Patents by Inventor Stefano Mazzali

Stefano Mazzali 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: 6762452
    Abstract: A memory device may include a semiconductor substrate, an oxide layer defining spaced apart active areas in the semiconductor substrate, and a floating gate region on each respective active area. The floating gate region may have sidewalls that are slanted with respect to a surface of the semiconductor substrate. Moreover, the memory device may also include a plug in the oxide layer.
    Type: Grant
    Filed: December 20, 2002
    Date of Patent: July 13, 2004
    Assignee: STMicroelectronics S.r.l.
    Inventors: Nicola Nastasi, Dorotea Arcidiacono, Stefano Mazzali
  • Publication number: 20030092237
    Abstract: A method is provided for manufacturing electronic non-volatile memory devices on a semiconductor substrate including a matrix of memory cells having floating gate regions formed on respective active areas and an oxide layer separating the active areas. The method may include forming sidewalls of the floating gate regions that are slanted with respect to a surface of the semiconductor substrate, forming a trench in the oxide layer following the formation of the floating gate regions, and forming a plug of polycrystalline silicon in the trench. The slanted sidewalls of the floating gate regions provide a lead-in for the formation of upper layers.
    Type: Application
    Filed: December 20, 2002
    Publication date: May 15, 2003
    Applicant: STMicroelectronics S.r.I.
    Inventors: Nicola Nastasi, Dorotea Arcidiacono, Stefano Mazzali
  • Patent number: 6498083
    Abstract: A method is provided for manufacturing electronic non-volatile memory devices on a semiconductor substrate including a matrix of memory cells having floating gate regions formed on respective active areas and an oxide layer separating the active areas. The method may include forming sidewalls of the floating gate regions that are slanted with respect to a surface of the semiconductor substrate, forming a trench in the oxide layer following the formation of the floating gate regions, and forming a plug of polycrystalline silicon in the trench. The slanted sidewalls of the floating gate regions provide a leading for the formation of upper layers.
    Type: Grant
    Filed: December 28, 2000
    Date of Patent: December 24, 2002
    Assignee: STMicroelectronics S.r.l.
    Inventors: Nicola Nastasi, Dorotea Arcidiacono, Stefano Mazzali
  • Publication number: 20010016379
    Abstract: A method is provided for manufacturing electronic non-volatile memory devices on a semiconductor substrate including a matrix of memory cells having floating gate regions formed on respective active areas and an oxide layer separating the active areas. The method may include forming sidewalls of the floating gate regions that are slanted with respect to a surface of the semiconductor substrate, forming a trench in the oxide layer following the formation of the floating gate regions, and forming a plug of polycrystalline silicon in the trench. The slanted sidewalls of the floating gate regions provide a lead-in for the formation of upper layers.
    Type: Application
    Filed: December 28, 2000
    Publication date: August 23, 2001
    Applicant: STMicroelectronics S.r.I.
    Inventors: Nicola Nastasi, Dorotea Arcidiacono, Stefano Mazzali
  • Patent number: 5644526
    Abstract: The integrated circuit tolerant of large manufacturing defects comprising a first plurality of first conductors made of a first material with relatively low conductivity and each having a plurality of first electrical connection points arranged along itself and a second corresponding plurality of second conductors made of a second material with relatively high conductivity and each having a plurality of second electrical connection points arranged along itself and said plurality of first points are electrically connected to said plurality of second points respectively in such a manner as to reduce the series resistance of the first conductors and the second conductors are interrupted between some second consecutive points in such a manner as to leave relatively large areas of the integrated circuit not traversed by the second conductors.
    Type: Grant
    Filed: October 2, 1995
    Date of Patent: July 1, 1997
    Assignee: SGS-Thomson Microelectronics S.r.l.
    Inventor: Stefano Mazzali
  • Patent number: 5590075
    Abstract: A method for testing an electrically erasable and programmable memory device comprising a matrix of memory cells and redundancy memory cells for functionally substituting defective memory cells, comprises the steps of: programing all the memory cells of the memory device; submitting all the memory cells of the memory device to a preliminary electrical erasure for a time much shorter than an average erasing time of the memory cells; reading the information stored in all the memory cells of the memory device; memorizing the addresses of defective memory cells which have been read as erased memory cell; storing the addresses of the defective memory cells in redundancy registers associated to redundancy memory cells which must substitute the defective memory cells.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: December 31, 1996
    Assignee: SGS-Thomson Microelectronics S.r.l.
    Inventor: Stefano Mazzali
  • Patent number: 5196914
    Abstract: A table cloth matrix of EPROM memory cells comprises a semiconductor substrate, parallel source lines and drain lines, floating gate areas interposed in a checkerboard pattern between the source lines and the drain lines and control gate lines, parallel to one another and perpendicular to the source lines and to the drain lines. There are obtained in the semiconductor substrate extensive oxide areas, with which the floating gates are in contact by means of their asymmetrical lateral fin.
