Patents by Inventor Zhiyuan Fang

Zhiyuan Fang 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: 20190323109
    Abstract: The present invention provides a high strength, high toughness, heat-cracking resistant bainite steel wheel for rail transportation and a manufacturing method thereof. Components are: carbon 0.10-0.40%, silicon 1.00-2.00%, manganese 1.00-2.50%, copper 0.20-1.00%, boron 0.0001-0.035%, nickel 0.10-1.00%, phosphorus?0.020%, and sulphur?0.020%, where the remaining is iron and unavoidable residual elements, 1.50%?Si+Ni?3.00%, and 1.50%?Mn+Ni+Cu?3.00%. Compared with the prior art, in the present invention, by using design of the chemical compositions of steel and wheel manufacturing processes, especially a heat treatment process and technology, a rim of the wheel obtains a carbide-free bainite structure, and a web and a wheel hub obtain a metallographic structure based on granular bainite and a supersaturated ferritic structure.
    Type: Application
    Filed: July 6, 2017
    Publication date: October 24, 2019
    Inventors: Mingru Zhang, Zheng Fang, Feng Zhang, Chaohai Yin, Yumei Pu, Zhiyuan Cheng, Hai Zhao
  • Patent number: 9240320
    Abstract: Provided are plasma enhanced chemical vapor deposition methods of depositing smooth and conformal ashable hard mask films on substrates containing raised or recessed features. The methods involve using precursors having relatively high C:H ratios, such as acetylene (C:H ratio of 1), and plasmas having low ion energies and fluxes. According to various embodiments, the methods involve depositing smooth ashable hard mask films using high frequency radio frequency-generated plasmas with no low frequency component and/or relatively high pressures. Also provided are methods of depositing ashable hard mask films having good selectivity and improved side wall coverage and roughness. The methods involve depositing a first ashable hard mask film on a substrate having a feature using a process optimized for selectivity and/or optical properties and then depositing a smoothing layer on the first ashable hard mask film using an HF-only process.
    Type: Grant
    Filed: April 3, 2013
    Date of Patent: January 19, 2016
    Assignee: Novellus Systems, Inc.
    Inventors: Pramod Subramonium, Zhiyuan Fang, Shawn Hancock, Mike Pierce, Jon Henri
  • Patent number: 8669181
    Abstract: Films having high hermeticity and a low dielectric constant can be used as copper diffusion barrier films, etch stop films, CMP stop films and other hardmasks during IC fabrication. Hermetic films can protect the underlying layers, such as layers of metal and dielectric, from exposure to atmospheric moisture and oxygen, thereby preventing undesirable oxidation of metal surfaces and absorption of moisture by a dielectric. Specifically, a bi-layer film having a hermetic bottom layer composed of hydrogen doped carbon and a low dielectric constant (low-k) top layer composed of low-k silicon carbide (e.g., high carbon content hydrogen doped silicon carbide) can be employed. Such bi-layer film can be deposited by PECVD methods on a partially fabricated semiconductor substrate having exposed layers of dielectric and metal.
    Type: Grant
    Filed: February 22, 2011
    Date of Patent: March 11, 2014
    Assignee: Novellus Systems, Inc.
    Inventors: Yongsik Yu, Pramod Subramonium, Zhiyuan Fang, Jon Henri, Elizabeth Apen, Dan Vitkavage
  • Publication number: 20140053867
    Abstract: Improved methods and apparatuses for removing residue from the interior surfaces of the deposition reactor are provided. The methods involve increasing availability of cleaning reagent radicals inside the deposition chamber by generating cleaning reagent radicals in a remote plasma generator and then further delivering in-situ plasma energy while the cleaning reagent mixture is introduced into the deposition chamber. Certain embodiments involve a multi-stage process including a stage in which the cleaning reagent mixture is introduced at a high pressure (e.g., about 0.6 Torr or more) and a stage the cleaning reagent mixture is introduced at a low pressure (e.g., about 0.6 Torr or less).
    Type: Application
    Filed: October 30, 2013
    Publication date: February 27, 2014
    Applicant: Novellus Systems, Inc.
    Inventors: Zhiyuan Fang, Pramod Subramonium, Jon Henri, Keith Fox
  • Patent number: 8591659
    Abstract: Improved methods and apparatuses for removing residue from the interior surfaces of the deposition reactor are provided. The methods involve increasing availability of cleaning reagent radicals inside the deposition chamber by generating cleaning reagent radicals in a remote plasma generator and then further delivering in-situ plasma energy while the cleaning reagent mixture is introduced into the deposition chamber. Certain embodiments involve a multi-stage process including a stage in which the cleaning reagent mixture is introduced at a high pressure (e.g., about 0.6 Torr or more) and a stage the cleaning reagent mixture is introduced at a low pressure (e.g., about 0.6 Torr or less).
    Type: Grant
    Filed: January 16, 2009
    Date of Patent: November 26, 2013
    Assignee: Novellus Systems, Inc.
    Inventors: Zhiyuan Fang, Pramod Subramonium, Jon Henri, Keith Fox
  • Patent number: 8435608
    Abstract: Provided are plasma enhanced chemical vapor deposition methods of depositing smooth and conformal ashable hard mask films on substrates containing raised or recessed features. The methods involve using precursors having relatively high C:H ratios, such as acetylene (C:H ratio of 1), and plasmas having low ion energies and fluxes. According to various embodiments, the methods involve depositing smooth ashable hard mask films using high frequency radio frequency-generated plasmas with no low frequency component and/or relatively high pressures (e.g., 2-5 Torr). Also provided are methods of depositing ashable hard mask films having good selectivity and improved side wall coverage and roughness. The methods involve depositing a first ashable hard mask film on a substrate having a feature using a process optimized for selectivity and/or optical properties and then depositing a smoothing layer on the first ashable hard mask film using an HF-only process.
