Simultaneous Fabrication Of Periphery And Memory Cells (epo) Patents (Class 257/E21.691)
  • Publication number: 20090180324
    Abstract: Some embodiments include methods of forming semiconductor constructions. Alternating layers of n-type doped material and p-type doped material may be formed. The alternating layers may be patterned into a plurality of vertical columns that are spaced from one another by openings. The openings may be lined with tunnel dielectric, charge-storage material and blocking dielectric. Alternating layers of insulative material and conductive control gate material may be formed within the lined openings. Some embodiments include methods of forming NAND unit cells. Columns of alternating n-type material and p-type material may be formed. The columns may be lined with a layer of tunnel dielectric, a layer of charge-storage material, and a layer of blocking dielectric. Alternating layers of insulative material and conductive control gate material may be formed between the lined columns. Some embodiments include semiconductor constructions, and some embodiments include NAND unit cells.
    Type: Application
    Filed: January 15, 2008
    Publication date: July 16, 2009
    Inventors: D.V. Nirmal Ramaswamy, Gurtej S. Sandhu
  • Patent number: 7557004
    Abstract: The method for fabricating the semiconductor device includes the steps of: forming an insulating film 20, a conductive film 22 and an insulating film 24 over a semiconductor substrate 10 having a first to a third region; removing an insulating film 24, the conductive film 22 and an insulating film 20 formed in the second region and the third region; forming an insulating film 38 in the second region and the third region; removing the insulating film 24 in the first region and the insulating film 38 in the third region; forming an insulating film 44 in the third region; after a conductive film 52 has been formed, patterning the conductive films 22, 52 in the first region to form a gate electrode 58; and patterning the conductive film 52 to form gate electrodes 62 in the second region and the third region while removing the conductive film 52 over the gate electrode 58.
    Type: Grant
    Filed: November 9, 2006
    Date of Patent: July 7, 2009
    Assignee: Fujitsu Microelectronics Limited
    Inventors: Hiroyuki Ogawa, Hideyuki Kojima
  • Publication number: 20090162977
    Abstract: Fabricating semiconductor-based non-volatile memory that includes composite storage elements, such as those with first and second charge storage regions, can include etching more than one charge storage layer. To avoid inadvertent shorts between adjacent storage elements, a first charge storage layer for a plurality of non-volatile storage elements is formed into rows prior to depositing the second charge storage layer. Sacrificial features can be formed between the rows of the first charge storage layer that are adjacent in a column direction, before or after forming the rows of the first charge layer. After forming interleaving rows of the sacrificial features and the first charge storage layer, the second charge storage layer can be formed. The layers can then be etched into columns and the substrate etched to form isolation trenches between adjacent columns. The second charge storage layer can then be etched to form the second charge storage regions for the storage elements.
    Type: Application
    Filed: December 19, 2007
    Publication date: June 25, 2009
    Inventors: Vinod Robert Purayath, George Matamis, Takashi Orimoto, James Kai
  • Patent number: 7538380
    Abstract: Disclosure is semiconductor device of a selective gate region, comprising a semiconductor layer, a first insulating film formed on the semiconductor layer, a first electrode layer formed on the first insulating layer, an element isolating region comprising an element isolating insulating film formed to extend through the first electrode layer and the first insulating film to reach an inner region of the semiconductor layer, the element isolating region isolating a element region and being self-aligned with the first electrode layer, a second insulating film formed on the first electrode layer and the element isolating region, an open portion exposing a surface of the first electrode layer being formed in the second insulating film, and a second electrode layer formed on the second insulating film and the exposed surface of the first electrode layer, the second electrode layer being electronically connected to the first electrode layer via the open portion.
    Type: Grant
    Filed: November 3, 2006
    Date of Patent: May 26, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Michiharu Matsui, Seiichi Mori, Riichiro Shirota, Yuji Takeuchi, Takeshi Kamigaichi
  • Patent number: 7528036
    Abstract: A semiconductor device, which ensures device reliability especially in fine regions and enables great capacitance and high-speed operations, has memory cells including, in a first region of a main surface of a semiconductor substrate, a gate insulating film, a floating gate electrode, an interlayer insulating film, a control gate electrode, and source and drain regions of the second conduction type arranged in a matrix, with a shallow isolation structure for isolating the memory cells. When using a shallow structure buried with an insulating film for element isolation, the isolation withstand voltage in fine regions can be prevented from lowering and the variation in threshold level of selective transistors can be reduced. When the memory cells in a memory mat are divided by means of selective transistors, the disturb resistance of the memory cells can be improved.
