Semiconductor Edge Seal Moat Trench Without Hard Mask Arcing
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Solution Overview
Problem
Metal hard mask arcing occurs during the manufacture of edge seals for semiconductor devices, posing a challenge in the production process.
Innovation Solution
A method involving the formation of a conductive edge seal structure by filling a continuous moat trench with conductive material, which includes forming peripheral discrete openings and via cavities through a conductive hard mask layer, and then isotropically expanding these cavities to create a laterally undulating trench.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional edge seal formation process is used, then the manufacturing process is simpler, but metal hard mask arcing occurs causing process failures
Solution Approach 1:
The patent divides the continuous hard mask layer into discrete segments by forming isolated openings at regular intervals along the edge seal region. This segmentation prevents arcing by breaking the continuous conductive path that would otherwise allow electrical discharge through the hard mask layer during subsequent processing steps.
Solution Approach 2:
The patent performs preliminary etching of via holes through the hard mask layer and dielectric layer before forming the edge seal structure. This preliminary action creates discrete openings that prevent arcing during later processing steps, addressing the reliability issue before the edge seal is actually formed.
2Manufacturing precision
If the hard mask layer is made more conductive to improve edge seal formation, then the edge seal quality improves, but metal hard mask arcing occurs
Solution Approach 1:
The patent extracts or removes portions of the continuous hard mask layer by forming discrete openings through it. This takes out the problematic continuous conductive path while retaining the hard mask layer in other regions where it provides beneficial edge seal formation, thus separating the harmful arcing effect from the useful edge seal function.
Solution Approach 2:
The patent introduces dielectric material as an intermediary substance filling the openings formed through the hard mask layer. This intermediary prevents direct electrical contact across the hard mask layer, blocking the arcing path while allowing the hard mask layer to maintain its conductive properties for edge seal formation in the continuous regions.
3Object-generated harmful factors
If discrete openings are formed through the hard mask layer to prevent arcing, then arcing is prevented, but the manufacturing process becomes more complex
Solution Approach 1:
The patent makes the discrete openings serve multiple functions: they prevent hard mask arcing by breaking the conductive path, and they simultaneously serve as via holes for forming subsequent conductive structures and edge seal contacts. This multi-functionality reduces the need for separate process steps, offsetting the added complexity with process integration benefits.
Solution Approach 2:
The patent merges the formation of arcing-prevention openings with the formation of via holes for the edge seal structure. By combining these two functions into a single set of openings formed through the same process steps, the patent reduces the overall process complexity compared to forming separate openings for each function.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Prevents metal hard mask arcing and ensures the formation of a robust conductive edge seal structure, enhancing the manufacturing process efficiency and device integrity.
Implementation Method 1
forming a set of peripheral discrete via cavities through the dielectric material portion down to a top surface of the semiconductor substrate by performing an anisotropic etch process that etches a material of the dielectric material portion underneath the set of peripheral discrete openings
Implementation Method 2
forming a continuous moat trench that laterally surrounds an inner region of the dielectric material portion by isotropically expanding the set of peripheral discrete via cavities
Data Source
AI summary
A conductive hard mask layer can be patterned with peripheral discrete openings. An anisotropic etch process can be performed to form peripheral discrete via cavities, which are subsequently expanded to form a continuous moat trench. An edge seal structure can be formed in the continuous moat trench. Alternatively, a conductive bridge structure may be formed prior to formation of a patterned conductive hard mask layer, and a moat trench can be formed around a periphery of the semiconductor die while the conductive bridge structure provides electrical connection between an inner portion and an outer portion of the conductive hard mask layer. The entire conductive hard mask layer can be electrically connected to a semiconductor substrate to reduce or prevent arcing during an anisotropic etch process that forms the peripheral discrete via cavities or the moat trench.