Edge Seal Moat Trench Etching Without Metal 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 hard mask layer with peripheral discrete openings, followed by an anisotropic etch process to create peripheral discrete via cavities, which are then expanded to form a continuous moat trench, and a conductive edge seal structure is formed to prevent arcing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a continuous conductive hard mask layer is formed over the dielectric material portion, then the edge seal structure can be formed, but metal hard mask arcing occurs during the etch process
Solution Approach 1:
The continuous conductive hard mask layer is segmented into discrete openings at peripheral locations. This segmentation breaks the electrical continuity of the hard mask layer, preventing arcing during the etch process while maintaining sufficient coverage to define the edge seal structure. The peripheral discrete openings are strategically positioned to interrupt potential arc paths without compromising the edge seal formation.
Solution Approach 2:
The hard mask layer exhibits different properties in different regions: in the central region, it forms a continuous layer for proper edge seal definition, while at peripheral locations, it has discrete openings to prevent arcing. This local variation in continuity allows the structure to simultaneously achieve reliable edge seal formation and eliminate arcing hazards at critical peripheral areas where arcing is most likely to occur.
2Object-affected harmful factors
If peripheral discrete openings are formed in the conductive hard mask layer, then arcing is prevented, but the manufacturing process complexity increases
Solution Approach 1:
The peripheral discrete openings are formed in the hard mask layer before the edge seal etch process begins. This preliminary action ensures that the arcing prevention feature is already in place when etching commences, eliminating the need for additional corrective steps or post-processing to address arcing issues. The openings are pre-configured to match the expected arc paths based on device geometry and process conditions.
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
The method effectively reduces or prevents arcing during the etch process, ensuring the integrity and reliability of semiconductor device manufacturing.
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.