Patents by Inventor Iulian NISTOR
Iulian NISTOR 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: 20240063267Abstract: A Metal Oxide Semiconductor (MOS) cell design has traditional planar cells extending in a first dimension, and trenches with their length extending in a third dimension, orthogonal to the first dimension in a top view. The manufacturing process includes forming a horizontal channel, and a plurality of trenches discontinued in the planar cell regions. Horizontal planar channels are formed in the mesa of the orthogonal trenches. A series connected horizontal planar channel and a vertical trench channel are formed along the trench regions surrounded by the first base. The lack of a traditional vertical channel is important to avoid significant reliability issues (shifts in threshold voltage Vth). The planar cell design offers a range of advantages both in terms of performance and processability. Manufacture of the planar cell is based on a self-aligned process with minimum number of masks, with the potential of applying additional layers or structures.Type: ApplicationFiled: September 21, 2023Publication date: February 22, 2024Inventors: Munaf RAHIMO, Iulian NISTOR
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Publication number: 20240055498Abstract: A Metal Oxide Semiconductor (MOS) trench cell concept adopts on a first surface of a semiconductor body a plurality of main gates extending lengthwise parallel to one another, and forming MOS channels, with transistor cell regions formed in a mesa of the semiconductor body between neighbouring main gates, and a drift layer in the semiconductor body s. The power semiconductor includes a plurality of second gates interwoven with the main gates at an angle of 45 degrees to 90 degrees to the longitudinal direction of the main gates. An additional gate structure can also be added to interconnect the second gates, leading to additional design flexibility by enabling forming additional MOS channels in the power semiconductor. The new design can be applied to both IGBTs and MOSFETs based on silicon or wide bandgap materials such as Silicon Carbide SiC or Gallium Nitride GaN.Type: ApplicationFiled: October 2, 2020Publication date: February 15, 2024Inventors: Munaf RAHIMO, Iulian NISTOR
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Patent number: 11804524Abstract: A Metal Oxide Semiconductor (MOS) cell design has traditional planar cells extending in a first dimension, and trenches with their length extending in a third dimension, orthogonal to the first dimension in a top view. The manufacturing process includes forming a horizontal channel, and a plurality of trenches discontinued in the planar cell regions. Horizontal planar channels are formed in the mesa of the orthogonal trenches. A series connected horizontal planar channel and a vertical trench channel are formed along the trench regions surrounded by the first base. The lack of a traditional vertical channel is important to avoid significant reliability issues (shifts in threshold voltage Vth). The planar cell design offers a range of advantages both in terms of performance and processability. Manufacture of the planar cell is based on a self-aligned process with minimum number of masks, with the potential of applying additional layers or structures.Type: GrantFiled: August 7, 2020Date of Patent: October 31, 2023Assignee: MQSEMI AGInventors: Munaf Rahimo, Iulian Nistor
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Patent number: 11522047Abstract: A thin non-punch-through semiconductor device with a patterned collector layer on the collector side is proposed. The thin NPT RC-IGBT semiconductor device has a collector layer with a pattern of p/n shorts, an emitter side structured as a functional MOS cell, a base layer arranged between the emitter and the collector sides, but without the use of a buffer/field-stop layer. A low doped bipolar gain control layer having a thickness of less than 10 ?m may be used in combination with a short pattern of the collector to reduce the bipolar gain and achieve thinner devices with lower losses and high operating temperature capability. The doping concentration of the base layer and a thickness of the base layer are adapted such that the distance from the end of the electric field region to the patterned collector, at breakdown voltage, is less than 15% of the total device thickness.Type: GrantFiled: June 10, 2020Date of Patent: December 6, 2022Assignee: MQSEMI AGInventors: Munaf Rahimo, Iulian Nistor
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Publication number: 20220384578Abstract: A Metal Oxide Semiconductor (MOS) transistor cell design has multiple trench recesses embedding trench gate electrodes longitudinally extending in a third dimension, with interconnected first base layer, source regions, and a second base layer covering portions of the regions between adjacent trench recesses and longitudinally extending in the same third dimension. When a control voltage greater than a threshold value is applied on the trench gate electrodes, no vertical MOS channels are formable on the trench walls because each of trench recesses abuts at least one source regions and a connected highly doped second base layer. Instead, the charge carriers flow from a singular point within the source region, into a radial MOS channel formed only on the lateral walls of those trench regions abutting the first base layer, but not the higher doped second base layer.Type: ApplicationFiled: May 31, 2022Publication date: December 1, 2022Inventors: Munaf RAHIMO, Iulian NISTOR
