Pixel Isolation Wall Structure for CMOS Sensor Color Mixing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solid-state imaging devices, such as CMOS image sensors, face challenges in improving sensitivity while minimizing color mixing, as increasing the height of inter-pixel light shielding films to prevent color mixing leads to reduced sensitivity.
Innovation Solution
A solid-state imaging device is designed with a first wall between pixels, comprising at least two layers: a light shielding film as the lowermost layer and a low refractive index film with a refractive index lower than the light shielding film. This configuration helps to isolate pixels and improve sensitivity while reducing color mixing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the height of the light shielding film is increased to prevent color mixing, then color mixing is reduced, but sensitivity is greatly reduced
Solution Approach 1:
The light shielding film is divided into multiple layers with different functions: a lower light shielding film for color mixing prevention and an upper light shielding film for additional isolation, allowing each layer to be optimized independently for its specific function while maintaining overall sensitivity
Solution Approach 2:
A reflective film is introduced as an intermediary layer between the lower and upper light shielding films. This reflective film redirects oblique light back toward the pixel, preventing color mixing while recovering light that would otherwise be lost, thereby maintaining sensitivity
2Measurement precision
If the partition wall is made higher to improve color mixing prevention, then color mixing is improved, but sensitivity is greatly reduced
Solution Approach 1:
The light shielding structure is made adjustable and configurable with multiple layers that can be independently optimized. The upper and lower light shielding films can have different heights, widths, and materials, allowing dynamic optimization of the balance between color mixing prevention and light collection efficiency
Solution Approach 2:
The light shielding structure uses composite material configuration with different films serving different functions. The lower light shielding film uses one material configuration optimized for color mixing prevention, while the upper light shielding film uses another configuration optimized for light blocking with minimal sensitivity impact
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 proposed solution effectively enhances the sensitivity of the solid-state imaging device while minimizing color mixing, thereby improving image quality without the need for extreme pupil correction.
Implementation Method 1
a low refractive index film of which refractive index is lower than the light shielding film
Implementation Method 2
a light shielding film of a lowermost layer
Data Source
AI summary
The present technology relates to a solid-state imaging device, a manufacturing method, and an electronic device, which can improve sensitivity while improving color mixing.The solid-state imaging device includes a first wall provided between a pixel and a pixel arranged two-dimensionally to isolate the pixels, in which the first wall includes at least two layers including a light shielding film of a lowermost layer and a low refractive index film of which refractive index is lower than the light shielding film. The present technology can be applied to, for example, a solid-state imaging device, an electronic device having an imaging function, and the like.