With Recessed Gate (epo) Patents (Class 257/E21.419)
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Publication number: 20100240183Abstract: A mask layer having a plurality of openings is formed on the first layer. A second layer having a second conductivity type different from the first conductivity type is formed on the first layer by introducing impurities using the mask layer. A third layer having the first conductivity type is formed on the second layer by introducing impurities using the mask layer. A trench extending through the second layer and the third layer to the first layer is formed by carrying out etching using an etching mask including at least the mask layer. A gate insulation film covering a sidewall of the trench is formed. A trench gate filling the trench is formed on the gate insulation film.Type: ApplicationFiled: September 14, 2009Publication date: September 23, 2010Applicant: MITSUBISHI ELECTRIC CORPORATIONInventor: Atsushi NARAZAKI
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Patent number: 7800185Abstract: A semiconductor power device includes a plurality of closed N-channel MOSFET cells surrounded by trenched gates constituting substantially a square or rectangular cell. The trenched gates are further extended to a gate contact area and having greater width as wider trenched gates for electrically contacting a gate pad wherein the semiconductor power device further includes a source region disposed only in regions near the trenched gates in the closed N-channel MOSFET cells and away from regions near the wider trenched gate whereby a device ruggedness is improved. The source region is further disposed at a distance away from a corner or an edge of the semiconductor power device and away from a termination area. The semiconductor device further includes multiple trenched rings disposed in a termination area opposite the active area and the trenched rings having a floating voltage. The closed N-channel MOSFET cells are further supported on a red phosphorous substrate.Type: GrantFiled: January 28, 2007Date of Patent: September 21, 2010Assignee: Force-MOS Technology Corp.Inventor: Fwu-Iuan Hshieh
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Publication number: 20100171173Abstract: A trench MOSFET with improved source-body contact structure is disclosed. The improved contact structure can enlarge the P+ area below to wrap the sidewalls and bottom of source-body contact within P-body region to further enhance the avalanche capability. On the other hand, one of the embodiments disclosed a wider tungsten plug structure to connect source metal, which helps to further reduce the source contact resistance.Type: ApplicationFiled: January 8, 2009Publication date: July 8, 2010Applicant: FORCE MOS TECHNOLOGY CO. LTD.Inventor: FU-YUAN HSIEH
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Patent number: 7749846Abstract: A method of forming a contact structure includes forming an isolation region defining active regions in a semiconductor substrate. Gate patterns extending to the isolation region while crossing the active regions are formed. A sacrificial layer is formed on the semiconductor substrate having the gate patterns. Sacrificial patterns remaining on the active regions are formed by patterning the sacrificial layer. Molding patterns are formed on the isolation region. Contact holes exposing the active regions at both sides of the gate patterns are formed by etching the sacrificial patterns using the molding patterns and the gate patterns as an etching mask. Contact patterns respectively filling the contact holes are formed. The disclosed method of forming a contact structure may be used in fabricating a semiconductor device.Type: GrantFiled: March 13, 2008Date of Patent: July 6, 2010Assignee: Samsung Electronics Co., Ltd.Inventors: Hyeoung-Won Seo, Sun-Hoo Park, Soo-Ho Shin
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Patent number: 7728380Abstract: Embodiments relate to a semiconductor device. In embodiments, a semiconductor device may include a semiconductor substrate having isolation layers and a well region, a gate electrode formed within a trench having a predetermined depth in the well region, source/drain regions formed at both sides of the trench, respectively, an interlayer dielectric layer formed on the semiconductor substrate to have predetermined contact holes, and metal interconnections formed within the contact holes, respectively.Type: GrantFiled: December 26, 2006Date of Patent: June 1, 2010Assignee: Dongbu HiTek Co., LtdInventor: Jae Hwan Shim
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Patent number: 7713822Abstract: A method of forming a monolithically integrated trench FET and Schottky diode includes the following steps. Two trenches are formed extending through an upper silicon layer and terminating within a lower silicon layer. The upper and lower silicon layers have a first conductivity type. First and second silicon regions of a second conductivity type are formed in the upper silicon layer between the pair of trenches. A third silicon region of the first conductivity type is formed extending into the first and second silicon regions between the pair of trenches such that remaining lower portions of the first and second silicon regions form two body regions separated by a portion of the upper silicon layer. A silicon etch is performed to form a contact opening extending through the first silicon region such that outer portions of the first silicon region remain, the outer portions forming source regions.Type: GrantFiled: October 10, 2008Date of Patent: May 11, 2010Assignee: Fairchild Semiconductor CorporationInventors: Paul Thorup, Ashok Challa, Bruce Douglas Marchant
