Optical detection device, manufacturing method of optical detection device, and electronic apparatus
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Solution Overview
Problem
Existing through electrodes in optical detection devices face challenges in achieving low resistance with large diameters for power source lines and high aspect ratios in narrow areas, making it difficult to design efficient power distribution and signal transmission.
Innovation Solution
The optical detection device employs a dual-conductor system where a first conductor with a large width and low-resistance material, such as copper, penetrates the semiconductor layer, and a second conductor with a smaller width and high-aspect-ratio, using tungsten, is formed using a via middle method, reducing galvanic corrosion and allowing for efficient power distribution and signal transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a through electrode is designed with a large diameter to reduce resistance for power source lines, then electrical conductivity is improved, but the aspect ratio decreases and it becomes difficult to form in narrow areas
Solution Approach 1:
The through electrode is divided into multiple conductors with different functions: a first conductor (larger diameter) for power source lines to reduce resistance, and a second conductor (smaller diameter, higher aspect ratio) for signal transmission in narrow areas. This segmentation allows each conductor to be optimized for its specific function without compromise.
Solution Approach 2:
Different materials and dimensions are used for different conductors based on their specific requirements. The first conductor uses a material and diameter optimized for low resistance in power source applications, while the second conductor uses a different material and smaller diameter optimized for high aspect ratio formation in narrow signal transmission areas.
2Area of stationary object
If a through electrode with high aspect ratio is formed in narrow areas, then it fits the narrow space requirements, but resistance increases and power transmission capability deteriorates
Solution Approach 1:
The through electrode system is segmented into two distinct conductors: one optimized for power transmission with larger diameter and lower resistance, and another optimized for narrow area placement with smaller diameter and higher aspect ratio. This allows the system to simultaneously satisfy both low resistance and narrow area requirements.
Solution Approach 2:
The second conductor is specifically designed with smaller diameter and appropriate material selection to achieve high aspect ratio formation in narrow areas, while the first conductor maintains larger dimensions for optimal power transmission. Each conductor's properties are locally optimized for its specific function.
3Reliability
If different materials are used for through electrodes to optimize specific functions, then performance is improved, but galvanic corrosion occurs at material interfaces
Solution Approach 1:
An insulation film is introduced as an intermediary layer between the first conductor and the second conductor where they make contact. This insulation film prevents direct galvanic contact between the dissimilar materials, eliminating galvanic corrosion while allowing the conductors to maintain their different material properties for optimized performance.
4Ease of manufacture
If a single material is used for all through electrodes, then manufacturing is simplified, but it is impossible to simultaneously achieve low resistance in power lines and high aspect ratio in narrow areas
Solution Approach 1:
The through electrode system is segmented into multiple conductors with different materials and dimensions. The first conductor uses a material optimized for low resistance (such as copper), while the second conductor uses a different material optimized for high aspect ratio formation (such as tungsten). This segmentation enables design flexibility to meet different functional requirements.
Solution Approach 2:
Different materials are selected for different conductors based on their specific functional requirements. The first conductor uses a material with high electrical conductivity for power transmission, while the second conductor uses a material suitable for high aspect ratio formation in narrow areas. This local optimization of material properties enhances overall design versatility.
Data Source
AI summary
An optical detection device including a through electrode is provided. The optical detection device includes a first semiconductor layer having a photoelectric conversion region, a first surface, and a second surface that is a light entrance surface, a second semiconductor layer with a third surface and a fourth surface, a second wiring layer overlapped with the third surface, a third wiring layer overlapped with the fourth surface, a first wiring layer with one surface overlapped with the first surface and another surface overlapped with one of the second wiring layer and the third wiring layer, a first conductor that has a first width, includes a first material, and penetrates the second semiconductor layer in a thickness direction, and a second conductor that has a second width smaller than the first width, includes a second material different from the first material, and penetrates the second semiconductor layer in the thickness direction.