Erase-verify method for three-dimensional memories and memory system
First Claim
1. An erase-verify method for a three-dimensional (3D) memory, the 3D memory including at least one memory cell string including a plurality of memory cells, the memory cells including a first group of memory cells and a second group of memory cells, each of the memory cells coupled to a word line, the erase-verify method comprising:
- performing a first erase-verify operation on the first group of memory cells, wherein the first erase-verify operation comprises;
applying an erase-verify voltage to the word lines coupled to a first portion of the first group of memory cells and a first pass voltage to the word lines coupled to a second portion of the first group of memory cells in a first phase of the first erase-verify operation, the second portion of the first group of memory cells is different from the first portion of the first group of memory cells; and
after the first phase of the first erase-verify operation, applying the erase-verify voltage to the word lines coupled to the memory cells in the second portion of the first group of memory cells and the first pass voltage to the word lines coupled to the memory cells in the first portion of the first group of memory cells in a second phase of the first erase-verify operation; and
after performing the first erase-verify operation on the first group of memory cells, performing a second erase-verify operation on the second group of memory cells in condition that the first group of memory cells are verified as erased successfully, wherein the second erase-verify operation comprises;
applying the erase-verify voltage to the word lines coupled to a first portion of the second group of memory cells and a second pass voltage to the word lines coupled to a second portion of the second group of memory cells in a first phase of the second erase-verify operation, the second portion of the second group of memory cells is different from the first portion of the second group of memory cells; and
after the first phase of the first erase-verify operation, applying the verify voltage to the word lines coupled to the second portion of the second group of memory cells and the second pass voltage to the word lines coupled to the first portion of the second group of memory cells in a second phase of the second erase-verify operation.
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Abstract
An erase-verify method for a three-dimensional (3D) memory and a memory system are provided. The 3D memory includes at least one memory cell string including a plurality of memory cells, and the memory cells include a first group of memory cells and a second group of memory cells. Each of the memory cells is coupled to a word line. The method comprises the following steps. A first erase-verify operation is performed on the first group of memory cells. After performing the first erase-verify operation on the first group of memory cells, a second erase-verify operation is performed on the second group of memory cells in condition that the first group of memory cells are verified as erased successfully.
36 Citations
12 Claims
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1. An erase-verify method for a three-dimensional (3D) memory, the 3D memory including at least one memory cell string including a plurality of memory cells, the memory cells including a first group of memory cells and a second group of memory cells, each of the memory cells coupled to a word line, the erase-verify method comprising:
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performing a first erase-verify operation on the first group of memory cells, wherein the first erase-verify operation comprises; applying an erase-verify voltage to the word lines coupled to a first portion of the first group of memory cells and a first pass voltage to the word lines coupled to a second portion of the first group of memory cells in a first phase of the first erase-verify operation, the second portion of the first group of memory cells is different from the first portion of the first group of memory cells; and after the first phase of the first erase-verify operation, applying the erase-verify voltage to the word lines coupled to the memory cells in the second portion of the first group of memory cells and the first pass voltage to the word lines coupled to the memory cells in the first portion of the first group of memory cells in a second phase of the first erase-verify operation; and after performing the first erase-verify operation on the first group of memory cells, performing a second erase-verify operation on the second group of memory cells in condition that the first group of memory cells are verified as erased successfully, wherein the second erase-verify operation comprises; applying the erase-verify voltage to the word lines coupled to a first portion of the second group of memory cells and a second pass voltage to the word lines coupled to a second portion of the second group of memory cells in a first phase of the second erase-verify operation, the second portion of the second group of memory cells is different from the first portion of the second group of memory cells; and after the first phase of the first erase-verify operation, applying the verify voltage to the word lines coupled to the second portion of the second group of memory cells and the second pass voltage to the word lines coupled to the first portion of the second group of memory cells in a second phase of the second erase-verify operation. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A memory system, comprising:
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a three dimensional (3D) memory, including at least one memory cell string extending vertically through layers of the 3D memory, the at least one memory cell string including a plurality of memory cells, the memory cells including a first group of memory cells and a second group of memory cells, each of the memory cells coupled to a word line; and a controller, coupled to the 3D memory, for performing a first erase-verify operation on the first group of memory cells, wherein the first erase-verify operation comprises that the controller applies a erase-verify voltage to the word lines coupled to a first portion of the first group of memory cells and a first pass voltage to the word lines coupled to a second portion of the first group of memory cells in a first phase of the first erase-verify operation, and after the first phase of the first erase-verify operation, the controller applies the erase-verify voltage to the word lines coupled to the second portion of the first group of memory cells and the first pass erase-voltage to the word lines coupled to the first portion of the first group of memory cells in a second phase of the first erase-verify operation, wherein the second portion of the first group of memory cells is different from the first portion of the first group of memory cells; and after performing the first erase-verify operation on the first group of memory cells, performing a second erase-verify operation on the second group of memory cells in condition that the first group of memory cells are verified as erased successfully, wherein the second erase-verify operation comprises that the controller applies the erase-verify voltage to the word lines coupled to a first portion of the second group of memory cells and a second pass voltage to the word lines coupled to a second portion of the second group of memory cells in a first phase of the second erase-verify operation, and after the first phase of the first erase-verify operation, the controller applies the erase-verify voltage to the word lines coupled to the second portion of the second group of memory cells and the second pass voltage to the word lines coupled to the first portion of the second group of memory cells in a second phase of the second erase-verify operation, wherein the second portion of the second group of memory cells is different from the first portion of the second group of memory cells. - View Dependent Claims (8, 9, 10, 11, 12)
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Specification