Patents by Inventor Steven T. Harshfield

Steven T. Harshfield 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: 20020190289
    Abstract: An inverted PCRAM cell is formed by plating the bottom electrode, made of copper for example, with a conductive material, such as silver. Chalcogenide material is disposed over the plated electrode and subjected to a conversion process so that ions from the plated material diffuse into the chalcogenide material.
    Type: Application
    Filed: July 25, 2002
    Publication date: December 19, 2002
    Inventors: Steven T. Harshfield, David Q. Wright
  • Publication number: 20020179896
    Abstract: A method and an apparatus for manufacturing a memory cell having a non-volatile resistive memory element with a limited size active area. The method comprises a first step of providing a dielectric volume and forming a plug opening within the dielectric volume. A recessed plug of a conductive material is then formed within a lower portion of the opening and a dielectric spacer is formed along the sidewalls of an upper portion of the opening. The spacer is cylindrical and has a central hole. A contact plug is subsequently formed within the central hole, the contact plug electrically coupled to the recessed plug. The contact plug can include a memory element or an additional memory element can be applied over the contact plug.
    Type: Application
    Filed: May 30, 2002
    Publication date: December 5, 2002
    Inventor: Steven T. Harshfield
  • Publication number: 20020179956
    Abstract: Methods are provided for selective formation of oxidation-resistant caps for conductive plugs in semiconductor device fabrication. One embodiment of the present invention forms a sacrificial layer over a recessed polysilicon plug. The sacrificial layer is readily planarized using chemical mechanical planarization to isolate the cap within a recessed via. Then, an immersion plating process is used to replace the atoms of the sacrificial layer with atoms of a desired metal, such as platinum, thereby creating a metal cap isolated within the via. The advantages of planarization to isolate material within recessed via are thus obtained without having to planarize or otherwise etch the desired metal. The cap layer can be further reacted to form a barrier compound prior to forming a capacitor over the plug. Advantageously, the plug structure resists oxidation during fabrication of overlying capacitors that incorporate high dielectric constant materials.
    Type: Application
    Filed: August 5, 2002
    Publication date: December 5, 2002
    Inventors: Allen McTeer, Steven T. Harshfield
  • Publication number: 20020168852
    Abstract: An inverted PCRAM cell is formed by plating the bottom electrode, made of copper for example, with a conductive material, such as silver. Chalcogenide material is disposed over the plated electrode and subjected to a conversion process so that ions from the plated material diffuse into the chalcogenide material.
    Type: Application
    Filed: May 11, 2001
    Publication date: November 14, 2002
    Inventors: Steven T. Harshfield, David Q. Wright
  • Publication number: 20020160551
    Abstract: Annular, linear, and point contact structures are described which exhibit a greatly reduced susceptibility to process deviations caused by lithographic and deposition variations than does a conventional circular contact plug. In one embodiment, a standard conductive material such as carbon or titanium nitride is used to form the contact. In an alternative embodiment, a memory material itself is used to form the contact. These contact structures may be made by various processes, including chemical mechanical planarization and facet etching.
    Type: Application
    Filed: March 15, 2001
    Publication date: October 31, 2002
    Inventor: Steven T. Harshfield
  • Patent number: 6455424
    Abstract: Methods are provided for selective formation of oxidation-resistant caps for conductive plugs in semiconductor device fabrication. One embodiment of the present invention forms a sacrificial layer over a recessed polysilicon plug. The sacrificial layer is readily planarized using chemical mechanical planarization to isolate the cap within a recessed via. Then, an immersion plating process is used to replace the atoms of the sacrificial layer with atoms of a desired metal, such as platinum, thereby creating a metal cap isolated within the via. The advantages of planarization to isolate material within recessed via are thus obtained without having to planarize or otherwise etch the desired metal. The cap layer can be further reacted to form a barrier compound prior to forming a capacitor over the plug. Advantageously, the plug structure resists oxidation during fabrication of overlying capacitors that incorporate high dielectric constant materials.
    Type: Grant
    Filed: August 7, 2000
    Date of Patent: September 24, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Allen McTeer, Steven T. Harshfield
  • Patent number: 6440837
    Abstract: Annular and linear contact structures are described which exhibit a greatly reduced susceptibility to process deviations caused by lithographic and deposition variations than does a conventional circular contact plug. In one embodiment, a standard conductive material such as carbon or titanium nitride is used to form the contact. In an alternative embodiment, a memory material itself is used to form the contact. These contact structures may be made by various processes, including chemical mechanical planarization and facet etching.
    Type: Grant
    Filed: July 14, 2000
    Date of Patent: August 27, 2002
    Assignee: Micron Technology, Inc.
