Light-Guiding Structures for CMOS Image Sensors
Solution Overview
Problem
Conventional CMOS image sensors face challenges in enhancing image quality due to inefficient light capture and direction onto sensing elements, leading to suboptimal image detection.
Innovation Solution
A semiconductor structure featuring a substrate with image sensing devices, a passivation layer, metal patterns, gaps, insulating layers, and tall, slender light-guiding structures with anchor portions securely fixed by the metal patterns, which direct incident light onto the image sensing devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If light-guiding structures are made tall and slender to improve light guidance efficiency, then light guidance efficacy is improved, but structural stability deteriorates causing collapse
Solution Approach 1:
The light-guiding structure is segmented into multiple portions along its height, with support structures provided at intermediate levels. This segmentation divides the tall structure into smaller stable segments, preventing collapse while maintaining overall height for effective light guidance.
Solution Approach 2:
Support structures act as intermediary elements between the tall light-guiding structure and the substrate. These intermediaries provide mechanical stability and prevent collapse, enabling the structure to maintain its tall and slender form for improved light guidance without compromising structural integrity.
2Device complexity
If conventional structures are used without additional support, then device complexity is reduced, but light capture efficiency deteriorates
Solution Approach 1:
The support structures extend vertically at intermediate levels of the light-guiding structure, adding a dimensional element that provides mechanical reinforcement. This vertical dimensionality allows the structure to maintain its tall form for light guidance while incorporating support mechanisms that prevent collapse, thereby improving light capture efficiency without excessive complexity.
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 semiconductor structure effectively improves image quality by securely fixing light-guiding structures to enhance light capture and direction, preventing collapse and improving the aspect ratio for more efficacious light guidance.
Implementation Method 1
a plurality of light-guiding structures respectively formed in the gaps. The light-guiding structures respectively include an anchor portion and a body portion
Data Source
AI summary
A semiconductor structure includes a substrate, a plurality of image sensing devices formed in the substrate, at least a passivation layer formed on the substrate, a plurality of first metal patterns formed on the passivation layer, a plurality of gaps formed between the first metal patterns, an insulating layer lining the gaps, and a plurality of light-guiding structures respectively formed in the gaps. The light-guiding structures respectively include an anchor portion and a body portion, and bottom surfaces of the anchor portions being lower than top surfaces of the first metal patterns.