    Type: Grant
    Filed: April 18, 2005
    Date of Patent: May 5, 2009
    Assignee: Renesas Technology Corp.
    Inventors: Tetsuo Adachi, Masataka Kato, Toshiaki Nishimoto, Nozomu Matsuzaki, Takashi Kobayashi, Yoshimi Sudou, Toshiyuki Mine
  • Patent number: 7517737
    Abstract: A memory device and peripheral circuitry on a substrate are described, made by a process that includes forming a charge trapping structure having a first thickness over a first area. A first gate dielectric layer having a second thickness is formed for low-voltage transistors. A second gate dielectric layer having a third thickness, greater than the second thickness, is formed for high-voltage transistors. Polysilicon is deposited and patterned to define word lines and transistor gates. The thickness of the second gate dielectric layer in regions adjacent the gates, and over a source and drain regions, is reduced to a thickness that is close to that of the second thickness. Dopants are implanted for formation of source and drain regions in the second and third areas. A silicon nitride spacer material is deposited over the word lines and gates, and etched to form sidewall spacers on the gates. Dopants are implanted aligned with the sidewall spacers in the second and third areas.
    Type: Grant
    Filed: February 7, 2007
    Date of Patent: April 14, 2009
    Assignee: Macronix International Co., Ltd.
    Inventors: Yi Hung Li, Jen Chuan Pan, Jongoh Kim
  • Publication number: 20090065845
    Abstract: Provided are an embedded semiconductor device and a method of manufacturing an embedded semiconductor device. In a method of manufacturing the embedded semiconductor device, layers of at least one cell gate stack may be formed in a cell area of a substrate. A logic gate structure may be formed in a logic area of the substrate. First source/drain regions may be formed adjacent to the logic gate structure, and metal silicide patterns may be formed on the logic gate structure and the first source/drain regions. At least one hard mask may be formed on the layers of the at least one cell gate stack, and a blocking pattern may be formed to cover the logic gate structure and the first source/drain regions. The at least one cell gate stack may be formed in the cell area by etching the layers of the at least one cell gate stack using the at least one hard mask as an etching mask.
    Type: Application
    Filed: September 8, 2008
    Publication date: March 12, 2009
    Inventors: Young-Ho Kim, Hee-Seog Jeon, Yong-Kyu Lee
  • Publication number: 20090039408
    Abstract: A nonvolatile semiconductor memory of an aspect of the present invention comprises a first element isolation insulating film containing an organic substance which surrounds a first region, a memory cell arranged in the first region, a second element isolation insulating film containing an organic substance which surrounds a second region, a peripheral transistor arranged in the second region, and a first impurity layer which is provided in the semiconductor substrate along a side surface of the second element isolation insulating film.
    Type: Application
    Filed: August 7, 2008
    Publication date: February 12, 2009
    Inventors: Tomoaki Hatano, Toshifumi Minami, Norihisa Arai
  • Publication number: 20090039412
    Abstract: A semiconductor device including a nonvolatile memory and the fabrication method of the semiconductor device is described.
    Type: Application
    Filed: October 6, 2008
    Publication date: February 12, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Shota KITAMURA
  • Patent number: 7476583
    Abstract: An insulating film provided below a floating gate electrode includes a first insulating film located at both end portions below the floating gate electrode, and a second insulating film sandwiched between the first insulating films and located in a middle portion below the floating gate electrode. The first insulating film and the second insulating film are formed in separate steps, and the first insulating film is thicker than the second insulating film. With this structure, when an insulating film is provided between the floating gate electrode and a silicon substrate to have a thickness more increased at its end portion than at its middle portion, the thickness can be increased more freely and a degree of the increase can be controlled more readily.
    Type: Grant
    Filed: March 5, 2007
    Date of Patent: January 13, 2009
    Assignee: Renesas Technology Corp.
