Hole Penetrating Stack Structure Etching via Reflective Metal and Etch Stop Layers
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Solution Overview
Problem
The manufacturing process for three-dimensional memory devices becomes increasingly difficult and prone to defects as the number of stacked memory cells increases, leading to challenges in achieving high integration and reliability.
Innovation Solution
A method involving the formation of a first stacked structure, followed by the creation of a hole penetrating this structure, the deposition of a reflective metal pattern and an etch stop layer, and subsequent formation of a second stacked structure with a second hole to expose the etch stop layer, which simplifies the etching process and stabilizes the formation of holes, thereby reducing manufacturing complexity and defect rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of stacked memory cells is increased to achieve high integration, then the degree of integration is improved, but the manufacturing process becomes more difficult and defect rates increase
Solution Approach 1:
The patent applies preliminary action by forming etch stop layers and reflective metal patterns in holes before completing the stacking process. This allows subsequent etching operations to be more precise and stable, as the etch stop layers provide clear termination points for etching through multiple stacked structures, thereby reducing manufacturing difficulty despite increased integration levels
Solution Approach 2:
The patent introduces etch stop layers as intermediary elements between stacked memory cell layers. These etch stop layers serve as mediators that facilitate precise etching operations by providing distinct etching termination points, enabling accurate formation of holes through multiple stacked structures without increasing defect rates
2Productivity
If the number of stacked memory cells is increased to achieve high integration, then the degree of integration is improved, but defect rates increase
Solution Approach 1:
The patent forms reflective metal patterns and etch stop layers in advance before completing the stacking process. This preliminary action ensures that subsequent etching operations have precise stopping points, reducing variability and defects in hole formation through multiple stacked structures, thereby maintaining reliability despite higher integration
Solution Approach 2:
The patent replaces reliance on purely mechanical/physical stacking with a controlled chemical etching process guided by etch stop layers. This substitution allows for more precise and repeatable hole formation through the stacked structures, reducing defects caused by mechanical alignment variations
Data Source
AI summary
A manufacturing method for a semiconductor device includes forming a first stacked structure, forming a first hole penetrating the first stacked structure, forming a reflective metal pattern in the first hole, filling an etch stop layer in the first hole and over the reflective metal pattern, forming a second stacked structure over the first stacked structure, and forming a second hole penetrating the second stacked structure to expose the etch stop layer.