Protective Liner for Memory Block Isolation
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Solution Overview
Problem
The existing methods for isolating memory blocks in vertical memory arrays using insulating materials often damage the memory structures and staircase regions due to contamination, leading to electrical issues and contact formation problems.
Innovation Solution
A method involving a single, relatively thick protective liner layer is used to protect memory structures and avoid interference with electrical contacts, where the liner is formed on the memory structures and in the opening between blocks, and the isolating material is disposed on the liner, with both layers being removed to minimize electrical interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If isolating material is disposed across the entire memory array to fill slits between memory blocks, then memory blocks are effectively isolated, but memory structures and staircase contacts are damaged due to contamination from the isolating material
Solution Approach 1:
A protective liner layer is introduced as an intermediary between the memory structures and the isolating material. This liner is formed conformally over the memory structures and in the slits, then selectively removed from the memory structures while remaining in the slits to provide isolation. The liner acts as a temporary mediator that prevents direct contact between the isolating material and memory structures, thereby eliminating contamination damage while maintaining effective block isolation.
Solution Approach 2:
The protective liner is formed in advance before the isolating material is deposited. This preliminary protective layer is deposited conformally to cover the memory structures and extend into the slits, providing pre-protection against subsequent isolating material contamination. The liner is then selectively removed from the memory structure surfaces while retaining its isolation function in the slits.
2Object-affected harmful factors
If a protective liner layer is formed to protect memory structures from isolating material, then damage to memory structures is prevented, but the liner may interfere with contact formation in staircase regions
Solution Approach 1:
The protective liner is applied with spatially varying properties: it is formed conformally over all surfaces including memory structures and staircase regions, then selectively removed from the memory structures while being retained in the slits and staircase regions. This creates local quality differences where the liner provides protection where needed (in slits) while being absent where it would interfere (on memory structure tops). The local removal strategy ensures both protection and electrical contact functionality.
3Object-affected harmful factors
If multiple process steps are used to protect and then remove liner material, then memory structures are protected during isolation, but the process complexity increases and productivity decreases
Solution Approach 1:
The removal of the protective liner from memory structures and the deposition of isolating material are merged into a single continuous process flow. The liner is formed conformally, then selectively removed in-situ using a targeted etch or dissolution process that removes the liner only from memory structure surfaces while leaving it intact in the slits. This eliminates separate protection and removal steps, reducing process complexity while maintaining protection during isolation.
Data Source
AI summary
Computer memory technology is disclosed. In one example, a method for isolating computer memory blocks in a memory array from one another can include forming an opening between adjacent blocks of memory structures. The method can also include forming a protective liner layer on at least the memory structures. The method can further include disposing isolating material in the opening and on the protective liner layer. The method can even further include removing the isolating material on the protective liner layer. The method can additionally include removing the protective liner layer on the memory structures. Associated devices and systems are also disclosed.