Dummy Word Line Plug Layout for Backside Source Diffusion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In vertical planar memory cells, the backside source formation process leads to inefficiencies due to source material diffusion into unintended regions, affecting voltage threshold control and reliability, and the connection between conductive plugs and bit line structures results in varying electric fields and reduced current flow.
Innovation Solution
A combined plug, selector, and voltage line structure is implemented, with the plug connected to bit line structures through a curved connection region, and voltage lines positioned to maintain consistent electric fields, reducing source material diffusion and enhancing current flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional plug structure is used in vertical planar memory cells, then the structure is simple, but source material diffuses into unintended regions during backside source formation, affecting voltage threshold control and reliability
Solution Approach 1:
The plug structure is segmented into multiple functional regions: a main plug body, a curved connection region with rounded corners, and an extended portion. This segmentation allows each region to serve its specific function - the main body provides structural support, the curved region minimizes source material diffusion, and the extended portion ensures proper electrical connection, thereby improving reliability without excessive complexity
Solution Approach 2:
The curved connection region with rounded corners is designed in advance to prevent source material diffusion during the backside source formation process. By pre-configuring this protective geometric feature before the diffusion process occurs, the patent proactively prevents contamination of unintended regions, ensuring voltage threshold control and reliability
2Productivity
If a straight connection between plug and bit line structures is used, then the structure is simple, but varying electric fields are created that reduce current flow efficiency
Solution Approach 1:
The connection region between the plug and bit line structures uses curved geometries with rounded corners instead of sharp angles or straight lines. This curvature creates a more uniform distribution of electric fields in the connection region, eliminating field concentration effects that would reduce current flow. The curved design improves current flow efficiency while adding minimal structural complexity
Solution Approach 2:
The patent modifies the geometric parameters of the connection region by introducing curved paths and rounded corners with specific radius values. These parameter changes optimize the electric field distribution and current flow characteristics, transforming the connection region from a simple straight path into an optimized curved pathway that enhances productivity
Data Source
AI summary
Methods, systems, and devices for dummy word line positioning for a plug for protection of backside source formation of vertical planar memory cells are described. A plug structure within a memory system may reduce exposure of portions of the memory system to a source material during a backside source formation process while improving current flow via bit line structures connected to the plug. During the backside source formation, the plug may stop diffused source materials from affecting access lines or other areas of the memory system. The plug may be in contact with a selector and one or more voltage lines configured to activate the bit line structures. The physical positioning of the voltage lines relative to the bit line structures, as well as various magnitudes of voltages applied to the voltage lines during access operations, may increase string current through the plug and bit line structures.