disposed in the substrate adjacent to the implanted device region, a doped extension region of the second conductivity type extending between the implanted device region and a first edge of the shallow trench adjacent to the implanted device region, a junction termination extension region of the second conductivity type formed in the shallow trench contacting the extension region and extending past a second edge of the shallow trench opposite the implanted device region, an insulating layer formed over at least a portion of the extension region and over the junction termination extension region, and a metal layer formed over the insulating layer extending into at least a portion of the shallow trench and electrically connected to the extension region.Type: ApplicationFiled: June 19, 2019Publication date: December 10, 2020Applicant: Microchip Technology Inc.Inventors: Amaury Gendron-Hansen, Dumitru Sdrulla
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Patent number: 10566416Abstract: A semiconductor device constituted of: a semiconductor layer; and a field layer patterned on said semiconductor layer, said field layer constituted of material having characteristics which block diffusion of mobile ions and maintain structural integrity at activation temperatures of up to 1200 degrees centigrade.Type: GrantFiled: August 15, 2018Date of Patent: February 18, 2020Assignee: Microsemi CorporationInventors: Amaury Gendron-Hansen, Bruce Odekirk, Nathaniel Berliner, Dumitru Sdrulla
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Publication number: 20190058032Abstract: A semiconductor device constituted of: a semiconductor layer; and a field layer patterned on said semiconductor layer, said field layer constituted of material having characteristics which block diffusion of mobile ions and maintain structural integrity at activation temperatures of up to 1200 degrees centigrade.Type: ApplicationFiled: August 15, 2018Publication date: February 21, 2019Inventors: Amaury Gendron-Hansen, Bruce Odekirk, Nathaniel Berliner, Dumitru Sdrulla
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Patent number: 9478606Abstract: A high power, high current Unidirectional Transient Voltage Suppressor, formed on SiC starting material is disclosed. The device is structured to avalanche uniformly across the entire central part (active area) such that very high currents can flow while the device is reversely biased. Forcing the device to avalanche uniformly across designated areas is achieved in different ways but consistently in concept, by creating high electric fields where the device is supposed to avalanche (namely the active area) and by relaxing the electric field across the edge of the structure (namely in the termination), which in all embodiments meets the conditions for an increased reliability under harsh environments.Type: GrantFiled: February 13, 2015Date of Patent: October 25, 2016Assignee: Microsemi CorporationInventors: Dumitru Sdrulla, Bruce Odekirk, Cecil Kent Walters
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Publication number: 20160126306Abstract: A high power, high current Unidirectional Transient Voltage Suppressor, formed on SiC starting material is disclosed. The device is structured to avalanche uniformly across the entire central part (active area) such that very high currents can flow while the device is reversely biased. Forcing the device to avalanche uniformly across designated areas is achieved in different ways but consistently in concept, by creating high electric fields where the device is supposed to avalanche (namely the to active area) and by relaxing the electric field across the edge of the structure (namely in the termination), which in all embodiments meets the conditions for an increased reliability under harsh environments.Type: ApplicationFiled: February 13, 2015Publication date: May 5, 2016Inventors: Dumitru Sdrulla, Bruce Odekirk, Cecil Kent Walters
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Patent number: 9040377Abstract: A Vertical Multiple Implanted Silicon Carbide Power MOSFET (VMIMOSFET) includes a first conductivity semiconductor substrate, a first conductivity semiconductor drift layer on the top of the substrate, a multitude of second conductivity layers implanted in the drift layer. The body layer is where the channel is formed. A first conductivity source layer is interspaced appropriately inside of the second conductivity layers. A gate oxide of a certain thickness and another oxide of a different thickness, a greater thickness than the gate oxide, placed in between the body layers but in such way that its shape does not distort the gate oxide in the channel. A charge compensated body layer of the second conductivity formed outside of the channel region and only at specific high electric field locations in the structure. The device and the manufacturing method deliver a power SiC MOSFET with increased frequency of operation and reduced switching losses.Type: GrantFiled: November 13, 2013Date of Patent: May 26, 2015Assignee: MICROSEMI CORPORATIONInventors: Dumitru Sdrulla, Bruce Odekirk, Marc H. Vandenberg
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Publication number: 20140339625Abstract: A Vertical Power MOSFET (VDMOS) device with special features that enable the Power MOSFET or IGBT device to withstand harsh radiation environments and the process of making such a device is described. All implanted and diffused layers are “self aligned” to a “Sacrificial Poly” layer, which later on is removed, preparing the wafers for a “late gate” oxide to be grown. A starting material with graded doping profile in the epitaxial layer on the substrate is shown to increase the SEB capability of the Power MOSFET.Type: ApplicationFiled: July 22, 2014Publication date: November 20, 2014Inventors: Dumitru Sdrulla, Marc H. Vandenberg, Eric Karlsson
