Patents by Inventor David Laforet
David Laforet 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: 20250063794Abstract: A transistor device includes a semiconductor substrate having a first major surface and one or more transistor cells. Each transistor cell may include a columnar trench in the semiconductor substrate. The columnar trench includes a field dielectric, base, and a side wall. The side wall may extend from the base to the first major surface. The field dielectric may line the base and side wall of the columnar trench. A first thickness of the field dielectric at a first distance from the base is smaller than a second thickness of the field dielectric at a second distance from the base. The first distance is greater than the second distance. A columnar field plate with a cavity may be arranged in the columnar trench. A first perimeter of the columnar field plate at the first distance is greater than a second perimeter of the columnar field plate at the second distance.Type: ApplicationFiled: August 8, 2024Publication date: February 20, 2025Inventors: David Laforet, Thomas Ralf Siemieniec
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Patent number: 12230706Abstract: In an embodiment, a transistor device a semiconductor substrate having a main surface, and a cell field including a plurality of transistor cells of a power transistor. The cell field further includes: a body region of a second conductivity type; a source region of a first conductivity type on or in the body region, the first conductivity type opposing the second conductivity type; a gate trench in the main surface of the semiconductor substrate; a gate dielectric lining the gate trench; a metal gate electrode arranged in the gate trench on the gate dielectric; and an electrically insulating cap arranged on the metal gate electrode. A method of fabricating a gate of the transistor device is also described.Type: GrantFiled: January 30, 2023Date of Patent: February 18, 2025Assignee: Infineon Technologies Austria AGInventors: Ingmar Neumann, Michael Hutzler, David Laforet, Roland Moennich, Thomas Ralf Siemieniec
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Publication number: 20240395926Abstract: In an embodiment, a semiconductor device includes an edge termination region laterally surrounding an active area. The active area includes active transistor cells. The edge termination region includes one or more inactive cells, each including a first columnar trench and a first termination mesa arranged adjacent to the first columnar trench. Each first columnar trench includes a base, a side wall, a field plate, and a field dielectric arranged on the base and the side wall and surrounding the field plate. Each first termination mesa includes a drift region of a first conductivity type and a body region of a second conductivity type arranged above the drift region. Each field dielectric of the first columnar trenches has a first thickness in an upper region of the field plate and a second thickness in a lower region of the field plate, the first thickness being smaller than the second thickness.Type: ApplicationFiled: May 7, 2024Publication date: November 28, 2024Inventors: Thomas Ralf Siemieniec, David Laforet
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Publication number: 20240339507Abstract: A transistor device includes a semiconductor substrate having a first major surface and one or more transistor cells. Each transistor cell includes a columnar trench formed in the substrate, a columnar field plate arranged in the columnar trench, and a mesa arranged around the columnar trench. The columnar trench includes a field dielectric, a base, and a side wall. The side wall extends from the base to the first major surface. The field dielectric lines the base and side wall. A first thickness of the field dielectric at a first distance from the base is smaller than a second thickness of the field dielectric at a second distance from the base, the first distance being greater than the second distance. A first perimeter of the columnar field plate at the first distance is greater than a second perimeter of the columnar field plate at the second distance.Type: ApplicationFiled: April 3, 2024Publication date: October 10, 2024Inventors: Thomas Ralf Siemieniec, David Laforet, Christof Altstätter, Heimo Hofer
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Patent number: 11848379Abstract: A vertical power semiconductor transistor device includes: a drain region of a first conductivity type; a body region of a second conductivity type; a drift region of the first conductivity type which separates the body region from the drain region; a source region of the first conductivity type separated from the drift region by the body region; a gate trench extending through the source and body regions and into the drift region, the gate trench including a gate electrode; and a field electrode in the gate trench or in a separate trench. The drift region has a generally linearly graded first doping profile which increases from the body region toward a bottom of the trench that includes the field electrode, and a graded second doping profile that increases at a greater rate than the first doping profile from an end of the first doping profile toward the drain region.Type: GrantFiled: September 23, 2021Date of Patent: December 19, 2023Assignee: Infineon Technologies Austria AGInventors: Ralf Siemieniec, David Laforet, Cédric Ouvrard
