Vertical Transistors (epo) Patents (Class 257/E29.313)
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Patent number: 7704836Abstract: In a trench MOSFET, the lower portion of the trench contains a buried source electrode, which is insulated from the epitaxial layer and semiconductor substrate but in electrical contact with the source region. When the MOSFET is in an “off” condition, the bias of the buried source electrode causes the “drift” region of the mesa to become depleted, enhancing the ability of the MOSFET to block current. The doping concentration of the drift region can therefore be increased, reducing the on-resistance of the MOSFET. The buried source electrode also reduces the gate-to-drain capacitance of the MOSFET, improving the ability of the MOSFET to operate at high frequencies. The substrate may advantageously include a plurality of annular trenches separated by annular mesas and a gate metal layer that extends outward from a central region in a plurality of gate metal legs separated by source metal regions.Type: GrantFiled: March 31, 2008Date of Patent: April 27, 2010Assignee: Siliconix incorporatedInventors: Deva N. Pattanayak, Yuming Bai, Kyle Terrill, Christiana Yue, Robert Xu, Kam Hong Lui, Kuo-In Chen, Sharon Shi
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Patent number: 7679133Abstract: In a semiconductor device, and a method of manufacturing thereof, the device includes a substrate of single-crystal semiconductor material extending in a horizontal direction and a plurality of interlayer dielectric layers on the substrate. A plurality of gate patterns are provided, each gate pattern being between a neighboring lower interlayer dielectric layer and a neighboring upper interlayer dielectric layer. A vertical channel of single-crystal semiconductor material extends in a vertical direction through the plurality of interlayer dielectric layers and the plurality of gate patterns, a gate insulating layer being between each gate pattern and the vertical channel that insulates the gate pattern from the vertical channel.Type: GrantFiled: November 3, 2008Date of Patent: March 16, 2010Assignee: Samsung Electronics Co., Ltd.Inventors: Yong-Hoon Son, Jong-Wook Lee
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Patent number: 7670911Abstract: A method for manufacturing a vertical MOS transistor comprising forming a protrusion-like region, forming a silicon oxide film on an exposed surface of the protrusion-like region and a surface of the silicon semiconductor substrate, increasing a film thickness of at least the silicon oxide film on the silicon semiconductor substrate by thermal oxidation to form a first insulating film, forming a lower impurity diffusion region, removing the silicon oxide film to expose a silicon side of the protrusion-like region, thermally oxidizing the silicon side to form a second insulating film having a thinner film thickness than a film thickness of the first insulating film, forming a gate electrode over a side of the protrusion-like region, and forming an upper impurity diffusion region.Type: GrantFiled: July 31, 2008Date of Patent: March 2, 2010Assignee: Elpida Memory, Inc.Inventor: Kiyonori Oyu
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Patent number: 7663184Abstract: A memory and a method of fabricating the same are provided. The memory is disposed on a substrate in which a plurality of trenches is arranged in parallel. The memory includes a gate structure and a doped region. The gate structure is disposed between the trenches. The doped region is disposed at one side of the gate structure, in the substrate between the trenches and in the sidewalls and bottoms of the trenches. The top surface of the doped region in the substrate between the trenches is lower than the surface of the substrate under the gate structure by a distance, and the distance is greater than 300 ?.Type: GrantFiled: July 31, 2008Date of Patent: February 16, 2010Assignee: MACRONIX International Co., Ltd.Inventors: Yao-Fu Chan, Ta-Kang Chu, Jung-Chuan Ting, Cheng-Ming Yih
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Publication number: 20100003573Abstract: A method for processing at least one wall of an opening formed in a silicon substrate, successively including the steps of implanting fluorine atoms into an upper portion of the wall of the opening, performing an oxidization step, and applying a specific processing to at least a portion of the non-implanted portion of the opening.Type: ApplicationFiled: July 16, 2008Publication date: January 7, 2010Applicant: STMicroelectronics S.A.Inventors: Edgard Jeanne, Sylvain Nizou
