Patents by Inventor John H. Zhang

John H. Zhang 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).

  • Publication number: 20210343829
    Abstract: An interconnect structure for use in coupling transistors in an integrated circuit is disclosed, including various configurations in which ferroelectric capacitors exhibiting negative capacitance are coupled in series with dielectric capacitors. In one embodiment, the negative capacitor includes a dielectric/ferroelectric bi-layer. When a negative capacitor is electrically coupled in series with a conventional dielectric capacitor, the series combination behaves like a stable ferroelectric capacitor for which the overall capacitance can be measured experimentally, and tuned to a desired value. The composite capacitance of a dielectric capacitor and a ferroelectric capacitor having negative capacitance coupled in series is, in theory, infinite, and in practice, very large. A series combination of positive and negative capacitors within a microelectronic interconnect structure can be used to make high capacity DRAM memory cells.
    Type: Application
    Filed: July 12, 2021
    Publication date: November 4, 2021
    Applicant: STMICROELECTRONICS, INC.
    Inventor: John H. ZHANG
  • Patent number: 11152307
    Abstract: A semiconductor structure includes a plurality of field effect transistors formed on a substrate including p-type doped field effect transistors (pFETs) and n-type doped field effect transistors (nFETs). A self-aligned buried local interconnect electrically connects a bottom source or drain region of the pFET with an adjacent bottom source or drain region of the nFET. The self-aligned buried local interconnect is serially aligned with and intermediate opposing ends of a gate electrode. Other embodiments include methods for forming the buried local interconnect.
    Type: Grant
    Filed: December 18, 2018
    Date of Patent: October 19, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo Cheng, Lawrence A. Clevenger, Carl Radens, Junli Wang, John H. Zhang
  • Publication number: 20210273116
    Abstract: A vacuum channel transistor having a vertical gate-all-around (GAA) architecture provides high performance for high-frequency applications, and features a small footprint compared with existing planar devices. The GAA vacuum channel transistor features stacked, tapered source and drain regions that are formed by notching a doped silicon pillar using a lateral oxidation process. A temporary support structure is provided for the pillar during formation of the vacuum channel. Performance of the GAA vacuum channel transistor can be tuned by replacing air in the channel with other gases such as helium, neon, or argon. A threshold voltage of the GAA vacuum channel transistor can be adjusted by altering dopant concentrations of the silicon pillar from which the source and drain regions are formed.
    Type: Application
    Filed: May 17, 2021
    Publication date: September 2, 2021
    Applicant: STMICROELECTRONICS, INC.
    Inventor: John H. ZHANG
  • Patent number: 11063112
    Abstract: An interconnect structure for use in coupling transistors in an integrated circuit is disclosed, including various configurations in which ferroelectric capacitors exhibiting negative capacitance are coupled in series with dielectric capacitors. In one embodiment, the negative capacitor includes a dielectric/ferroelectric bi-layer. When a negative capacitor is electrically coupled in series with a conventional dielectric capacitor, the series combination behaves like a stable ferroelectric capacitor for which the overall capacitance can be measured experimentally, and tuned to a desired value. The composite capacitance of a dielectric capacitor and a ferroelectric capacitor having negative capacitance coupled in series is, in theory, infinite, and in practice, very large. A series combination of positive and negative capacitors within a microelectronic interconnect structure can be used to make high capacity DRAM memory cells.
    Type: Grant
    Filed: October 18, 2018
    Date of Patent: July 13, 2021
    Assignee: STMicroelectronics, Inc.
    Inventor: John H. Zhang
  • Publication number: 20210202313
    Abstract: A semiconductor device includes a first trench on a mandrel line through a top mask layer and stopping at a middle mask layer; and a second trench on a non-mandrel line through the top mask layer and stopping at the middle mask layer. A spacer material is removed from a structure resulting from etching the first trench and the second trench. The device includes a first via structure, formed using a removable material, in the first trench; a second via structure, formed using a removable material, in the second trench; an air-gap formed in a third trench created at a location of the spacer; a fourth trench formed by etching, to remove the first via structure and a first portion of a bottom mask layer under the first via structure; and a self-aligned line-end via on the mandrel line formed by filling the fourth trench with a conductive metal.
