3D NAND Pillar Formation With Merged Source Contact Etch
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Solution Overview
Problem
Conventional processes for forming memory cell pillars and contact pillars in 3-D NAND memory devices require separate steps, which can impact the structure of the memory cell pillars and increase manufacturing costs.
Innovation Solution
A process is introduced to merge the formation of memory cell pillars and contact pillars, allowing for concurrent formation at different locations in the source structure, thereby improving the etch profile and reducing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If separate process steps are used to form memory cell pillars and contact pillars, then the structure of memory cell pillars can be maintained, but manufacturing cost increases and etch profile is impacted
Solution Approach 1:
The patent merges the formation of memory cell pillars and contact pillars into a single concurrent etch process. By using a unified mask pattern and performing one etch operation instead of separate steps, the process reduces complexity while maintaining etch profile quality. The merged process forms both pillar structures simultaneously from the same source structure, eliminating the need for multiple sequential process steps.
2Ease of manufacture
If separate process steps are used to form memory cell pillars and contact pillars, then manufacturing precision can be maintained, but manufacturing cost increases
Solution Approach 1:
The patent combines the formation of memory cell pillars and contact pillars into a single manufacturing step, reducing the total number of process steps required. This merger lowers manufacturing cost by reducing equipment usage, material consumption, and processing time while maintaining structure integrity through a unified etch process that preserves the source structure.
Solution Approach 2:
The unified etch process serves multiple functions simultaneously: it forms memory cell pillars, forms contact pillars, and maintains the source structure integrity. This multi-functional approach eliminates the need for separate dedicated processes for each structure type, improving ease of manufacture while preserving manufacturing precision.
3Productivity
If concurrent formation process is used for memory cell pillars and contact pillars, then manufacturing cost is reduced and etch profile is improved, but process complexity increases
Solution Approach 1:
The patent integrates memory cell pillar and contact pillar formation into a single concurrent process step, improving productivity by reducing the total number of manufacturing steps. The process integration is achieved through a unified mask and etch operation that simultaneously creates both pillar types, reducing equipment cycles and manufacturing time while managing process complexity through standardized procedures.
Data Source
AI summary
Some embodiments include apparatuses and methods of forming the apparatuses. One of the methods includes forming levels of materials one over another; forming a first opening and a second opening in the levels of materials; forming at least one dielectric material in the first and second openings; forming tiers of materials over the levels of materials and over the dielectric material in the first and second openings; forming a first pillar of a memory cell string, the first pillar extending through the tiers of materials and extending partially into a location of the first opening; and forming a second pillar of a contact structure, the second pillar extending through the tiers of materials and through a location of the second opening.