Including Elongated Source Or Drain Region Disposed Under Thick Oxide Regions (e.g., Buried Or Diffused Bitline, Etc.) Patents (Class 438/262)
  • Patent number: 5661055
    Abstract: A memory device, such as a flash EEPROM, has zero birds' beaks and vertically overlapping gates to facilitate high cell density in the EEPROM's core. During fabrication, a layer of field oxide is formed over the core. The active regions are exposed by etching through the layer of field oxide to form vertically walled cavities around the active regions. The tunnel oxide, floating gate, interpoly dielectric, and the control gate are formed within each cavity so that the floating gate overlaps the control gate along the vertical walls. As a result, capacitive coupling between the gates is maintained, yet the horizontal dimensions of the cell decrease. Similarly, the absence of birds' beaks facilitates higher cell density in the core.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: August 26, 1997
    Assignee: Advanced Micro Devices, Inc.
    Inventors: James Juen Hsu, Steven W. Longcor, Jih-Chang Lien
  • Patent number: 5656513
    Abstract: A memory device, such as a flash EEPROM, employs a high energy implantation to form common source line, avoiding the necessity of self-aligned source etch processes. The use of the high energy implantation, and avoiding the etching process, provides for greater cell uniformity, and better V.sub.T distribution.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: August 12, 1997
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Hsingya Arthur Wang, James Juen Hsu