Patents by Inventor Herbert L. Ho

Herbert L. Ho 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: 7816728
    Abstract: The present invention provides two-transistor silicon-oxide-nitride-oxide-semiconductor (2-Tr SONOS) non-volatile memory cells with randomly accessible storage locations as well as method of fabricating the same. In one embodiment, a 2-Tr SONOS cell is provided in which the select transistor is located within a trench structure having trench depth from 1 to 2 ?m and the memory transistor is located on a surface of a semiconductor substrate adjoining the trench structure. In another embodiment, a 2-Tr SONOS memory cell is provided in which both the select transistor and the memory transistor are located within a trench structure having the depth mentioned above.
    Type: Grant
    Filed: April 12, 2005
    Date of Patent: October 19, 2010
    Assignee: International Business Machines Corporation
    Inventors: Herbert L. Ho, Jack A. Mandelman, Tak H. Ning, Yoichi Otani
  • Patent number: 7807526
    Abstract: The present invention provides two-transistor silicon-oxide-nitride-oxide-semiconductor (2-Tr SONOS) non-volatile memory cells with randomly accessible storage locations as well as method of fabricating the same. In one embodiment, a 2-Tr SONOS cell is provided in which the select transistor is located with a trench structure having trench depth from 1 to 2 ?m and the memory transistor is located on a surface of a semiconductor substrate adjoining the trench structure. In another embodiment, a 2-Tr SONOS memory cell is provided in which both the select transistor and the memory transistor are located within a trench structure having the depth mentioned above.
    Type: Grant
    Filed: October 30, 2007
    Date of Patent: October 5, 2010
    Assignee: International Business Machines Corporation
    Inventors: Herbert L. Ho, Jack A. Mandelman, Tak H. Ning, Yoichi Otani
  • 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
  • Publication number: 20100207683
    Abstract: The present invention provides a “collector-less” silicon-on-insulator (SOI) bipolar junction transistor (BJT) that has no impurity-doped collector. Instead, the inventive vertical SOI BJT uses a back gate-induced, minority carrier inversion layer as the intrinsic collector when it operates. In accordance with the present invention, the SOI substrate is biased such that an inversion layer is formed at the bottom of the base region serving as the collector. The advantage of such a device is its CMOS-like process. Therefore, the integration scheme can be simplified and the manufacturing cost can be significantly reduced. The present invention also provides a method of fabricating BJTs on selected areas of a very thin BOX using a conventional SOI starting wafer with a thick BOX. The reduced BOX thickness underneath the bipolar devices allows for a significantly reduced substrate bias compatible with the CMOS to be applied while maintaining the advantages of a thick BOX underneath the CMOS.
    Type: Application
    Filed: February 17, 2010
    Publication date: August 19, 2010
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Herbert L. Ho, Mahender Kumar, Qiqing Ouyang, Paul A. Papworth, Christopher D. Sheraw, Michael D. Steigerwalt
  • 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
  • Patent number: 7763518
    Abstract: The present invention provides a “collector-less” silicon-on-insulator (SOI) bipolar junction transistor (BJT) that has no impurity-doped collector. Instead, the inventive vertical SOI BJT uses a back gate-induced, minority carrier inversion layer as the intrinsic collector when it operates. In accordance with the present invention, the SOI substrate is biased such that an inversion layer is formed at the bottom of the base region serving as the collector. The advantage of such a device is its CMOS-like process. Therefore, the integration scheme can be simplified and the manufacturing cost can be significantly reduced. The present invention also provides a method of fabricating BJTs on selected areas of a very thin BOX using a conventional SOI starting wafer with a thick BOX. The reduced BOX thickness underneath the bipolar devices allows for a significantly reduced substrate bias compatible with the CMOS to be applied while maintaining the advantages of a thick BOX underneath the CMOS.
    Type: Grant
    Filed: April 8, 2008
    Date of Patent: July 27, 2010
    Assignee: International Business Machines Corporation
    Inventors: Herbert L. Ho, Mahender Kumar, Qiqing Ouyang, Paul A. Papworth, Christopher D. Sheraw, Michael D. Steigerwalt
  • Patent number: 7750388
    Abstract: The present invention relates to a semiconductor device that contains a trench metal-insulator-metal (MIM) capacitor and a field effect transistor (FET), and a design structure including the semiconductor device embodied in a machine readable medium. The trench MIM capacitor comprises a first metallic electrode layer located over interior walls of a trench in a substrate, a dielectric layer located in the trench over the first metallic electrode layer, and a second metallic electrode layer located in the trench over the dielectric layer. The FET comprises a source region, a drain region, a channel region between the source and drain regions, and a gate electrode over the channel region. The trench MIM capacitor is connected to the FET by a metallic strap.
