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Flash memory cell with vertical channels, and source/drain bus lines

  • US 6,011,288 A
  • Filed: 12/22/1997
  • Issued: 01/04/2000
  • Est. Priority Date: 12/22/1997
  • Status: Expired due to Term
First Claim
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1. A vertical memory device on a silicon semiconductor substrate comprising:

  • a floating gate trench in said silicon semiconductor substrate, said trench having trench surfaces, said trench having a depth from about 100 Å

    to about 20,000 Å

    ,the walls of said floating gate trench doped with a threshold implant through said trench surfaces,a tunnel oxide layer on said trench surfaces, said tunnel oxide layer having outer surfaces, said tunnel oxide layer having a thickness from about 70 Å

    to about 200 Å

    ,a floating gate electrode in said trench on said outer surfaces of said tunnel oxide layer,said floating gate electrode comprises doped polysilicon with a thickness from about 1,000 Å

    to about 3,000 Å

    ,source/drain regions in said substrate self-aligned with said floating gate electrode,said source/drain regions were implanted with a dopant selected from the group consisting of arsenic and phosphorus with a concentration of from about 1 E 14 atoms/cm3 to about 1 E 16 atoms/cm3,a source line region is provided on the source side of said trench aligned with and over said source region,a drain line region is provided on the drain side of said trench aligned with and over said drain region,an interelectrode dielectric layer over the top surface of said floating gate electrode, and said source line and said drain line, anda control gate electrode over said interelectrode dielectric layer over the top surface of said floating gate electrode.

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