Segmented Isolation Structure for Pixel Crosstalk Reduction
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Solution Overview
Problem
Current image sensor technologies face challenges in reducing crosstalk between pixels, which affects image quality and is costly to address.
Innovation Solution
A method is developed to fabricate an isolation structure using a semiconductor substrate with a trench, a dielectric layer, and a reflective material layer, where the reflective material is etched to form a top and bottom portion, reducing crosstalk and lowering fabrication costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional methods are used to reduce crosstalk between pixels, then image quality is improved, but fabrication cost increases
Solution Approach 1:
The isolation structure is divided into multiple segments including a first isolation structure and a second isolation structure, with the second isolation structure having a smaller area than the first. This segmented approach effectively reduces crosstalk between adjacent pixels while controlling fabrication complexity through hierarchical isolation zones.
Solution Approach 2:
Different isolation structures are applied at different locations based on local requirements. The first isolation structure with larger area is used where greater isolation is needed, while the second isolation structure with smaller area is used where less isolation is required, optimizing both crosstalk reduction and fabrication cost.
2Object-affected harmful factors
If isolation structures are added to reduce crosstalk, then image quality is improved, but device complexity increases
Solution Approach 1:
The isolation structure is divided into multiple segments including a first isolation structure and a second isolation structure, with the second isolation structure having a smaller area than the first. This segmented approach effectively reduces crosstalk between adjacent pixels while controlling fabrication complexity through hierarchical isolation zones.
Solution Approach 2:
Instead of using a single complex isolation structure, the patent uses a combination of simpler isolation structures with different areas. The first isolation structure provides primary isolation, while the second isolation structure provides additional localized isolation where needed, achieving better performance through inverted thinking about structure design.
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 isolation structure effectively reduces crosstalk between pixels in image sensors while minimizing fabrication costs by using a cost-effective etching process.
Implementation Method 1
a reflective material layer is formed on the trench portion of the dielectric layer. Thereafter, the reflective material layer is etched to form an isolation structure
Data Source
AI summary
A semiconductor device and a method for fabricating the same are provided. In the method for fabricating the semiconductor device, at first, a semiconductor substrate is provided. Then, a trench is formed in the semiconductor substrate. Thereafter, a dielectric layer is formed to cover the semiconductor substrate, in which the dielectric layer has a trench portion located in the trench of the semiconductor substrate. Then, a reflective material layer is formed on the trench portion of the dielectric layer. Thereafter, the reflective material layer is etched to form an isolation structure, in which the isolation structure includes a top portion located on the semiconductor substrate and a bottom portion located in a trench formed by the trench portion of the dielectric layer.