    Inventor: Takashi Terauchi
  • Publication number: 20090003081
    Abstract: The number of process steps for manufacturing a non-volatile memory is reduced while the performance of the non-volatile memory is improved. The non-volatile memory has a memory cell in which first, second and third P-type diffusion regions are formed in an N-type well, a select gate is formed via a select-gate insulating film over a channel between the first and second P-type diffusion regions, and a floating gate is formed via a floating-gate insulating film over a channel between the second and third P-type diffusion regions. The non-volatile memory has a peripheral circuit in which fourth and fifth P-type diffusion regions are formed in an N-type well, and a peripheral-circuit gate is formed via a peripheral-circuit gate insulating film over a channel between the fourth and fifth P-type diffusion regions. The film thickness of the floating-gate insulating film is greater than that of the select-gate insulating film and peripheral-circuit gate insulating film.
    Type: Application
    Filed: June 23, 2008
    Publication date: January 1, 2009
    Applicant: NEC Electronics Corporation
    Inventors: Kenichi Hidaka, Noriaki Kodama
  • Publication number: 20080308859
    Abstract: A semiconductor device including a semiconductor substrate, and a memory cell and a peripheral circuit provided on the semiconductor substrate, the memory cell having a first insulating film, a first electrode layer, a second insulating film, and a second electrode layer provided on the semiconductor substrate in order, and the peripheral circuit having the first insulating film, the first electrode layer, the second insulating film having an opening for the peripheral circuit, and the second electrode layer electrically connected to the first electrode layer through the opening for the peripheral circuit, wherein a thickness of the first electrode layer under the second insulating film of the peripheral circuit is thicker than a thickness of the first electrode layer of the memory cell.
    Type: Application
    Filed: June 9, 2008
    Publication date: December 18, 2008
    Inventors: Masao Iwase, Tadashi Iguchi
  • Publication number: 20080268595
    Abstract: A NAND includes a device isolation pattern disposed in a region of a substrate defining a plurality of active regions. Memory transistors having memory gate patterns, constituting a cell string, cross the plurality of active regions. Select transistors are disposed over the memory transistors, and lower plugs are disposed on each side of the cell string to electrically connect the plurality of active regions on both sides of the cell string and the select transistors.
    Type: Application
    Filed: July 3, 2008
    Publication date: October 30, 2008
    Inventors: Ji-Hwon Lee, Sung-Hoi Hur
  • Patent number: 7439133
    Abstract: A memory structure formed between two doping regions in a semiconductor substrate includes two conductive blocks functioning as floating gates formed at two sides of a first conductive line functioning as a select gat and insulated from the first conductive line with two first dielectric spacers therebetween, wherein the two conductive blocks each have a raised top and raised parts of sides relative to the top of the first conductive line. A first dielectric layer is formed on the tops and the parts of the sides of the two conductive blocks. A second conductive line functioning as a word line is formed on the first dielectric layer, wherein the second conductive line has a part deposited between the two conductive blocks and is substantially perpendicular to the first conductive line and two doping region functioning as bit lines.
    Type: Grant
    Filed: January 2, 2006
    Date of Patent: October 21, 2008
    Assignee: Skymedi Corporation
    Inventors: Ming-Hung Chou, Fu-Chia Shone
  • Publication number: 20080254584
    Abstract: A method for manufacturing a flash memory device including providing a semiconductor substrate having a cell region and a periphery region; and then adjusting a threshold voltage of the cell region; and then forming a memory device on the cell region and forming a transistor on the periphery region; and then forming an interlayer dielectric layer on the memory device and the transistor, wherein the height of a first portion of the interlayer dielectric layer at the cell region is greater the height of a second portion of the interlayer dielectric layer at the periphery region; and then removing the height difference between the first portion of the interlayer dielectric layer and the second portion of the interlayer dielectric layer.
    Type: Application
    Filed: April 14, 2008
    Publication date: October 16, 2008
    Inventor: Jae-Young Choi
  • Patent number: 7399672
    Abstract: Methods of forming a memory device include forming a device isolation layer in a semiconductor substrate including a cell array region and a resistor region, the device isolation layer extending into the resistor region and defining an active region in the semiconductor substrate. A first conductive layer is formed on the device isolation layer in the resistor region. The semiconductor substrate is exposed in the cell array region. A cell insulation layer is formed on a portion of the semiconductor substrate including the exposed cell array region, the active region and the device isolation layer in the resistor region. A second conductive layer is formed on the cell insulation layer in the portion of the semiconductor substrate including the exposed cell array region, the active region and the device isolation layer in the resistor region.