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Publication number: 20220384577Abstract: A semiconductor device with an active transistor cell comprising a p-doped first and second base layers, surrounding an n type source region, the device further comprising a plurality of first gate electrodes embedded in trench recesses, has additional fortifying p-doped layers embedding the opposite ends of the trench recesses. The additional fortifying layers do not affect the active cell design in terms of cell pitch i.e., the design rules for transistor cell spacing, or hole drainage between the transistor cells, but reduce the gate-collector parasitic capacitance of the semiconductor, hence leading to optimum low conduction and switching losses. To further reduce the gate-collector capacitance, the trench recesses embedding the first gate electrodes can be formed with thicker insulating layers in regions that do not abut the first base layers, so as not to negatively impact the value of the threshold voltage.Type: ApplicationFiled: May 31, 2022Publication date: December 1, 2022Inventors: Munaf RAHIMO, Iulian NISTOR
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Publication number: 20220352315Abstract: In this patent application, a new Metal Oxide Semiconductor MOS planar cell design concept is proposed. The inventive power semiconductor includes a planar cell forming a horizontal channel and a plurality of trenches, which are arranged orthogonally to the plane of the planar cells. A second p base layer is introduced which extends perpendicularly deeper than the source region and laterally to the same distance/extent as the source region. Therefore, a vertical channel is prevented from forming in the trench regions while allowing the horizontal channels to form. This is extremely important in order to avoid significant issues (i.e. shifts in Vth) encountered in prior art IGBT designs. The new cell concept adopts planar MOS channel and Trench technology in a single MOS cell structure.Type: ApplicationFiled: July 10, 2020Publication date: November 3, 2022Inventors: Munaf RAHIMO, Iulian NISTOR
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Patent number: 11411076Abstract: Power transistors relying on planar MOS cell designs suffer from the “hole drainage effect”; addition of an enhancement layer creates significant loss of breakdown voltage capability. The Fortified Enhanced Planar MOS cell design provides an alternative that uses enhancement layers, field oxides, and gate trenches without suffering from the loss of blocking voltage. A low doped P-type “fortifying layer” reduces the high peak electric fields that develop in blocking mode in critical regions. The fortifying layer can be electrically biased through an additional electrical contact, which can be arranged at die level, not at transistor cell level. Due to the low dopant concentration of the fortifying layer, no additional MOS channels need to be formed, and the electrons will flow thru the non-inverted regions of the fortifying layer. The new design shows advantages in performance, ease of processing, and applicability.Type: GrantFiled: March 10, 2021Date of Patent: August 9, 2022Assignee: mqSemi AGInventors: Munaf Rahimo, Iulian Nistor
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Patent number: 11404542Abstract: A power transistor layout structure is described that includes a planar cell with a planar gate electrode forming an horizontal MOS channel, and a plurality of trench recesses with gate electrodes, which are arranged at various angles to the longitudinal direction of the planar cells. This cell concept can adopt both planar MOS channels, and Trench MOS channels in a single MOS cell structure. As an alternative, the planar cell gate electrode may be grounded. The device is easy to manufacture based on a self-aligned process with minimum number of masks, with the potential of applying additional layers.Type: GrantFiled: February 12, 2021Date of Patent: August 2, 2022Assignee: mqSemi AGInventors: Munaf Rahimo, Iulian Nistor
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Publication number: 20220216331Abstract: A semiconductor device with an active transistor cell comprising a p-type first and second base layers, surrounding an n-type source region, the device further comprising a plurality of first gate electrodes embedded in trench recesses, has additional gate runners formed adjacent to the first base layer, outside the active cell, and contacting the first gate electrodes at the cross points thereof. The additional gate runners do not affect the active cell design in terms of cell pitch i.e., the design rules for cell spacing, hole drainage between the cells, or gate-collector capacitance, hence resulting in optimum low conduction and switching losses. The transistor cell and layout designs offer a range of advantages both in terms of performance and manufacturability, with the potential of applying additional layers or structures.Type: ApplicationFiled: January 6, 2022Publication date: July 7, 2022Inventors: Munaf RAHIMO, Iulian NISTOR