    Type: Grant
    Filed: December 20, 2007
    Date of Patent: July 6, 2010
    Assignee: International Business Machines Corporation
    Inventors: Herbert L. Ho, Subramanian S. Iyer, Vidhya Ramachandran
  • Patent number: 7705386
    Abstract: A memory cell has an access transistor and a capacitor with an electrode disposed within a deep trench. STI oxide covers at least a portion of the electrode, and a liner covers a remaining portion of the electrode. The liner may be a layer of nitride over a layer of oxide. Some of the STI may cover a portion of the liner. In a memory array a pass wordline may be isolated from the electrode by the STI oxide and the liner.
    Type: Grant
    Filed: January 7, 2008
    Date of Patent: April 27, 2010
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Johnathan E. Faltermeier, Herbert L. Ho, Paul C. Parries
  • Patent number: 7691716
    Abstract: The present invention provides a “subcollector-less” silicon-on-insulator (SOI) bipolar junction transistor (BJT) that has no impurity-doped subcollector. Instead, the inventive vertical SOI BJT uses a back gate-induced, majority carrier accumulation layer as the subcollector when it operates. The SOI substrate is biased such that the accumulation layer is formed at the bottom of the first semiconductor layer. The advantage of such a device is its CMOS-like process. Therefore, the integration scheme can be simplified and the manufacturing cost can be significantly reduced. The present invention also provides a method of fabricating BJTs on selected areas of a very thin BOX using a conventional SOI starting wafer with a thick BOX. The reduced BOX thickness underneath the bipolar devices allows for a significantly reduced substrate bias compatible with the CMOS to be applied while maintaining the advantages of a thick BOX underneath the CMOS. A back-gated CMOS device is also provided.
    Type: Grant
    Filed: June 24, 2008
    Date of Patent: April 6, 2010
    Assignee: International Business Machines Corporation
    Inventors: Herbert L. Ho, Mahender Kumar, Qiging Ouyang, Paul A. Papworth, Christopher D. Sheraw, Michael D. Steigerwalt
  • Publication number: 20100038725
    Abstract: Ion implantation to change an effective work function for dual work function metal gate integration is presented. One method may include forming a high dielectric constant (high-k) layer over a first-type field effect transistor (FET) region and a second-type FET region; forming a metal layer having a first effective work function compatible for a first-type FET over the first-type FET region and the second-type FET region; and changing the first effective work function to a second, different effective work function over the second-type FET region by implanting a species into the metal layer over the second-type FET region.
    Type: Application
    Filed: August 12, 2008
    Publication date: February 18, 2010
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Michael P. Chudzik, Martin M. Frank, Herbert L. Ho, Mark J. Hurley, Rashmi Jha, Naim Moumen, Vijay Narayanan, Dae-Gyu Park, Vamsi K. Paruchuri
  • 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: 20090230508
    Abstract: An SOI layer has an initial trench extending therethrough, prior to deep trench etch. An oxidation step, such as thermal oxidation is performed to form a band of oxide on an inner periphery of the SOI layer to protect it during a subsequent RIE step for forming a deep trench. The initial trench may stop on BOX underlying the SOI. The band of oxide may also protect the SOI during buried plate implant or gas phase doping.
    Type: Application
    Filed: March 14, 2008
    Publication date: September 17, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Thomas W. Dyer, Herbert L. Ho, Ravi M. Todi
  • Publication number: 20090224308
    Abstract: A semiconductor memory device in which a vertical trench semiconductor-oxide-nitride-oxide-semiconductor (SONOS) memory cell is created in a semiconductor-on-insulator (SOI) substrate is provided that allows for the integration of dense non-volatile random access memory (NVRAM) cells in SOI-based complementary metal oxide semiconductor (CMOS) technology. The trench is processed using conventional trench processing and it is processed near the beginning of the inventive method that allows for the fabrication of the memory cell to be fully separated from SOI logic processing.