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Patent number: 11764272Abstract: The disclosure relates to a semiconductor device having a first active region, a plurality of elongated gate regions having an elongated extension in a first lateral direction, respectively, a plurality of elongated field plate regions having an elongated extension in the first lateral direction, respectively, and a first additional gate region, wherein a first one of the elongated gate regions is arranged in a first elongated gate trench at a first side of the first active region, and a second one of the elongated gate regions is arranged in a second elongated gate trench at a second side of the first active region, the second side lying opposite to the first side with respect to a second lateral direction, and wherein the first additional gate region is arranged in a first additional gate trench which extends at least proportionately in the second lateral direction through the first active region.Type: GrantFiled: May 17, 2021Date of Patent: September 19, 2023Assignee: Infineon Technologies Austria AGInventors: David Laforet, Cesar Augusto Braz, Alessandro Ferrara, Cédric Ouvrard, Li Juin Yip
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Publication number: 20230178647Abstract: In an embodiment, a transistor device a semiconductor substrate having a main surface, and a cell field including a plurality of transistor cells of a power transistor. The cell field further includes: a body region of a second conductivity type; a source region of a first conductivity type on or in the body region, the first conductivity type opposing the second conductivity type; a gate trench in the main surface of the semiconductor substrate; a gate dielectric lining the gate trench; a metal gate electrode arranged in the gate trench on the gate dielectric; and an electrically insulating cap arranged on the metal gate electrode. A method of fabricating a gate of the transistor device is also described.Type: ApplicationFiled: January 30, 2023Publication date: June 8, 2023Inventors: Ingmar Neumann, Michael Hutzler, David Laforet, Roland Moennich, Thomas Ralf Siemieniec
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Patent number: 11600723Abstract: In an embodiment, a transistor device includes a semiconductor substrate having a main surface, a cell field including a plurality of transistor cells, and an edge termination region laterally surrounding the cell field. The cell field includes a gate trench in the main surface of the semiconductor substrate, a gate dielectric lining the gate trench, a metal gate electrode arranged in the gate trench on the gate dielectric, and an electrically insulating cap arranged on the metal gate electrode and within the gate trench.Type: GrantFiled: February 1, 2021Date of Patent: March 7, 2023Assignee: Infineon Technologies Austria AGInventors: Ingmar Neumann, Michael Hutzler, David Laforet, Roland Moennich, Ralf Siemieniec
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Publication number: 20230055891Abstract: In an embodiment, a transistor device comprises a semiconductor body comprising a plurality of transistor cells comprising a drift region of a first conductivity type, a body region of a second conductivity type forming a first pn junction with the drift region, the second conductivity type opposing the first conductivity type, a source region of the first conductivity type forming a second pn junction with the body region, a columnar field plate trench extending into a major surface of a semiconductor body and comprising a columnar field plate and a gate trench structure extending into the major surface of the semiconductor body and comprising a gate electrode. At least one of the depth and doping level of the body region locally varies within the transistor cell to improve VGSTH homogeneity within the transistor cell.Type: ApplicationFiled: February 7, 2020Publication date: February 23, 2023Inventors: Oliver Blank, Cesar Augusto Braz, Yan Gao, Olivier Guillemant, Franz Hirler, David Laforet, Peter Lagger, Cédric Ouvrard, Elias Pree, Li Juin Yip
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Publication number: 20220376062Abstract: A semiconductor device includes a transistor cell region, and a first termination region devoid of transistor cells. The transistor cell region includes a gate structure, a plurality of needle-shaped first field plate structures, body regions of a second conductivity type, and source regions of a first conductivity type. The first termination region surrounds the transistor cell region and includes needle-shaped second field plate structures. The needle-shaped first field plate structures are arranged in a first pattern and the needle-shaped second field plate structures are arranged in a second pattern.Type: ApplicationFiled: August 5, 2022Publication date: November 24, 2022Inventors: Ralf Siemieniec, Oliver Blank, Franz Hirler, Michael Hutzler, David Laforet, Cédric Ouvrard, Li Juin Yip
