Including Transistor Formed On Trench Sidewalls Patents (Class 438/242)
  • Patent number: 7195972
    Abstract: A trench capacitor DRAM cell in an SOI wafer uses the silicon device layer in the array as part of passing wordlines, stripping the silicon device layer in the array outside the wordlines and uses the BOX layer as the array top oxide separating the passing wordlines from the substrate.
    Type: Grant
    Filed: July 6, 2004
    Date of Patent: March 27, 2007
    Assignee: International Business Machines Corporation
    Inventors: Dureseti Chidambarrao, Ramachandra Divakaruni, Deok-kee Kim
  • Patent number: 7161217
    Abstract: A non-volatile memory cell structure that is capable of holding two data bits. The structure includes a trench in a substrate with two sides of the trench being lined with a trapping material. The trench is filled with an oxide dielectric material and a control gate is formed over the oxide-filled trench. Source/drain regions are adjacent the trench sides with the trapping material. An energy barrier between the drain and source regions has two local high points that correspond to the trench corners. To read the device, sufficient gate voltage is applied to invert the channel and a sufficient drain voltage is applied to pull down the drain-side barrier. If charges of opposite polarity are trapped in the source-side trench corner, the source barrier will be significantly lowered so that current flows between source and drain under read conditions.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: January 9, 2007
    Assignee: Micron Technology, Inc.
    Inventor: Michael Smith
  • Patent number: 7151024
    Abstract: A single transistor vertical memory gain cell with long data retention times. The memory cell is formed from a silicon carbide substrate to take advantage of the higher band gap energy of silicon carbide as compared to silicon. The silicon carbide provides much lower thermally dependent leakage currents which enables significantly longer refresh intervals. In certain applications, the cell is effectively non-volatile provided appropriate gate bias is maintained. N-type source and drain regions are provided along with a pillar vertically extending from a substrate, which are both p-type doped. A floating body region is defined in the pillar which serves as the body of an access transistor as well as a body storage capacitor. The cell provides high volumetric efficiency with corresponding high cell density as well as relatively fast read times.
    Type: Grant
    Filed: August 30, 2005
    Date of Patent: December 19, 2006
    Assignee: Micron Technology, Inc.
    Inventor: Leonard Forbes
  • Patent number: 7135732
    Abstract: In order to supply a semiconductor device having high-reliability, there are used a first capacitor electrode, a capacitor insulating film formed in contact with the first capacitor electrode and mainly composed of titanium oxide, and a second capacitor electrode formed in contact with the capacitor insulating film, and there is used a conductive oxide film mainly composed of ruthenium oxide or iridium oxide for the first capacitor electrode and the second capacitor electrode. Alternatively, there is used a gate insulating film having a titanium silicate film and titanium oxide which suppress leakage current.
    Type: Grant
    Filed: June 4, 2002
    Date of Patent: November 14, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Tomio Iwasaki, Hiroshi Moriya, Hideo Miura, Shuji Ikeda
  • Patent number: 7132322
    Abstract: Form a dielectric layer on a semiconductor substrate. Deposit an amorphous Si film or a poly-Si film on the dielectric layer. Then deposit a SiGe amorphous-Ge or polysilicon-Ge thin film theteover. Pattern and etch the SiGe film using a selective etch leaving the SiGe thin film intact in a PFET region and removing the SiGe film exposing the top surface of the Si film in an NFET region. Anneal to drive Ge into the Si film in the PFET region. Deposit a gate electrode layer covering the SiGe film in the PFET region and cover the exposed portion of the Si film in the NFET region. Pattern and etch the gate electrode layer to form gates. Form FET devices with sidewall spacers and source regions and drains regions in the substrate aligned with the gates.
    Type: Grant
    Filed: May 11, 2005
    Date of Patent: November 7, 2006
    Assignee: International Business Machines Corporation
    Inventors: Brian Joseph Greene, Kern Rim, Clement Wann
  • Patent number: 7129129
    Abstract: A method of forming a trench in a semiconductor substrate includes a step of converting the cross section of the upper portion of the trench from octagonal to rectangular, so that sensitivity to alignment errors between the trench lithography and the active area lithography is reduced. Applications include a vertical transistor that becomes insensitive to misalignment between the trench and the litho for the active area, in particular a DRAM cell with a vertical transistor.
    Type: Grant
    Filed: March 29, 2004
    Date of Patent: October 31, 2006
    Assignee: International Business Machines Corporation
    Inventors: Thomas N. Adam, David C. Ahlgren, Kangguo Cheng, Ramachandra Divakaruni
  • Patent number: 7122438
    Abstract: In a semiconductor memory including a dynamic random access memory, a memory cell of the dynamic random access memory includes: a semiconductor pillar (a silicon pillar); a capacitor in which one side of the silicon pillar is used as a charge accumulation electrode; and a longitudinal insulated gate static induction transistor in which the other side of the silicon pillar is used as an active region (a source region, a channel formation region and a drain region), and a bit line is connected to the silicon pillar.
