Patents by Inventor Geng Wang

Geng Wang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7790530
    Abstract: A DRAM memory cell and process sequence for fabricating a dense (20 or 18 square) layout is fabricated with silicon-on-insulator (SOI) CMOS technology. Specifically, the present invention provides a dense, high-performance SRAM cell replacement that is compatible with existing SOI CMOS technologies. Various gain cell layouts are known in the art. The present invention improves on the state of the art by providing a dense layout that is fabricated with SOI CMOS. In general terms, the memory cell includes a first transistor provided with a gate, a source, and a drain respectively; a second transistor having a first gate, a second gate, a source, and a drain respectively; and a capacitor having a first terminal, wherein the first terminal of said capacitor and the second gate of said second transistor comprise a single entity.
    Type: Grant
    Filed: October 21, 2008
    Date of Patent: September 7, 2010
    Assignee: International Business Machines Corporation
    Inventors: Jack A. Mandelman, Kangguo Cheng, Ramachandra Divakaruni, Carl J. Radens, Geng Wang
  • Patent number: 7791124
    Abstract: A bottle shaped trench for an SOI capacitor is formed by a simple processing sequence. A non-conformal dielectric layer with an optional conformal dielectric diffusion barrier layer underneath is formed on sidewalls of a deep trench. Employing an isotropic etch, the non-conformal dielectric layer is removed from a bottom portion of the deep trench, leaving a dielectric spacer covering sidewalls of the buried insulator layer and the top semiconductor layer. The bottom portion of the deep trench is expanded to form a bottle shaped trench, and a buried plated is formed underneath the buried insulator layer. The dielectric spacer may be recessed during formation of a buried strap to form a graded thickness dielectric collar around the upper portion of an inner electrode. Alternately, the dielectric spacer may be removed prior to formation of a buried strap.
    Type: Grant
    Filed: May 21, 2008
    Date of Patent: September 7, 2010
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Herbert L. Ho, Paul C. Parries, Geng Wang
  • Patent number: 7785959
    Abstract: A method is provided for fabricating a multi-port memory in which a plurality of parallel connected capacitors are in a cell. A plurality of trench capacitors are formed which have capacitor dielectric layers extending along walls of the plurality of trenches, the plurality of trench capacitors having first capacitor plates and second capacitor plates opposite the capacitor dielectric layers from the first capacitor plates. The first capacitor plates are conductively tied together and the second capacitor plates are conductively tied together. In this way, the first capacitor plates are adapted to receive a same variable voltage and the second capacitor plates are adapted to receive a same fixed voltage.
    Type: Grant
    Filed: December 16, 2008
    Date of Patent: August 31, 2010
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Jack A. Mandelman, Carl J. Radens, Geng Wang
  • Publication number: 20100207179
    Abstract: A semiconductor fin having a doping of the first conductivity type and a semiconductor column are formed on a substrate. The semiconductor column and an adjoined end portion of the semiconductor fin are doped with dopants of a second conductivity type, which is the opposite of the first conductivity type. The doped semiconductor column constitutes an inner electrode of a capacitor. A dielectric layer and a conductive material layer are formed on the semiconductor fin and the semiconductor column. The conductive material layer is patterned to form an outer electrode for the capacitor and a gate electrode. A single-sided halo implantation may be performed. Source and drain regions are formed in the semiconductor fin to form an access transistor. The source region is electrically connected to the inner electrode of the capacitor. The access transistor and the capacitor collectively constitute a DRAM cell.
    Type: Application
    Filed: February 5, 2010
    Publication date: August 19, 2010
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Roger A. Booth, JR., Kangguo Cheng, Chengwen Pei, Geng Wang
  • Patent number: 7776706
    Abstract: A method of forming a trench memory cell includes forming a trench capacitor within a substrate material, the trench capacitor including a node dielectric layer formed within a trench and a conductive capacitor electrode material formed within the trench in contact with the node dielectric layer; forming a strap mask so as cover one side of the trench and removing one or more materials from an uncovered opposite side of the trench; and forming a conductive buried strap material within the trench; wherein the strap mask is patterned in a manner such that a single-sided buried strap is defined within the trench, the single-sided buried strap configured in a manner such that the deep trench capacitor is electrically accessible at only one side of the trench.