    Type: Grant
    Filed: March 15, 2006
    Date of Patent: July 15, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Chang-Hyun Lee, Jung-Dal Choi, Chang-Seok Kang, Yoo-Cheol Shin, Jong-Sun Sel
  • Publication number: 20080160693
    Abstract: A method of forming a non-volatile memory device includes forming first mask patterns, which can have relatively large distances therebetween. A distance regulating layer is formed that conformally covers the first mask patterns. Second mask patterns are formed in grooves on the distance regulating layer between the first mask patterns.
    Type: Application
    Filed: November 27, 2007
    Publication date: July 3, 2008
    Inventors: Jae-Hwang Sim, Yong-Sik Yim, Ki-Nam Kim, Jae-Kwan Park
  • Publication number: 20080157176
    Abstract: A nonvolatile memory device having lower bit line contact resistance and a method of fabricating the same is provided. In the nonvolatile memory device, a semiconductor substrate of a first conductivity type may include first and second fins. A common bit line electrode may connect one end of the first fin to one end of the second fin. A plurality of control gate electrodes may cover the first and second fins and expand across the top surface of each of the first and second fins. A first string selection gate electrode may be positioned between the common bit line electrode and the plurality of control gate electrodes. The first string selection gate electrode may cover the first and second fins and expand across the top surface of each of the first and second fins. A second string selection gate electrode may be positioned between the first string selection gate electrode and the plurality of control gate electrodes.
    Type: Application
    Filed: September 21, 2007
    Publication date: July 3, 2008
    Inventors: Won-joo Kim, Yoon-dong Park, June-mo Koo, Suk-pil Kim, Sung-jae Byun
  • Publication number: 20080150011
    Abstract: A method for forming an integrated circuit system is provided including forming a substrate having a core region and a periphery region, forming a charge storage stack over the substrate in the core region, forming a gate stack with a stack header having a metal portion over the substrate in the periphery region, and forming a memory system with the stack header over the charge storage stack.
    Type: Application
    Filed: December 18, 2007
    Publication date: June 26, 2008
    Applicants: SPANSION LLC, ADVANCED MICRO DEVICES, INC.
    Inventors: Simon Siu-Sing Chan, Lei Xue, YouSeok Suh, Amol Ramesh Joshi, Hidehiko Shiraiwa, Harpreet Sachar, Kuo-Tung Chang, Connie Pin Chin Wang, Paul R. Besser, Shenqing Fang, Meng Ding, Takashi Orimoto, Wei Zheng, Fred TK Cheung
  • Publication number: 20080153225
    Abstract: A method, apparatus, and system in which an embedded memory fabricated in accordance with a conventional logic process includes one or more electrically-alterable non-volatile memory cells, each having a programming transistor, a read transistor and a control capacitor, which share a common floating gate electrode. The under-diffusion of the source/drain regions of the programming transistor and control capacitor are maximized. In one embodiment, the source/drain regions of the programming transistor are electrically shored by transistor punch-through (or direct contact).
    Type: Application
    Filed: March 10, 2008
    Publication date: June 26, 2008
    Applicant: MoSys, Inc.
    Inventors: Gang-Feng Fang, Dennis Sinitsky, Wingyu Leung
  • Patent number: 7391073
    Abstract: A method of fabricating a non-volatile memory is described. A substrate having a tunneling layer and a floating gate layer thereon is provided. A mask layer is formed on the floating gate. The mask layer has openings that expose a portion of the floating gate layer. Then, a portion of the floating gate layer is removed from the openings to form sunken regions on the surface of the floating gate layer. An inter-gate dielectric layer is formed on the floating gate layer. A control gate layer is formed on the inter-gate dielectric layer. After that, the mask layer and the floating gate layer under the mask layer are removed to form another opening. A select gate layer is formed inside the opening.
    Type: Grant
    Filed: September 13, 2005
    Date of Patent: June 24, 2008
    Assignee: Powerchip Semiconductor Corp.
