Method of programming non-volatile memory device

1. A method of programming a non-volatile memory device, the method comprising:

during a first channel initialization period, applying a first voltage to a selected word line and a first word line group proximate to the selected word line, and applying a second voltage lower than the first voltage to a second word line group distal from the selected word line, wherein a program operation is performed on the first word line group and the second word line group before the first channel initialization period;

applying a first program voltage to the selected word line during a first program execution period in order to perform a first program operation for data;

during a second channel initialization period, applying the first voltage to the selected word line and the first word line group, and applying the second voltage to the second word line group;

applying a second program voltage to the selected word line during a second program execution period in order to perform a second program operation for the data;

performing the program operation on an adjacent word line included in a third word line group between the first program execution period and the second channel initialization period; and

applying the first voltage to the adjacent word line during the second channel initialization period,

wherein the second channel initialization period follows the program operation on the adjacent word line.

2. The method of claim 1 , wherein the selected word line is disposed between the third word line group and the first word line group, the first word line group is disposed above the selected word line, and the second word line group is disposed above the first word line group.

3. The method of claim 2 , further comprising:

applying ground voltage to the first word line group during the first channel initialization period; and

applying ground voltage to at least one word line other than the adjacent word line in the first word line group, in the second channel initialization period.

4. The method of claim 2 , further comprising:

during a word line setup period between the second channel initialization period and the second program execution period, applying a third voltage lower than the second voltage to the first word line group, the second word line group and the selected word line, and

applying a fourth voltage equal to or lower than the first voltage to the adjacent word line.

5. The method of claim 4 , wherein during the word line setup period, a program operation on memory cells connected to the first word line group and the second word line group is completed, and a program operation on a memory cell connected to the adjacent word line is not completed.

6. The method of claim 1 , further comprising:

during a word line setup period between the first channel initialization period and the first program execution period, applying a third voltage lower than the first voltage and lower than the second voltage to the first word line group, the second word line group and the selected word line.

7. The method of claim 6 , wherein the third voltage is ground voltage.

8. The method of claim 1 , wherein a program operation programming data to a memory cell connected to the selected word line is completed by the first program operation and the second program operation,

the memory cell is programmed from an erase state to one of N program states by the first program operation, N being a positive integer, and

the second program operation is a reprogram operation.

9. The method of claim 1 , wherein a program operation programming data to a memory cell connected to the selected word line is completed by the first program operation and the second program operation,

the memory cell is programmed from an erase state to one of M program states by the first program operation, M being a positive integer, and thereafter, and

the memory cell is programmed from the one of M program states to one of N program states by the second program operation, N being a positive integer greater than M.

10. The method of claim 1 , wherein the second word line group is disposed on an upper portion of a substrate, the first word line group is disposed on an upper portion of the second word line group, the selected word line is disposed on an upper portion of the first word line group, and a third word line group is disposed above the selected word line, and

the method further comprises:

performing a program operation on an adjacent word line included in the third word line group between the first program execution period and the second channel initialization period.

11. The method of claim 1 , wherein during each of the first channel initialization period and the second channel initialization period, a precharge voltage is applied to a common source line, a bit line program voltage is applied to a selected bit line, and a bit line program inhibit voltage is applied to an unselected bit line.

12. The method of claim 1 , wherein a program operation programming data to a memory cell connected to the selected word line is completed by the first program operation and the second program operation.

13. The method of claim 1 , wherein the non-volatile memory device includes a first memory stack on a substrate and a second memory stack vertically stacked on the first memory stack,

the selected word line, the first word line group, and the second word line group are connected to at least one of the first memory stack and the second memory stack,

during the first channel initialization period and the second channel initialization period, a same voltage is applied to word lines connected to the second memory stack, and

during the first channel initialization period and the second channel initialization period, a same voltage is applied to word lines connected to the first memory stack.