SEMICONDUCTOR MEMORY DEVICE AND METHOD OF OPERATING THE SAME

• US 20190333593A1
• Filed: 07/12/2019
• Published: 10/31/2019
• Est. Priority Date: 12/29/2016
• Status: Active Grant

• Current Assignee: SK Hynix Inc.
• Original Assignee: SK Hynix Inc.
• Inventors: LEE, Hye Lyoung, LEE, Bong Hoon, LIM, Chan
• Granted Patent: US 11,114,173 B2
• Time in Patent Office: Days
• CPC Class Codes: G11C 11/5628 Programming or writing circuits; Data input circuits
• CPC Class Codes: G11C 11/5671 using charge trapping in an insulator
• CPC Class Codes: G11C 16/0483 comprising cells having several storage transistors connected in series
• CPC Class Codes: G11C 16/08 Address circuits; Decoders; Word-line control circuits
• CPC Class Codes: G11C 16/10 Programming or data input circuits
• CPC Class Codes: G11C 16/26 Sensing or reading circuits; Data output circuits
• CPC Class Codes: G11C 16/30 Power supply circuits
• CPC Class Codes: G11C 16/3459 Circuits or methods to verify correct programming of nonvolatile memory cells
• CPC Class Codes: G11C 2211/5621 Multilevel programming verification
• CPC Class Codes: G11C 2211/5642 Multilevel memory with buffers, latches, registers at input or output

Abstract

Provided herein may be a semiconductor memory device and a method of operating the same. The semiconductor memory device may include peripheral circuits configured to perform a verify operation on selected memory cells by applying a verify voltage to a word line, and perform a compensation program operation on the selected memory cells by applying a compensation program voltage to the word line; and a control logic configured to control the peripheral circuits such that the compensation program operation is performed by applying the compensation program voltage to the selected memory cells to be programmed to a selected threshold voltage distribution among the threshold voltage distributions other than a highest threshold voltage distribution, wherein the compensation program voltage has a positive voltage lower than the main program voltage most recently applied to the word line.

Claims

1. A semiconductor memory device comprising:

a plurality of memory cells configured to be programmed to have different threshold voltage distributions;

peripheral circuits configured to perform a program operation on selected memory cells among the plurality of memory cells by applying a main program voltage to a word line coupled to the plurality of memory cells, perform a verify operation on the selected memory cells by applying a verify voltage to the word line, and perform a compensation program operation on the selected memory cells by applying a compensation program voltage to the word line; and

a control logic configured to control the peripheral circuits such that the compensation program operation is performed by applying the compensation program voltage to the selected memory cells to be programmed to a selected threshold voltage distribution among the threshold voltage distributions other than a highest threshold voltage distribution,

wherein the compensation program voltage has a positive voltage lower than the main program voltage most recently applied to the word line.

2. The semiconductor memory device according to claim 1, wherein the peripheral circuits program the selected memory cells by applying the main program voltage to the word line, and then performs the compensation program operation by applying the compensation program voltage to the word line before performing the verify operation on the selected memory cells.

3. The semiconductor memory device according to claim 2,

wherein the peripheral circuits perform a plurality of program loops including the program operation and the verify operation such that the selected memory cells have the selected threshold voltage distribution,

wherein the peripheral circuits perform the compensation program operation on some program loops among the program loops.

4. The semiconductor memory device according to claim 3, wherein, in the some program loops, the compensation program operation is performed by applying the main program voltage to the word line, applying the compensation program voltage to the word line, and then applying the verify voltage to the word line.

5. The semiconductor memory device according to claim 1, wherein the peripheral circuits program the selected memory cells by applying the main program voltage to the word line, and then perform the compensation program operation by performing the verify operation on the selected memory cells and then applying the compensation program voltage to the word line.

6. The semiconductor memory device according to claim 5, wherein the peripheral circuits comprise:

a voltage generation circuit configured to generate and output the main program voltage, the verify voltage, or the compensation program voltage under control of the control logic; and

page buffers coupled to the plurality of memory cells through bit lines, and including first latches configured to be used during the verify operation, and second latches configured to temporarily store original data.

7. The semiconductor memory device according to claim 6,

wherein the page buffers further include third latches configured to temporarily store the original data input from an external device,

wherein the page buffers temporarily store the original data input from the external device in the third latches, and

wherein the page buffers transmit the original data stored in the third latches to the first and the second latches.

8. The semiconductor memory device according to claim 7,

wherein the original data stored in the first latches varies depending on a result of the verify operation, and

wherein the original data stored in the second latches is transmitted to the first latches after the verify operation is performed.

9. The semiconductor memory device according to claim 8, wherein, when the original data stored in the second latches is transmitted to the first latches, the page buffers selectively precharge the bit lines depending on the original data input to the first latches.

10. The semiconductor memory device according to claim 9, wherein, when the bit lines are selectively precharged, the voltage generation circuit outputs the compensation program voltage.