Protective structure to prevent short circuits in a three-dimensional memory device

摘要

In a three-dimensional stacked non-volatile memory device, a short circuit is prevented in a select gate layer by providing a protective material such as a diode, capacitor, linear resistor or varistor between select gate lines and a remaining portion of the select gate layer. Charges which are accumulated in the select gate lines due to plasma etching are therefore prevented from discharging through the remaining portion in a short circuit path when the select gate lines are driven. The protective material can comprise a p-n diode, an n-i-n or p-i-p resistor, a thin oxide layer between doped polysilicon layers in a capacitor, or a variable-resistance material such as ZnO2 between oxide layers in a varistor.

主权项

1. A memory device, comprising:
a stacked three-dimensional memory structure comprising alternating conductive layers and dielectric layers, the conductive layers comprising a select gate layer, the select gate layer comprises parallel select gate lines and a remaining portion of the select gate layer, the remaining portion of the select gate layer extends transversely to the parallel select gate lines and is separated from the parallel select gate lines by an end trench at one end of the parallel select gate lines, the parallel select gate lines are separated from one another by side trenches, the end trench is connected to the side trenches, an oxide is provided in the side trenches, a protective structure is provided in the end trench, and a breakdown voltage of the protective structure is higher than a breakdown voltage of the oxide in the side trenches.