    Type: Grant
    Filed: January 13, 2004
    Date of Patent: October 17, 2006
    Assignee: Sony Corporation
    Inventor: Masayoshi Sasaki
  • Patent number: 7122439
    Abstract: A method of fabricating a bottle trench and a bottle trench capacitor. The method including: providing a substrate; forming a trench in the substrate, the trench having sidewalls and a bottom, the trench having an upper region adjacent to a top surface of the substrate and a lower region adjacent to the bottom of the trench; forming an oxidized layer of the substrate in the bottom region of the trench; and removing the oxidized layer of the substrate from the bottom region of the trench, a cross-sectional area of the lower region of the trench greater than a cross-sectional area of the upper region of the trench.
    Type: Grant
    Filed: November 17, 2004
    Date of Patent: October 17, 2006
    Assignees: International Business Machines Corporation, Infineon Technologies AG
    Inventors: Oh-Jung Kwon, Kenneth T. Settlemyer, Jr., Ravikumar Ramachandran, Min-Soo Kim
  • Patent number: 7112490
    Abstract: A programmable storage device includes a first diffusion region underlying a portion of a first trench defined in a semiconductor substrate and a second diffusion region occupying an upper portion of the substrate adjacent to the first trench. The device includes a charge storage stack lining sidewalls and a portion of a floor of the first trench. The charge storage stack includes a layer of discontinuous storage elements (DSEs). Electrically conductive spacers formed on opposing sidewalls of the first trench adjacent to respective charge storage stacks serve as control gates for the device. The DSEs may be silicon, polysilicon, metal, silicon nitride, or metal nitride nanocrystals or nanoclusters. The storage stack includes a top dielectric of CVD silicon oxide overlying the nanocrystals overlying a bottom dielectric of thermally formed silicon dioxide. The device includes first and second injection regions in the layer of DSEs proximal to the first and second diffusion regions.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: September 26, 2006
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Cheong Hong, Chi-Nan Li
  • Patent number: 7091537
    Abstract: A ferroelectric memory device includes a first trench formed in a semiconductor substrate and having a first depth, a second trench formed in the substrate and having a second depth, a first element isolation insulating film buried in the first trench, a first gate electrode formed in a lower region of the second trench, a first insulating film formed in an upper region of the second trench, first and second diffusion layers formed in the substrate on both side surface in the second trench, a first ferroelectric capacitor disposed on the first diffusion layer, a first contact disposed on the first ferroelectric capacitor, a first wiring layer disposed on the first contact, a second contact disposed on the second diffusion layer, and a second wiring layer disposed on the second contact and disposed in the same level as that of the first wiring layer.
    Type: Grant
    Filed: September 3, 2004
    Date of Patent: August 15, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Tohru Ozaki
  • Patent number: 7067372
    Abstract: A memory cell has a trench, in which a trench capacitor is disposed. Furthermore a vertical transistor is formed in the trench above the trench capacitor. A barrier layer is disposed for the electric connection of the conductive trench filling to a lower doping region of the vertical transistor. The barrier layer is a diffusion barrier for dopants or impurities that are contained in the conductive trench filling.
    Type: Grant
    Filed: September 9, 2003
    Date of Patent: June 27, 2006
    Assignee: Infineon Technologies AG
    Inventors: Martin Schrems, Rolf Weis
  • Patent number: 7064365
    Abstract: Ferroelectric capacitors include a support insulating film on an integrated circuit substrate and having a trench therein. A lower electrode is on sidewalls and a bottom surface of the trench. A seed conductive film covers the lower electrode. A ferroelectric film is provided on the support insulating film and the seed conductive film and an upper electrode is provided on the ferroelectric film. The lower electrode may fill the trench and the ferroelectric film may extend over all of the seed conductive film and the support insulating film adjacent the seed conductive film.
    Type: Grant
    Filed: November 10, 2003
    Date of Patent: June 20, 2006
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hyeong-Geun An, Sang-Woo Lee, Hyoung-Joon Kim
  • Patent number: 7049196
    Abstract: A vertical gain memory cell including an n-channel metal-oxide semiconductor field-effect transistor (MOSFET) and p-channel junction field-effect transistor (JFET) transistors formed in a vertical pillar of semiconductor material is provided. The body portion of the p-channel transistor is coupled to a second source/drain region of the MOSFET which serves as the gate for the JFET. The second source/drain region of the MOSFET is additionally coupled to a charge storage node. Together the second source/drain region and charge storage node provide a bias to the body of the JFET that varies as a function of the data stored by the memory cell. A non destructive read operation is achieved. The stored charge is sensed indirectly in that the stored charge modulates the conductivity of the JFET so that the JFET has a first turn-on threshold for a stored logic “1” condition and a second turn-on threshold for a stored logic “0” condition.
    Type: Grant
    Filed: December 16, 2003
    Date of Patent: May 23, 2006
    Assignee: Micron Technology, Inc.
    Inventor: Wendell P. Noble
  • Patent number: 7049647
    Abstract: A semiconductor memory cell is formed in a substrate and includes a trench capacitor and a selection transistor. The trench capacitor includes a capacitor dielectric and a conductive trench filling. Disposed on the conductive trench filling is a diffusion barrier on which an epitaxial layer is formed. The selection transistor is disposed as a planar transistor above the trench capacitor. A drain doping region of the selection transistor is disposed in the epitaxial layer.
