Overlapping Feature Stack With Dummy Supports for Memory Arrays
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Solution Overview
Problem
In integrated circuit fabrication, the formation of smaller and denser memory cells is hindered by the lack of support for stair-like end portions in arrays, leading to potential sagging or breaking of floors/ceilings between void spaces during processing.
Innovation Solution
The implementation of a stack of horizontally extending and vertically overlapping features, where dummy structures are formed in the end portion to support the features from vertical movement, preventing sagging or breaking by laterally engaging side portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If memory cells are made smaller to increase density, then productivity and circuit density improve, but structural stability deteriorates due to lack of support in stair-like end portions
Solution Approach 1:
Dummy structures are formed in advance in the end portion of the stack to provide support before actual processing occurs. This preliminary structural reinforcement prevents sagging or breaking of floors/ceilings during subsequent fabrication steps, enabling the production of smaller, denser memory cells without compromising structural integrity.
2Reliability
If dummy structures are added to support end portions, then structural stability improves, but device complexity increases
Solution Approach 1:
The stack is divided into two functional regions: a primary portion containing operative structures and an end portion containing dummy structures. This segmentation allows the dummy structures to be localized only where structural support is needed, rather than complicating the entire device structure. The dummy structures serve as a separate support system that does not interfere with the functional operative structures.
3Length of moving object
If features are made smaller to reduce component size, then component size decreases, but manufacturing precision requirements increase due to potential sagging or breaking
Solution Approach 1:
Dummy structures are positioned in advance in the end portion to act as a cushioning support system. This preliminary support structure prevents floors/ceilings from sagging or breaking during processing, thereby maintaining dimensional control and manufacturing precision even when features are scaled down to smaller sizes.
Data Source
AI summary
A method of forming circuitry components includes forming a stack of horizontally extending and vertically overlapping features. The features extend horizontally though a primary portion of the stack with at least some of the features extending farther in the horizontal direction in an end portion. Operative structures are formed vertically through the features in the primary portion and dummy structures are formed vertically through the features in the end portion. Openings are formed through the features to form horizontally elongated and vertically overlapping lines from material of the features. The lines individually extend laterally about sides of vertically extending portions of both the operative structures and the dummy structures. Sacrificial material that is elevationally between the lines is at least partially removed in the primary and end portions laterally between the openings. Other aspects and implementations are disclosed.