Via Configuration Under Wiring Bending Portions
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Solution Overview
Problem
In conventional semiconductor devices, vias formed under bending portions often have notches, leading to low metal filling rates and decreased manufacturing yield due to deformed shapes.
Innovation Solution
The vias are designed to avoid overlapping with bending portions, with specific configurations such as longer lengths in one direction and projections to include bending portions, ensuring no notches and improved metal filling rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a via is formed under a bending portion of a wiring using conventional self-alignment method, then the via formation process is simplified, but the via shape becomes deformed with notches leading to low metal filling rates
Solution Approach 1:
The via pattern is designed in advance to be offset from the bending portion of the wiring pattern. This preliminary positioning prevents the self-alignment process from creating notched via shapes, thereby maintaining via shape accuracy while still using the simplified self-aligned formation process.
2Device complexity
If the via pattern is aligned with the wiring pattern for self-alignment, then the alignment process is simplified, but the via overlaps with the bending portion causing shape deformation
Solution Approach 1:
The via pattern is intentionally positioned asymmetrically relative to the wiring pattern, specifically offset from the bending portion. This asymmetric placement prevents overlap with the bending region while still maintaining a simplified alignment process based on the wiring pattern.
3Area of stationary object
If via patterns are formed with standard minimum dimensions, then the wiring density is increased, but the via shapes become deformed when located under bending portions
Solution Approach 1:
The via pattern positioning is adjusted locally based on its proximity to wiring bending portions. Vias near bending portions are offset to avoid deformation, while other vias can maintain standard minimum dimensions. This localized adjustment preserves overall wiring density while ensuring reliable metal filling for critical vias.
Data Source
AI summary
A first wiring (1) has a bending portion (2), a first wiring region (1a) extending from the bending portion (2) in the X direction, and a second wiring region (1b) extending from the bending portion (2) in the Y direction. A via (3) is formed under the wiring (1). The via (3) is formed so as not to overlap with a region of the bending portion (2) in the first wiring region (1a). The length of the via (3) in the X direction (x) is longer than the length thereof in the Y direction (y) and both ends of the via (3) in the Y direction overlap with both ends of the first wiring region (1a) in the Y direction.