    Inventor: Steven T. Harshfield
  • Patent number: 6440795
    Abstract: Disclosed is a method of growing hemispherical grained silicon (HSG silicon) over a conductive seed layer. In a preferred embodiment, a contact window is etched in an insulating layer to expose a circuit node, such as an active area of a substrate or a contact plug leading to an active area A layer of titanium nitride is deposited over the insulating layer and into the contact window. The titanium nitride (TiN) serves as the seed layer for HSG silicon growth to follow. Polysilicon is deposited and grows around nucleation sites on the TiN surface. The TiN provides both electrical and mechanical support for the HSG silicon. Additionally, as TiN is an effective diffusion barrier, the HSG silicon may be heavily doped without undue risk of dopant diffusion to the active area.
    Type: Grant
    Filed: November 2, 2000
    Date of Patent: August 27, 2002
    Assignee: Micron Technology, Inc.
    Inventor: Steven T. Harshfield
  • Patent number: 6420725
    Abstract: A method and an apparatus for manufacturing a memory cell having a non-volatile resistive memory element with a limited size active area. The method comprises a first step of providing a dielectric volume and forming a plug opening within the dielectric volume. A recessed plug of a conductive material is then formed within a lower portion of the opening and a dielectric spacer is formed along the sidewalls of an upper portion of the opening. The spacer is cylindrical and has a central hole. A contact plug is subsequently formed within the central hole, the contact plug electrically coupled to the recessed plug. The contact plug can include a memory element or an additional memory element can be applied over the contact plug.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: July 16, 2002
    Assignee: Micron Technology, Inc.
    Inventor: Steven T. Harshfield
  • Publication number: 20020086524
    Abstract: Annular and linear contact structures are described which exhibit a greatly reduced susceptibility to process deviations caused by lithographic and deposition variations than does a conventional circular contact plug. In one embodiment, a standard conductive material such as carbon or titanium nitride is used to form the contact. In an alternative embodiment, a memory material itself is used to form the contact. These contact structures may be made by various processes, including chemical mechanical planarization and facet etching.
    Type: Application
    Filed: December 14, 2001
    Publication date: July 4, 2002
    Inventor: Steven T. Harshfield
  • Patent number: 6413812
    Abstract: A cost-competitive, dense, CMOS compatible ZPROM memory array design and method of manufacture is disclosed. The method of manufacture includes a novel method for forming extremely thin diodes and thin strips of other materials such as conductors by using oxide spacers as an etching mask.
    Type: Grant
    Filed: June 5, 2001
    Date of Patent: July 2, 2002
    Assignee: Micron Technology, Inc.
    Inventor: Steven T. Harshfield
  • Publication number: 20020031887
    Abstract: A cost-competitive, dense, CMOS compatible ZPROM memory array design and method of manufacture is disclosed. The method of manufacture includes a novel method for forming extremely thin diodes and thin strips of other materials such as conductors by using oxide spacers as an etching mask.
    Type: Application
    Filed: June 5, 2001
    Publication date: March 14, 2002
    Inventor: Steven T. Harshfield
  • Patent number: 6187631
    Abstract: Disclosed is a method of growing hemispherical grained silicon (HSG silicon) over a conductive seed layer. In a preferred embodiment, a contact window is etched in an insulating layer to expose a circuit node, such as an active area of a substrate or a contact plug leading to an active area. A layer of titanium nitride is deposited over the insulating layer and into the contact window. The titanium nitride (TiN) serves as the seed layer for HSG silicon growth to follow. Polysilicon is deposited and grows around nucleation sites on the TiN surface. The TiN provides both electrical and mechanical support for the HSG silicon. Additionally, as TiN is an effective diffusion barrier, the HSG silicon may be heavily doped without undue risk of dopant diffusion to the active area.
    Type: Grant
    Filed: February 4, 1999
    Date of Patent: February 13, 2001
    Assignee: Micron Technology, Inc.
    Inventor: Steven T. Harshfield
  • Patent number: 6117720
    Abstract: A method and an apparatus for manufacturing a memory cell having a non-volatile resistive memory element with a limited size active area. The method comprises a first step of providing a dielectric volume and forming a plug opening within the dielectric volume. A recessed plug of a conductive material is then formed within a lower portion of the opening and a dielectric spacer is formed along the sidewalls of an upper portion of the opening. The spacer is cylindrical and has a central hole. A contact plug is subsequently formed within the central hole, the contact plug electrically coupled to the recessed plug. The contact plug can include a memory element or an additional memory element can be applied over the contact plug.
    Type: Grant
    Filed: April 28, 1997
    Date of Patent: September 12, 2000
    Assignee: Micron Technology, Inc.