    Type: Grant
    Filed: March 17, 2003
    Date of Patent: May 23, 2006
    Assignee: Infineon Technologies AG
    Inventors: Wolfram Karcher, Dietmar Temmler, Martin Schrems
  • Patent number: 7045426
    Abstract: A power MOSFET comprising a drain layer of a first conductivity type, a drift layer of the first conductivity type provided on the drain layer, a base layer of a first or a second conductivity type provided on the drift layer, a source region of the first conductivity type provided on the base layer, a gate insulating film formed on an inner wall surface of a trench penetrating the base layer and reaching at the drift layer, and a gate electrode provided on the gate insulating film inside the trench, wherein the gate insulating film is formed such that a portion thereof adjacent to the drift layer is thicker than a portion thereof adjacent to the base layer, and the drift layer has an impurity concentration gradient higher in the vicinity of the drain layer and lower in the vicinity of the source region along a depth direction of trench.
    Type: Grant
    Filed: April 19, 2004
    Date of Patent: May 16, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Syotaro Ono, Yusuke Kawaguchi
  • Patent number: 7030440
    Abstract: A method for forming, within a double well formation, an array of DRAM memory cells isolated from each other by shallow trench isolation (STI), each cell comprising a MOSFET access transistor and a storage trench capacitor. A top plate of said capacitor is the trench wall within a deep N-well portion of the double well and the bottom plate is formed of a doped polysilicon layer within the trench, which layer is partially separated from the trench sidewalls by a dielectric layer whose upper portion is removed to allow the formation of a autodiffused doped channel between said polysilicon plate and the source region of the access transistor. The method uses a single dielectric layer deposition to serve as both a gate dielectric for the MOSFET and a capacitor dielectric and requires only a single deposition of polysilicon to serve as both the transistor gate electrode and a capacitor plate.
    Type: Grant
    Filed: July 20, 2004
    Date of Patent: April 18, 2006
    Assignee: Taiwan Semiconductor Manufacturing Co., Ltd.
    Inventor: Jenn-Ming Huang
  • Patent number: 7012592
    Abstract: A voltage storage cell circuit includes an access transistor and a storage capacitor, wherein the source of said access transistor is connected to a bitline, the gate of said access transistor is connected to a wordline, and wherein the drain of said access transistor is connected to a first plate of said storage capacitor forming a storage node, and wherein the second plate of said storage capacitor is connected to a pump signal. This arrangement allows for a novel pixel circuit design with area requirements comparable to that of a 1T1C DRAM-like pixel cell, but with the advantage of an output voltage swing of the full range allowed by the breakdown voltage of the pass transistor. A spatial light modulator such as a micromirror array can comprise such a voltage storage cell.
    Type: Grant
    Filed: January 10, 2003
    Date of Patent: March 14, 2006
    Assignee: Reflectivity, INC
    Inventor: Peter W. Richards
  • Patent number: 6998666
    Abstract: A method of fabricating an integrated circuit device comprises etching a trench in a substrate and forming a dynamic random access memory (DRAM) cell having a storage capacitor at a lower end and an overlying vertical metal oxide semiconductor field effect transistor (MOSFET) comprising a gate conductor and a boron-doped channel. The method includes forming trenches adjacent the DRAM cell and a silicon-oxy-nitride isolation liner on either side of the DRAM cell, adjacent the gate conductor. Isolation regions are then formed in the trenches on either side of the DRAM cell. Thereafter, the DRAM cell, including the boron-containing channel region adjacent the gate conductor, is subjected to elevated temperatures by thermal processing, for example, forming a support device on the substrate adjacent the isolation regions. The nitride-containing isolation liner reduces segregation of the boron in the channel region, as compared to an essentially nitrogen-free oxide-containing isolation liner.
    Type: Grant
    Filed: January 9, 2004
    Date of Patent: February 14, 2006
    Assignee: International Business Machines Corporation
    Inventors: Jochen Beintner, Rama Divakaruni, Rajarao Jammy
  • Patent number: 6989561
    Abstract: Afin-type trench capacitor structure includes a buried plate diffused into a silicon substrate. The buried plate, which surrounds a bottle-shaped lower portion of the trench capacitor structure, is electrically connected to an upwardly extending annular poly electrode, thereby enabling the buried plate and the annular poly electrode to constitute a large-area capacitor electrode of the trench capacitor structure. A capacitor storage node consisting of a surrounding conductive layer, a central conductive layer and a collar conductive layer encompasses the upwardly extending annular poly electrode. A first capacitor dielectric layer isolates the capacitor storage node from the buried plate. A second capacitor dielectric layer and a third capacitor dielectric layer isolate the upwardly extending annular poly electrode from the capacitor storage node.
    Type: Grant
    Filed: December 2, 2003
    Date of Patent: January 24, 2006
    Assignee: Nanya Technology Corp.