    Type: Grant
    Filed: June 27, 2008
    Date of Patent: May 7, 2013
    Assignee: Novellus Systems, Inc.
    Inventors: Pramod Subramonium, Zhiyuan Fang, Shawn Hancock, Mike Pierce, Jon Henri
  • Patent number: 8110493
    Abstract: A method for forming a PECVD deposited amorphous carbon or ashable hard mask (AHM) in a trench or a via with less than 30% H content at a process temperature below 500° C., e.g., about 400° C. produces low H content hard masks with high selectivity and little or no hard mask on the sidewalls. The deposition method utilizes a pulsed precursor delivery with a plasma etch while the precursor flow is off.
    Type: Grant
    Filed: March 14, 2008
    Date of Patent: February 7, 2012
    Assignee: Novellus Systems, Inc.
    Inventors: Pramod Subramonium, Zhiyuan Fang, Jon Henri
  • Patent number: 7981777
    Abstract: The present invention provides PECVD methods for forming stable and hermetic ashable hard masks (AHMs). The methods involve depositing AHMs using dilute hydrocarbon precursor gas flows and/or high LFRF/HFRF ratios. In certain embodiments, the AHMs are transparent and have high etch selectivities. Single and dual layer hermetic AHM stacks are also provided. According to various embodiments, the dual layer stack includes an underlying AHM layer having tunable optical properties and a hermetic cap layer.
    Type: Grant
    Filed: February 22, 2007
    Date of Patent: July 19, 2011
    Assignee: Novellus Systems, Inc.
    Inventors: Pramod Subramonium, Yongsik Yu, Zhiyuan Fang, Jon Henri
  • Patent number: 7981810
    Abstract: The present invention addresses this need by providing a method for forming transparent PECVD deposited ashable hardmasks (AHMs) that have high plasma etch selectivity to underlying layers. Methods of the invention involve depositing the AHM using dilute hydrocarbon precursor gas flows and/or low process temperatures. The AHMs produced are transparent (having absorption coefficients of less than 0.1 in certain embodiments). The AHMs also have the property of high selectivity of the hard mask film to the underlying layers for successful integration of the film, and are suitable for use with 193 nm generation and below lithography schemes wherein high selectivity of the hard mask to the underlying layers is required. The lower temperature process also allows reduction of the overall thermal budget for a wafer.
    Type: Grant
    Filed: June 8, 2006
    Date of Patent: July 19, 2011
    Assignee: Novellus Systems, Inc.
    Inventors: Pramod Subramonium, Zhiyuan Fang, Jon Henri
  • Patent number: 7915166
    Abstract: Films having high hermeticity and a low dielectric constant can be used as copper diffusion barrier films, etch stop films, CMP stop films and other hardmasks during IC fabrication. Hermetic films can protect the underlying layers, such as layers of metal and dielectric, from exposure to atmospheric moisture and oxygen, thereby preventing undesirable oxidation of metal surfaces and absorption of moisture by a dielectric. Specifically, a bi-layer film having a hermetic bottom layer composed of hydrogen doped carbon and a low dielectric constant (low-k) top layer composed of low-k silicon carbide (e.g., high carbon content hydrogen doped silicon carbide) can be employed. Such bi-layer film can be deposited by PECVD methods on a partially fabricated semiconductor substrate having exposed layers of dielectric and metal.
    Type: Grant
    Filed: February 22, 2007
    Date of Patent: March 29, 2011
    Assignee: Novellus Systems, Inc.
    Inventors: Yongsik Yu, Pramod Subramonium, Zhiyuan Fang, Jon Henri, Elizabeth Apen, Dan Vitkavage
  • Patent number: 7381644
    Abstract: A method for forming a PECVD deposited ashable hardmask (AHM) with less than 30% H content at a process temperature below 500° C., e.g., about 400° C. produces low H content hard masks having the property of high selectivity of the hard mask film to the underlying layers for successful integration of the film, and are suitable for use with 193 nm generation and below lithography schemes wherein high selectivity of the hard mask to the underlying layers is required. The low temperature, low H films are produced by use of a pulsed film hydrocarbon precursor plasma treatment that reduces the amount of hydrogen incorporated in the film and therefore drives down the etch rate of the hard mask thus increasing the selectivity. The lower temperature process also allows reduction of the overall thermal budget for a wafer.
    Type: Grant
    Filed: December 23, 2005
    Date of Patent: June 3, 2008
    Assignee: Novellus Systems, Inc.
    Inventors: Pramod Subramonium, Zhiyuan Fang, Jon Henri
  • Publication number: 20040091717
    Abstract: Nitrogen-free reactant gas containing silicon, oxygen, and fluorine atoms is flowed to a nitrogen-free CVD reaction chamber. Preferably, SiH4 gas, SiF4 gas, and CO2 are flowed to the reaction chamber. Radio-frequency power is applied to form a plasma. Preferably, the reaction chamber is part of a dual-frequency PECVD or HPD-CVD apparatus. Reactive components formed in the plasma react to form low-dielectric-constant nitrogen-free fluorine-doped silicate glass (FSG) on a substrate surface.
    Type: Application
    Filed: November 13, 2002
    Publication date: May 13, 2004
    Applicant: Novellus Systems, Inc.
    Inventors: Ming Li, Yang Zhuang, Jason L. Tian, Zhiyuan Fang