    Type: Application
    Filed: February 22, 2021
    Publication date: July 1, 2021
    Inventors: Lawrence A. Clevenger, Carl J. Radens, John H. Zhang
  • Patent number: 11031504
    Abstract: A vacuum channel transistor having a vertical gate-all-around (GAA) architecture provides high performance for high-frequency applications, and features a small footprint compared with existing planar devices. The GAA vacuum channel transistor features stacked, tapered source and drain regions that are formed by notching a doped silicon pillar using a lateral oxidation process. A temporary support structure is provided for the pillar during formation of the vacuum channel. Performance of the GAA vacuum channel transistor can be tuned by replacing air in the channel with other gases such as helium, neon, or argon. A threshold voltage of the GAA vacuum channel transistor can be adjusted by altering dopant concentrations of the silicon pillar from which the source and drain regions are formed.
    Type: Grant
    Filed: May 19, 2020
    Date of Patent: June 8, 2021
    Assignee: STMICROELECTRONICS, INC.
    Inventor: John H. Zhang
  • Patent number: 10985063
    Abstract: A first TS is coupled to first S/D over first fin, second TS coupled to second S/D over first fin, third TS coupled to third S/D over second fin, fourth TS coupled to fourth S/D over second fin, gate metal over first and second fins, and gate cap over gate metal. First TS cap is on first TS, second TS cap on second TS, third TS cap on third TS, and fourth TS cap on fourth TS. ILD is formed on top of gate cap and first through fourth TS caps. First opening is through ILD and second TS cap such that part of gate metal is exposed, after removing part of gate cap. Second opening is through ILD to expose another part of gate metal. Combined gate metal contact and local metal connection is formed in first opening and individual gate metal contact is formed in second opening.
    Type: Grant
    Filed: August 16, 2019
    Date of Patent: April 20, 2021
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo Cheng, Lawrence A. Clevenger, Carl Radens, Junli Wang, John H. Zhang
  • Publication number: 20210098593
    Abstract: Energy bands of a thin film containing molecular clusters are tuned by controlling the size and the charge of the clusters during thin film deposition. Using atomic layer deposition, an ionic cluster film is formed in the gate region of a nanometer-scale transistor to adjust the threshold voltage, and a neutral cluster film is formed in the source and drain regions to adjust contact resistance. A work function semiconductor material such as a silver bromide or a lanthanum oxide is deposited so as to include clusters of different sizes such as dimers, trimers, and tetramers, formed from isolated monomers. A type of Atomic Layer Deposition system is used to deposit on semiconductor wafers molecular clusters to form thin film junctions having selected energy gaps. A beam of ions contains different ionic clusters which are then selected for deposition by passing the beam through a filter in which different apertures select clusters based on size and orientation.
    Type: Application
    Filed: December 11, 2020
    Publication date: April 1, 2021
    Inventor: John H. ZHANG
  • Patent number: 10964551
    Abstract: CMP selectivity, removal rate, and uniformity are controlled both locally and globally by altering electric charge at the wafer surface. Surface charge characterization is performed by an on-board metrology module. Based on a charge profile map, the wafer can be treated in an immersion bath to impart a more positive or negative charge overall, or to neutralize the entire wafer before the CMP operation is performed. If charge hot spots are detected on the wafer, a charge pencil can be used to neutralize localized areas. One type of charge pencil bears a tapered porous polymer tip that is placed in close proximity to the wafer surface. Films present on the wafer absorb ions from, or surrender ions to, the charge pencil tip, by electrostatic forces. The charge pencil can be incorporated into a CMP system to provide an in-situ treatment prior to the planarization step or the slurry removal step.
    Type: Grant
    Filed: March 30, 2016
    Date of Patent: March 30, 2021
    Assignee: STMICROELECTRONICS, INC.
    Inventor: John H. Zhang
  • Patent number: 10950722
    Abstract: Vertical GAA FET structures are disclosed in which a current-carrying nanowire is oriented substantially perpendicular to the surface of a silicon substrate. The vertical GAA FET is intended to meet design and performance criteria for the 7 nm technology generation. In some embodiments, electrical contacts to the drain and gate terminals of the vertically oriented GAA FET can be made via the backside of the substrate. Examples are disclosed in which various n-type and p-type transistor designs have different contact configurations. In one example, a backside gate contact extends through the isolation region between adjacent devices. Other embodiments feature dual gate contacts for circuit design flexibility. The different contact configurations can be used to adjust metal pattern density.