    Inventors: Shian-Jyh Lin, Sam Liao, Chia-Sheng Yu
  • Patent number: 6989318
    Abstract: A method for reducing shallow trench isolation (STI) consumption during semiconductor device processing includes forming a hardmask over a semiconductor substrate, patterning the hardmask and forming a trench within the substrate. The trench is filled with an insulative material that is implanted with boron ions and thereafter annealed.
    Type: Grant
    Filed: October 22, 2003
    Date of Patent: January 24, 2006
    Assignee: International Business Machines Corporation
    Inventors: Bruce B. Doris, Ying Li
  • Patent number: 6987042
    Abstract: A method of forming collar isolation for a trench storage memory cell structure is provided in which amorphous Si (a:Si) and silicon germanium (SiGe) are first formed into a trench structure. An etching process that is selective to a:Si as compared to SiGe is employed in defining the regions in which the collar isolation will be formed. The selective etching process employed in the present invention is a wet etch process that includes etching with HF, rinsing, etching with NH4OH, rinsing, and drying with a monohydric alcohol such as isopropanol. The sequence of NH4OH etching and rinsing may be repeated any number of times. The conditions used in the selective etching process of the present invention are capable of etching a:Si at a faster rate than SiGe.
    Type: Grant
    Filed: May 30, 2003
    Date of Patent: January 17, 2006
    Assignee: International Business Machines Corporation
    Inventors: Jochen Beintner, Naim Moumen, Porshia S. Wrschka
  • Patent number: 6987044
    Abstract: A method for forming a volatile memory structure. A buried trench capacitor in each of a pair of neighboring trenches formed in a substrate. An asymmetric collar insulating layer is formed over an upper portion of the sidewall of each trench and has a high and a low level portions. A conductive layer is formed overlying the buried trench capacitor and below the surface of the substrate. The high level portion is adjacent to the substrate between the neighboring trenches and the low level portion is covered by the conductive layer. A dielectric layer is formed overlying the conductive layer. Two access transistors are formed on the substrate outside of the pair of the neighboring trenches, respectively, which have source/drain regions electrically connecting to the conductive layer. A volatile memory structure is also disclosed.
    Type: Grant
    Filed: September 25, 2003
    Date of Patent: January 17, 2006
    Assignee: ProMOS Technologies Inc.
    Inventors: Shih-Lung Chen, Yueh-Chuan Lee
  • Patent number: 6974743
    Abstract: Semiconductor devices having improved isolation are provided along with methods of fabricating such semiconductor devices. The improved isolation includes an encapsulated spacer formed within a gate region of a device.
    Type: Grant
    Filed: February 2, 2004
    Date of Patent: December 13, 2005
    Assignees: Infineon Technologies AG, International Business Machines Corporation
    Inventors: Ramac Divakaruni, Stephan Kudelka, Jack Mandelman
  • Patent number: 6964926
    Abstract: A method of forming capacitors with geometric deep trenches. First, a substrate with a pad structure formed thereon is provided, and a first hard mask layer is formed on the pad structure. Next, a second hard mask layer is formed on the first hard mask layer. Next, a spacer layer is formed in the first opening on the first hard mask layer to expose a second opening. Next, a third hard mask layer is filled the second opening, and the spacer layer is removed. Next, the first hard mask layer is etched to expose a third opening with a salient of the first hard mask layer, with the second hard mask layer and the third hard mask layer acting as masks. Finally, the first hard mask layer, the pad structure, and the substrate are etched to form a geometric deep trench.
    Type: Grant
    Filed: December 4, 2003
    Date of Patent: November 15, 2005
    Assignee: Nanya Technology Corporation
    Inventors: Tse-Yao Huang, Yi-Nan Chen, Tzu-Ching Tsai
  • Patent number: 6958275
    Abstract: Trench MOSFETs and self aligned processes for fabricating trench MOSFETs. These processes produce a higher density of trenches per unit area than can be obtained using prior art masking techniques. The invention self aligns all processing steps (implants, etches, depositions, etc.) to a single mask, thus reducing the pitch of the trenches by the added distances required for multiple masking photolithographic tolerances. The invention also places the source regions and contacts within the side walls of the trenches, thus eliminating the lateral dimensions required, for masking and source depositions or implants from the top surface, from the pitch of the trenches. Various embodiments are disclosed.
    Type: Grant
    Filed: March 11, 2003
    Date of Patent: October 25, 2005
    Assignee: Integrated Discrete Devices, LLC
    Inventor: Richard A. Metzler
  • Patent number: 6943396
    Abstract: As disclosed herein, an electrostatic discharge (ESD) protection circuit is provided for an integrated circuit including a semiconductor substrate. The ESD protection circuit includes a plurality of active devices formed in the semiconductor substrate, the active devices being formed by a process including a plurality of steps carried out to form, at the same time, a plurality of active devices having a function other than ESD protection. For example, the ESD circuit may include an array of vertical transistors formed according to a process including many of the steps used to form, at the same time, vertical transistors of a DRAM array. Also disclosed is the formation of an ESD circuit in an “unusable” area of a semiconductor chip, such as under a bond pad, land or under bump metallization of the chip.