    Type: Grant
    Filed: July 9, 2008
    Date of Patent: August 17, 2010
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Herbert L. Ho, Geng Wang
  • Publication number: 20100203732
    Abstract: A semiconductor device is formed by providing a substrate and forming a semiconductor-containing layer atop the substrate. A mask having a plurality of openings is then formed atop the semiconductor-containing layer, wherein adjacent openings of the plurality of openings of the mask are separated by a minimum feature dimension. Thereafter, an angled ion implantation is performed to introduce dopants to a first portion of the semiconductor-containing layer, wherein a remaining portion that is substantially free of dopants is present beneath the mask. The first portion of the semiconductor-containing layer containing the dopants is removed selective to the remaining portion of semiconductor-containing layer that is substantially free of the dopants to provide a pattern of sublithographic dimension, and the pattern is transferred into the substrate to provide a fin structure of sublithographic dimension.
    Type: Application
    Filed: February 10, 2009
    Publication date: August 12, 2010
    Applicant: International Business Machines Corporation
    Inventors: Bruce B. Doris, Kangguo Cheng, Geng Wang
  • Publication number: 20100200949
    Abstract: A method of forming a deep trench capacitor includes providing a wafer. Devices are formed on a front side of the wafer. A through-silicon-via is formed on a substrate of the wafer. Deep trenches are formed on a back side of the wafer. A deep trench capacitor is formed in the deep trench. The through-silicon-via connects the deep trench capacitor to the devices.
    Type: Application
    Filed: February 12, 2009
    Publication date: August 12, 2010
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Roger A. Booth, JR., Kangguo Cheng, Robert Hannon, Ravi M. Todi, Geng Wang
  • Patent number: 7732872
    Abstract: A metal gate stack containing a metal layer having a mid-band-gap work function is formed on a high-k gate dielectric layer. A threshold voltage adjustment oxide layer is formed over a portion of the high-k gate dielectric layer to provide devices having a work function near a first band gap edge, while another portion of the high-k dielectric layer remains free of the threshold voltage adjustment oxide layer. A gate stack containing a semiconductor oxide based gate dielectric and a doped polycrystalline semiconductor material may also be formed to provide a gate stack having a yet another work function located near a second band gap edge which is the opposite of the first band gap edge. A dense circuit containing transistors of p-type and n-type with the mid-band-gap work function are formed in the region containing the threshold voltage adjustment oxide layer.
    Type: Grant
    Filed: October 25, 2007
    Date of Patent: June 8, 2010
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Michael P. Chudzik, Ramachandra Divakaruni, Geng Wang, Robert C. Wong, Haining S. Yang
  • Patent number: 7723201
    Abstract: A method for manufacturing a device includes forming trenches of different morphologies into a substrate. At the upper surfaces, the trenches have different orientations with respect to each other. In an aspect, windows for the trenches are aligned along the <100> and <110> directions of a silicon substrate. The trenches of different morphologies may be formed into capacitors having different capacitance levels. Also included are devices prepared by the method.
    Type: Grant
    Filed: January 9, 2006
    Date of Patent: May 25, 2010
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Geng Wang
  • Patent number: 7668003
    Abstract: Disclosed is a DRAM circuit that incorporates an improved reference cell, has half the capacitance of the memory cell, does not require a particular reference voltage, and can be formed using the same fabrication processes as the memory cell. This DRAM circuit comprises a memory cell with a single trench capacitor and a reference cell having two trench capacitors. The two reference cell trench capacitors are connected in series through a merged buried capacitor plate such that they provide half the capacitance of the memory cell trench capacitor. Additionally, the reference cell trench capacitors have essentially the same structure as the memory cell trench capacitor so that they can be formed in conjunction with the memory cell trench capacitor. Also disclosed are a design structure for the above-described memory circuit and a method for forming the above-described memory circuit.
