Systems and methods in accordance with various embodiments can provide for
reduced program disturb in non-volatile semiconductor memory. In one
embodiment, select memory cells such as those connected to a last word
line of a NAND string are programmed using one or more program verify
levels or voltages that are different than a corresponding level used to
program other cells or word lines. One exemplary embodiment includes
using a lower threshold voltage verify level for select physical states
when programming the last word line to be programmed for a string during
a program operation. Another embodiment includes applying a lower program
voltage to program memory cells of the last word line to select physical
states. Additional read levels are established for reading the states
programmed using lower verify levels in some exemplary implementations. A
second program voltage step size that is larger than a nominal step size
is used in one embodiment when programming select memory cells or word
lines, such as the last word line to be programmed for a NAND string.