3D Memory Word Line Groups With Dummy Lines
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Solution Overview
Problem
The reliability of program operations in memory devices is compromised due to changes in threshold voltages of unselected memory cells caused by voltages applied to selected and unselected word lines in three-dimensional memory structures.
Innovation Solution
A memory device configuration that includes first and second word line groups with a dummy line group between them, where specific pass voltages are applied to unselected word lines and dummy lines to maintain voltage stability during program operations, and compensation voltages are applied to unselected word lines between the selected word line and the dummy line group to prevent voltage differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If program voltage is applied to selected word line in 3D memory structure, then memory cells in selected page are programmed, but threshold voltages of unselected memory cells change due to voltage influence
Solution Approach 1:
A dummy line group is introduced as an intermediary element between the first and second word line groups. This dummy line group acts as a voltage buffer that prevents direct voltage coupling between selected word lines in different groups, thereby preventing threshold voltage changes in unselected memory cells while maintaining program operation efficiency
Solution Approach 2:
The word lines are segmented into multiple independent groups (first word line group and second word line group) separated by the dummy line group. This segmentation allows independent voltage control of each group, enabling program operations on selected word lines without affecting unselected word lines in other groups
2Quantity of substance
If multiple word line groups are used in 3D memory structure, then memory capacity is increased, but voltage interference between groups affects program operation reliability
Solution Approach 1:
The dummy line group serves as a voltage isolation intermediary between multiple word line groups, preventing voltage interference while allowing all groups to operate simultaneously for increased memory capacity
Solution Approach 2:
The dummy line group extracts or removes the harmful voltage coupling effect between word line groups by introducing a separate voltage path that prevents direct interference, thereby enabling high-capacity operation without sacrificing reliability
Data Source
AI summary
A memory device, and a method of operating the same, includes a memory block to which first and second word line groups are coupled, and to which a first dummy line group disposed between the first and second word line groups is coupled. The memory device also includes a peripheral circuit configured to program memory cells coupled to a selected word line of the first or second word line group. The peripheral circuit is configured to, when the selected word line is included in the second word line group, when a program voltage is applied to the selected word line, apply a first pass voltage to unselected word lines included in the first and second word line groups and to dummy lines included in the first dummy line group.