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Publication number: 20100105182Abstract: Fabricating a semiconductor device includes forming a hard mask on a substrate having a top substrate surface, forming a trench in the substrate through the hard mask, depositing gate material in the trench, where the amount of gate material deposited in the trench extends beyond the top substrate surface, and removing the hard mask to leave a gate having a gate top surface that extends substantially above the top substrate surface at least in center region of the trench opening, the gate having a vertical edge that includes an extended portion, the extended portion extending above the trench opening and being substantially aligned with the trench wall.Type: ApplicationFiled: December 22, 2009Publication date: April 29, 2010Inventors: Sung-Shan Tai, Tiesheng Li, Anup Bhalla, Hong Chang, Moses Ho
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Publication number: 20100099230Abstract: This invention discloses a method of manufacturing a trenched semiconductor power device with split gate filling a trench opened in a semiconductor substrate wherein the split gate is separated by an inter-poly insulation layer disposed between a top and a bottom gate segments. The method further includes a step of forming the inter-poly layer by applying a RTP process after a HDP oxide deposition process to bring an etch rate of the HDP oxide layer close to an etch rate of a thermal oxide.Type: ApplicationFiled: October 16, 2009Publication date: April 22, 2010Inventors: Sung-Shan Tai, Yong-Zhong Hu, François Hébert, Hong Chang, Mengyu Pan, Yingying Lou, Yu Wang
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Patent number: 7700441Abstract: The invention includes methods of forming field effect transistors, methods of forming field effect transistor gates, methods of forming integrated circuitry comprising a transistor gate array and circuitry peripheral to the gate array, and methods of forming integrated circuitry comprising a transistor gate array including first gates and second grounded isolation gates. In one implementation, a method of forming a field effect transistor includes forming masking material over semiconductive material of a substrate. A trench is formed through the masking material and into the semiconductive material. Gate dielectric material is formed within the trench in the semiconductive material. Gate material is deposited within the trench in the masking material and within the trench in the semiconductive material over the gate dielectric material. Source/drain regions are formed. Other aspects and implementations are contemplated.Type: GrantFiled: February 2, 2006Date of Patent: April 20, 2010Assignee: Micron Technology, Inc.Inventors: Young Pil Kim, Kunal R. Parekh
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Patent number: 7696045Abstract: A method of manufacturing a semiconductor device according to an embodiment of the present invention includes: forming a first insulating film on a semiconductor substrate; forming a mask with an opening of a predetermined pattern in the first insulating film; performing anisotropic etching on the semiconductor substrate with the mask used as an etching mask to form a trench; forming a second insulating film on a surface of an inner wall of the trench with the mask used as a selective oxidation mask; removing the mask; forming a conductive film on the semiconductor substrate to fill the trench with the conductive film; and etching back the conductive film until at least a surface of the semiconductor substrate is exposed.Type: GrantFiled: August 18, 2007Date of Patent: April 13, 2010Assignee: NEC Electronics CorporationInventor: Minoru Kawahara
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Publication number: 20100078715Abstract: A LDMOS transistor and a method for fabricating the same. A LDMOS transistor may include a P-type body region formed over a N-well. A LDMOS transistor may include a source region and a source contact region formed over a P-type body region. A LDMOS transistor may include a drain region spaced a distance from a P-type body region. A LOCOS may be formed over a surface of a N-well between a P-type body region and a drain region. A LDMOS transistor may include a main gate electrode formed over at least a portion of a LOCOS and a N-well. A LDMOS transistor may include a sub-gate electrode formed between a source region and a source contact region. A method for fabricating a LDMOS transistor is described herein.Type: ApplicationFiled: September 29, 2009Publication date: April 1, 2010Inventor: Sang-Yong Lee
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Publication number: 20100078717Abstract: In one embodiment, a vertical MOS transistor is formed without a thick field oxide and particularly without a thick field oxide in the termination region of the transistor.Type: ApplicationFiled: December 3, 2009Publication date: April 1, 2010Inventor: Prasad Venkatraman
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Publication number: 20100078707Abstract: A semiconductor device includes a source metallization, a source region of a first conductivity type in contact with the source metallization, a body region of a second conductivity type which is adjacent to the source region. The semiconductor device further includes a first field-effect structure including a first insulated gate electrode and a second field-effect structure including a second insulated gate electrode which is electrically connected to the source metallization. The capacitance per unit area between the second insulated gate electrode and the body region is larger than the capacitance per unit area between the first insulated gate electrode and the body region.Type: ApplicationFiled: September 30, 2008Publication date: April 1, 2010Applicant: INFINEON TECHNOLOGIES AUSTRIA AGInventors: Oliver Haeberlen, Joachim Krumrey, Franz Hirler, Walter Rieger
