Method and device for programming non-volatile memory

Patent metadata

Field	Value
Publication number	US-10445173-B2
Application number	US-201715632460-A
Country	US
Kind code	B2
Filing date	Jun 26, 2017
Priority date	Jun 26, 2017
Publication date	Oct 15, 2019
Grant date	Oct 15, 2019

Abstract

A method for programming a non-volatile memory in a programming operation is provided. The non-volatile memory has a number of cells and each of part of the cells stores data having at least 2 bits at least corresponding to a first page and a second page. The first programming-verifying operation including programming the first page and verifying whether the first page is successfully programmed is performed. When a first original fail-bit number for the first page is more than a predetermined fail-bit value, a second programming-verifying operation to the first page is performed to obtain a first over-counting fail-bit number for the first page and reduce the first original fail-bit number by the first over-counting fail-bit number. When the reduced first original fail-bit number is not more than the predetermined fail-bit value, the first page is set as successfully programmed.

First claim

What is claimed is:

1. A method for programming a non-volatile memory in a programming operation, wherein each of part of a plurality of cells of the non-volatile memory stores data having at least 2 bits at least corresponding to a first page and a second page, the method comprising:
performing a first programming-verifying operation to the cells of the first page, the first programming-verifying operation comprising programming the cells of the first page and verifying whether the cells of the first page is successfully programmed;
determining whether a first original fail-bit number for the cells of the first page is more than a predetermined value, if yes, setting the first page as failed;
performing a second programming-verifying operation to the cells of the first page when the first page is set as failed, the second programming-verifying operation comprising obtaining a first over-counting fail-bit number for the first page and reducing the first original fail-bit number by the first over-counting fail-bit number; and
determining whether the reduced first original fail-bit number is more than the predetermined value, if not, setting the first page as successfully programmed.

2. The method according to claim 1 , wherein in the step of performing a first programming-verifying operation, at least one programming pulse is provided for programming the cells of the first page, and at least one first program-verify pulse is provided for verifying whether the cells of the first page is successfully programmed.

3. The method according to claim 2 , further comprising:
providing a retry-out pulse when a number of the provided at least one programming pulse is equal to a limit.

4. The method according to claim 3 , wherein the second programming-verifying operation is performed after providing the retry-out pulse.

5. The method according to claim 1 , wherein each of the cells has at least a first state, a second state, a third state, and a fourth state, and the first original fail-bit number is the sum of a third state fail-bit number and a fourth state fail-bit number, and the first over-counting fail-bit number is a fourth state to third state fail-bit number.

6. The method according to claim 1 , further comprising:
determining whether a second original fail-bit number for the cells of the second page is more than the predetermined value, if yes, setting the second page as failed;
performing the second programming-verifying operation to the cells of the second page when the second page is set as failed, the second programming-verifying operation further comprising obtaining a second over-counting fail-bit number for the second page and reducing the second original fail-bit number by the second over-counting fail-bit number; and
determining whether the reduced second original fail-bit number is more than the predetermined value, if not, setting the second page as successfully programmed.

7. The method according to claim 6 , wherein each of the cells has at least a first state, a second state, a third state, and a fourth state, and the second original fail-bit number is the sum of a second state fail-bit number, a third state fail-bit number, and a fourth state fail-bit number, and the second over-counting fail-bit number is the sum of a third state to second state fail-bit number and a fourth state to first state fail-bit number.

8. The method according to claim 1 , wherein the first page is set as failed by enabling a program-fail-reference signal, and the first page is set as successfully programmed by disabling the program-fail-reference signal.

9. A method for programming a non-volatile memory in a programming operation, wherein the non-volatile memory has a plurality of multi-level cells, each of part of the multi-level cells stores data having at least 2 bits at least corresponding to a first page and a second page, the method comprising:
obtaining a first original fail-bit number and a first over-counting fail-bit number for the first page;
reducing the first original fail-bit number by the first over-counting fail-bit number; and
determining whether the reduced first original fail-bit number is more than a predetermined value, if not, setting the first page as successfully programmed.

10. The method according to claim 9 , wherein the step of obtaining the first over-counting fail-bit number comprises providing at least one first program-verify pulse to obtain the first over-counting fail-bit number for the first page.

11. The method according to claim 9 , wherein each of the cells has at least a first state, a second state, a third state, and a fourth state, and the first original fail-bit number is the sum of a third state fail-bit number and a fourth state fail-bit number, and the first over-counting fail-bit number is a fourth state to third state fail-bit number.

12. The method according to claim 9 , further comprising:
obtaining a second original fail-bit number and a second over-counting fail-bit number for the second page;
reducing the second original fail-bit number by the second over-counting fail-bit number; and
determining whether the reduced second original fail-bit number is more than the predetermined value, if not, setting the second page as successfully programmed.

13. The method according to claim 12 , wherein each of the cells has at least a first state, a second state, a third state, and a fourth state, and the second original fail-bit number is the sum of a second state fail-bit number, a third state fail-bit number, and a fourth state fail-bit number, and the second over-counting fail-bit number is the sum of a third state to second state fail-bit number and a fourth state to first state fail-bit number.

14. The method according to claim 12 , wherein the step of obtaining the second over-counting fail-bit number comprises providing at least one second program-verify pulse to obtain the second over-counting fail-bit number for the second page.

Assignees

• Macronix Int Co Ltd

Inventors

• Huang Shih-Chang
• Lee Kun-Tse

Classifications

• G06F11/1072 Primary

  in multilevel memories · CPC title

• G06F11/102 Primary

  Error in check bits · CPC title