    Type: Grant
    Filed: August 29, 1991
    Date of Patent: March 23, 1993
    Assignee: SGS-Thomson Microelectronics s.r.l.
    Inventor: Stefano Mazzali
  • Patent number: 5122473
    Abstract: Through a process perfectly suitable for fabricating integrated MISFET devices with an extremely high packing density, the field isolation structure and the gate structures of MISFET devices are simultaneously formed while attending an excellent planarity of the front of the wafer without the need of particularly burdensome techniques in order to preserve the crystallographic integrity of the substrate which is often negatively affected through conventional nitride process or by the etching of the silicon substrate as in BOX isolation processes. A patterned matrix layer of polycrystalline silicon is used for masking the active areas from the isolation implantation and from a subsequent low pressure chemical vapor deposition of a TEOS layer having a thickness substantially equal to the thickness of the masking matrix layer of polycrystalline silicon to form the field isolation structure.
    Type: Grant
    Filed: October 12, 1990
    Date of Patent: June 16, 1992
    Assignee: SGS-Thomson Microelectronics s.r.l.
    Inventor: Stefano Mazzali
  • Patent number: 5081056
    Abstract: A process for fabricating an integrated memory matrix of EPROM cells having a "tablecloth" organization, with source and drain lines parallel among each other and running between parallel strips of isolating field oxide, floating gate structures formed between said source and drain lines and control gate lines running parallel among each other and perpendicularly to said source and drain lines and over said floating gate structures, utilizes a mask through which a stack, formed by a second level polysilicon layer, an interpoly isolating dielectric layer, a first level polysilicon layer and a gate oxide layer, is etched for defining in a longitudinal sense the gate structures (i.e. the channel length) of the EPROM cells. The gate structures are subsequently defined in a transversal sense by etching through another mask a stack comprising a third level polysilicon layer deposited directly over said second level polysilicon layer, said interpoly dielectric layer and said first level polysilicon layer.
    Type: Grant
    Filed: April 6, 1990
    Date of Patent: January 14, 1992
    Assignee: SGS-Thomas Microelectronics s.r.l.
    Inventors: Stefano Mazzali, Massimo Melanotte, Luisa Masini, Mario Sali
  • Patent number: 5036018
    Abstract: A method of manufacturing memory cells is described, wherein the great selectivity of polysilicon etching with respect to oxide is employed for the elimination of the self-aligned polysilicon mask for the definition of the floating gate of the EPROM cell. In fact, according to the invention, the mask for the formation of the source and drain regions of one of the CMOS transistors is used for the removal of the oxide separating the two layers of polysilicon on the active region defining a memory cell, and the mask for the formation of the source and drain regions of the other CMOS transistor is employed for the removal of the lower layer of polysilicon around the floating gate of the memory cell, wherein the silicon portions which are not to be removed are covered by oxide.
    Type: Grant
    Filed: July 25, 1988
    Date of Patent: July 30, 1991
    Assignee: SGS-Thomson Microelectronics S.p.A.
    Inventor: Stefano Mazzali
  • Patent number: 5028979
    Abstract: The table cloth matrix comprises a semiconductor substrate, wherein there are contained in deep layers, under strips of field oxide, source lines and drain lines parallel to one another, areas of floating gate connecting said source lines and drain lines and control gate lines, parallel to one another and perpendicular to said source lines and drain lines, in a condition superimposed over said floating gate areas. Each source line is alternated with two drain lines separated by an insulation zone, so that each drain line is associated with a single row of matrix cells.
    Type: Grant
    Filed: March 5, 1990
    Date of Patent: July 2, 1991
    Assignee: SGS-Thomson Microelectronics, s.r.l.
    Inventor: Stefano Mazzali
  • Patent number: 5005060
    Abstract: The memory matrix comprises parallel and alternating source and drain lines, floating gate areas placed between the source and drain lines and control gate lines parallel to each other and perpendicular to the source and drain lines superimposed on the floating gate areas. The floating gate areas are arranged in rows parallel to the source and drain lines in positions longitudinally staggered in relation to those of the adjacent row in such a manner that the floating gate areas of one row underlie a first plurality of control gate lines and the floating gate areas of the adjacent row underlie a second plurality alternating with the first of the control gate lines. The floating gate areas together with the adjacent source and drain lines and with the superimposed control gate lines define respective EPROM cells arranged in a staggered manner in the memory matrix.
    Type: Grant
    Filed: March 21, 1989
    Date of Patent: April 2, 1991
    Assignee: SGS-Thomson Microelectronics S.r.l.
    Inventor: Stefano Mazzali