Method of programming in flash memory devices
A method of programming a flash memory device includes selecting a first wordline of a plurality of wordlines to select a selected wordline, the selected wordline corresponding to a target memory cell and performing a programming loop. The programming loop includes applying a program voltage to the selected wordline and performing a verification to the target memory cell. The verification includes applying a pre-pulse voltage to the selected wordline, applying a plurality of pass voltages to unselected wordlines of the plurality of wordlines, after applying the pre-pulse voltage, applying a series of incremental verifying voltages to the selected wordline, and after applying the pre-pulse voltage, applying a floating voltage to a second wordline of the plurality of wordlines. The second wordline being adjacent to the selected wordline is programmed after the selected wordline.
1. A method of programming a flash memory device, comprising:
selecting a first wordline of a plurality of wordlines to select a selected wordline, the selected wordline corresponding to a target memory cell; and
performing a programming loop comprising:
applying a program voltage to the selected wordline; and
performing a verification to the target memory cell, the verification comprising:
applying a pre-pulse voltage to the selected wordline;
applying a plurality of pass voltages to unselected wordlines of the plurality of wordlines;
after applying the pre-pulse voltage, applying a series of incremental verifying voltages to the selected wordline; and
after applying the pre-pulse voltage, applying a floating voltage to a second wordline of the plurality of wordlines, the second wordline being adjacent to the selected wordline which is programmed after the selected wordline.
2. The method of claim 1 , the programming loop further comprising discharging each of the plurality of wordlines after the verification.
3. The method of claim 1 , the programming loop further comprising ending the programming loop if a number of memory cells having threshold voltages greater than target voltages is greater than a predetermined number.
4. The method of claim 1 , the programming loop further comprising increasing the program voltage.
5. The method of claim 1 further comprising ending the programming loop if a programming loop count reaches a maximum loop count.
6. A method of programming a flash memory device, comprising:
selecting a first wordline of a plurality of wordlines to select a selected wordline, the selected wordline corresponding to a target memory cell; and
performing a programming loop comprising:
applying a program voltage to the selected wordline; and
performing a verification to the target memory cell, the verification comprising:
applying a pre-pulse voltage to the selected wordline;
applying a plurality of pass voltages to unselected wordlines of the plurality of wordlines;
after applying the pre-pulse voltage, applying a series of incremental verifying voltages to the selected wordline; and
after applying the pre-pulse voltage, discharging a second wordline of the plurality of wordlines to a system voltage level, the second wordline being adjacent to the selected wordline which is programmed after the selected wordline; and
after discharging the second wordline to the system voltage level, applying a floating voltage to the second wordline.
7. The method of claim 6 , the programming loop further comprising discharging each of the plurality of wordlines after the verification.
8. The method of claim 6 , the programming loop further comprising ending the programming loop if a number of memory cells having threshold voltages greater than target voltages is greater than a predetermined number.
9. The method of claim 6 , the programming loop further comprising increasing the program voltage.
10. The method of claim 6 further comprising ending the programming loop if a programming loop count reaches a maximum loop count.
11. A method of programming a flash memory device, comprising:
selecting a first wordline of a plurality of wordlines to select a selected wordline, the selected wordline corresponding to a target memory cell; and
performing a programming loop comprising:
applying a program voltage to the selected wordline; and
performing a verification to the target memory cell, the verification comprising:
applying a pre-pulse voltage to the selected wordline;
applying a plurality of pass voltages to unselected wordlines of the plurality of wordlines;
after applying the pre-pulse voltage, applying a series of incremental verifying voltages to the selected wordline; and
after applying the pre-pulse voltage, discharging a second wordline of the plurality of wordlines to a ground voltage level, the second wordline adjacent to the selected wordline and on a side of the selected wordline nearest a bitline transistor; and
after discharging the second wordline to the ground voltage level, applying a floating voltage to the second wordline.
12. The method of claim 11 , the programming loop further comprising discharging each of the plurality of wordlines after the verification.
13. The method of claim 11 , the programming loop further comprising ending the programming loop if a number of memory cells having threshold voltages greater than target voltages is greater than a predetermined number.
14. The method of claim 11 , the programming loop further comprising increasing the program voltage.
15. The method of claim 11 further comprising ending the programming loop if a programming loop count reaches a maximum loop count.