Erasing method for flash memory

Erasing method for flash memory

  • CN 1,393,888 A
  • Filed: 06/25/2001
  • Published: 01/29/2003
  • Est. Priority Date: 06/25/2001
  • Status: Active Application
First Claim
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1. the erasing method of a flash memory comprises plurality of memory cells in this flash memory, and this method comprises:

  • carry out first section and erase, it is to apply bias voltage V on a plurality of grids of these storage unit g, and in the plurality of sources/drain electrode of these storage unit, apply bias voltage V dErase to carry out storage unit, check then whether these storage unit are erased fully, then finish this erase step in this way, as otherwise carry out second section and erase, it comprises boosting and erase-check step at least once, till definite these storage unit are all erased, it is characterized in that;

    at bias voltage V dBegin to be incremented between the default value the neither step of checking by an initial value;

    Carrying out second section when erasing, the step of erasing-check of boosting for the i time comprises of continuing T (i) time erase step of boosting and checks step, wherein the bias voltage V of the 1st erase step of boosting with thereafter one dBe higher than this default value, and when i>

    1, the bias voltage V of the i time erase step of boosting dThe bias voltage V that is higher than the i-1 time erase step of boosting d

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