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Publication number: 20100065905Abstract: A semiconductor structure comprises a drift region of a first conductivity type in a semiconductor region. A well region of a second conductivity type is over the drift region. A source region of the first conductivity type is in an upper portion of the well region. A heavy body region of the second conductivity type extends in the well region. The heavy body region has a higher doping concentration than the well region. A first diffusion barrier region at least partially surrounds the heavy body region. A gate electrode is insulated from the semiconductor region by a gate dielectric.Type: ApplicationFiled: September 17, 2008Publication date: March 18, 2010Inventor: James Pan
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Publication number: 20100035366Abstract: The invention relates to a method for producing VDMOS transistors in which a specific layer arrangement and a specific method sequence allow setting up an improved gate contact when simultaneously producing source and gate contacts using a single contact hole mask (photo mask).Type: ApplicationFiled: April 10, 2006Publication date: February 11, 2010Applicant: X-FAB Semiconductor Foundries AGInventors: Jochen Doehnel, Siegfried Hering
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Publication number: 20100019250Abstract: A semiconductor device and a method of forming thereof has a base body has a field stopping layer, a drift layer, a current spreading layer, a body region, and a source contact region layered in the order on a substrate. A trench that reaches the field stopping layer or the substrate is provided. A gate electrode is provided in the upper half section in the trench. In a section deeper than the position of the gate electrode in the trench, an insulator is buried that has a normal value of insulation breakdown electric field strength equal to or greater than the value of the insulation breakdown electric field strength of the semiconductor material of the base body. This inhibits short circuit between a gate and a drain due to insulation breakdown of an insulator film at the bottom of the trench to realize a high breakdown voltage in a semiconductor device using a semiconductor material such as SiC. The sidewall surfaces of the trench located below the gate electrode is inclined to form a trapezoidal profile.Type: ApplicationFiled: October 7, 2009Publication date: January 28, 2010Applicant: FUJI ELECTRIC HOLDINGS CO., LTD.Inventors: Shun-Ichi NAKAMURA, Yoshiyuki YONEZAWA
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Publication number: 20100015770Abstract: This invention discloses a method for manufacturing a trenched semiconductor power device that includes step of opening a trench in a semiconductor substrate. The method further includes a step of opening a top portion of the trench first then depositing a SiN on sidewalls of the top portion followed by etching a bottom surface of the top portion of the trench then silicon etching to open a bottom portion of the trench with a slightly smaller width than the top portion of the trench. The method further includes a step of growing a thick oxide layer along sidewalls of the bottom portion of the trench thus forming a bird-beak shaped layer at an interface point between the top portion and bottom portion of the trench.Type: ApplicationFiled: September 18, 2009Publication date: January 21, 2010Inventors: Sung-Shan Tai, Yongzhong Hu
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Publication number: 20090309156Abstract: A manufacturing process and design structure for a super self-aligned trench power MOSFET. A plurality of super self-aligned trenches of different depths are formed into the body layer and epitaxial layers, preferably by using a multilayer stack of dielectric material etched to form spacers. Respective trenches contain gate conductors, body-contact conductors, and preferably a third trench containing a recessed field plate. This results in a MOSFET structure having high cell density and low gate charges and gate-drain charges.Type: ApplicationFiled: February 25, 2009Publication date: December 17, 2009Applicant: MAXPOWER SEMICONDUCTOR INC.Inventors: Mohamed N. Darwish, Jun Zeng
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Patent number: 7629211Abstract: A method of forming a field effect transistor comprises providing a semiconductor substrate, a gate electrode being formed over the semiconductor substrate. At least one cavity is formed adjacent the gate electrode. A strain-creating element is formed in the at least one cavity. The strain-creating element comprises a compound material comprising a first chemical element and a second chemical element. A first concentration ratio between a concentration of the first chemical element in a first portion of the strain-creating element and a concentration of the second chemical element in the first portion of the strain-creating element is different from a second concentration ratio between a concentration of the first chemical element in a second portion of the strain-creating element and a concentration of the second chemical element in the second strain-creating element.Type: GrantFiled: March 9, 2007Date of Patent: December 8, 2009Assignee: Advanced Micro Devices, Inc.Inventors: Sven Beyer, Thorsten Kammler, Rolf Stephan, Manfred Horstmann
