DRAM Capacitor Support Lattice for Lateral Movement Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Dynamic Random Access Memory (DRAM) cells are prone to lateral movement of capacitor elements, which can lead to damage and inoperability due to lateral contact between adjacent capacitors, compromising the integrity of the memory cell array.
Innovation Solution
A support lattice is formed around the capacitor elements in the DRAM array, using a mask to create self-aligned openings that limit lateral movement while allowing access to portions of the memory cells, thereby preventing contact between capacitors and maintaining array integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If capacitor elements are made movable or flexible, then ease of manufacture is improved, but reliability deteriorates due to lateral contact between adjacent capacitors
Solution Approach 1:
The support structure is segmented into a lattice pattern with discrete openings rather than a continuous structure. This segmentation provides support at critical locations while allowing capacitor elements to move freely in supported directions, preventing lateral contact between adjacent capacitors while maintaining manufacturing flexibility.
Solution Approach 2:
The support lattice provides different support characteristics in different locations and directions. The structure offers strong support in directions where lateral movement would cause capacitor contact, while allowing movement in directions that do not compromise reliability, optimizing both manufacturing ease and operational reliability.
2Reliability
If support structure is added to prevent lateral movement, then reliability is improved, but device complexity increases
Solution Approach 1:
Rather than adding a complex continuous support structure, the invention uses a segmented lattice pattern that provides necessary support with minimal material and structural complexity. The discrete openings reduce the overall complexity while maintaining reliability.
Solution Approach 2:
The support lattice acts as an intermediary structure between the substrate and capacitor elements, providing the necessary mechanical support to prevent lateral contact. This intermediary structure is designed with a simple lattice pattern that balances support functionality with low structural complexity.
3Reliability
If continuous support structure is used, then reliability is improved, but access to memory cells below is restricted
Solution Approach 1:
The continuous support structure is segmented into a lattice pattern with strategic openings. These openings provide access pathways to memory cells below while the remaining lattice portions continue to provide reliability support, resolving the contradiction between support continuity and access requirements.
Solution Approach 2:
The support structure has varying properties in different locations: solid lattice portions provide support for reliability where needed, while openings provide access pathways where required. This local differentiation allows the structure to simultaneously improve reliability and maintain ease of operation for accessing underlying memory cells.
Data Source
AI summary
Memory cell support lattices and methods of forming the same are described herein. As an example, a method of forming a memory cell support lattice includes forming a mask on a number of capacitor elements in an array, such that a space between vertically and horizontally adjacent capacitor elements is fully covered and a space between diagonally adjacent capacitor elements is partially covered and forming a support lattice in a support material by etching the support material to remove portions of the support material below the openings in the mask.