    Inventors: Tsung-Lung Chen, Hui-Hung Kuo, Cheng-Yuan Hsu, Chih-Wei Hung
  • Patent number: 7390749
    Abstract: A method for providing features in an etch layer with a memory region and a peripheral region is provided. A memory patterned mask is formed over a first sacrificial layer. A first set of sacrificial layer features is etched into the first sacrificial layer and a second sacrificial layer. Features of the first set of sacrificial layer features are filled with filler material. The first sacrificial layer is removed. The spaces are shrunk with a shrink sidewall deposition. A second set of sacrificial layer features is etched into the second sacrificial layer. The filler material and shrink sidewall deposition are removed. A peripheral patterned mask is formed over the memory region and peripheral region. The second sacrificial layer is etched through the peripheral patterned mask. The peripheral patterned mask is removed. Features are etched into the etch layer from the second sacrificial layer.
    Type: Grant
    Filed: November 9, 2006
    Date of Patent: June 24, 2008
    Assignee: Lam Research Corporation
    Inventors: Ji Soo Kim, Sangheon Lee, Daehan Choi, S. M. Reza Sadjadi
  • Patent number: 7384843
    Abstract: A method of manufacturing a semiconductor memory device comprises forming floating gates on active regions of a semiconductor substrate and forming a capping layer on the floating gates. An isolation layer located in the semiconductor substrate between the floating gates is anisotropically etched using the capping layer as an etch mask to form recessed regions. The recessed regions are formed to have a width smaller than a distance between the floating gates, and bottom surfaces positioned below bottom surfaces of the floating gates. Control gate electrodes are formed across the active regions over the floating gates and the control gate electrodes have control gate extensions formed within the recessed regions between the floating gates.
    Type: Grant
    Filed: October 28, 2005
    Date of Patent: June 10, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Dong-Chan Kim, Chang-Jin Kang, Kyeong-Koo Chi, Seung-Pil Chung
  • Publication number: 20080128791
    Abstract: A semiconductor structure includes a memory cell in a first region and a logic MOS device in a second region of a semiconductor substrate. The memory cell includes a first gate electrode over the semiconductor substrate; a first gate spacer on a sidewall of the first gate electrode, wherein the first gate spacer comprises a storage on a tunneling layer; and a first lightly-doped source or drain (LDD) region and a first pocket region adjacent to the first gate electrode. The logic MOS device includes a second gate electrode on the semiconductor substrate; a second gate spacer on a sidewall of the second gate electrode; a second LDD region and a second pocket region adjacent the second gate electrode, wherein at least one of the first LDD region and the first pocket region has a higher impurity concentration than a impurity concentration of the respective second LDD region and the second pocket region.
    Type: Application
    Filed: December 5, 2006
    Publication date: June 5, 2008
    Inventors: Tzyh-Cheang Lee, Fu-Liang Yang
  • Patent number: 7378315
    Abstract: A method for fabricating a semiconductor device for a system on chip (SOC) for embodying a transistor for a logic device, an electrical erasable programmable read only memory (EEPROM) cell and a flash memory cell in one chip is provided. Floating gates of the EEPROM cell and the flash memory cell are formed by using a first polysilicon layer; and a gate electrode of the logic device and control gates of the EEPROM cell and the flash memory cell are formed by using a second polysilicon layer. Thus, it is possible to stably form the logic device, the EEPROM cell and the flash memory cell in one chip.
    Type: Grant
    Filed: December 6, 2005
    Date of Patent: May 27, 2008
    Assignee: Magnachip Semiconductor Ltd.
    Inventor: Yong-Sik Jeong
  • Patent number: 7351630
    Abstract: A method of manufacturing a flash memory device, including the steps of forming a gate on a semiconductor substrate in which a cell region, a source selection line region, and a drain selection line region are defined and then forming spacers on sidewalls of the gate; depositing a nitride film and a first interlayer insulating film on the entire structure, etching a region of the first interlayer insulating film to form a source contact hole, forming a conductive film on the entire structure to bury the source contact hole, and polishing the conductive film; forming a second interlayer insulating film on the entire structure, and then etching the second and first interlayer insulating films and the nitride film using a mask through which regions in which a cell region and a drain contact will be formed are opened; and, forming a polysilicon layer on the entire structure.