    Type: Grant
    Filed: December 31, 2014
    Date of Patent: March 16, 2021
    Assignees: STMICROELECTRONICS, INC., INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: John H. Zhang, Carl Radens, Lawrence A. Clevenger, Yiheng Xu
  • Patent number: 10943837
    Abstract: An analog integrated circuit is disclosed in which short channel transistors are stacked on top of long channel transistors, vertically separated by an insulating layer. With such a design, it is possible to produce a high density, high power, and high performance analog integrated circuit chip including both short and long channel devices that are spaced far enough apart from one another to avoid crosstalk. In one embodiment, the transistors are FinFETs and the long channel devices are multi-gate FinFETs. In one embodiment, single and dual damascene devices are combined in a multi-layer integrated circuit cell. The cell may contain various combinations and configurations of the short and long-channel devices. A high density cell can be made by simply shrinking the dimensions of the cells and replicating two or more cells in the same size footprint as the original cell.
    Type: Grant
    Filed: April 30, 2019
    Date of Patent: March 9, 2021
    Assignee: STMICROELECTRONICS, INC.
    Inventors: Qing Liu, John H. Zhang
  • Patent number: 10937811
    Abstract: Single gate and dual gate FinFET devices suitable for use in an SRAM memory array have respective fins, source regions, and drain regions that are formed from portions of a single, contiguous layer on the semiconductor substrate, so that STI is unnecessary. Pairs of FinFETs can be configured as dependent-gate devices wherein adjacent channels are controlled by a common gate, or as independent-gate devices wherein one channel is controlled by two gates. Metal interconnects coupling a plurality of the FinFET devices are made of a same material as the gate electrodes. Such structural and material commonalities help to reduce costs of manufacturing high-density memory arrays.
    Type: Grant
    Filed: May 14, 2019
    Date of Patent: March 2, 2021
    Assignee: STMICROELECTRONICS, INC.
    Inventor: John H. Zhang
  • Patent number: 10930553
    Abstract: A semiconductor device includes a first trench on a mandrel line through a top mask layer and stopping at a middle mask layer; and a second trench on a non-mandrel line through the top mask layer and stopping at the middle mask layer. A spacer material is removed from a structure resulting from etching the first trench and the second trench. The device includes a first via structure, formed using a removable material, in the first trench; a second via structure, formed using a removable material, in the second trench; an air-gap formed in a third trench created at a location of the spacer; a fourth trench formed by etching, to remove the first via structure and a first portion of a bottom mask layer under the first via structure; and a self-aligned line-end via on the mandrel line formed by filling the fourth trench with a conductive metal.
    Type: Grant
    Filed: January 25, 2019
    Date of Patent: February 23, 2021
    Assignee: Tessera, Inc.
    Inventors: Lawrence A. Clevenger, Carl J. Radens, John H. Zhang
  • Patent number: 10910385
    Abstract: A vertical tunneling FET (TFET) provides low-power, high-speed switching performance for transistors having critical dimensions below 7 nm. The vertical TFET uses a gate-all-around (GAA) device architecture having a cylindrical structure that extends above the surface of a doped well formed in a silicon substrate. The cylindrical structure includes a lower drain region, a channel, and an upper source region, which are grown epitaxially from the doped well. The channel is made of intrinsic silicon, while the source and drain regions are doped in-situ. An annular gate surrounds the channel, capacitively controlling current flow through the channel from all sides. The source is electrically accessible via a front side contact, while the drain is accessed via a backside contact that provides low contact resistance and also serves as a heat sink. Reliability of vertical TFET integrated circuits is enhanced by coupling the vertical TFETs to electrostatic discharge (ESD) diodes.
    Type: Grant
    Filed: July 12, 2019
    Date of Patent: February 2, 2021
    Assignee: STMICROELECTRONICS, INC.
    Inventor: John H. Zhang
  • Patent number: 10892344
    Abstract: Energy bands of a thin film containing molecular clusters are tuned by controlling the size and the charge of the clusters during thin film deposition. Using atomic layer deposition, an ionic cluster film is formed in the gate region of a nanometer-scale transistor to adjust the threshold voltage, and a neutral cluster film is formed in the source and drain regions to adjust contact resistance. A work function semiconductor material such as a silver bromide or a lanthanum oxide is deposited so as to include clusters of different sizes such as dimers, trimers, and tetramers, formed from isolated monomers. A type of Atomic Layer Deposition system is used to deposit on semiconductor wafers molecular clusters to form thin film junctions having selected energy gaps. A beam of ions contains different ionic clusters which are then selected for deposition by passing the beam through a filter in which different apertures select clusters based on size and orientation.
