Two-side staircase pre-charge in sub-block mode of three-tier non-volatile memory architecture

A controller in communication with a memory apparatus including memory cells each connected to one of a plurality of word lines and disposed in strings and configured to retain a threshold voltage corresponding to one of a plurality of data states, the controller configured to:

• instruct the memory apparatus to ramp a voltage applied to a selected one of the plurality of word lines from a verify voltage to a reduced voltage during at least one program-verify portion of at least one program loop of a program operation, and
• instruct the memory apparatus to successively ramp voltages applied to each of a plurality of neighboring ones of the plurality of word lines from a read pass voltage to the reduced voltage beginning with ones of the plurality of neighboring ones of the plurality of word lines immediately adjacent the selected one of the plurality of word lines and progressing to others of the plurality of neighboring ones of the plurality of word lines disposed increasingly remotely from the selected one of the plurality of word lines during the at least one program-verify portion of the at least one program loop of the program operation.

A method of operating a memory apparatus including memory cells each connected to one of a plurality of word lines and disposed in strings and configured to retain a threshold voltage corresponding to one of a plurality of data states, the method comprising the steps of:

• ramping a voltage applied to a selected one of the plurality of word lines from a verify voltage to a reduced voltage during at least one program-verify portion of at least one program loop of a program operation;
• and
• successively ramping voltages applied to each of a plurality of neighboring ones of the plurality of word lines from a read pass voltage to the reduced voltage beginning with ones of the plurality of neighboring ones of the plurality of word lines immediately adjacent the selected one of the plurality of word lines and progressing to others of the plurality of neighboring ones of the plurality of word lines disposed increasingly remotely from the selected one of the plurality of word lines during the at least one program-verify portion of the at least one program loop of the program operation.