    Type: Grant
    Filed: June 16, 2006
    Date of Patent: April 1, 2008
    Assignee: Hynix Semiconductor Inc.
    Inventor: Woo Yung Jung
  • Publication number: 20080056004
    Abstract: A NAND flash memory device, and more particularly, to NAND flash memory device and method of manufacturing operating the same as described. A dielectric film and a conduction layer are formed between cell gates so that between-cell gates are buried. Therefore, an interference effect between floating gates, which becomes profound with the level of integration increasing, and program threshold voltage distributions between cells can be improved.
    Type: Application
    Filed: November 1, 2007
    Publication date: March 6, 2008
    Applicant: HYNIX SEMICONDUCTOR INC.
    Inventor: Tae Youn
  • Publication number: 20080014701
    Abstract: A semiconductor device has: an isolation region formed on a semiconductor substrate and defining a continuous active region including a select transistor region and a direct tunnel element region; a gate insulating film formed on a channel region of the select transistor region; a tunnel insulating film formed on a partial area of the direct tunnel element region and having a thickness different from a thickness of the gate insulating film; a continuous floating gate electrode formed above the gate insulating film and the tunnel insulating film; an inter-electrode insulating film formed on a surface of the floating gate electrode; a control gate electrode facing the floating gate electrode via the inter-electrode insulating film; and a pair of source/drain regions formed on both sides of the channel region of the select transistor region and not overlapping the tunnel insulating film.
    Type: Application
    Filed: August 28, 2007
    Publication date: January 17, 2008
    Applicant: FUJITSU LIMITED
    Inventors: Kouji Tsunoda, Tatsuya Usuki, Masao Taguchi
  • Patent number: 7314803
    Abstract: In a method for producing a semiconductor structure a semiconductor a substrate with a top surface is provided. A gate dielectric layer is provided on the top surface and on the gate dielectric layer is provided a memory cell array region with a first plurality of gate stacks and a peripheral element region with a second plurality of gate stacks. A dielectric layer is provided over the memory cell array region and the peripheral element region. A first source/drain implantation over the memory cell array region and the peripheral element region is carried out, a blocking mask over the memory cell array region is formed, the dielectric layer is removed using the blocking mask, and a second source/drain implantation over the memory cell array region and the peripheral element region is carried out, wherein the memory cell array region is protected by a mask.
    Type: Grant
    Filed: November 18, 2005
    Date of Patent: January 1, 2008
    Assignee: Infineon Technologies AG
    Inventors: Werner Graf, Lars Heineck, Jana Horst
  • Patent number: 7312503
    Abstract: A semiconductor memory device includes a plurality of memory cells, a plurality of local bit lines, a global bit line, a first switch element, and a holding circuit. The memory cell includes first and second MOS transistors. The first MOS transistor has a charge accumulation layer and a control gate. The second MOS transistor has one end of its current path connected to one end of a current path of the first MOS transistor. The local bit line connects other end of the current paths of the first MOS transistors. The first switch element makes a connection between the local bit lines and the global bit line. The holding circuit is connected to the global bit line and holds data to be written into the memory cells.
    Type: Grant
    Filed: January 9, 2004
    Date of Patent: December 25, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akira Umezawa, Takehiro Hasegawa
  • Publication number: 20070284645
    Abstract: A non-volatile memory device includes a substrate having a first region and a second region. A first gate electrode is disposed on the first region. A multi-layered charge storage layer is interposed between the first gate electrode and the substrate, the multi-layered charge storage including a tunnel insulation, a trap insulation, and a blocking insulation layer which are sequentially stacked. A second gate electrode is placed on the substrate of the second region, the second gate electrode including a lower gate and an upper gate connected to a region of an upper surface of the lower gate. A gate insulation layer is interposed between the second gate electrode and the substrate. The first gate electrode and the upper gate of the second gate electrode comprise a same material.
    Type: Application
    Filed: May 2, 2007
    Publication date: December 13, 2007
    Inventors: Chang-Hyun Lee, Kyu-Charn Park
  • Patent number: 7256086
    Abstract: A semiconductor device is provided that can be manufactured by a simpler process than a conventional lateral trench power MOSFET for use with an 80V breakdown voltage, and which has a lower device pitch and lower on-state resistance per unit area than a conventional lateral power MOSFET for use with a lower breakdown voltage than 80V. A gate oxide film is formed thinly along the lateral surfaces of a trench at a uniform thickness. Then, a gate oxide film is formed along the bottom surface of the trench by selective oxidation so as to be thicker than the gate oxide film on the lateral surfaces of the trench and so as to become progressively thicker from the edge of the bottom surface of the trench toward drain polysilicon.