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Patent number: 11462620Abstract: A semiconductor device includes a semiconductor substrate, a transistor cell region formed in the semiconductor substrate and an inner termination region formed in the semiconductor substrate and devoid of transistor cells. The transistor cell region includes a gate structure extending from a first surface into the semiconductor substrate, a plurality of needle-shaped first field plate structures extending from the first surface into the semiconductor substrate, body regions of a second conductivity type, and source regions of a first conductivity type formed between the body regions and the first surface. The inner termination region surrounds the transistor cell region and includes needle-shaped second field plate structures extending from the first surface into the semiconductor substrate. The needle-shaped first field plate structures are arranged in a first pattern and the needle-shaped second field plate structures are arranged in a second pattern.Type: GrantFiled: November 16, 2020Date of Patent: October 4, 2022Assignee: Infineon Technologies Austria AGInventors: Ralf Siemieniec, Oliver Blank, Franz Hirler, Michael Hutzler, David Laforet, Cédric Ouvrard, Li Juin Yip
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Patent number: 11296218Abstract: A semiconductor device includes a semiconductor body having first and second opposing surfaces, an active area including active transistor cells, and an edge termination region laterally surrounding the active area. Each active transistor cell includes a mesa and a columnar trench having a field plate. The edge termination region includes inactive cells each including a columnar termination trench having a field plate, and a termination mesa including a drift region of a first conductivity type. The edge termination region includes a transition region laterally surrounding the active region and an outer termination region laterally surrounding the transition region. In the transition region, the termination mesa includes a body region of a second conductivity type arranged on the drift region. In the outer termination region, the drift region extends to the first surface. A buried doped region of the edge termination region is positioned in the transition and outer termination regions.Type: GrantFiled: May 13, 2020Date of Patent: April 5, 2022Assignees: Infineon Technologies Austria AG, Infineon Technologies Americas Corp.Inventors: Ralf Siemieniec, Adam Amali, Michael Hutzler, Laszlo Juhasz, David Laforet, Cedric Ouvrard, Li Juin Yip
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Patent number: 11251275Abstract: A power semiconductor die has a semiconductor body coupled to first and second load terminals, and at least one power cell. In a horizontal cross-section of the at least one power cell, a contact has a contact region which horizontally overlaps with a field plate electrode and horizontally protrudes from the field plate trench, and a recess region does not horizontally overlap with the contact region and extends into a horizontal circumference of the field plate trench.Type: GrantFiled: August 9, 2019Date of Patent: February 15, 2022Assignee: Infineon Technologies Austria AGInventors: Christof Altstaetter, Marcel Rene Mueller, Oliver Blank, David Laforet
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Publication number: 20220013665Abstract: A vertical power semiconductor transistor device includes: a drain region of a first conductivity type; a body region of a second conductivity type; a drift region of the first conductivity type which separates the body region from the drain region; a source region of the first conductivity type separated from the drift region by the body region; a gate trench extending through the source and body regions and into the drift region, the gate trench including a gate electrode; and a field electrode in the gate trench or in a separate trench. The drift region has a generally linearly graded first doping profile which increases from the body region toward a bottom of the trench that includes the field electrode, and a graded second doping profile that increases at a greater rate than the first doping profile from an end of the first doping profile toward the drain region.Type: ApplicationFiled: September 23, 2021Publication date: January 13, 2022Inventors: Ralf Siemieniec, David Laforet, Cédric Ouvrard
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Publication number: 20210367045Abstract: The disclosure relates to a semiconductor device having a first active region, a plurality of elongated gate regions having an elongated extension in a first lateral direction, respectively, a plurality of elongated field plate regions having an elongated extension in the first lateral direction, respectively, and a first additional gate region, wherein a first one of the elongated gate regions is arranged in a first elongated gate trench at a first side of the first active region, and a second one of the elongated gate regions is arranged in a second elongated gate trench at a second side of the first active region, the second side lying opposite to the first side with respect to a second lateral direction, and wherein the first additional gate region is arranged in a first additional gate trench which extends at least proportionately in the second lateral direction through the first active region.Type: ApplicationFiled: May 17, 2021Publication date: November 25, 2021Inventors: David Laforet, Cesar Augusto Braz, Alessandro Ferrara, Cédric Ouvrard, Li Juin Yip