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Patent number: 7586130Abstract: A vertical field effect transistor includes: an active region with a bundle of linear structures functioning as a channel region; a lower electrode, functioning as one of source and drain regions; an upper electrode, functioning as the other of the source and drain regions; a gate electrode for controlling the electric conductivity of at least a portion of the bundle of linear structures included in the active region; and a gate insulating film arranged between the active region and the gate electrode to electrically isolate the gate electrode from the bundle of linear structures. The transistor further includes a dielectric portion between the upper and lower electrodes. The upper electrode is located over the lower electrode with the dielectric portion interposed and includes an overhanging portion sticking out laterally from over the dielectric portion. The active region is located right under the overhanging portion of the upper electrode.Type: GrantFiled: February 1, 2006Date of Patent: September 8, 2009Assignee: Panasonic CorporationInventors: Takahiro Kawashima, Tohru Saitoh, Takeshi Takagi
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Publication number: 20090108303Abstract: A semiconductor component and method of making a semiconductor component. One embodiment provides a first metallization structure electrically coupled to charge compensation zones via an ohmic contact and to drift zones via a Schottky contact. A second metallization structure, which is arranged opposite the first metallization structure, is electrically coupled to the charge compensation zones via a Schottky contact and to drift zones via an ohmic contact.Type: ApplicationFiled: October 30, 2008Publication date: April 30, 2009Applicant: Infineon Technologies Austria AGInventor: Frank Pfirsch
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Patent number: 7510955Abstract: A multi-fin field effect transistor includes a substrate, an oxide layer, a conductive layer, a gate oxide layer, and a doped region is provided. The substrate is surrounded by a trench, and there are at least two fin-type silicon layers formed in the substrate in a region prepared to form a gate thereon. The oxide layer is disposed in the trench and the top surface of the oxide layer is lower than that of the fin-type silicon layers. The conductive layer is disposed in the region prepared to form a gate. The top surface of the conductive layer is higher than that of the fin-type silicon layers. The gate oxide layer is disposed between the conductive layer and the fin-type silicon layers and disposed between the conductive layer and the substrate. The doped region is disposed in the substrate on both sides of the conductive layer.Type: GrantFiled: August 2, 2006Date of Patent: March 31, 2009Assignee: ProMOS Technologies Inc.Inventor: Hsiao-Che Wu
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Publication number: 20090078971Abstract: A semiconductor device with structured current spread region and method is disclosed. One embodiment provides a drift portion of a first conductivity type, a current spread portion of the first conductivity type and first portions of the first conductivity type. The current spread portion and the first portions are arranged in a first plane on the drift portion, wherein the current spread portion surrounds at least partially the first portions. The semiconductor body further includes spaced apart body regions of a second conductivity type which are arranged on the current spread portion. Further, the doping concentration of the current spread portion is higher than the doping concentrations of the drift portion and of the first portions.Type: ApplicationFiled: September 20, 2007Publication date: March 26, 2009Applicant: INFINEON TECHNOLOGIES AUSTRIA AGInventors: Michael Treu, Roland Rupp, Rudolf Elpelt
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Patent number: 7489011Abstract: A semiconductor device includes a field shield region that is doped opposite to the conductivity of the substrate and is bounded laterally by dielectric sidewall spacers and from below by a PN junction. For example, in a trench-gated MOSFET the field shield region may be located beneath the trench and may be electrically connected to the source region. When the MOSFET is reverse-biased, depletion regions extend from the dielectric sidewall spacers into the “drift” region, shielding the gate oxide from high electric fields and increasing the avalanche breakdown voltage of the device. This permits the drift region to be more heavily doped and reduces the on-resistance of the device. It also allows the use of a thin, 20 ? gate oxide for a power MOSFET that is to be switched with a 1V signal applied to its gate while being able to block over 30V applied across its drain and source electrodes, for example.Type: GrantFiled: November 12, 2005Date of Patent: February 10, 2009Inventor: Hamza Yilmaz
