Suppression of Read Disturb Fail Caused by Boosting Hot Carrier Injection Effect for 3-D Stack NAND Flash Memories

A new bias pulse method was proposed to suppress read disturbance in unselected strings of 3-D stack NAND flash memories. Using the proposed read method, we could suppress effectively a large cell Vth shift generated by boosting hot carrier injection. As a result, the cell Vth shift in unselected string is quite similar to normal read disturbance in select string. The proposed read method was verified by both measurement and simulation.