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).
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Publication number: 20210391356Abstract: 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: ApplicationFiled: January 26, 2021Publication date: December 16, 2021Inventor: John H. ZHANG
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Publication number: 20210343829Abstract: 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: ApplicationFiled: July 12, 2021Publication date: November 4, 2021Applicant: STMICROELECTRONICS, INC.Inventor: John H. ZHANG
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Patent number: 11152307Abstract: 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: GrantFiled: December 18, 2018Date of Patent: October 19, 2021Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Kangguo Cheng, Lawrence A. Clevenger, Carl Radens, Junli Wang, John H. Zhang
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Publication number: 20210273116Abstract: 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: ApplicationFiled: May 17, 2021Publication date: September 2, 2021Applicant: STMICROELECTRONICS, INC.Inventor: John H. ZHANG
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Patent number: 11063112Abstract: 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: GrantFiled: October 18, 2018Date of Patent: July 13, 2021Assignee: STMicroelectronics, Inc.Inventor: John H. Zhang
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Publication number: 20210202313Abstract: 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: ApplicationFiled: February 22, 2021Publication date: July 1, 2021Inventors: Lawrence A. Clevenger, Carl J. Radens, John H. Zhang
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Patent number: 11031504Abstract: 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: GrantFiled: May 19, 2020Date of Patent: June 8, 2021Assignee: STMICROELECTRONICS, INC.Inventor: John H. Zhang
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Patent number: 10985063Abstract: 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: GrantFiled: August 16, 2019Date of Patent: April 20, 2021Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Kangguo Cheng, Lawrence A. Clevenger, Carl Radens, Junli Wang, John H. Zhang
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Publication number: 20210098593Abstract: 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: ApplicationFiled: December 11, 2020Publication date: April 1, 2021Inventor: John H. ZHANG
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Patent number: 10964551Abstract: 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: GrantFiled: March 30, 2016Date of Patent: March 30, 2021Assignee: STMICROELECTRONICS, INC.Inventor: John H. Zhang
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Patent number: 10950722Abstract: 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: GrantFiled: December 31, 2014Date of Patent: March 16, 2021Assignees: STMICROELECTRONICS, INC., INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: John H. Zhang, Carl Radens, Lawrence A. Clevenger, Yiheng Xu
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Patent number: 10943837Abstract: 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: GrantFiled: April 30, 2019Date of Patent: March 9, 2021Assignee: STMICROELECTRONICS, INC.Inventors: Qing Liu, John H. Zhang
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Patent number: 10937811Abstract: 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: GrantFiled: May 14, 2019Date of Patent: March 2, 2021Assignee: STMICROELECTRONICS, INC.Inventor: John H. Zhang
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Patent number: 10930553Abstract: 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: GrantFiled: January 25, 2019Date of Patent: February 23, 2021Assignee: Tessera, Inc.Inventors: Lawrence A. Clevenger, Carl J. Radens, John H. Zhang
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Patent number: 10910385Abstract: 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: GrantFiled: July 12, 2019Date of Patent: February 2, 2021Assignee: STMICROELECTRONICS, INC.Inventor: John H. Zhang
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Patent number: 10892344Abstract: 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: GrantFiled: May 16, 2018Date of Patent: January 12, 2021Assignee: STMICROELECTRONICS, INC.Inventor: John H. Zhang
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Patent number: 10861984Abstract: 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: GrantFiled: September 9, 2019Date of Patent: December 8, 2020Assignee: STMicroelectronics, Inc.Inventors: Qing Liu, John H. Zhang
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Publication number: 20200373416Abstract: 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: ApplicationFiled: August 7, 2020Publication date: November 26, 2020Inventor: John H. ZHANG
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Patent number: 10833204Abstract: 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: GrantFiled: October 3, 2019Date of Patent: November 10, 2020Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Kangguo Cheng, Lawrence A. Clevenger, Carl Radens, Junli Wang, John H. Zhang
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Patent number: 10816729Abstract: 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: GrantFiled: March 4, 2019Date of Patent: October 27, 2020Assignee: STMICROELECTRONICS, INC.Inventor: John H. Zhang