    Type: Grant
    Filed: June 17, 2003
    Date of Patent: September 13, 2005
    Assignee: Infineon Technologies AG
    Inventor: Grant McNeil
  • Patent number: 6940144
    Abstract: Semiconductor equipment includes a semiconductor substrate with a semiconductor layer embedded therein and a vertical type transistor. The substrate has a principal side, a rear side opposite to the principal side, and a trench disposed in the rear side of the substrate. The vertical type transistor has a first electrode disposed in the principal side of the substrate, a second electrode disposed in the rear side, and a diffusion region disposed in the principal side. The first electrode connects to the diffusion region through an interlayer insulation film. The second electrode is disposed in the trench and connects to the semiconductor layer exposed in the trench. This vertical transistor has a low ON-state resistance.
    Type: Grant
    Filed: September 16, 2003
    Date of Patent: September 6, 2005
    Assignee: Denso Corporation
    Inventor: Yoshiaki Nakayama
  • Patent number: 6936510
    Abstract: A semiconductor memory device comprising: a first insulating film covering the upper and side surfaces of a gate electrode; a second insulating film formed on the substrate covering the first insulating film; a pair of contact holes formed through the second insulating film and reaching the impurity diffusion regions; a conductive plug embedded in one of the contact holes; a third insulating film formed on the second insulating film covering the conductive plug, and having a first aperture on the other contact hole; a bit line formed on the third insulating film and connected to the other impurity diffusion region through the first aperture and the other contact hole; a fourth insulating film covering the upper and side surfaces of the bit line; a second aperture formed through the third insulating film in alignment with the fourth insulating film covering the side surface of the bit line; a storage electrode formed to extend over the bit line, insulated from the bit line by the third and fourth insulating fi
    Type: Grant
    Filed: March 17, 2003
    Date of Patent: August 30, 2005
    Assignee: Fujitsu Limited
    Inventors: Kazuo Itabashi, Osamu Tsuboi, Yuji Yokoyama, Kenichi Inoue, Koichi Hashimoto, Wataru Futo
  • Patent number: 6936511
    Abstract: A simple method of forming the buried strap in a trench DRAM sets the separation between the buried strap and the vertical transistor channel by control of the overetch in forming a recess of the buried strap material, instead of setting the separation by the thickness of the trench top oxide.
    Type: Grant
    Filed: January 3, 2003
    Date of Patent: August 30, 2005
    Assignee: International Business Machines Corporation
    Inventors: Ramachandra Divakaruni, Thomas W. Dyer
  • Patent number: 6919245
    Abstract: A dynamic random access memory (DRAM) cell layout for arranging deep trenches and active areas and a fabrication method thereof. An active area comprises two vertical transistors, a common bitline contact and two deep trenches. The first vertical transistor is formed on a region where the first deep trench is partially overlapped with the first gate conductive line. The second vertical transistor is formed on a region where the second deep trench is partially overlapped with the second gate conductive line.
    Type: Grant
    Filed: October 25, 2004
    Date of Patent: July 19, 2005
    Assignee: Nanya Technology Corporation
    Inventors: Ming-Cheng Chang, Tieh-Chiang Wu, Yi-Nan Chen, Jeng-Ping Lin
  • Patent number: 6909136
    Abstract: A novel trench-capacitor DRAM cell structure is disclosed. The trench-capacitor DRAM cell of this invention includes an active area island having a horizontal semiconductor surface and a vertical sidewall contiguous with the horizontal semiconductor surface. A pass transistor is disposed at the corner of the active area island. The pass transistor includes a folded gate conductor strip extending from the horizontal semiconductor surface to the vertical sidewall of the active area island, a source formed in the horizontal semiconductor surface, a drain formed in the vertical sidewall, and a gate oxide layer underneath the folded gate conductor strip. The source and drain define a folded channel. The trench-capacitor DRAM cell further includes a trench capacitor that is insulated from the folded gate conductor strip by a trench top oxide (TTO) layer and is coupled to the pass transistor via the drain.
    Type: Grant
    Filed: July 14, 2003
    Date of Patent: June 21, 2005
    Assignee: Nanya Technology Corp.
    Inventors: Yinan Chen, Ming-Cheng Chang, Jeng-Ping Lin, Tse-Yao Huang, Change-Rong Wu, Hui-Min Mao
  • Patent number: 6905944
    Abstract: A method for fabricating a deep trench etched into a semiconductor substrate is provided by the present invention. The trench is divided into an upper portion and a lower portion and the method allows for the lower portion to be processed differently from the upper portion. After the trench is etched into the semiconductor substrate, a nitride layer is formed over a sidewall of the trench. A layer of oxide is then formed over the nitride layer. A filler material is then deposited and recessed to cover the oxide layer in the lower portion of the trench, followed by the removal of the oxide layer from the upper portion of the trench above the filler material. Once the oxide layer is removed from the upper portion of the trench, the filler material can also be removed, while allowing the oxide layer and the nitride layer to remain in the lower portion of the trench. Silicon is selectively deposited on the exposed nitride layer in the upper portion of the trench.
