Image sensor including a pixel separation structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image sensors face challenges in achieving high optical absorption efficiency and reducing crosstalk between neighboring pixels, particularly in high-resolution applications.
Innovation Solution
The image sensor incorporates a semiconductor substrate with a pixel separation structure that extends from both surfaces of the substrate, featuring a gap-fill dielectric layer with a pixel separation part and a scattering pattern part. This design increases the thickness of the semiconductor substrate and reduces crosstalk between pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the semiconductor substrate thickness is increased to improve optical absorption efficiency, then the optical absorption efficiency is improved, but the device complexity increases
Solution Approach 1:
The pixel separation structure is divided into two parts: a first pixel separation structure extending from the first surface and a second pixel separation structure extending from the second surface. These two structures work together to achieve complete pixel isolation and enhanced optical absorption without requiring a single excessively thick substrate, thereby managing device complexity while improving optical absorption efficiency.
Solution Approach 2:
Instead of solely increasing substrate thickness in one dimension, the patent introduces a dual-sided pixel separation approach that utilizes both surfaces of the substrate. This dimensional strategy allows for effective pixel isolation and light absorption enhancement without proportionally increasing overall device complexity.
2Object-affected harmful factors
If the pixel separation structure is extended to reduce crosstalk between pixels, then the crosstalk is reduced, but the manufacturing precision requirements increase
Solution Approach 1:
The pixel separation function is segmented into two independent structures: the first pixel separation structure from the first surface and the second pixel separation structure from the second surface. This segmentation allows each structure to be manufactured and positioned independently, reducing the cumulative precision requirements compared to a single extended structure while effectively minimizing crosstalk between adjacent pixels.
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 design enhances the optical absorption efficiency of incident light and reduces crosstalk between neighboring pixels, leading to improved image quality and resolution in image sensors.
Implementation Method 1
a scattering pattern part disposed in the second trench
Data Source
AI summary
An image sensor includes: a semiconductor substrate that has a first surface and a second surface opposite to each other. The semiconductor substrate includes: a first trench that vertically extends from the first surface of the semiconductor substrate and provides a pixel region, and a second trench that vertically extends from the first surface of the semiconductor substrate and is disposed on the pixel region. The image sensor further includes: a pixel separation structure that vertically extends from the second surface of the semiconductor substrate and overlaps the first trench; and a gap-fill dielectric layer disposed on the first surface of the semiconductor substrate, wherein the gap-fill dielectric layer includes a pixel separation part and a scattering pattern part, wherein the pixel separation part is disposed in the first trench, and the scattering pattern part is disposed in the second trench.