Stadium Structure Sidewall Coating to Prevent Micro-Trenching
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Solution Overview
Problem
Conventional vertical memory arrays face issues with micro-trenching when increasing the number of tiers of conductive structures, leading to device failure due to undesirably increasing the overall width of the stack structure.
Innovation Solution
The use of photoresist material coatings on sidewalls to absorb ion deflection during etching processes, preventing unintentional micro-trenching in stadium structures within the stack structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the quantity of tiers of conductive structures is increased to provide additional memory density, then memory density is improved, but micro-trenching occurs within the staircase structures leading to failure of the vertical memory array
Solution Approach 1:
A sacrificial material is introduced as an intermediary substance between the etching process and the stadium structure. This sacrificial material absorbs the harmful ion deflection during etching, preventing micro-trenching in the stadium structure while allowing the etching to proceed to create the desired staircase features for electrical access
2Quantity of substance
If the quantity of tiers of conductive structures is increased without increasing the overall width of the stack structure, then memory density is improved, but micro-trenching within the staircase structures occurs
Solution Approach 1:
The sacrificial material serves as a protective intermediary applied to the stadium structure before etching. It prevents ion-induced micro-trenching during the etching process, ensuring that the staircase structures maintain their intended geometry and manufacturing precision even as the number of tiers increases
3Manufacturing precision
If photoresist material coatings are applied on sidewalls to absorb ion deflection, then micro-trenching is prevented, but additional process steps are required
Solution Approach 1:
The sacrificial material acts as an intermediary protective layer that is applied to the stadium structure prior to etching. This material specifically targets and absorbs ion deflection during the etching process, preventing micro-trenching in the stadium structure while allowing the etching to proceed to form the staircase features
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method reduces and prevents micro-trenching, ensuring the stability and functionality of vertical memory arrays by maintaining the vertical position of stadium structures without widening the overall structure.
Implementation Method 1
The use of photoresist material coatings on sidewalls to absorb ion deflection during etching processes, preventing unintentional micro-trenching in stadium structures within the stack structure
Data Source
AI summary
A microelectronic device includes a stack structure including a vertically alternating sequence of conductive structures and insulating structures arranged in tiers, a dielectric-filled opening vertically extending into the stack structure and defined between two internal sidewalls of the stack structure, a stadium structure within the stack structure and comprising steps defined by horizontal ends of at least some of the tiers, a first ledge extending upward from a first uppermost step of the steps of the stadium structure and interfacing with a first internal sidewall of the two internal sidewalls of the stack structure, and a second ledge extending upward from a second, opposite uppermost step of the steps of the stadium structure and interfacing with a second, opposite internal sidewall of the two internal sidewalls.