    Type: Grant
    Filed: May 8, 2003
    Date of Patent: June 14, 2005
    Assignees: International Business Machines Corporation, Infineon Technologies AG
    Inventors: Michael Patrick Chudzik, Irene McStay, Helmut Horst Tews, Porshia Shane Wrschka
  • Patent number: 6897107
    Abstract: A structure and method which enables the deposit of a thin nitride liner just before Trench Top Oxide TTO (High Density Plasma) HDP deposition during the formation of a vertical MOSFET DRAM cell device. This liner is subsequently removed after TTO sidewall etch. One function of this liner is to protect the collar oxide from being etched during the TTO oxide sidewall etch and generally provides lateral etch protection which is not realized in the current processing scheme. The process sequence does not rely on previously deposited films for collar protection, and decouples TTO sidewall etch protection from previous processing steps to provide additional process flexibility, such as allowing a thinner strap Cut Mask nitride and greater nitride etching during node nitride removal and buried strap nitrided interface removal.
    Type: Grant
    Filed: November 24, 2003
    Date of Patent: May 24, 2005
    Assignees: International Business Machines Corporation, Infineon Technologies North America Corporation
    Inventors: Rama Divakaruni, Thomas W. Dyer, Rajeev Malik, Jack A. Mandelman, Venkatachajam C. Jaiprakash
  • Patent number: 6890815
    Abstract: A method of forming borderless contacts and a borderless contact structure for semiconductor devices. A preferred embodiment comprises using a second etch selectivity material disposed over a first etch selectivity material to preserve the first etch selectivity material during the etch processes for the various material layers of the semiconductor device while forming the borderless contacts.
    Type: Grant
    Filed: September 4, 2003
    Date of Patent: May 10, 2005
    Assignees: Infineon Technologies AG, International Business Machines Corporation
    Inventors: Johnathan Faltermeier, Jeremy Stephens, David Dobuzinsky, Larry Clevenger, Munir D. Naeem, Chienfan Yu, Larry Nesbit, Rama Divakaruni, Michael Maldei
  • Patent number: 6887761
    Abstract: A method and structure for increasing the threshold voltage of vertical semiconductor devices. The method comprises creating a deep trench in a substrate whose semiconductor material has an orientation plane perpendicular to the surface of the substrate. Then, vertical transistors are formed around and along the depth of the deep trench. Next, two shallow trench isolation are formed such that they sandwich the deep trench in an active region and the two shallow trench isolation regions abut the active region via planes perpendicular to the orientation plane. Then, the channel regions of the vertical transistors are exposed to the atmosphere in the deep trench and then chemically etched to planes parallel to the orientation plane. Then, a gate dielectric layer is formed on the wall of the deep trench. Finally, the deep trench is filled with poly-silicon to form the gate for the vertical transistors.
    Type: Grant
    Filed: March 17, 2004
    Date of Patent: May 3, 2005
    Assignees: International Business Machines Corporation, Infineon Technologies North America Corp.
    Inventors: Hiroyuki Akatsu, Thomas W. Dyer, Ravikumar Ramachandran, Kenneth T. Settlemyer, Jr.
  • Patent number: 6882000
    Abstract: Trench MIS devices including a thick insulative layer at the bottom of the trench are disclosed, along with methods of fabricating such devices. An exemplary trench MOSFET embodiment includes a thick oxide layer at the bottom of the trench, with no appreciable change in stress in the substrate along the trench bottom. The thick insulative layer separates the trench gate from the drain region at the bottom of the trench yielding a reduced gate-to-drain capacitance making such MOSFETs suitable for high frequency applications. In an exemplary fabrication process embodiment, the thick insulative layer is deposited on the bottom of the trench. A thin insulative gate dielectric is formed on the exposed sidewall and is coupled to the thick insulative layer. A gate is formed in the remaining trench volume. The process is completed with body and source implants, passivation, and metallization.
    Type: Grant
    Filed: August 10, 2001
    Date of Patent: April 19, 2005
    Assignee: Siliconix Incorporated
    Inventors: Mohamed N. Darwish, Frederick P. Giles, Kam Hong Lui, Kuo-In Chen, Kyle Terrill
  • Patent number: 6872619
    Abstract: A method for forming a semiconductor device having a trench top isolation layer. A collar insulating layer is formed over a lower portion of the sidewall of the trench formed in a substrate. A first conductive layer is formed in the lower portion of the trench and protrudes the collar insulating layer, and a second conductive layer is formed overlying the first conductive layer and covers the collar insulating layer. An insulating spacer is formed over an upper portion of the sidewall of the trench and separated from the second conductive layer by a gap. The second conductive layer is partially thermally oxidized to form an oxide layer thereon whereby the gap is filled. After the oxide layer is removed, a reverse T-shaped insulating layer is formed thereon by chemical vapor deposition to serve as a trench top isolation layer. Finally, the insulating spacer is removed.