    Type: Grant
    Filed: May 16, 2018
    Date of Patent: January 12, 2021
    Assignee: STMICROELECTRONICS, INC.
    Inventor: John H. Zhang
  • Patent number: 10861984
    Abstract: An integrated transistor in the form of a nanoscale electromechanical switch eliminates CMOS current leakage and increases switching speed. The nanoscale electromechanical switch features a semiconducting cantilever that extends from a portion of the substrate into a cavity. The cantilever flexes in response to a voltage applied to the transistor gate thus forming a conducting channel underneath the gate. When the device is off, the cantilever returns to its resting position. Such motion of the cantilever breaks the circuit, restoring a void underneath the gate that blocks current flow, thus solving the problem of leakage. Fabrication of the nano-electromechanical switch is compatible with existing CMOS transistor fabrication processes. By doping the cantilever and using a back bias and a metallic cantilever tip, sensitivity of the switch can be further improved. A footprint of the nano-electromechanical switch can be as small as 0.1×0.1 ?m2.
    Type: Grant
    Filed: September 9, 2019
    Date of Patent: December 8, 2020
    Assignee: STMicroelectronics, Inc.
    Inventors: Qing Liu, John H. Zhang
  • Publication number: 20200373416
    Abstract: Stress is introduced into the channel of an SOI FinFET device by transfer directly from a metal gate. In SOI devices in particular, stress transfer efficiency from the metal gate to the channel is nearly 100%. Either tensile or compressive stress can be applied to the fin channel by choosing different materials to be used in the gate stack as the bulk gate material, a gate liner, or a work function material, or by varying processing parameters during deposition of the gate or work function materials. P-gates and N-gates are therefore formed separately. Gate materials suitable for use as stressors include tungsten (W) for NFETs and titanium nitride (TiN) for PFETs. An optical planarization material assists in patterning the stress-inducing metal gates. A simplified process flow is disclosed in which isolation regions are formed without need for a separate mask layer, and gate sidewall spacers are not used.
    Type: Application
    Filed: August 7, 2020
    Publication date: November 26, 2020
    Inventor: John H. ZHANG
  • Patent number: 10833204
    Abstract: A technique relates to a semiconductor device. A first stack includes a first plurality of nanowires respectively coupled to first source and drain regions, and a second stack includes a second plurality of nanowires respectively coupled to second source and drain regions. First source and drain contacts couple to a first predefined number of the first plurality of nanowires. Second source and drain contacts to couple to a second predefined number of the second plurality of nanowires, wherein the first predefined number is different from the second predefined number.
    Type: Grant
    Filed: October 3, 2019
    Date of Patent: November 10, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo Cheng, Lawrence A. Clevenger, Carl Radens, Junli Wang, John H. Zhang
  • Patent number: 10816729
    Abstract: A sequence of processing steps presented herein is used to embed an optical signal path within an array of nanowires, using only one lithography step. Using the techniques disclosed, it is not necessary to mask electrical features while forming optical features, and vice versa. Instead, optical and electrical signal paths can be created substantially simultaneously in the same masking cycle. This is made possible by a disparity in the widths of the respective features, the optical signal paths being significantly wider than the electrical ones. Using a damascene process, the structures of disparate widths are plated with metal that over-fills narrow trenches and under-fills a wide trench. An optical cladding material can then be deposited into the trench so as to surround an optical core for light transmission.
    Type: Grant
    Filed: March 4, 2019
    Date of Patent: October 27, 2020
    Assignee: STMICROELECTRONICS, INC.
    Inventor: John H. Zhang
  • Patent number: 10804377
    Abstract: Stress is introduced into the channel of an SOI FinFET device by transfer directly from a metal gate. In SOI devices in particular, stress transfer efficiency from the metal gate to the channel is nearly 100%. Either tensile or compressive stress can be applied to the fin channel by choosing different materials to be used in the gate stack as the bulk gate material, a gate liner, or a work function material, or by varying processing parameters during deposition of the gate or work function materials. P-gates and N-gates are therefore formed separately. Gate materials suitable for use as stressors include tungsten (W) for NFETs and titanium nitride (TiN) for PFETs. An optical planarization material assists in patterning the stress-inducing metal gates. A simplified process flow is disclosed in which isolation regions are formed without need for a separate mask layer, and gate sidewall spacers are not used.
    Type: Grant
    Filed: March 13, 2018
    Date of Patent: October 13, 2020
    Assignee: STMICROELECTRONICS, INC.
    Inventor: John H. Zhang