Solid-State Imaging Device Wiring Shift for Peripheral Sensitivity
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Solution Overview
Problem
In solid-state imaging devices, downsizing leads to increased oblique light incidence in peripheral areas, causing light blockage by wiring layers and resulting in sensitivity deterioration, which conventional methods like shifting only the uppermost wiring layer cannot adequately address due to electrical connectivity constraints.
Innovation Solution
The solution involves shifting various wiring layers and contacts in a controlled manner across the imaging area, with specific shift amounts and arrangements to optimize light condensation while maintaining electrical connections, including the use of interlayer insulating layers and protection films to minimize light interception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the device is downsized, then the inter-pupillary distance is shortened, but the amount of oblique light incident on peripheral pixels increases causing sensitivity deterioration
Solution Approach 1:
The patent applies local quality by differentiating the wiring layer structures between central and peripheral regions of the imaging area. In peripheral regions where oblique light incidence is problematic, the wiring layers are designed with shifted arrangements and increased spacing to reduce light blockage, while central regions maintain standard configurations. This localized structural differentiation allows the device to maintain high sensitivity uniformity across the entire imaging area despite downsizing.
2Device complexity
If only the uppermost wiring layer is shifted, then the layout complexity is reduced, but light blockage by lower wiring layers still occurs causing sensitivity deterioration
Solution Approach 1:
The patent segments the wiring layer shifting strategy by layer, applying different shift amounts to different wiring layers based on their positions and functions. The uppermost wiring layer is shifted by a larger amount to primarily block oblique light, while lower wiring layers are shifted by smaller amounts to progressively reduce light blockage. This segmented approach balances layout complexity with sensitivity improvement by optimizing each layer's contribution to light management.
Solution Approach 2:
The patent implements partial shifting of wiring layers rather than uniform shifting of all layers. By selectively shifting only certain wiring layers by specific amounts, the design achieves sufficient light blockage reduction without requiring complete reconfiguration of all wiring layers. This partial action approach maintains reasonable layout complexity while effectively addressing sensitivity deterioration in peripheral regions.
3Manufacturing precision
If wiring layers are shifted to prevent light blockage, then light condensation rate improves, but electrical connectivity between wiring layers becomes more complex
Solution Approach 1:
The patent merges the shifting operations of multiple wiring layers into a coordinated pattern where shift amounts are systematically related. By combining the shifting strategies of different wiring layers into a unified design framework, the patent achieves improved light condensation rates while maintaining manageable electrical connectivity. The merged approach ensures that connection paths between shifted layers remain predictable and manufacturable.
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
This approach effectively suppresses sensitivity deterioration in peripheral areas by efficiently condensing incident light, maintaining high image quality and electrical connectivity with a simple layout.
Implementation Method 1
Many of the current solid-state imaging devices employ an on-chip microlens for each pixel for the purpose of improving the light condensing rate
Implementation Method 2
a photoelectric conversion section for photoelectrically converting the incident light
Data Source
AI summary
A solid-state imaging device includes a first wiring layer, a second wiring layer, a substrate contact, and a first contact. The arrangement of the substrate contact with respect to a light-receiving section forming a peripheral pixel is shifted, or not shifted, from the arrangement of the substrate contact with respect to a light-receiving section forming a central pixel, by a shift amount r from the peripheral portion toward the central portion. The arrangement of the first contact with respect to the light-receiving section of the peripheral pixel is shifted from the arrangement of the first contact with respect to the light-receiving section of the central pixel, by a shift amount s1 from the peripheral portion toward the central portion. The shift amount s1 is greater than the shift amount r.