    Type: Application
    Filed: March 25, 2009
    Publication date: September 10, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: David M. Dobuzinsky, Herbert L. Ho, Jack A. Mandelman, Yoichi Otani
  • Patent number: 7575970
    Abstract: Methods of forming a deep trench capacitor through an SOI substrate, and a capacitor are disclosed. In one embodiment, a method includes forming a trench opening into the SOI substrate to the silicon substrate; depositing a sidewall spacer in the trench opening; etching to form the deep trench into the silicon substrate; forming a first electrode by implanting a dopant into the silicon substrate, whereby the sidewall spacer protects the BOX layer and the silicon layer; removing the sidewall spacer; depositing a node dielectric within the deep trench; and forming a second electrode by depositing a conductor in the deep trench. Implanting creates a substantially uniform depth doped region except at a portion adjacent to a lowermost portion of the deep trench, which may be substantially bulbous. The BOX layer is protected from undercutting by the sidewall spacer, and the implantation removes the need for out-diffusing dopant from silica glass.
    Type: Grant
    Filed: September 7, 2006
    Date of Patent: August 18, 2009
    Assignee: International Business Machines Corporation
    Inventors: Herbert L. Ho, Kangguo Cheng, Yoichi Otani, Kevin R. Winstel
  • Publication number: 20090184356
    Abstract: A deep trench is formed to a depth midway into a buried insulator layer of a semiconductor-on-insulator (SOI) substrate. A top semiconductor layer is laterally recessed by an isotropic etch that is selective to the buried insulator layer. The deep trench is then etched below a bottom surface of the buried insulator layer. Ion implantation is performed at an angle into the deep trench to dope the sidewalls of the deep trench beneath the buried insulator layer, while the laterally recessed sidewalls of the top semiconductor layer are not implanted with dopant ions. A node dielectric and trench fill materials are deposited into the deep trench. A buried strap has an upper buried strap sidewall that is offset from a lower buried strap sidewall and a deep trench sidewall.
    Type: Application
    Filed: January 18, 2008
    Publication date: July 23, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: MaryJane Brodsky, Kangguo Cheng, Herbert L. Ho, Paul C. Parries, Kevin R. Winstel
  • Publication number: 20090173980
    Abstract: A memory cell has an access transistor and a capacitor with an electrode disposed within a deep trench. STI oxide covers at least a portion of the electrode, and a liner covers a remaining portion of the electrode. The liner may be a layer of nitride over a layer of oxide. Some of the STI may cover a portion of the liner. In a memory array a pass wordline may be isolated from the electrode by the STI oxide and the liner.
    Type: Application
    Filed: January 7, 2008
    Publication date: July 9, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo Cheng, Johnathan E. Faltermeier, Herbert L. Ho, Paul C. Parries
  • Publication number: 20090159948
    Abstract: The present invention relates to a semiconductor device that contains a trench metal-insulator-metal (MIM) capacitor and a field effect transistor (FET), and a design structure including the semiconductor device embodied in a machine readable medium. The trench MIM capacitor comprises a first metallic electrode layer located over interior walls of a trench in a substrate, a dielectric layer located in the trench over the first metallic electrode layer, and a second metallic electrode layer located in the trench over the dielectric layer. The FET comprises a source region, a drain region, a channel region between the source and drain regions, and a gate electrode over the channel region. The trench MIM capacitor is connected to the FET by a metallic strap.
    Type: Application
    Filed: December 20, 2007
    Publication date: June 25, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Herbert L. Ho, Subramanian S. Iyer, Vidhya Ramachandran
  • 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: 20090158234
    Abstract: A semiconductor memory device and a design structure including the semiconductor memory device embodied in a machine readable medium is provided. In particular the present invention includes a semiconductor memory device in which a vertical trench semiconductor-oxide-nitride-oxide-semiconductor (SONOS) memory cell is created in a semiconductor-on-insulator (SOI) substrate is provided that allows for the integration of dense non-volatile random access memory (NVRAM) cells in SOI-based complementary metal oxide semiconductor (CMOS) technology. The trench is processed using conventional trench processing and it is processed near the beginning of the inventive method that allows for the fabrication of the memory cell to be fully separated from SOI logic processing.
    Type: Application
    Filed: December 13, 2007
    Publication date: June 18, 2009
    Applicant: INTERNATIONAL MACHINES BUSINESS CORPORATION
    Inventors: David M. Dobuzinsky, Herbert L. Ho, Jack A. Mandelman, Yoichi Otani