Nonvolatile memory device and programming method

• US 8,254,181 B2
• Filed: 10/19/2009
• Issued: 08/28/2012
• Est. Priority Date: 11/24/2008
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Hwang, Soonwook, Park, Kitae, Lee, Jaewook, Joo, Han Sung
• Primary Examiner(s): Hur, J. H.
• Application Number:
  US12/581,479
• Publication Number:
  US 20100128532A1
• Time in Patent Office: 1,044 Days
• Field of Search: 365/185.29, 365/185.27, 365/185.25, 365/185.24, 365/185.22, 365/185.23, 365/185.17, 365/185.18, 365/185.13, 365/185.11
• US Class Current: 365/185.25
• CPC Class Codes: G11C 16/3404 Convergence or correction of memory cell threshold voltages; Repair or recovery of overerased or overprogrammed cells
• CPC Class Codes: G11C 16/344 Arrangements for verifying correct erasure or for detecting overerased cells

Abstract

A nonvolatile memory device includes; a memory cell array configured into a plurality of memory blocks, a decoder connected to the plurality of memory blocks via a word line, a page buffer connected to the plurality of memory blocks via a bit line, and control logic configured to define a control voltage applied to at least one of the word line and the bit line during a program/verify operation in accordance with a location of each one of the plurality of memory blocks within the memory cell array.

Claims

1. A nonvolatile memory device comprising:

a memory cell array configured into a plurality of memory blocks;

a decoder connected to the plurality of memory blocks via a word line;

a page buffer connected to the plurality of memory blocks via a bit line; and

a control logic configured to define a control voltage applied to at least one of the word line and the bit line during a program/verify operation in accordance with a location of each of the plurality of memory blocks within the memory cell array,

wherein the control voltage defines a develop time during which a precharge voltage is discharged, the precharge voltage being applied to the bit line.

2. The nonvolatile memory device of claim 1, wherein the plurality of memory blocks is series connected to the bit line;

and

the control logic is further configured to increase the develop time for each one of the plurality of memory blocks as a location of each memory block increases from one end of the bit line.

3. The nonvolatile memory device of claim 1, wherein the program/verify operation comprises:

executing an erase operation for memory cells of a top memory block and memory cells of a bottom memory block within the plurality of memory blocks; and

then

executing a post programming operation for the memory cells of the top memory block and memory cells of the bottom memory block, such that respective threshold voltage distributions for the memory cells of the top memory block and memory cells of the bottom memory block are substantially similar.

4. A computational system comprising:

a memory controller; and

a nonvolatile memory device operating in accordance with commands received from the memory controller, the nonvolatile memory device comprising;

a memory cell array configured into a plurality of memory blocks;

a decoder connected to the plurality of memory blocks via a word line;

a page buffer connected to the plurality of memory blocks via a bit line; and

control logic configured to define a control voltage applied to at least one of the word line and the bit line during a program/verify operation in accordance with a location of each of the plurality of memory blocks within the memory cell array, wherein the control voltage defines a develop time during which a precharge voltage is discharged, and the precharge voltage is applied to the bit line.

5. The computational system of claim 4, wherein the plurality of memory blocks is series connected to the bit line;

and

the control logic is further configured to increase develop time for each one of the plurality of memory blocks as a location of each memory block increases from one end of the bit line.

6. A method of programming a nonvolatile memory device, the nonvolatile memory device being configured into a plurality of memory blocks including a top memory block located at one end of a bit line and a bottom memory block located at an opposite end of the bit line, the method comprising:

executing an erase operation for memory cells of the top memory block and memory cells of the bottom memory block; and

then

executing a post programming operation for the memory cells of the top memory block and the memory cells of the bottom memory block, such that respective threshold voltage distributions for the memory cells of the top memory block and memory cells of the bottom memory block are substantially similar.

7. The method of claim 6, wherein executing the post programming operation comprises:

using a different develop time for the top memory block and the bottom memory block during which a precharge voltage is discharged, wherein each respective precharge voltage is applied to the bit line.

8. The method of claim 6, wherein executing the post programming operation comprises:

using a different verifying voltage for the top memory block and the bottom memory block, wherein each respective verifying voltage is applied to a word line.

9. The method of claim 6, wherein executing the post programming operation comprises:

using a different precharge voltage to the top memory block and the bottom memory block, wherein each respective precharge voltage is applied to the bit line.