Nonvolatile Memory Block Unselecting Circuit Row Decoder Area Reduction
Solution Overview
Problem
The existing nonvolatile memory devices have a large peripheral circuit area, particularly the row decoder, which increases costs due to the need to apply off-voltages to all string selection lines during block unselection, leading to inefficiencies and higher manufacturing costs.
Innovation Solution
A nonvolatile memory device design where the block unselecting circuit is connected only to specific string selection lines, rather than all of them, allowing for the application of off-voltages only to those lines during block unselection, thereby reducing the size and complexity of the row decoder.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the block unselecting circuit is connected to all string selection lines, then all string selection lines can be properly controlled during block unselection, but the peripheral circuit area and device complexity increase significantly
Solution Approach 1:
The patent segments the string selection lines into two groups: first string selection lines that are connected to the block unselecting circuit, and second string selection lines that are not connected. This segmentation allows the circuit to control only the necessary lines during block unselection, reducing the overall circuit area while maintaining proper control functionality.
Solution Approach 2:
The patent extracts or removes the connection between the block unselecting circuit and the second string selection lines. By taking out these unnecessary connections, the circuit complexity is reduced while the essential block unselection control for the first string selection lines remains intact.
2Reliability
If the block unselecting circuit is connected to all string selection lines, then complete control is achieved, but manufacturing costs increase due to larger peripheral circuit area
Solution Approach 1:
The patent segments the string selection lines into first and second groups, connecting the block unselecting circuit only to the first group. This segmentation reduces the number of connections required, thereby reducing manufacturing complexity and cost while maintaining adequate control functionality.
Solution Approach 2:
The patent extracts the unnecessary connections between the block unselecting circuit and second string selection lines. This extraction simplifies the manufacturing process and reduces costs while preserving the essential control capability for block unselection operations.
3Reliability
If the block unselecting circuit provides off-voltage to all string selection lines, then proper unselection is achieved, but the number of transistors and circuit elements increases
Solution Approach 1:
The patent segments the string selection lines into first and second groups, with the block unselecting circuit providing off-voltage only to the first group through non-selection path transistors. This segmentation reduces the total number of transistors required while maintaining proper unselection functionality for the connected lines.
Solution Approach 2:
The patent extracts the non-selection path transistors that would be needed for second string selection lines. By taking out these unnecessary transistors, the overall transistor count is reduced while the unselection functionality for the first string selection lines remains intact.
Data Source
AI summary
A nonvolatile memory device includes a first memory block including a plurality of cell transistors interconnected with a plurality of ground selection lines, a plurality of word lines, and a plurality of string selection lines, which are stacked in a direction perpendicular to a substrate, a block selecting circuit that is connected with the plurality of ground selection lines, the plurality of word lines, and the plurality of string selection lines, and provides corresponding driving voltages to the plurality of ground selection lines, the plurality of word lines, and the plurality of string selection lines in response to a block selection signal, respectively, and a block unselecting circuit that is connected only with specific string selection lines of the plurality of string selection lines, and provides an off-voltage only to the specific string selection lines in response to a block un-selection signal.