    Type: Grant
    Filed: July 16, 2003
    Date of Patent: March 29, 2005
    Assignee: Nanya Technology Corporation
    Inventors: Yi-Nan Chen, Tieh-Chiang Wu, Feng-Chuan Lin
  • Patent number: 6861311
    Abstract: In one aspect, the invention provides a method of forming an electrical connection in an integrated circuitry device. According to one preferred implementation, a diffusion region is formed in semiconductive material. A conductive line is formed which is laterally spaced from the diffusion region. The conductive line is preferably formed relative to and within isolation oxide which separates substrate active areas. The conductive line is subsequently interconnected with the diffusion region. According to another preferred implementation, an oxide isolation grid is formed within semiconductive material. Conductive material is formed within the oxide isolation grid to form a conductive grid therein. Selected portions of the conductive grid are then removed to define interconnect lines within the oxide isolation grid. According to another preferred implementation, a plurality of oxide isolation regions are formed over a semiconductive substrate.
    Type: Grant
    Filed: November 25, 2002
    Date of Patent: March 1, 2005
    Assignee: Micron Technology, Inc.
    Inventor: Wendell P. Noble
  • Patent number: 6858893
    Abstract: A semiconductor memory includes a silicon substrate having a cell array region wherein plural rectangular silicon pillars are formed in rows and columns by a trench having a width of 1a and formed in a lattice form, a storage node formed on at least a surface of a lower portion of the silicon pillar, a well region formed in an upper half above the storage node, a diffusion layer formed on an upper surface of the well region, a capacitor dielectric formed on the storage node to surround the lower portion of the silicon pillar, a plate electrode buried in the lower portion of the trench to substantially the same level as the upper end of the storage node, and a first gate electrode formed on the channel portion via a first gate insulator.
    Type: Grant
    Filed: December 10, 2002
    Date of Patent: February 22, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Shigeru Ishibashi
  • Patent number: 6855596
    Abstract: A method for manufacturing a trench capacitor includes the step of etching a shallow isolation trench in a two-step process flow. During a first etching step, an etch chemistry based on chlorine or bromine performs a highly selective etch for silicon. During a second step, the etch chemistry is based on SiF4 and O2 which rather equally etches polysilicon and the collar isolation. On top of the wafer, the deposition of silicon oxide on the hard mask predominates and avoids an erosion of the hard mask. On the bottom of the trench the conformal etching of polysilicon and collar isolation predominates. The method provides an economic process flow and is suitable for small feature sizes.
    Type: Grant
    Filed: November 17, 2003
    Date of Patent: February 15, 2005
    Assignee: Infineon Technologies AG
    Inventors: Gabriele Fichtl, Jana Haensel, Thomas Metzdorf, Thomas Morgenstern
  • Patent number: 6853023
    Abstract: A semiconductor memory cell configuration includes dynamic memory cells respectively having a trench capacitor and a vertical selection transistor, the memory cells being disposed in matrix form, the trench capacitors and the associated vertical selection transistors following one another in each case in the form of rows and/or columns.
    Type: Grant
    Filed: January 31, 2003
    Date of Patent: February 8, 2005
    Assignee: Infineon Technologies AG
    Inventors: Bernd Goebel, Jörn Lützen, Martin Popp, Harald Seidl
  • Patent number: 6849496
    Abstract: A semiconductor Dynamic Random Access Memory (DRAM) cell is fabricated using a vertical access transistor and a storage capacitor formed in a vertical trench. A Shallow Trench Isolation (STI) region is used as a masking region to confine the channel region of the access transistor, the first and second output regions of the access transistor, and a strap region connecting the second output region to the storage capacitor, to a narrow portion of the trench. The so confined second output region of the access transistor has reduced leakage to similar second output regions of adjacent memory cells. Adjacent memory cells can then be placed closer to one another without an increase in leakage and cross-talk between adjacent memory cells.
    Type: Grant
    Filed: July 11, 2003
    Date of Patent: February 1, 2005
    Assignee: Infineon Technologies AG
    Inventors: Venkatachalam C. Jaiprakash, Mihel Seitz, Norbert Arnold
  • Patent number: 6849890
    Abstract: A semiconductor device comprises a semiconductor substrate having first conductivity type, a trench capacitor, provided in the substrate, having a charge accumulation region, a gate electrode provided on the substrate via a gate insulating film, a gate side wall insulating film provided on a side surface of the gate electrode, drain and source regions, provided in the substrate, having a second conductivity type, an isolation insulating film provided adjacent to the trench capacitor in the substrate to cover an upper surface of the charge accumulation region, a buried strap region having the second conductivity type, the buried strap region being provided to electrically connect an upper portion of the charge accumulation region to the source region in the substrate, and a pocket implantation region having the first conductivity type, the pocket implantation region being provided below the drain and source regions and being spaced apart from the strap region.
