Interconnect Dummy Pattern Layout for Overlay Shift Reduction
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Solution Overview
Problem
As semiconductor devices integrate more components into smaller areas, issues arise with pattern density biases between neighboring regions, leading to overlay shifts and defects during manufacturing, which are not effectively addressed by existing technologies.
Innovation Solution
The formation of a dummy insertion structure with stepped pattern densities within dielectric layers helps to reduce pattern density biases by inserting dummy overlays in designated areas, improving the uniformity of pattern densities and reducing overlay shifts through the use of a dummy insertion template in the design system file.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If more components are integrated into a given area, then integration density is improved, but pattern density biases between neighboring regions worsen
Solution Approach 1:
The patent applies local quality by inserting dummy structures specifically in low-pattern-density regions to create localized pattern density adjustments. This allows neighboring regions to have more uniform pattern densities without changing the overall device design, resolving the contradiction between high integration density and pattern density uniformity.
Solution Approach 2:
The patent changes the pattern density parameter in specific regions by adding dummy structures with predetermined patterns. This modifies the local pattern density values to reduce biases between neighboring regions, enabling better overlay control while maintaining high component integration density.
2Length of moving object
If minimum feature size is reduced, then integration density is improved, but overlay shifts worsen
Solution Approach 1:
The patent addresses overlay alignment issues by applying local quality corrections through dummy structures in specific low-pattern-density regions. This compensates for overlay shifts that occur when minimum feature sizes are reduced, allowing continued scaling without sacrificing alignment precision.
Solution Approach 2:
The patent uses preliminary anti-action by pre-inserting dummy structures to counteract anticipated overlay shifts before the actual lithography process. This preemptive measure compensates for the increased overlay sensitivity that results from reduced minimum feature sizes.
3Manufacturing precision
If dummy structures are inserted to reduce pattern density biases, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent treats dummy structures as temporary, disposable elements that serve their purpose during manufacturing and are subsequently removed or rendered non-functional. This allows the use of complex-looking dummy structures to improve pattern density uniformity without permanently increasing device complexity, as these structures are not part of the final functional device.
Solution Approach 2:
The patent extracts only the necessary dummy structures from the overall device design, placing them only in low-pattern-density regions where they are needed. This selective approach improves pattern density uniformity while minimizing the addition of unnecessary structural complexity to the final device.
Data Source
AI summary
Semiconductor devices and methods of manufacturing the semiconductor devices are described herein. A method includes forming an interconnect structure over a device wafer. The device wafer includes a first integrated circuit, a semiconductor substrate, and a redistribution structure. The method further includes forming a metallization layer and a group of dummy insertion structures having a stepped pattern density in a topmost dielectric layer of the interconnect structure. The group of dummy insertion structures and the metallization layer are planarized with the dielectric layer. The method further includes forming a first bonding layer over the group of dummy insertion structures, the metallization layer, and the dielectric layer. The method further includes bonding a carrier wafer to the first bonding layer, forming an opening through the semiconductor substrate, and forming a conductive via in the opening and electrically coupled to the redistribution structure.