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Patent number: 11264475Abstract: A Metal Oxide Semiconductor (MOS) trench cell includes a plurality of main gate trenches etched in the semiconductor body. In conduction state, the main gate electrode forms vertical MOS channels on the short edges and at least on a portion of the long edges in a mesa of the semiconductor body between neighbouring trenches. The longitudinal direction of the main gate trenches is oriented at an angle between 45 degrees to 90 degrees compared to the longitudinal direction of the first main electrode contacts, in a top plane view. This design offers a wide range of advantages both in terms of performance (reduced losses, improved controllability and reliability) and processability (narrow mesa design rules) and can be applied to both IGBTs and MOSFETs based on silicon or wide bandgap materials such as silicon carbide SiC, zinc oxide (ZnO), gallium oxide (Ga2O3), gallium nitride (GaN), diamond.Type: GrantFiled: October 5, 2020Date of Patent: March 1, 2022Assignee: MQ SEMI AGInventors: Munaf Rahimo, Iulian Nistor
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Publication number: 20210288139Abstract: Power transistors relying on planar MOS cell designs suffer from the “hole drainage effect”; addition of an enhancement layer creates significant loss of breakdown voltage capability. The Fortified Enhanced Planar MOS cell design provides an alternative that uses enhancement layers, field oxides, and gate trenches without suffering from the loss of blocking voltage. A low doped P-type “fortifying layer” reduces the high peak electric fields that develop in blocking mode in critical regions. The fortifying layer can be electrically biased through an additional electrical contact, which can be arranged at die level, not at transistor cell level. Due to the low dopant concentration of the fortifying layer, no additional MOS channels need to be formed, and the electrons will flow thru the non-inverted regions of the fortifying layer. The new design shows advantages in performance, ease of processing, and applicability.Type: ApplicationFiled: March 10, 2021Publication date: September 16, 2021Inventors: Munaf RAHIMO, Iulian NISTOR
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Publication number: 20210257460Abstract: A power transistor layout structure is described that includes a planar cell with a planar gate electrode forming an horizontal MOS channel, and a plurality of trench recesses with gate electrodes, which are arranged at various angles to the longitudinal direction of the planar cells. This cell concept can adopt both planar MOS channels, and Trench MOS channels in a single MOS cell structure. As an alternative, the planar cell gate electrode may be grounded. The device is easy to manufacture based on a self-aligned process with minimum number of masks, with the potential of applying additional layers.Type: ApplicationFiled: February 12, 2021Publication date: August 19, 2021Inventors: Munaf RAHIMO, Iulian NISTOR
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Publication number: 20210134989Abstract: An Enhanced Planar MOS cell based on a simple and self-aligned process provides a structure where the lateral distance between the edge of the gate electrode opening and the end of the P-well region is less than 70% from the vertical distance between the surface of the substrate and the depth of the P-well region. Usually, for previous designs, this ratio was 70-80% or more. A spacer can be introduced at the edge of the polysilicon gate electrode openings after the diffusion of an enhancement layer. Using the spacer, a P-type implant is made, resulting in a shorter lateral MOS channel, while the vertical depth of the P-well remains unchanged. The design results in much lower on-state losses without affecting the voltage blocking capability of the device. This design offers advantages both in terms of performance and processability and can be applied to both IGBTs and MOSFETs.Type: ApplicationFiled: October 31, 2020Publication date: May 6, 2021Inventors: Munaf RAHIMO, Iulian NISTOR, Charalampos Papadopoulos
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Publication number: 20210104614Abstract: A Metal Oxide Semiconductor (MOS) trench cell includes a plurality of main gate trenches etched in the semiconductor body. In conduction state, the main gate electrode forms vertical MOS channels on the short edges and at least on a portion of the long edges in a mesa of the semiconductor body between neighbouring trenches. The longitudinal direction of the main gate trenches is oriented at an angle between 45 degrees to 90 degrees compared to the longitudinal direction of the first main electrode contacts, in a top plane view. This design offers a wide range of advantages both in terms of performance (reduced losses, improved controllability and reliability) and processability (narrow mesa design rules) and can be applied to both IGBTs and MOSFETs based on silicon or wide bandgap materials such as silicon carbide SiC, zinc oxide (ZnO), gallium oxide (Ga2O3), gallium nitride (GaN), diamond.Type: ApplicationFiled: October 5, 2020Publication date: April 8, 2021Inventors: Munaf RAHIMO, Iulian NISTOR
