Damascene Structure via Etch Stop Layer Alignment
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Solution Overview
Problem
The challenge in semiconductor manufacturing lies in forming reliable semiconductor devices at increasingly smaller sizes, where the complexity of processing and manufacturing increases due to decreasing feature sizes, leading to difficulties in achieving precise and reliable interconnections.
Innovation Solution
A semiconductor device structure is formed using a patterned etch stop layer between dielectric layers, with multiple mask elements to define precise positions for conductive vias and trenches, preventing overlay shifts and ensuring accurate formation of conductive features, thereby improving the quality and precision of the damascene structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If feature sizes continue to decrease to increase functional density, then production efficiency improves and costs lower, but processing complexity increases and manufacturing reliability deteriorates
Solution Approach 1:
The patent divides the interconnection formation process into multiple sequential steps: forming mandrels, depositing first spacers, forming trenches, depositing second spacers, and forming conductive features. This segmentation allows each step to be optimized independently, maintaining reliability while enabling smaller feature sizes.
Solution Approach 2:
The patent performs preliminary actions by forming mandrels and spacers before the actual conductive feature formation. The spacers are deposited and patterned in advance to define precise locations for subsequent trenches and conductive features, ensuring alignment accuracy even at reduced feature sizes.
2Manufacturing precision
If multiple mask elements and etch stop layers are used to ensure precise positioning, then manufacturing precision improves, but device complexity increases
Solution Approach 1:
The patent introduces intermediary structures (mandrels and spacers) that mediate between the patterning process and the final conductive feature formation. These intermediaries serve as temporary guides that simplify the overall process by breaking down complex positioning requirements into manageable steps.
Solution Approach 2:
The patent transitions from two-dimensional planar patterning to three-dimensional structures by forming vertical spacers and trenches. This dimensional change provides additional degrees of freedom for positioning, allowing precise control of conductive feature locations without requiring increasingly complex planar mask patterns.
Data Source
AI summary
A method for forming a semiconductor device structure includes forming a first dielectric layer over a semiconductor substrate and forming an etch stop layer with a hole over the first dielectric layer. The method also includes forming a second dielectric layer over the etch stop layer and forming a first mask element with a trench opening over the second dielectric layer. The method further includes forming a second mask element over the first mask element, and the second mask element has a via opening. In addition, the method includes etching the second dielectric layer through the via opening and etching the second dielectric layer through the trench opening. As a result, a trench and a via hole are formed in the second dielectric layer and the first dielectric layer, respectively. The method includes forming a conductive material in the via hole and the trench.