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Patent number: 7405452Abstract: A semiconductor device includes a field shield region that is doped opposite to the conductivity of the substrate and is bounded laterally by dielectric sidewall spacers and from below by a PN junction. For example, in a trench-gated MOSFET the field shield region may be located beneath the trench and may be electrically connected to the source region. When the MOSFET is reverse-biased, depletion regions extend from the dielectric sidewall spacers into the “drift” region, shielding the gate oxide from high electric fields and increasing the avalanche breakdown voltage of the device. This permits the drift region to be more heavily doped and reduces the on-resistance of the device. It also allows the use of a thin, 20 ? gate oxide for a power MOSFET that is to be switched with a 1V signal applied to its gate while being able to block over 30V applied across its drain and source electrodes, for example.Type: GrantFiled: February 2, 2004Date of Patent: July 29, 2008Inventor: Hamza Yilmaz
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Publication number: 20080093637Abstract: A vertical junction field effect transistor (VJFET) having a mesa termination and a method of making the device are described. The device includes: an n-type mesa on an n-type substrate; a plurality of raised n-type regions on the mesa comprising an upper n-type layer on a lower n-type layer; p-type regions between and adjacent the raised n-type regions and along a lower sidewall portion of the raised regions; dielectric material on the sidewalls of the raised regions, on the p-type regions and on the sidewalls of the mesa; and electrical contacts to the substrate (drain), p-type regions (gate) and the upper n-type layer (source). The device can be made in a wide-bandgap semiconductor material such as SiC. The method includes selectively etching through an n-type layer using a mask to form the raised regions and implanting p-type dopants into exposed surfaces of an underlying n-type layer using the mask.Type: ApplicationFiled: August 10, 2007Publication date: April 24, 2008Applicant: SEMISOUTH LABORATORIES, INC.Inventors: Igor SANKIN, Joseph MERRETT
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Patent number: 7279368Abstract: A vertical junction field effect transistor includes a trench formed in an epitaxial layer. The trench surrounds a channel region of the epitaxial layer. The channel region may have a graded or uniform dopant concentration profile. An epitaxial gate structure is formed within the trench by epitaxial regrowth. The epitaxial gate structure may include separate first and second epitaxial gate layers, and may have either a graded or uniform dopant concentration profile.Type: GrantFiled: March 4, 2005Date of Patent: October 9, 2007Assignee: Cree, Inc.Inventors: Christopher Harris, Andrei Konstantinov, Cem Basceri
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Patent number: 7276754Abstract: A memory structure having a vertically oriented access transistor with an annular gate region and a method for fabricating the structure. More specifically, a transistor is fabricated such that the channel of the transistor extends outward with respect to the surface of the substrate. An annular gate is fabricated around the vertical channel such that it partially or completely surrounds the channel. A buried annular bitline may also be implemented. After the vertically oriented transistor is fabricated with the annular gate, a storage device may be fabricated over the transistor to provide a memory cell.Type: GrantFiled: August 4, 2005Date of Patent: October 2, 2007Assignee: Micron Technology, Inc.Inventors: Lucien J. Bissey, Kevin G. Duesman
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Publication number: 20070202638Abstract: A semiconductor memory device includes a vertical MISFET having a source region, a channel forming region, a drain region, and a gate electrode formed on a sidewall of the channel forming region via a gate insulating film. In manufacturing the semiconductor memory device, the vertical MISFET in which leakage current (off current) is less can be realized by: counter-doping boron of a conductivity type opposite to that of phosphorus diffused into a poly-crystalline silicon film (10) constituting the channel forming region from an n type poly-crystalline silicon film (7) constituting the source region of the vertical MISFET, and the above-mentioned poly-crystalline silicon film (10); and reducing an effective impurity concentration in the poly-crystalline silicon film (10).Type: ApplicationFiled: April 24, 2007Publication date: August 30, 2007Inventors: Tsuyoshi Tabata, Kazuo Nakazato, Hiroshi Kujirai, Masahiro Moniwa, Hideyuki Matsuoka, Teruaki Kisu, Teruo Kisu, Haruko Kisu, Satoru Haga