    Type: Grant
    Filed: January 10, 2006
    Date of Patent: August 14, 2007
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Katsuya Tabuchi, Naoto Fujishima, Mutsumi Kitamura, Akio Sugi
  • Patent number: 7253031
    Abstract: A pin diode is formed by a p+ collector region, an n type buffer region, an n? region and an n+ cathode region. A trench is formed from the surface of n+ cathode region through n+ cathode region to reach n? region. An insulating film is formed along an inner wall surface of trench. A gate electrode layer is formed to oppose to the sidewall of n+ cathode region with insulating film interposed. A cathode electrode is formed to be electrically connected to n+ cathode region. An anode electrode is formed to be electrically connected to p+ collector region. The n+ cathode region is formed entirely over the surface between trenches extending parallel to each other. Thus, a power semiconductor device in which gate control circuit is simplified and which has good on property can be obtained.
    Type: Grant
    Filed: November 2, 2004
    Date of Patent: August 7, 2007
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tetsuo Takahashi, Katsumi Nakamura, Tadaharu Minato, Masana Harada
  • Patent number: 7253055
    Abstract: An array of a pillar-type nonvolatile memory cells (803) has each memory cell isolated from adjacent memory cells by a trench (810). Each memory cell is formed by a stacking process layers on a substrate: tunnel oxide layer (815), polysilicon floating gate layer (819), ONO or oxide layer (822), polysilicon control gate layer (825). Many aspects of the process are self-aligned. An array of these memory cells will require less segmentation. Furthermore, the memory cell has enhanced programming characteristics because electrons are directed at a normal or nearly normal angle (843) to the floating gate (819).
    Type: Grant
    Filed: March 29, 2006
    Date of Patent: August 7, 2007
    Assignee: SanDisk Corporation
    Inventors: Nima Mokhlesi, Jeffrey W. Lutze
  • Patent number: 7235823
    Abstract: A storage device structure (10) has two bits of storage per control gate (34) and uses source side injection (SSI) to provide lower programming current. A control gate (34) overlies a drain electrode formed by a doped region (22) that is positioned in a semiconductor substrate (12). Two select gates (49 and 50) are implemented with conductive sidewall spacers adjacent to and lateral to the control gate (34). A source doped region (60) is positioned in the semiconductor substrate (12) adjacent to one of the select gates for providing a source of electrons to be injected into a storage layer (42) underlying the control gate. Lower programming results from the SSI method of programming and a compact memory cell size exists.
    Type: Grant
    Filed: September 28, 2006
    Date of Patent: June 26, 2007
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Cheong M. Hong, Gowrishankar L. Chindalore
  • Patent number: 7176086
    Abstract: Field-effect transistors, select gates, and select lines have first and second conductive layers separated by an interlayer dielectric layer. A conductive strap is disposed on either side of the first and second conductive layers. Each strap electrically interconnects the first and second conductive layers.
    Type: Grant
    Filed: December 7, 2004
    Date of Patent: February 13, 2007
    Assignee: Micron Technology, Inc.
    Inventors: Michael Violette, Mark A. Helm
  • Patent number: 7122430
    Abstract: The memory cell transistor has a first cell site gate insulator, a first lower conductive layer on the first cell site gate insulator, a first inter-electrode dielectric on the first lower conductive layer, and a first upper conductive layer on the first inter-electrode dielectric. A select transistor has a second cell site gate insulator having a same thickness as the first cell site gate insulator, a second lower conductive layer on the second cell site gate insulator, a second inter-electrode dielectric on the second lower conductive layer, and a second upper conductive layer on the second inter-electrode dielectric. The peripheral transistor has a first peripheral site gate insulator having a thickness thinner than the first cell site gate insulator.
    Type: Grant
    Filed: December 20, 2005
    Date of Patent: October 17, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Atsuhiro Sato, Makoto Sakuma, Fumitaka Arai