Methods of erasing data in nonvolatile memory devices and nonvolatile memory devices performing the same

A method of operating a nonvolatile memory device includes erasing data within a NAND string of memory cells within the memory device by applying a non-zero erase voltage to a source/drain terminal at a first end of the NAND string. This erase voltage is applied concurrently with establishing gate-induced drain leakage (GIDL) in a pair of selection transistors within the NAND string. This GIDL can occur by applying unequal and non-zero first and second voltages to respective first and second gate terminals of the pair of selection transistors. The selection transistors can be string selection transistors or ground selection transistors.