{
  "patent_number": "US 9685235",
  "country": "US",
  "title": "How to Prepare 3D Flash Memory for Use",
  "original_title": "Method of initializing 3D non-volatile memory device",
  "summary": "This patent describes a method for setting up a 3D non-volatile memory chip, like those in SSDs, by precisely programming control transistors, including a special \"dummy\" one, to make sure the memory works correctly.",
  "what_it_does": "The patent describes a way to get a 3D non-volatile memory device ready for use. This involves carefully setting the \"threshold values\" (the voltage needed to turn them on) of specific transistors. Specifically, it programs multiple \"string selection transistors\" and a \"dummy string selection transistor\" (Claim 1). These transistors, once programmed, work together to select the correct memory \"strings\" (paths of memory cells) for reading or writing data. For example, the method might apply a program voltage to a selected string selection line, then check if the transistors reached their target threshold. If some haven't, it can then program other memory cells to act as \"screening transistors\" to block programming for already set transistors, allowing only the unprogrammed ones to be set (Claim 2). This ensures all necessary selection transistors are correctly configured.",
  "what_it_does_not_cover": [
    "Does not cover initialization methods for traditional 2D (planar) non-volatile memory devices.",
    "Does not cover memory architectures that do not include a \"dummy string selection line\" as part of their structure.",
    "Does not cover initialization processes that do not involve programming string selection transistors to specific threshold values.",
    "Does not cover memory devices where channel lines are not coupled to bitlines via first ends and common source lines via second ends.",
    "Does not cover initialization methods that don't use the dummy string selection transistor together with other string selection transistors."
  ],
  "filed": "2016-11-14",
  "granted": "2017-06-20",
  "expires": "2036-11-14",
  "status": "active",
  "holder": "Seoul National University R&DB Foundation",
  "holder_url": "https://patentbrief.org/company/seoul-national-university-rdb-foundation",
  "inventors": [
    {
      "name": "Dae Woong KWON",
      "url": "https://patentbrief.org/inventor/dae-woong-kwon"
    },
    {
      "name": "Byung Gook Park",
      "url": "https://patentbrief.org/inventor/byung-gook-park"
    },
    {
      "name": "Sang Ho Lee",
      "url": "https://patentbrief.org/inventor/sang-ho-lee"
    },
    {
      "name": "Do Bin KIM",
      "url": "https://patentbrief.org/inventor/do-bin-kim"
    }
  ],
  "times_cited": 9,
  "tags": [
    "semiconductors",
    "consumer_electronics",
    "telecommunications",
    "software"
  ],
  "abstract": "A 3D non-volatile memory device may include a dummy string selection line, string selection lines, wordlines, bitlines, a ground selection line, and memory layers. Each of the memory layers comprising channel lines respectively coupled to the bitlines via first ends and coupled to a common source line of the memory layer via second ends. The dummy string selection line, the string selection lines, the wordlines, and the ground selection line intersect with the channel lines, and each of the channel lines defines a memory string. Initializing the 3D non-volatile memory device may include programming string selection transistors coupled with the string selection lines to have one or more threshold values, and programming a dummy string selection transistor coupled with the dummy string selection line to have a predetermined threshold value, such that the dummy string selection transistor together with the string selection transistors function as string selection transistors.",
  "url": "https://patentbrief.org/patent/us/9685235/method-of-initializing-3d-non-volatile-memory-device",
  "markdown_url": "https://patentbrief.org/patent/us/9685235/method-of-initializing-3d-non-volatile-memory-device/md",
  "google_patents_url": "https://patents.google.com/patent/US9685235",
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}