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Patent number: 8841718Abstract: A Vertical Power MOSFET (VDMOS) device with special features that enable the Power MOSFET or IGBT device to withstand harsh radiation environments and the process of making such a device is described. All implanted and diffused layers are “self aligned” to a “Sacrificial Poly” layer, which later on is removed, preparing the wafers for a “late gate” oxide to be grown. A starting material with graded doping profile in the epitaxial layer on the substrate is shown to increase the SEB capability of the Power MOSFET.Type: GrantFiled: January 15, 2013Date of Patent: September 23, 2014Assignee: Microsemi CorporationInventors: Dumitru Sdrulla, Marc H. Vandenberg, Eric Karlsson
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Patent number: 8674439Abstract: A Vertical Multiple Implanted Silicon Carbide Power MOSFET (VMIMOSFET) includes a first conductivity semiconductor substrate, a first conductivity semiconductor drift layer on the top of the substrate, a multitude of second conductivity layers implanted in the drift layer. The body layer is where the channel is formed. A first conductivity source layer is interspaced appropriately inside of the second conductivity layers. A gate oxide of a certain thickness and another oxide of a different thickness, a greater thickness than the gate oxide, placed in between the body layers but in such way that its shape does not distort the gate oxide in the channel. A charge compensated body layer of the second conductivity formed outside of the channel region and only at specific high electric field locations in the structure. The device and the manufacturing method deliver a power SiC MOSFET with increased frequency of operation and reduced switching losses.Type: GrantFiled: August 1, 2011Date of Patent: March 18, 2014Assignee: Microsemi CorporationInventors: Dumitru Sdrulla, Bruce Odekirk, Marc Vandenberg
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Publication number: 20140065778Abstract: A Vertical Multiple Implanted Silicon Carbide Power MOSFET (VMIMOSFET) includes a first conductivity semiconductor substrate, a first conductivity semiconductor drift layer on the top of the substrate, a multitude of second conductivity layers implanted in the drift layer. The body layer is where the channel is formed. A first conductivity source layer is interspaced appropriately inside of the second conductivity layers. A gate oxide of a certain thickness and another oxide of a different thickness, a greater thickness than the gate oxide, placed in between the body layers but in such way that its shape does not distort the gate oxide in the channel. A charge compensated body layer of the second conductivity formed outside of the channel region and only at specific high electric field locations in the structure. The device and the manufacturing method deliver a power SiC MOSFET with increased frequency of operation and reduced switching losses.Type: ApplicationFiled: November 13, 2013Publication date: March 6, 2014Applicant: MICROSEMI CORPORATIONInventors: Dumitru Sdrulla, Bruce Odekirk, Marc H. Vandenberg
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Publication number: 20130313570Abstract: A SIC VDMOS transistor is integrated with a SiC SBD, in a seamless way, without any increase of the device area. The SiC SBD is integrated in the active area of the VDMOS by splitting the P-Wells, such that the lightly doped drift region extents all the way to the surface of semiconductor, and by trenching through the source of the VDMOS and partially through the P-Wells to reach the peak of the P-type doping in the P-Well regions. The source of the VDMOS is contacted from the top surface and from the vertical sidewalls of the trenched source and the forward voltage of the Schottky Barrier diode is tailored by using two different metals for the ohmic contact on the source and for the SBD.Type: ApplicationFiled: May 24, 2013Publication date: November 28, 2013Applicant: MICROSEMI CORPORATIONInventors: Dumitru Sdrulla, Marc H. Vandenberg, Bruce Odekirk
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Publication number: 20130256698Abstract: A Vertical Multiple Implanted Silicon Carbide Power MOSFET (VMIMOSFET) includes a first conductivity semiconductor substrate, a first conductivity semiconductor drift layer on the top of the substrate, a multitude of second conductivity layers implanted in the drift layer. The body layer is where the channel is formed. A first conductivity source layer is interspaced appropriately inside of the second conductivity layers. A gate oxide of a certain thickness and another oxide of a different thickness, a greater thickness than the gate oxide, placed in between the body layers but in such way that its shape does not distort the gate oxide in the channel. A charge compensated body layer of the second conductivity formed outside of the channel region and only at specific high electric field locations in the structure. The device and the manufacturing method deliver a power SiC MOSFET with increased frequency of operation and reduced switching losses.Type: ApplicationFiled: August 1, 2011Publication date: October 3, 2013Applicant: MICROSEMI CORPORATIONInventors: Dumitru Sdrulla, Bruce Odekirk, Marc Vandenberg
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Patent number: 8476691Abstract: A high voltage power semiconductor device includes high reliability-high voltage junction termination with a charge dissipation layer. An active device area is surrounded by a junction termination structure including one or more regions of a polarity opposite the substrate polarity. A tunneling oxide layer overlays the junction termination area surrounding the active device area in contact with the silicon substrate upper surface. A layer of undoped polysilicon overlays the tunneling oxide layer and spans the junction termination area, with connections to an outer edge of the junction termination structure and to a grounded electrode inside of the active area. The tunneling oxide layer has a thickness that permits hot carriers formed at substrate upper surface to pass through the tunneling oxide layer into the undoped polysilicon layer to be dissipated but sufficient to mitigate stacking faults at the silicon surface.Type: GrantFiled: February 18, 2011Date of Patent: July 2, 2013Assignee: Microsemi CorporationInventors: Dumitru Sdrulla, Duane Edward Levine, James M. Katana, Martin David Birch