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Publication number: 20210043734Abstract: A Metal Oxide Semiconductor (MOS) cell design has traditional planar cells extending in a first dimension, and trenches with their length extending in a third dimension, orthogonal to the first dimension in a top view. The manufacturing process includes forming a horizontal channel, and a plurality of trenches discontinued in the planar cell regions. Horizontal planar channels are formed in the mesa of the orthogonal trenches. A series connected horizontal planar channel and a vertical trench channel are formed along the trench regions surrounded by the first base. The lack of a traditional vertical channel is important to avoid significant reliability issues (shifts in threshold voltage Vth). The planar cell design offers a range of advantages both in terms of performance and processability. Manufacture of the planar cell is based on a self-aligned process with minimum number of masks, with the potential of applying additional layers or structures.Type: ApplicationFiled: August 7, 2020Publication date: February 11, 2021Inventors: Munaf RAHIMO, Iulian NISTOR
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Publication number: 20200395442Abstract: A thin non-punch-through semiconductor device with a patterned collector layer on the collector side is proposed. The thin NPT RC-IGBT semiconductor device has a collector layer with a pattern of p/n shorts, an emitter side structured as a functional MOS cell, a base layer arranged between the emitter and the collector sides, but without the use of a buffer/field-stop layer. A low doped bipolar gain control layer having a thickness of less than 10 ?m may be used in combination with a short pattern of the collector to reduce the bipolar gain and achieve thinner devices with lower losses and high operating temperature capability. The doping concentration of the base layer and a thickness of the base layer are adapted such that the distance from the end of the electric field region to the patterned collector, at breakdown voltage, is less than 15% of the total device thickness.Type: ApplicationFiled: June 10, 2020Publication date: December 17, 2020Inventors: Munaf RAHIMO, Iulian NISTOR
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Publication number: 20180264450Abstract: The precursor of a hydroprocessing catalyst is made by impregnating a metal oxide component comprising at least one metal from Group 6 of the Periodic Table and at least one metal from Groups 8-10 of the Periodic Table with an amide formed from a first organic compound containing at least one amine group, and a second organic compound containing at least one carboxylic acid group. Following impregnation heat treatment follows to form in situ generated unsaturation additional to that in the two organic compounds. The catalyst precursor is sulfided to form an active, sulfide hydroprocessing catalyst.Type: ApplicationFiled: April 27, 2018Publication date: September 20, 2018Inventors: STUART L. SOLED, SABATO MISEO, JOSEPH E. BAUMGARTNER, IULIAN NISTOR, PARTHA NANDI, JAVIER GUZMAN, DORON LEVIN, Keith Wilson, JACOB ARIE BERGWERFF, RONALD HUIBERTS, ARNOLD VAN LOEVEZIJN
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Patent number: 10022712Abstract: The precursor of a hydroprocessing catalyst is made by impregnating a metal oxide component comprising at least one metal from Group 6 of the Periodic Table and at least one metal from Groups 8-10 of the Periodic Table with an amide formed from a first organic compound containing at least one amine group, and a second organic compound containing at least one carboxylic acid group. Following impregnation heat treatment follows to form in situ generated unsaturation additional to that in the two organic compounds. The catalyst precursor is sulfided to form an active, sulfide hydroprocessing catalyst.Type: GrantFiled: May 5, 2014Date of Patent: July 17, 2018Assignee: EXXONMOBIL RESEARCH AND ENGINEERING COMPANYInventors: Stuart L. Soled, Sabato Miseo, Joseph E. Baumgartner, Iulian Nistor, Partha Nandi, Javier Guzman, Doron Levin, Keith Wilson, Jacob Arie Bergweff, Ronald Jan Huiberts, Arnold Van Loevezijn
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Patent number: 9859360Abstract: A termination region of an IGBT is described, in which surface p-rings are combined with oxide/polysilicon-filled trenches, buried p-rings and surface field plates, so as to obtain an improved distribution of potential field lines in the termination region. The combination of surface ring termination and deep ring termination offers a significant reduction in the amount silicon area which is required for the termination region.Type: GrantFiled: June 16, 2016Date of Patent: January 2, 2018Assignee: ABB Schweiz AGInventors: Marina Antoniou, Florin Udrea, Iulian Nistor, Munaf Rahimo, Chiara Corvasce