    Type: Grant
    Filed: April 24, 2008
    Date of Patent: February 23, 2010
    Assignee: International Business Machines Corporation
    Inventors: John E. Barth, Jr., Kangguo Cheng, Hoki Kim, Geng Wang
  • Publication number: 20100032742
    Abstract: A method of forming an integrated circuit comprises: providing a semiconductor topography comprising an active transistor laterally adjacent to a trench capacitor formed in a semiconductor substrate, the active transistor comprising a source junction and a drain junction, wherein a barrier layer is disposed along a periphery of the trench capacitor for isolating the trench capacitor; forming an interlevel dielectric across the semiconductor topography; concurrently etching (i) a first opening through the interlevel dielectric to the drain junction of the active transistor and the trench capacitor, and (ii) a second opening through the interlevel dielectric to the source junction of the active transistor; and filling the first opening and the second opening with a conductive material to form a strap for electrically connecting the trench capacitor to the drain junction of the active transistor and to also form a contact for electrically connecting the source junction to an overlying level of the integrated cir
    Type: Application
    Filed: August 6, 2008
    Publication date: February 11, 2010
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: John E. Barth, JR., Kangguo Cheng, Michael Sperling, Geng Wang
  • Publication number: 20090315124
    Abstract: Embedded DRAM MOSFETs including an array NFET having a gate stack comprising a high-K dielectric layer upon which is deposited a first metal oxide layer (CD1) then a conductive layer (TiN), and then a polysilicon layer (Poly). A logic PFET having substantially the same gate stack as the array NFET, and a logic NFET having a third gate stack comprising the high-K dielectric layer upon which is deposited the conductive layer (TiN) and then the polysilicon layer (Poly), without the first metal oxide layer (CD1) between the high-K dielectric layer and the conductive layer (TiN). The array NFET may therefore have a higher gate stack work function than the logic NFET, but substantially the same gate stack work function as the logic PFET.
    Type: Application
    Filed: June 18, 2008
    Publication date: December 24, 2009
    Applicant: International Business Machines Corporation
    Inventors: Xiangdong Chen, Herbert L. Ho, Geng Wang
  • Publication number: 20090289291
    Abstract: A bottle shaped trench for an SOI capacitor is formed by a simple processing sequence. A non-conformal dielectric layer with an optional conformal dielectric diffusion barrier layer underneath is formed on sidewalls of a deep trench. Employing an isotropic etch, the non-conformal dielectric layer is removed from a bottom portion of the deep trench, leaving a dielectric spacer covering sidewalls of the buried insulator layer and the top semiconductor layer. The bottom portion of the deep trench is expanded to form a bottle shaped trench, and a buried plated is formed underneath the buried insulator layer. The dielectric spacer may be recessed during formation of a buried strap to form a graded thickness dielectric collar around the upper portion of an inner electrode. Alternately, the dielectric spacer may be removed prior to formation of a buried strap.
    Type: Application
    Filed: May 21, 2008
    Publication date: November 26, 2009
    Applicant: International Business Machines Corporation
    Inventors: Kangguo Cheng, Herbert L. Ho, Paul C. Parries, Geng Wang
  • Publication number: 20090268510
    Abstract: Disclosed is a DRAM circuit that incorporates an improved reference cell, has half the capacitance of the memory cell, does not require a particular reference voltage, and can be formed using the same fabrication processes as the memory cell. This DRAM circuit comprises a memory cell with a single trench capacitor and a reference cell having two trench capacitors. The two reference cell trench capacitors are connected in series through a merged buried capacitor plate such that they provide half the capacitance of the memory cell trench capacitor. Additionally, the reference cell trench capacitors have essentially the same structure as the memory cell trench capacitor so that they can be formed in conjunction with the memory cell trench capacitor. Also disclosed are a design structure for the above-described memory circuit and a method for forming the above-described memory circuit.
    Type: Application
    Filed: April 24, 2008
    Publication date: October 29, 2009
    Inventors: John E. Barth, JR., Kangguo Cheng, Hoki Kim, Geng Wang
  • Patent number: 7596038
    Abstract: A system including a DRAM memory device on an integrated circuit (IC) using a control logic device to initiate a body refresh operation to provide a means for maintaining a low voltage at a floating body and discourage data loss, and a design structure including the DRAM memory device embodied in a machine readable medium is provided. A plurality of DRAM cells are connected to a first word line circuit and a first bit line circuit. The control logic device is coupled to the DRAM memory device and the IC for initiating the body refresh cycle. The control logic communicates with a first bit line and word line circuits and communicates with a reference word line and bit line circuits. A sense amplifier circuit and signal is provided for amplifying the voltage at the first bit line and the reference bit line. The body refresh cycle includes deactivating the first word line voltage while the first bit line and reference bit line voltages continue.