    Inventor: Steven T. Harshfield
  • Patent number: 6111264
    Abstract: A method for fabricating an ultra-small pore or contact for use in chalcogenide memory cells specifically and in semiconductor devices generally in which disposable spacers are utilized to fabricate ultra-small pores or contacts. The pores thus defined have minimum lateral dimensions ranging from approximately 500 to 4000 Angstroms. The pores thus defined may then be used to fabricate a chalcogenide memory cell or other semiconductor devices.
    Type: Grant
    Filed: November 13, 1997
    Date of Patent: August 29, 2000
    Assignee: Micron Technology, Inc.
    Inventors: Graham R. Wolstenholme, Steven T. Harshfield, Raymond A. Turi, Fernando Gonzalez, Guy T. Blalock, Donwon Park
  • Patent number: 6077729
    Abstract: A memory device having a plurality of memory arrays. Each array has a plurality of memory cells, each memory cell including an electrode defining a respective contact area. Each memory array is formed by depositing a continuous chalcogenide layer. This chalcogenide layer, even when continuous, will have active areas formed above the electrodes, and a conductive layer electrically coupling at least a portion of the active areas. The memory array can also include a dielectric volume surrounding at least a portion of the plurality of electrodes. The electrodes can be contacts, plugs or pillars deposited in etched openings in the dielectric volume.
    Type: Grant
    Filed: February 5, 1999
    Date of Patent: June 20, 2000
    Assignee: Micron Technology, Inc.
    Inventor: Steven T. Harshfield
  • Patent number: 6077740
    Abstract: A structure and process for forming a contact to a semiconductor substrate on a semiconductor device comprises the step of forming a patterned mask over a semiconductor substrate and over a field oxide region, then etching the semiconductor substrate and the field oxide region to form a trench. The trench comprises a bottom and a first sidewall consisting of silicon and a second sidewall comprising field oxide. The etching step removes a part of a doped region in the substrate. Next, a blanket nitride layer and a blanket oxide layer is formed over the substrate, and a spacer etch is performed on the nitride and oxide layer leaving nitride and oxide over the first and second sidewalls. The trench bottom is oxidized to form a layer of oxide over the bottom of the trench thereby insulating the trench bottom, and the oxide encroaches under the nitride and oxide on the sidewalls to join with the field oxide.
    Type: Grant
    Filed: February 17, 1998
    Date of Patent: June 20, 2000
    Assignee: Micron Technology, Inc.
    Inventors: Nanseng Jeng, Steven T. Harshfield, Paul J. Schuele
  • Patent number: 6031287
    Abstract: Annular and linear contact structures are described which exhibit a greatly reduced susceptibility to process deviations caused by lithographic and deposition variations than does a conventional circular contact plug. In one embodiment, a standard conductive material such as carbon or titanium nitride is used to form the contact. In an alternative embodiment, a memory material itself is used to form the contact. These contact structures may be made by various processes, including chemical mechanical planarization and facet etching.
    Type: Grant
    Filed: June 18, 1997
    Date of Patent: February 29, 2000
    Assignee: Micron Technology, Inc.
    Inventor: Steven T. Harshfield
  • Patent number: 5899725
    Abstract: Disclosed is a method of growing hemispherical grained silicon (HSG silicon) over a conductive seed layer. In a preferred embodiment, a contact window is etched in an insulating layer to expose a circuit node, such as an active area of a substrate or a contact plug leading to an active area. A layer of titanium nitride is deposited over the insulating layer and into the contact window. The titanium nitride (TiN) serves as the seed layer for HSG silicon growth to follow. Polysilicon is deposited and grows around nucleation sites on the TiN surface. The TiN provides both electrical and mechanical support for the HSG silicon. Additionally, as TiN is an effective diffusion barrier, the HSG silicon may be heavily doped without undue risk of dopant diffusion to the active area.
    Type: Grant
    Filed: January 8, 1997
    Date of Patent: May 4, 1999
    Assignee: Micron Technology, Inc.
    Inventor: Steven T. Harshfield
  • Patent number: 5869843
    Abstract: A memory device having a plurality of memory arrays. Each array has a plurality of memory cells, each memory cell including an electrode defining a respective contact area. Each memory array is formed by depositing a continuous chalcogenide layer. This chalcogenide layer, even when continuous, will have active areas formed above the electrodes, and a conductive layer electrically coupling at least a portion of the active areas. The memory array can also include a dielectric volume surrounding at least a portion of the plurality of electrodes. The electrodes can be contacts, plugs or pillars deposited in etched openings in the dielectric volume.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: February 9, 1999
    Assignee: Micron Technology, Inc.
    Inventor: Steven T. Harshfield