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Patent number: 7592233Abstract: A method for forming a memory device with a recessed gate is disclosed. A substrate with a pad layer thereon is provided. The pad layer and the substrate are patterned to form at least two trenches. A deep trench capacitor is formed in each trench. A protrusion is formed on each deep trench capacitor, wherein a top surface level of each protrusion is higher than that of the pad layer. Spacers are formed on sidewalls of the protrusions, and the pad layer and the substrate are etched using the spacers and the protrusions as a mask to form a recess. A recessed gate is formed in the recess.Type: GrantFiled: September 20, 2007Date of Patent: September 22, 2009Assignee: Nanya Technology CorporationInventors: Pei-Ing Lee, Chung-Yuan Lee, Chien-Li Cheng
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Publication number: 20090224314Abstract: A power MOSFET exhibits a high breakdown voltage and low ON-state resistance. The device includes a trench formed in a semiconductor substrate, a gate electrode located along a side wall of the trench and a bottom wall of the trench near a side wall thereof, a pillar section, a first drain region of a first conductivity type in the pillar section, a base region of a second conductivity type in contact with the side wall of the trench in a bottom portion thereof and the bottom wall of the trench, a source region of the first conductivity type in a surface portion of the base region, a RESURF region of the second conductivity type in the pillar section, the RESURF region being formed in contact with the first drain region; and a second drain region of the first conductivity type in a side wall surface portion of the pillar section.Type: ApplicationFiled: March 10, 2009Publication date: September 10, 2009Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.Inventor: Mutsumi KITAMURA
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Patent number: 7572703Abstract: A method manufactures a vertical-gate MOS transistor integrated in a semiconductor chip having a main surface. The method includes: forming a trench gate extending into the chip from the main surface to a gate depth, by forming a control gate and an insulation layer for insulating the control gate from the chip. Forming the trench gate includes: forming a trench extending into the chip from the main surface to a protection depth less than the gate depth, the trench having a lateral wall and a bottom wall with an edge portion of the lateral wall extending from the main surface being inclined outwardly with respect to the remaining portion of the lateral wall; forming a first auxiliary insulation layer in the trench; removing a bottom wall of the first auxiliary insulation layer; extending the trench to the gate depth; and forming a second auxiliary insulation layer in the trench.Type: GrantFiled: November 9, 2006Date of Patent: August 11, 2009Assignee: STMicroelectronics S.r.l.Inventors: Marco Annese, Pietro Montanini, Riccardo Depetro
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Patent number: 7573089Abstract: Non-volatile memory devices and a method of manufacturing the same, wherein data storage of two bits per cell is enabled and the devices can pass the limit in terms of layout, whereby channel length can be controlled. The non-volatile memory device includes gate lines formed in one direction on a semiconductor substrate in which trenches are formed, wherein the gate lines gap-fill the trenches, a dielectric layer formed between the semiconductor substrate and the gate lines, bit separation insulating layers formed between the semiconductor substrate and the dielectric layer under the trenches, and isolation structures formed by etching the trenches, and the dielectric layer and the semiconductor substrate between the trenches in a line form vertical to the gate lines and gap-filling an insulating layer.Type: GrantFiled: December 6, 2006Date of Patent: August 11, 2009Assignee: Hynix Semiconductor Inc.Inventors: Nam Kyeong Kim, Jae Chul Om
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Patent number: 7566622Abstract: A method of fabricating a power semiconductor device in which contact trenches are formed prior to forming the gate trenches.Type: GrantFiled: June 5, 2006Date of Patent: July 28, 2009Assignee: International Rectifier CorporationInventor: Adam I Amali
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Publication number: 20090117699Abstract: A method for preparing a recessed transistor structure comprises the steps of performing an implanting process to form a doped layer in a substrate, forming a plurality of gate-isolation blocks on the substrate, forming a plurality of first spacers on sidewalls of the gate-isolation blocks, removing a portion of the substrate not covered by the first spacers and the gate-isolation blocks to form a plurality of depressions in the substrate between the first spacers, forming a gate oxide layer on inner sidewalls of the depressions, and forming a gate structure on the gate oxide layer to complete the recessed transistor structure.Type: ApplicationFiled: February 19, 2008Publication date: May 7, 2009Applicant: PROMOS TECHNOLOGIES INC.Inventor: HUNG YANG LIN
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Patent number: 7517746Abstract: A method of manufacturing a metal oxide semiconductor transistor having a metal gate is provided. The method firstly includes a step of providing a substrate. A dummy gate is formed on the substrate, a spacer is formed around the dummy gate, and doped regions are formed in the substrate outside of the dummy gate. A bevel edge is formed on the spacer, and a trench is formed in the inner sidewall of the spacer. A barrier layer, and a metal gate are formed in the trench and on the bevel edge, and the barrier layer will not form poor step coverage.Type: GrantFiled: April 24, 2007Date of Patent: April 14, 2009Assignee: United Microelectronics Corp.Inventors: Chin-Hsiang Lin, Chia-Jung Hsu, Li-Wei Cheng
