Support Pillars in Vertical Memory Slots to Prevent Stack Collapse
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Solution Overview
Problem
Vertical memory arrays in non-volatile memory devices face issues of stack collapse during processing due to increased height, leading to reduced reliability and potential for undesirable tier deformations and current leakage.
Innovation Solution
Incorporation of support pillars within slot regions between pillar array blocks, combined with a barrier material, provides structural support to the stack during conductive structure formation, preventing tier collapse and reducing current leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the height of stacks is increased to provide additional memory density, then memory density is improved, but the stacks become prone to toppling or collapse during processing
Solution Approach 1:
The invention divides the slot region into multiple segments by forming barrier material portions at different vertical levels within the slot. These barrier material segments create discrete support pillar openings at different heights, allowing support pillars to be positioned at multiple levels along the stack. This segmentation provides distributed structural support throughout the stack height, preventing collapse while maintaining high memory density.
2Reliability
If replacement gate processing is conducted to form conductive structures, then electrical connections are improved, but tier collapse may occur during or after removal of portions of tiers
Solution Approach 1:
The invention performs preliminary action by forming barrier material portions within the slot region before conducting replacement gate processing. These pre-formed barrier material structures provide structural support to the tiers during the subsequent removal and replacement operations. The support pillars are positioned in advance to prevent tier collapse during or after the removal of tier portions, ensuring both electrical connection quality and structural integrity.
3Strength
If support pillars are added to prevent stack collapse, then structural integrity is improved, but device complexity increases
Solution Approach 1:
The invention applies multi-functionality by using barrier material that serves dual purposes: (1) as a structural support element to prevent stack collapse, and (2) as a defining structure for creating support pillar openings. The same barrier material formation process that creates structural support also establishes the precise locations for support pillars. This universal approach provides structural integrity while minimizing additional fabrication steps and device complexity.
Data Source
AI summary
An electronic device comprises a stack comprising tiers of alternating conductive levels and insulative levels overlying a source, slots extending vertically through the stack and dividing the stack into blocks, and support pillars within the slots and extending vertically through the stack. The support pillars exhibit a lateral dimension in a first horizontal direction relatively larger than a lateral dimension of the slots in the first horizontal direction, substantially orthogonal to a second horizontal direction in which the slots extend. Related memory devices, systems, and methods are also described.