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Patent number: 11158735Abstract: A vertical power semiconductor transistor device includes: a drain region of a first conductivity type; a body region of a second conductivity type; a drift region of the first conductivity type which separates the body region from the drain region; a source region of the first conductivity type separated from the drift region by the body region; a gate trench extending through the source and body regions and into the drift region, the gate trench including a gate electrode; and a field electrode in the gate trench or in a separate trench. The drift region has a generally linearly graded first doping profile which increases from the body region toward a bottom of the trench that includes the field electrode, and a graded second doping profile that increases at a greater rate than the first doping profile from an end of the first doping profile toward the drain region.Type: GrantFiled: February 5, 2020Date of Patent: October 26, 2021Assignee: Infineon Technologies Austria AGInventors: Ralf Siemieniec, David Laforet, Cedric Ouvrard
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Publication number: 20210249534Abstract: In an embodiment, a transistor device includes a semiconductor substrate having a main surface, a cell field including a plurality of transistor cells, and an edge termination region laterally surrounding the cell field. The cell field includes a gate trench in the main surface of the semiconductor substrate, a gate dielectric lining the gate trench, a metal gate electrode arranged in the gate trench on the gate dielectric, and an electrically insulating cap arranged on the metal gate electrode and within the gate trench.Type: ApplicationFiled: February 1, 2021Publication date: August 12, 2021Inventors: Ingmar Neumann, Michael Hutzler, David Laforet, Roland Moennich, Ralf Siemieniec
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Publication number: 20210242340Abstract: A vertical power semiconductor transistor device includes: a drain region of a first conductivity type; a body region of a second conductivity type; a drift region of the first conductivity type which separates the body region from the drain region; a source region of the first conductivity type separated from the drift region by the body region; a gate trench extending through the source and body regions and into the drift region, the gate trench including a gate electrode; and a field electrode in the gate trench or in a separate trench. The drift region has a generally linearly graded first doping profile which increases from the body region toward a bottom of the trench that includes the field electrode, and a graded second doping profile that increases at a greater rate than the first doping profile from an end of the first doping profile toward the drain region.Type: ApplicationFiled: February 5, 2020Publication date: August 5, 2021Inventors: Ralf Siemieniec, David Laforet, Cedric Ouvrard
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Publication number: 20210066459Abstract: A semiconductor device includes a semiconductor substrate, a transistor cell region formed in the semiconductor substrate and an inner termination region formed in the semiconductor substrate and devoid of transistor cells. The transistor cell region includes a gate structure extending from a first surface into the semiconductor substrate, a plurality of needle-shaped first field plate structures extending from the first surface into the semiconductor substrate, body regions of a second conductivity type, and source regions of a first conductivity type formed between the body regions and the first surface. The inner termination region surrounds the transistor cell region and includes needle-shaped second field plate structures extending from the first surface into the semiconductor substrate. The needle-shaped first field plate structures are arranged in a first pattern and the needle-shaped second field plate structures are arranged in a second pattern.Type: ApplicationFiled: November 16, 2020Publication date: March 4, 2021Inventors: Ralf Siemieniec, Oliver Blank, Franz Hirler, Michael Hutzler, David Laforet, Cédric Ouvrard, Li Juin Yip
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Patent number: 10872957Abstract: A semiconductor device includes a semiconductor substrate, a transistor cell region formed in the semiconductor substrate and an inner termination region formed in the semiconductor substrate and devoid of transistor cells. The transistor cell region includes a plurality of transistor cells and a gate structure that forms a grid separating transistor sections of the transistor cells from each other, each of the transistor sections including a needle-shaped first field plate structure extending from a first surface into the semiconductor substrate. The inner termination region surrounds the transistor cell region and includes needle-shaped second field plate structures extending from the first surface into the semiconductor substrate. The first field plate structures form a first portion of a regular pattern and the second field plate structures form a second portion of the same regular pattern.Type: GrantFiled: November 22, 2019Date of Patent: December 22, 2020Assignee: Infineon Technologies Austria AGInventors: Ralf Siemieniec, Oliver Blank, Franz Hirler, Michael Hutzler, David Laforet, Cedric Ouvrard, Li Juin Yip