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Patent number: 7507630Abstract: A method of fabricating a semiconductor device includes: forming an insulating film on a semiconductor body to cover a termination area surrounding a cell area; forming a mask material film to cover the cell area and the insulating film; forming a resist film to cover the mask material film; patterning the resist film to have an opening serving as a gate-use resist pattern above the cell area and another opening serving as a dummy resist pattern above the insulating film; selectively etching the mask material film by use of the patterned resist film as a mask so that the insulating film is remained under the dummy resist pattern; selectively etching the semiconductor body by use of the patterned mask material film as another mask to form a trench in the cell area as corresponding to the gate-use resist pattern; and burying gate material in the trench to form the trench gate.Type: GrantFiled: December 13, 2005Date of Patent: March 24, 2009Assignee: Kabushiki Kaisha ToshibaInventors: Masanobu Tsuchitani, Hitoshi Shinohara, Keiko Kawamura
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Patent number: 7508030Abstract: A semiconductor device includes a base region formed above a semiconductor substrate, a source region formed above the base region, a gate electrode filled inside a trench formed above the semiconductor substrate, an interlayer insulation film formed all over the semiconductor substrate, a first contact hole formed in the interlayer insulation film to expose the gate electrode, a second contact hole formed in the interlayer insulation film and the source region to expose the base region, and a conductive film formed above a trench where the first contact hole is formed.Type: GrantFiled: November 3, 2005Date of Patent: March 24, 2009Assignee: NEC Electronics CorporationInventor: Kenya Kobayashi
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Patent number: 7504305Abstract: A method of manufacturing a semiconductor device is disclosed and starts with a semiconductor substrate having a heavily doped N region at the bottom main surface and having a lightly doped N region at the top main surface. There are a plurality of trenches in the substrate, with each trench having a first extending portion extending from the top main surface towards the heavily doped region. Each trench has two sidewall surfaces in parallel alignment with each other. A blocking layer is formed on the sidewalls and the bottom of each trench. Then a P type dopant is obliquely implanted into the sidewall surfaces to form P type doped regions. The blocking layer is then removed. The bottom of the trenches is then etched to remove any implanted P type dopants. The implants are diffused and the trenches are filled.Type: GrantFiled: January 31, 2006Date of Patent: March 17, 2009Assignee: Third Dimension (3D) Semiconductor, Inc.Inventor: Richard A. Blanchard
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Patent number: 7501334Abstract: In one embodiment, a semiconductor device comprises an active region isolated by a device isolation layer placed in a semiconductor substrate having a main surface. A molding hole is placed in the semiconductor substrate on the active region. A pocket insulating layer pattern conformally covers the molding hole. A pocket line extends across the active region, filling the molding hole and protruding from the main surface of the semiconductor substrate. The pocket line includes a pocket conductive layer line, a lower metal layer line, and an upper metal layer line, which are sequentially stacked on the pocket insulating layer pattern. The device further may further include a line capping layer pattern placed on the pocket line. The line capping layer pattern and the pocket conductive layer line may surround the lower and upper metal layer lines.Type: GrantFiled: January 23, 2007Date of Patent: March 10, 2009Assignee: Samsung Electronics Co., Ltd.Inventors: Jun-Kyo Cho, Young-Joon Choi, Byung-Yong Kim
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Publication number: 20090061584Abstract: The present invention provides a semiconductor process for a trench power MOSFET. The semiconductor process includes providing a substrate, forming an EPI wafer on the surface, performing trench dry etching, performing HTP hard mask oxide deposition and channel self- align implant, performing boron (B) implant and completing the P-body region through a thermal process, performing arsenic (As) implant and completing the n+ source region through a thermal process, and depositing BPSG ILD, front side metal Al, and backside metal Ti/Ni/Ag.Type: ApplicationFiled: February 12, 2008Publication date: March 5, 2009Inventors: Wei-Chieh Lin, Jen-Hao Yeh, Ming-Jang Lin, Hsin-Yen Chiu
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Patent number: 7485557Abstract: A method for fabricating a semiconductor device having a flask type recess gate includes forming a hard mask pattern on a substrate, etching the substrate to a predetermined depth using the hard mask pattern to form a first recess pattern, forming a passivation layer on sidewalls of the first recess pattern and the hard mask pattern, etching a bottom surface of the first recess pattern exposed by the passivation layer to form a second recess pattern, oxidizing sidewalls of the second recess pattern to form a silicon oxide layer, removing the passivation layer and the silicon oxide layer in sequential order, and forming a gate pattern over an intended recess pattern including the first recess pattern and the second recess pattern.Type: GrantFiled: August 1, 2006Date of Patent: February 3, 2009Assignee: Hynix Semiconductor Inc.Inventors: Ky-Hyun Han, Sang-Soo Park
