Non-volatile memory having 3D array architecture with bit line voltage control and methods thereof

摘要

In a 3D memory with vertical local bit lines, each local bit line is switchably connected to a node on a global bit line having first and second ends, the local bit line voltage is maintained at a predetermined reference level in spite of being driven by a bit line driver from a first end of the global bit line that constitutes variable circuit path length and circuit serial resistance. This is accomplished by a feedback voltage regulator comprising a voltage clamp at the first end of the global bit line controlled by a bit line voltage comparator at the second end of the global bit line. The comparator compares the bit line voltage sensed from the second end with the predetermined reference level and outputs a control voltage to control the voltage clamp In this way the voltage at the local bit line is regulated at the reference voltage.

主权项

1. A non-volatile memory, comprising:
a local bit line; a global bit line of finite resistance having first and second ends; a switch for switchably connecting said local bit line to a node on said global bit line; a voltage supply for supply a first voltage to the first end of said global bit line; so that a local bit line voltage appears at the node connecting to said local bit line; a bit line voltage control circuit having a voltage clamp and a comparator; the comparator responsive to a comparison between a predetermined reference voltage and a second voltage sensed from the second end to output a control voltage; and the voltage clamp, responsive to the control voltage, controls the first voltage at the first end such that the local bit line is maintained at the predetermined reference voltage irrespective of the resistance in said global bit line.