Patents Assigned to Actrans System Incorporation, USA
  • Publication number: 20060203552
    Abstract: Self-aligned split-gate flash memory cell array and process of fabrication in which erase and select gates are positioned on opposite sides of stacked floating and control gates, with source regions in the substrate beneath the erase gates, bit line diffusions which are partially overlapped by select gates at the ends of the rows of the cells. The floating and control gates are self-aligned with each other, and the erase and select gates are split from but self-aligned with the stacked gates. With the floating gates surrounded by the other gates and the source regions, high voltage coupling for both programming and erase operations is significantly enhanced. The memory cells are substantially smaller than prior art cells, and the array is biased so that all of the memory cells in it can be erased simultaneously, while programming is bit selectable.
    Type: Application
    Filed: April 27, 2006
    Publication date: September 14, 2006
    Applicant: Actrans System Incorporation, USA
    Inventors: Chiou-Feng Chen, Prateep Tuntasood, Der-Tsyr Fan
  • Patent number: 7046552
    Abstract: Self-aligned split-gate flash memory cell array and process of fabrication in which erase and select gates are positioned on opposite sides of stacked floating and control gates, with source regions in the substrate beneath the erase gates, bit line diffusions which are partially overlapped by select gates at the ends of the rows of the cells. The floating and control gates are self-aligned with each other, and the erase and select gates are split from but self-aligned with the stacked gates. With the floating gates surrounded by the other gates and the source regions, high voltage coupling for both programming and erase operations is significantly enhanced. The memory cells are substantially smaller than prior art cells, and the array is biased so that all of the memory cells in it can be erased simultaneously, while programming is bit selectable.
    Type: Grant
    Filed: March 17, 2004
    Date of Patent: May 16, 2006
    Assignee: Actrans System Incorporation, USA
    Inventors: Chiou-Feng Chen, Prateep Tuntasood, Der-Tsyr Fan
  • Patent number: 7037787
    Abstract: Flash memory and process of fabrication in which memory cells are formed with select gates in trenches between stacked, self-aligned floating and control gates, with buried source and drain regions which are gated by the select gates. Erase paths are formed between projecting rounded edges of the floating gates and the select gates, and programming paths extend from the mid-channel regions between the select gates and floating gates through the gate oxide to the edges of the floating gates. Trenched select gates can be provided on one or both sides of the floating and control gates, depending upon array architecture, and the stacked gates and dielectric covering them are used as a self-aligned mask in etching the substrate and other materials to form the trenches.
    Type: Grant
    Filed: February 16, 2005
    Date of Patent: May 2, 2006
    Assignees: Actrans System Inc., Actrans System Incorporation, USA
    Inventors: Der-Tsyr Fan, Jung-Chang Lu, Chiou-Feng Chen, Prateep Tuntasood
  • Patent number: 6992929
    Abstract: Self-aligned split-gate NAND flash memory cell array and process of fabrication in which rows of self-aligned split-gate cells are formed between a bit line diffusion and a common source diffusion in the active area of a substrate. Each cell has control and floating gates which are stacked and self-aligned with each other, and erase and select gates which are split from and self-aligned with the stacked gates, with select gates at both ends of each row which partially overlap the bit line the source diffusions. The channel regions beneath the erase gates are heavily doped to reduce the resistance of the channel between the bit line and source diffusions, and the floating gates are surrounded by the other gates in a manner which provides significantly enhanced high voltage coupling to the floating gates from the other gates.
    Type: Grant
    Filed: March 17, 2004
    Date of Patent: January 31, 2006
    Assignee: Actrans System Incorporation, USA
    Inventors: Chiou-Feng Chen, Caleb Yu-Sheng Cho, Ming-Jer Chen, Der-Tsyr Fan, Prateep Tuntasood
  • Patent number: 6894339
    Abstract: Flash memory and process of fabrication in which memory cells are formed with select gates in trenches between stacked, self-aligned floating and control gates, with buried source and drain regions which are gated by the select gates. Erase paths are formed between projecting rounded edges of the floating gates and the select gates, and programming paths extend from the mid-channel regions between the select gates and floating gates through the gate oxide to the edges of the floating gates. Trenched select gates can be provided on one or both sides of the floating and control gates, depending upon array architecture, and the stacked gates and dielectric covering them are used as a self-aligned mask in etching the substrate and other materials to form the trenches.
    Type: Grant
    Filed: January 2, 2003
    Date of Patent: May 17, 2005
    Assignees: Actrans System Inc., Actrans System Incorporation, USA
    Inventors: Der-Tsyr Fan, Jung-Chang Lu, Chiou-Feng Chen, Prateep Tuntasood