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Publication number: 20090014790Abstract: A semiconductor device includes a gate electrode formed through an insulating film in a groove having a first side surface adjacent to a source region and a base region, and a second conductive type first impurity region formed adjacent to a second side surface of the groove between the groove and a lead-out portion of a drain region existing below the base region so as to extend downward beyond a lower end of the groove.Type: ApplicationFiled: July 3, 2008Publication date: January 15, 2009Applicants: Sanyo Electric Co., Ltd., Sanyo Semiconductor Co., Ltd.Inventors: Seiji OTAKE, Yasuhiro TAKEDA, Kenichi MAKI
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Patent number: 7476589Abstract: A field effect transistor is formed as follows. A trench is formed in a semiconductor region. A dielectric layer lining the trench sidewalls and bottom is formed. The trench is filled with a conductive material. The conductive material is recessed into the trench to thereby form a shield electrode in a bottom portion of the trench. The recessing of the conductive material includes isotropic etching of the conductive material. An inter-electrode dielectric (IED) is formed over the recessed shield electrode.Type: GrantFiled: June 29, 2006Date of Patent: January 13, 2009Assignee: Fairchild Semiconductor CorporationInventors: Thomas E. Grebs, Nathan Lawrence Kraft, Rodney Ridley
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Patent number: 7470589Abstract: A trench-structure semiconductor device is highly reliable and has an increased resistance to hydrofluoric acid cleaning or other cleaning of an insulation film between a gate electrode, which is embedded in a trench, and source electrode. In a trench-structure semiconductor device, a silicon nitride film is over the gate electrode and embedded up to a point close to the open edge on the inside of trench. A source electrode is formed in contact with the surface of the silicon nitride film and the surface of the source region.Type: GrantFiled: December 13, 2006Date of Patent: December 30, 2008Assignee: Rohm Co., Ltd.Inventor: Kenichi Yoshimochi
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Patent number: 7456466Abstract: A NAND flash memory device and method of manufacturing the same is disclosed. Source and drain select transistor gates are recessed lower than an active region of a semiconductor substrate. A valid channel length of the source and drain select transistor gates is longer than a channel length of memory cell gates. Accordingly, an electric field between a source region and a drain region of the select transistor can be reduced. It is thus possible to prevent program disturbance from occurring in edge memory cells adjacent to the source and drain select transistors in non-selected cell strings.Type: GrantFiled: June 2, 2006Date of Patent: November 25, 2008Assignee: Hynix Semiconductor Inc.Inventors: Jae Chul Om, Nam Kyeong Kim, Se Jun Kim
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Patent number: 7446374Abstract: A monolithically integrated trench FET and Schottky diode includes a pair of trenches terminating in a first silicon region of first conductivity type. Two body regions of a second conductivity type separated by a second silicon region of the first conductivity type are located between the pair of trenches. A source region of the first conductivity type is located over each body region. A contact opening extends between the pair of trenches to a depth below the source regions. An interconnect layer fills the contact opening so as to electrically contact the source regions and the second silicon region. Where the interconnect layer electrically contacts the second silicon region, a Schottky contact is formed.Type: GrantFiled: March 24, 2006Date of Patent: November 4, 2008Assignee: Fairchild Semiconductor CorporationInventors: Paul Thorup, Ashok Challa, Bruce Douglas Marchant
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Patent number: 7439137Abstract: In a MOSFET, after an element region is formed, a wiring layer is formed subsequently to a barrier metal layer, and hydrogen annealing is performed. However, in the case of an n-channel MOSFET, a threshold voltage is lowered due to an occlusion characteristic of the barrier metal layer. Thus, an increased impurity concentration in a channel layer causes a problem that reduction in an on-resistance is inhibited. According to the present invention, after a barrier metal layer is formed, an opening is provided in the barrier metal layer on an interlayer insulating film, and hydrogen annealing treatment is performed after a wiring layer is formed. Thus, an amount of hydrogen which reaches a substrate is further increased, and lowering of a threshold voltage is suppressed. Moreover, since an impurity concentration in a channel layer can be lowered, an on-resistance is reduced.Type: GrantFiled: May 6, 2005Date of Patent: October 21, 2008Assignee: Sanyo Electric Co., Ltd.Inventors: Hiroyasu Ishida, Hirotoshi Kubo, Shouji Miyahara, Masato Onda