    Type: Grant
    Filed: May 23, 2003
    Date of Patent: February 1, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Koichi Kokubun
  • Publication number: 20040256665
    Abstract: To fabricate a vertical transistor, a trench is provided, the side wall of which is formed by a semiconductor substrate in single crystal form and the base of which is formed by a polycrystalline semiconductor substrate. A transition region is arranged between the side wall and the base. A semiconductor layer is deposited so that an epitaxial semiconductor layer grows on the side wall and a semiconductor layer grows on the base, with a space remaining between these layers. The semiconductor layers are covered with a thin dielectric, which partially limits a flow of current, and the space is filled. During a subsequent heat treatment, dopants diffuse out of the conductive material into the epitaxial semiconductor layer, where they form a doping region. The thin dielectric limits the diffusion of the dopants into the semiconductor substrate and prevents the propagation of crystal lattice defects into the epitaxial semiconductor layer.
    Type: Application
    Filed: August 9, 2004
    Publication date: December 23, 2004
    Inventors: Albert Birner, Joern Luetzen
  • Patent number: 6825078
    Abstract: A method for forming, within a double well formation, an array of DRAM memory cells isolated from each other by shallow trench isolation (STI), each cell comprising a MOSFET access transistor and a storage trench capacitor. A top plate of said capacitor is the trench wall within a deep N-well portion of the double well and the bottom plate is formed of a doped polysilicon layer within the trench, which layer is partially separated from the trench sidewalls by a dielectric layer whose upper portion is removed to allow the formation of a autodiffused doped channel between said polysilicon plate and the source region of the access transistor. The method uses a single dielectric layer deposition to serve as both a gate a gate dielectric for the MOSFET and a capacitor dielectric and requires only a single deposition of polysilicon to serve as both the transistor gate electrode and a capacitor plate.
    Type: Grant
    Filed: May 23, 2003
    Date of Patent: November 30, 2004
    Assignee: Taiwan Semiconductor Manufacturing Company
    Inventor: Jenn-Ming Huang
  • Patent number: 6818939
    Abstract: In one embodiment, a compound semiconductor vertical FET device (11) includes a first trench (29) formed in a body of semiconductor material (13), and a second trench (34) formed within the first trench (29) to define a channel region (61). A doped gate region (59) is then formed on the sidewalls and the bottom surface of the second trench (34). Source regions (26) are formed on opposite sides of the double trench structure (28). Localized gate contact regions (79) couple individual doped gate regions (59) together. Contacts (84, 85, 87) are then formed to the localized gate contact regions (79), the source regions (26), and an opposing surface (21) of the body of semiconductor material (13). The structure provides a compound semiconductor vertical FET device (11, 41, 711, 712, 811, 812) having enhanced blocking capability and improved switching performance.
    Type: Grant
    Filed: July 18, 2003
    Date of Patent: November 16, 2004
    Assignee: Semiconductor Components Industries, L.L.C.
    Inventor: Peyman Hadizad
  • Publication number: 20040219747
    Abstract: A method for forming a vertical transistor and a trench capacitor. A semiconductor substrate having a pad stacked layer on the surface and a trench formed therein is provided. A capacitor is formed at the bottom part of the trench and a portion of the upper sidewall of the trench is exposed. A conductive wire is then formed on the capacitor, followed by forming a dielectric layer on the exposed sidewalls of the trench. A trench top dielectric is then formed by liquid phase deposition on the conductive wire. A transistor is then formed on the trench top dielectric, which isolates the transistor from the capacitor.
    Type: Application
    Filed: August 13, 2003
    Publication date: November 4, 2004
    Applicant: Nanya Technology Corporation
    Inventors: Shian-Jyh Lin, Yi-Nan Chen
  • Patent number: 6812091
    Abstract: An improved sub 8F2 memory cell is disclosed. The sub 8F2 cell includes a shallow transistor trench in which a buried portion of the transistor occupies.
    Type: Grant
    Filed: September 26, 2000
    Date of Patent: November 2, 2004
    Assignee: Infineon Technologies AG
    Inventors: Ulrike Gruening, Johann Alsmeier
  • Patent number: 6812076
    Abstract: A FinFet-type semiconductor device includes a fin structure on which a relatively thin amorphous silicon layer and then an undoped polysilicon layer is formed. The semiconductor device may be planarized using a chemical mechanical polishing (CMP) in which the amorphous silicon layer acts as a stop layer to prevent damage to the fin structure.
    Type: Grant
    Filed: January 8, 2004
    Date of Patent: November 2, 2004
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Krishnashree Achuthan, Shibly S. Ahmed, Haihong Wang, Bin Yu
  • Patent number: 6808979
    Abstract: A method for forming a vertical transistor and a trench capacitor. A semiconductor substrate having a pad stacked layer on the surface and a trench formed therein is provided. A capacitor is formed at the bottom part of the trench and a portion of the upper sidewall of the trench is exposed. A conductive wire is then formed on the capacitor, followed by forming a dielectric layer on the exposed sidewalls of the trench. A trench top dielectric is then formed by liquid phase deposition on the conductive wire. A transistor is then formed on the trench top dielectric, which isolates the transistor from the capacitor.
    Type: Grant
    Filed: August 13, 2003
    Date of Patent: October 26, 2004
    Assignee: Nanya Technology Corporation
    Inventors: Shian-Jyh Lin, Yi-Nan Chen