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Patent number: 8436367Abstract: A SiC Power Semiconductor device of the Field Effect Type (MOSFET, IGBT or the like) with “muted” channel conduction, negative temperature coefficient of channel mobility, in situ “ballasted” source resistors and optimized thermal management of the cells for increased Safe Operating Area is described. Controlling the location of the Zero Temperature Crossover Point (ZTCP) in relationship to the drain current is achieved by the partition between the “active” and “inactive” channels and by adjusting the mobility of the carriers in the channel for the temperature range of interest. The “Thermal management” is realized by surrounding the “active” cells/fingers with “inactive” ones and the “negative” feedback of the drain/collector current due to local increase of the gate bias is achieved by implementing in-situ “ballast” resistors inside of each source contact.Type: GrantFiled: September 13, 2011Date of Patent: May 7, 2013Assignee: Microsemi CorporationInventors: Dumitru Sdrulla, Bruce Odekirk, Marc Vandenberg
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Patent number: 8110888Abstract: High voltage semiconductor devices with high-voltage termination structures are constructed on lightly doped substrates. Lightly doped p-type substrates are particularly prone to depletion and inversion from positive charges, degrading the ability of associated termination structures to block high voltages. To improve the efficiency and stability of termination structures, second termination regions of the same dopant type as the substrate, more heavily doped than the substrate but more lightly doped than first termination regions, are positioned adjoining the first termination regions. The second termination regions raise the field threshold voltage where the surface is vulnerable and render the termination structure substantially insensitive to positive charges at the surface. The use of higher dopant concentration in the gap region without causing premature avalanche is facilitated by only creating second termination regions for regions lacking field plate protection.Type: GrantFiled: September 9, 2008Date of Patent: February 7, 2012Assignee: Microsemi CorporationInventors: Jinshu Zhang, Dumitru Sdrulla, Dah Wen Tsang
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Publication number: 20110037139Abstract: A merged PN/Schottky diode is provided having a substrate of a first conductivity type and a grid of doped wells of the second conductivity type embedded in the substrate. A Schottky barrier metal layer makes a Schottky barrier contact with the surface of the substrate above the grid. Selected embedded wells in the grid may make electrical contact to the Schottky bather metal layer, while most embedded wells do not. The diode forward voltage drop is reduced for the same diode area with reverse blocking benefits similar to a conventional JBS structure.Type: ApplicationFiled: October 26, 2010Publication date: February 17, 2011Applicant: MICROSEMI CORPORATIONInventors: Feng Zhao, Bruce Odekirk, Dumitru Sdrulla
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Patent number: 7851881Abstract: A merged PN/Schottky diode is provided having a substrate of a first conductivity type and a grid of doped wells of the second conductivity type embedded in the substrate. A Schottky barrier metal layer makes a Schottky barrier contact with the surface of the substrate above the grid. Selected embedded wells in the grid make a Schottky barrier contact to the Schottky barrier metal layer, while most embedded wells do not. The diode forward voltage drop is reduced for the same diode area with reverse blocking benefits similar to a conventional JBS structure.Type: GrantFiled: February 3, 2009Date of Patent: December 14, 2010Assignee: Microsemi CorporationInventors: Feng Zhao, Bruce Odekirk, Dumitru Sdrulla
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Patent number: 7671410Abstract: An improved Fast Recovery Diode comprises a main PN junction defining a central conduction region for conducting high current in a forward direction and a peripheral field spreading region surrounding the central conduction region for blocking high voltage in the reverse direction. The main PN junction has an avalanche voltage equal to or lower than an avalanche voltage of the peripheral field spreading region so substantially the entire said main PN junction participates in avalanche conduction. This rugged FRED structure can also be formed in MOSFETS, IGBTS and the like.Type: GrantFiled: December 21, 2006Date of Patent: March 2, 2010Assignee: Microsemi CorporationInventors: Shanqi Zhao, Dumitru Sdrulla
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Publication number: 20090072340Abstract: High voltage semiconductor devices with high-voltage termination structures are constructed on lightly doped substrates. Lightly doped p-type substrates are particularly prone to depletion and inversion from positive charges, degrading the ability of associated termination structures to block high voltages. To improve the efficiency and stability of termination structures, second termination regions of the same dopant type as the substrate, more heavily doped than the substrate but more lightly doped than first termination regions, are positioned adjoining the first termination regions. The second termination regions raise the field threshold voltage where the surface is vulnerable and render the termination structure substantially insensitive to positive charges at the surface. The use of higher dopant concentration in the gap region without causing premature avalanche is facilitated by only creating second termination regions for regions lacking field plate protection.Type: ApplicationFiled: September 9, 2008Publication date: March 19, 2009Applicant: MICROSEMI CORPORATIONInventors: Jinshu Zhang, Dumitru Sdrulla, Dah Wen Tsang