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Patent number: 7416948Abstract: A field effect transistor is formed as follows. Trenches are formed in a semiconductor region of a first conductivity type. Each trench is partially filled with one or more materials. A dual-pass angled implant is carried out to implant dopants of a second conductivity type into the semiconductor region through an upper surface of the semiconductor region and through upper trench sidewalls not covered by the one or more material. A high temperature process is carried out to drive the implanted dopants deeper into the mesa region thereby forming body regions of the second conductivity type between adjacent trenches. Source regions of the first conductivity type are then formed in each body region.Type: GrantFiled: October 23, 2006Date of Patent: August 26, 2008Assignee: Fairchild Semiconductor CorporationInventors: Nathan L. Kraft, Ashok Challa, Steven P. Sapp, Hamza Yilmaz, Daniel Calafut, Dean E. Probst, Rodney S. Ridley, Thomas E. Grebs, Christopher B. Kocon, Joseph A. Yedinak, Gary M. Dolny
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Publication number: 20080199997Abstract: A method for forming power semiconductor devices having an inter-electrode dielectric (IPD) layer inside a trench includes providing a semiconductor substrate with a trench, lining the sidewalls and bottom of the trench with a first layer of dielectric material, filling the trench with a first layer of conductive material to form a first electrode, recessing the first layer of dielectric material and the first layer of conductive material to a first depth inside the trench, forming a layer of polysilicon material on a top surface of the dielectric material and conductive material inside the trench, oxidizing the layer of polysilicon material, and forming a second electrode inside the trench atop the oxidized layer and isolated from trench sidewalls by a second dielectric layer. The oxidation step can be enhanced by either chemically or physically altering the top portion polysilicon such as by implanting impurities.Type: ApplicationFiled: March 3, 2008Publication date: August 21, 2008Inventors: Thomas E. Grebs, Rodney S. Ridley, Steven P. Sapp, Peter H. Wilson, Babak S. Sani, Gary M. Dolny, John Mytych, Becky Losee, Adam Selsley, Christopher B. Kocon
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Patent number: 7413969Abstract: A varying-width recess gate structure having a varying-width recess formed in a semiconductor device can sufficiently increase the channel length of the transistor having a gate formed in the varying-width recess, thereby effectively reducing the current leakage and improving the refresh characteristics. In the method of manufacturing the recess gate structure, etching is performed twice or more, so as to form a gate recess having varying width in the substrate, and a gate is formed in the gate recess.Type: GrantFiled: December 27, 2005Date of Patent: August 19, 2008Assignee: Hynix Semiconductor Inc.Inventors: Jong Man Kim, Chang Goo Lee, Jong Sik Kim, Se Ra Won
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Patent number: 7399677Abstract: A method for manufacturing a semiconductor device including the steps of: forming a hole having a predetermined depth in a semiconductor layer of a first conductivity type in correspondence with a drain region, the semiconductor layer being formed on a semiconductor substrate; forming a diffusion source layer containing impurities of a second conductivity type different from the first conductivity type in the hole; forming a source region of the first conductivity type in a region shallower than the depth of the hole in the semiconductor layer; forming a channel region of the second conductivity type to be disposed between the drain region and the source region in a region deeper than the depth of the source region in the semiconductor layer; and heating the semiconductor substrate to a first temperature after completing the diffusion source layer forming step to diffuse the impurities of the second conductivity type from the diffusion source layer into the channel region, thereby forming a low resistance regType: GrantFiled: August 17, 2006Date of Patent: July 15, 2008Assignee: Rohm Co., Ltd.Inventor: Masaru Takaishi
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Publication number: 20080142880Abstract: A method is provided for forming a power semiconductor device. The method begins by providing a substrate of a second conductivity type and then forming a voltage sustaining region on the substrate. The voltage sustaining region is formed by depositing an epitaxial layer of a first conductivity type on the substrate and forming at least one terraced trench in the epitaxial layer. The terraced trench has a plurality of portions that differ in width to define at least one annular ledge therebetween. A barrier material is deposited along the walls of the trench. A dopant of a second conductivity type is implanted through the barrier material lining the annular ledge and said trench bottom and into adjacent portions of the epitaxial layer. The dopant is diffused to form at least one annular doped region in the epitaxial layer and at least one other region located below the annular doped region.Type: ApplicationFiled: December 4, 2007Publication date: June 19, 2008Applicant: Vishay General Semiconductor LLCInventors: Richard A. Blanchard, Jean-Michel Guillot
