Patents by Inventor H. Zhang

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).

  • 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: 10828511
    Abstract: A method and apparatus is presented for optimizing a treatment plan for irradiation therapy. The method includes determining voxels in a reference frame of a radiation source that rotates at an angular rate of change and emits a beam at a plurality of angles. The beam has a beam intensity and a cross sectional shape based on an aperture of a collimator at each angle. The method includes determining an initial aperture value at each angle and minimizing a single objective function subject to a constraint on an aperture rate of change to determine an aperture and beam intensity at each angle. The method also includes delivering a beam of radiation with controlled intensity at each angle based on the beam intensity and aperture and turning the beam of radiation off at an intervening angle not included in the plurality of angles.
    Type: Grant
    Filed: August 3, 2017
    Date of Patent: November 10, 2020
    Assignee: UNIVERSITY OF MARYLAND, BALTIMORE
    Inventors: Hao H. Zhang, Gokhan Kirlik, Warren D. D'Souza, Byong Young Yi
  • 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: 10828510
    Abstract: A method and apparatus for irradiation therapy using voxel based function measurements of organs-at-risk (OAR). The method includes determining size and location of each voxel of a plurality of voxels in a reference frame of a radiation device. The method further includes obtaining measurements that relate to utility of tissue type at each voxel. The method further includes determining a subset of the voxels that enclose an organ-at-risk (OAR) volume. The method further includes determining a value of a utility measure fj at each voxel of the subset based on a corresponding value of the measurements. The method further includes determining a series of beam shapes and intensities which minimize a value of an objective function that is based on a computed dose delivered to an OAR voxel multiplied by the utility measure fj for that voxel summed over all voxels.
    Type: Grant
    Filed: March 8, 2018
    Date of Patent: November 10, 2020
    Assignee: University of Maryland, Baltimore
    Inventors: Hao H. Zhang, Warren D. D'Souza, Nilesh N. Mistry, Hamid R. Ghaffari
  • 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
  • Publication number: 20200295187
    Abstract: A tunneling transistor is implemented in silicon, using a FinFET device architecture. The tunneling FinFET has a non-planar, vertical, structure that extends out from the surface of a doped drain formed in a silicon substrate. The vertical structure includes a lightly doped fin defined by a subtractive etch process, and a heavily-doped source formed on top of the fin by epitaxial growth. The drain and channel have similar polarity, which is opposite that of the source. A gate abuts the channel region, capacitively controlling current flow through the channel from opposite sides. Source, drain, and gate terminals are all electrically accessible via front side contacts formed after completion of the device. Fabrication of the tunneling FinFET is compatible with conventional CMOS manufacturing processes, including replacement metal gate and self-aligned contact processes. Low-power operation allows the tunneling FinFET to provide a high current density compared with conventional planar devices.
    Type: Application
    Filed: May 28, 2020
    Publication date: September 17, 2020
    Inventors: Qing LIU, John H. ZHANG
  • Publication number: 20200279954
    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 19, 2020
    Publication date: September 3, 2020
    Inventor: John H. ZHANG
  • Patent number: 10741698
    Abstract: A semi-floating gate transistor is implemented as a vertical FET built on a silicon substrate, wherein the source, drain, and channel are vertically aligned, on top of one another. Current flow between the source and the drain is influenced by a control gate and a semi-floating gate. Front side contacts can be made to each one of the source, drain, and control gate terminals of the vertical semi-floating gate transistor. The vertical semi-floating gate FET further includes a vertical tunneling FET and a vertical diode. Fabrication of the vertical semi-floating gate FET is compatible with conventional CMOS manufacturing processes, including a replacement metal gate process. Low-power operation allows the vertical semi-floating gate FET to provide a high current density compared with conventional planar devices.
    Type: Grant
    Filed: March 15, 2019
    Date of Patent: August 11, 2020
    Assignee: STMICROELECTRONICS, INC.
    Inventors: Qing Liu, John H. Zhang
  • Patent number: 10734289
    Abstract: A semiconductor device is formed to include a fin structure, a first trench at a first lateral end of the fin, a second trench at a second lateral end of the fin, and a filler filled on a first traverse side of the fin and a second traverse side of the fin. The filler is contained between the first trench and the second trench, and oxidized in-place to cause a stress to be exerted on the first and second traverse sides of the fin, the stress causing the fin to exhibit a tensile strain in a lateral running direction of the fin.
    Type: Grant
    Filed: August 13, 2019
    Date of Patent: August 4, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Kangguo Cheng, Junli Wang, Lawrence A. Clevenger, Carl Radens, John H. Zhang
  • Patent number: 10700194
    Abstract: A tunneling transistor is implemented in silicon, using a FinFET device architecture. The tunneling FinFET has a non-planar, vertical, structure that extends out from the surface of a doped drain formed in a silicon substrate. The vertical structure includes a lightly doped fin defined by a subtractive etch process, and a heavily-doped source formed on top of the fin by epitaxial growth. The drain and channel have similar polarity, which is opposite that of the source. A gate abuts the channel region, capacitively controlling current flow through the channel from opposite sides. Source, drain, and gate terminals are all electrically accessible via front side contacts formed after completion of the device. Fabrication of the tunneling FinFET is compatible with conventional CMOS manufacturing processes, including replacement metal gate and self-aligned contact processes. Low-power operation allows the tunneling FinFET to provide a high current density compared with conventional planar devices.
    Type: Grant
    Filed: July 3, 2018
    Date of Patent: June 30, 2020
    Assignee: STMICROELECTRONICS, INC.
    Inventors: Qing Liu, John H. Zhang
  • Patent number: 10700214
    Abstract: Processes and overturned thin film device structures generally include a gate having a concave shape defined by three faces. The processes generally include forming the overturned thin film device structures such that the channel self-aligns to the gate and the source/drain contacts include a self-aligned step height.
    Type: Grant
    Filed: April 5, 2018
    Date of Patent: June 30, 2020
    Assignees: INTERNATIONAL BUSINESS MACHINES CORPORATION, STMICROELECTRONICS, INC.
    Inventors: Lawrence A. Clevenger, Carl J. Radens, Yiheng Xu, John H. Zhang