    Type: Grant
    Filed: December 12, 2007
    Date of Patent: September 29, 2009
    Assignee: International Business Machines Corporation
    Inventors: Hoki Kim, Geng Wang
  • Publication number: 20090196213
    Abstract: A system and a device for controlling bearer change are provided. The system includes a bearer change notifying entity and a bearer change control entity. The bearer change notifying entity is adapted to acquire information that a bearer needs to be changed, and send a bearer change notice to the bearer change control entity. The bearer change control entity is adapted to determine and control conversion from a multicast bearer mode to a unicast bearer mode or conversion from the unicast bearer mode to the multicast bearer mode according to the received bearer change notice. Further, a method for controlling bearer change is also provided.
    Type: Application
    Filed: April 8, 2009
    Publication date: August 6, 2009
    Applicant: HUAWEI TECHNOLOGIES CO., LTD.
    Inventors: Jianfeng ZHONG, Geng WANG
  • Publication number: 20090176339
    Abstract: A method is provided for fabricating a multi-port memory in which a plurality of parallel connected capacitors are in a cell. A plurality of trench capacitors are formed which have capacitor dielectric layers extending along walls of the plurality of trenches, the plurality of trench capacitors having first capacitor plates and second capacitor plates opposite the capacitor dielectric layers from the first capacitor plates. The first capacitor plates are conductively tied together and the second capacitor plates are conductively tied together. In this way, the first capacitor plates are adapted to receive a same variable voltage and the second capacitor plates are adapted to receive a same fixed voltage.
    Type: Application
    Filed: December 16, 2008
    Publication date: July 9, 2009
    Inventors: Kangguo Cheng, Ramachandra Divakaruni, Jack A. Mandelman, Carl J. Radens, Geng Wang
  • Publication number: 20090174031
    Abstract: By controlling buried plate doping level and bias condition, different capacitances can be obtained from capacitors on the same chip with the same layout and deep trench process. The capacitors may be storage capacitors of DRAM/eDRAM cells. The doping concentration may be less than 3E19cm?3, a voltage difference between the biases of the buried electrodes may be at least 0.5V, and a capacitance of one capacitor may be at least 1.2 times, such as 2.0 times the capacitance of another capacitor.
    Type: Application
    Filed: January 7, 2008
    Publication date: July 9, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Geng Wang, Kangguo Cheng, Johnathan E. Faltermeier, Paul C. Parries
  • Patent number: 7550359
    Abstract: A method for fabricating silicon-on-insulator (SOI) trench memory includes forming a trench on a substrate, wherein a buried oxide layer is disposed on the substrate, a SOI layer is disposed on the buried oxide layer, and a hardmask layer is disposed on the SOI layer, implanting ions into the substrate and the SOI layer on a first opposing side of the trench and a second opposing side the trench to partially form a capacitor, depositing a node dielectric in the trench, filling the trench with a first polysilicon, removing a portion of the first polysilicon from the trench, removing an exposed portion of the node dielectric, filling the trench with a second polysilicon, masking to define an active region on the hardmask layer, forming shallow trench isolation (STI) such that the STI contacts a portion of the buried oxide layer, removing the hardmask layer, and forming a transistor.
    Type: Grant
    Filed: May 7, 2008
    Date of Patent: June 23, 2009
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Herbert L. Ho, Geng Wang
  • Publication number: 20090154258
    Abstract: A system including a DRAM memory device on an integrated circuit (IC) using a control logic device to initiate a body refresh operation to provide a means for maintaining a low voltage at a floating body and discourage data loss, and a design structure including the DRAM memory device embodied in a machine readable medium is provided. A plurality of DRAM cells are connected to a first word line circuit and a first bit line circuit. The control logic device is coupled to the DRAM memory device and the IC for initiating the body refresh cycle. The control logic communicates with a first bit line and word line circuits and communicates with a reference word line and bit line circuits. A sense amplifier circuit and signal is provided for amplifying the voltage at the first bit line and the reference bit line. The body refresh cycle includes deactivating the first word line voltage while the first bit line and reference bit line voltages continue.
    Type: Application
    Filed: December 12, 2007
    Publication date: June 18, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Hoki Kim, Geng Wang