Nonvolatile memory device and method of operating the same

A method of performing a program operation using a nonvolatile memory device, the method comprising:

• when a verification voltage of a selected memory cell coupled to a selected word line is higher than a reference voltage, supplying a first pass voltage to a number of word lines other than the selected word line or, when the verification voltage of the selected memory cell is lower than the reference voltage, supplying a second pass voltage lower than the first pass voltage to a number of the word lines other than the selected word line;
• and
• supplying a verification voltage to the selected word line.

A method of performing a program operation using a nonvolatile memory device, the method comprising:

• during a verification operation, supplying a first pass voltage to a number of word lines other than a selected word line, when a verification voltage of a selected memory cell coupled to the selected word line is lower than a first reference voltage, supplying a second pass voltage higher than the first pass voltage to a number of the word lines other than the selected word line when the verification voltage is higher than the first reference voltage but lower than a second reference voltage, and supplying a third pass voltage higher than the second pass voltage to a number of the word lines other than the selected word line when the verification voltage is higher than the second reference voltage;
• and
• supplying a verification voltage to the selected word line.