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Publication number: 20080121989Abstract: An improved trench MOS-gated device comprises a monocrystalline semiconductor substrate on which is disposed a doped upper layer. The upper layer includes at an upper surface a plurality of heavily doped body regions having a first polarity and overlying a drain region. The upper layer further includes at its upper surface a plurality of heavily doped source regions having a second polarity opposite that of the body regions. A gate trench extends from the upper surface of the upper layer to the drain region and separates one source region from another. The trench has a floor and sidewalls comprising a layer of dielectric material and contains a conductive gate material filled to a selected level and an isolation layer of dielectric material that overlies the gate material and substantially fills the trench. The upper surface of the overlying layer of dielectric material in the trench is thus substantially coplanar with the upper surface of the upper layer.Type: ApplicationFiled: October 31, 2007Publication date: May 29, 2008Applicant: Fairchild Semiconductor CorporationInventors: Christopher B. Kocon, Jun Zeng
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Publication number: 20080116510Abstract: An improved trench MOS-gated device comprises a monocrystalline semiconductor substrate on which is disposed a doped upper layer. The upper layer includes at an upper surface a plurality of heavily doped body regions having a first polarity and overlying a drain region. The upper layer further includes at its upper surface a plurality of heavily doped source regions having a second polarity opposite that of the body regions. A gate trench extends from the upper surface of the upper layer to the drain region and separates one source region from another. The trench has a floor and sidewalls comprising a layer of dielectric material and contains a conductive gate material filled to a selected level and an isolation layer of dielectric material that overlies the gate material and substantially fills the trench. The upper surface of the overlying layer of dielectric material in the trench is thus substantially coplanar with the upper surface of the upper layer.Type: ApplicationFiled: October 31, 2007Publication date: May 22, 2008Applicant: Fairchild Semiconductor CorporationInventors: Christopher B. Kocon, Jun Zeng
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Publication number: 20080116511Abstract: According to one embodiment, a method for manufacturing a semiconductor device includes forming trenches in a first side of a semiconductor material and forming a thick oxide layer on the trenches and on the first side. A part of the first side and the trenches is masked using a first mask, and the semiconductor material is doped by implantation through the thick oxide layer while the first mask is present. At least part of the thick oxide layer is removed while the first mask remains.Type: ApplicationFiled: November 16, 2006Publication date: May 22, 2008Applicant: Infineon Technologies Austria AGInventors: Markus Zundel, Franz Hirler, Rudolf Zelsacher, Erwin Bacher
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Patent number: 7368353Abstract: A method for manufacturing a trench type power semiconductor device which includes process steps for forming proud gate electrodes in order to decrease the resistivity thereof.Type: GrantFiled: November 4, 2004Date of Patent: May 6, 2008Assignee: International Rectifier CorporationInventors: Jianjun Cao, Paul Harvey, Dave Kent, Robert Montgomery, Hugo Burke, Kyle Spring
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Patent number: 7354829Abstract: A trench-gate type transistor has a gate insulating film formed on an inner wall of a trench. The gate insulating film includes a first portion located on a wall of the trench and a second portion located on upper and bottom portions of the trench. The first portion includes a first oxide film, a nitride film, and a second oxide film. The second portion includes only an oxide film and is thicker than the first portion. Accordingly, electric field concentration on upper and lower corner portions of the trench can be reduced to improve the withstand voltage. In addition, and end of the trench may have an insulation layer that is thicker than the first portion.Type: GrantFiled: October 28, 2004Date of Patent: April 8, 2008Assignee: DENSO CORPORATIONInventors: Takaaki Aoki, Yutaka Tomatsu, Akira Kuroyanagi, Mikimasa Suzuki, Hajime Soga
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Patent number: 7348244Abstract: A semiconductor device includes a semiconductor substrate, a cell region in a surface portion of the substrate for operating as a transistor, a gate lead wiring region having a gate lead pattern on the substrate, a trench in the surface portion of the substrate extending from the cell region to the gate lead wiring region, an oxide film on an inner surface of the trench, and a gate electrode in the trench insulated with at least the oxide film from the substrate. A speed of formation of a main portion of the sidewalls of the trench at the gate lead wiring region is greater than that of a main portion of the sidewalls of the trench at the cell region, so that a thickness of the oxide film at the gate lead wiring region is greater than that at the cell region.Type: GrantFiled: February 2, 2006Date of Patent: March 25, 2008Assignee: DENSO CORPORATIONInventors: Takaaki Aoki, Yukio Tsuzuki
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Patent number: 7300831Abstract: A polycrystalline silicon thin film transistor of a bottom gate structure is used as a switching element and a mask having transmissive, half-transmissive and blocking areas is used so that an array substrate for a liquid crystal display device having a monolithic driving circuit can be fabricated through a six-mask process.Type: GrantFiled: April 6, 2005Date of Patent: November 27, 2007Assignee: LG.Philips LCD Co., Ltd.Inventors: Kum-Mi Oh, Kwang-Sik Hwang