Amorphous Charge Passivation Layer for Image Sensor Dark Current
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current image sensors face challenges in improving dark state characteristics, leading to reliability issues such as dark current, white spots, and dark shading due to grain boundary defects in crystallized charge passivation layers.
Innovation Solution
The implementation of an amorphous crystal structure in the charge passivation layer, composed of multiple metal or metalloid elements, which reduces grain boundary effects and increases the crystallization temperature, thereby mitigating dark current issues and enhancing reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a crystallized charge passivation layer is used, then the manufacturing process is simpler, but grain boundary defects cause dark current and reduce reliability
Solution Approach 1:
The patent changes the crystal structure parameter of the charge passivation layer from crystalline to amorphous. This parameter change eliminates grain boundary defects while maintaining the passivation function, thereby reducing dark current and improving dark state characteristics without significantly complicating the manufacturing process
Solution Approach 2:
The patent employs a composite charge passivation layer comprising multiple materials (e.g., silicon oxide, silicon nitride, silicon oxynitride) in specific combinations. This composite structure achieves both the desired amorphous phase stability and effective charge passivation, resolving the contradiction between manufacturing ease and reliability
2Ease of manufacture
If the charge passivation layer crystallizes easily, then the manufacturing process is more straightforward, but it leads to grain boundary defects and performance degradation
Solution Approach 1:
The patent modifies the structural parameter of the charge passivation layer by inducing an amorphous phase instead of a crystalline phase. This change prevents grain boundary formation while maintaining manufacturing feasibility through controlled deposition processes that favor amorphous structure formation
Solution Approach 2:
The patent applies different material compositions and structural properties to different regions or aspects of the charge passivation layer. By creating a multi-material amorphous composite, it achieves local optimization where each material contributes specific properties that collectively prevent crystallization and eliminate grain boundary defects
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 amorphous crystal structure in the charge passivation layer improves the dark state characteristics of image sensors, reducing defects and enhancing reliability by preventing easy crystallization and maintaining performance under various light conditions.
Implementation Method 1
the charge passivation layer including an amorphous crystal structure
Data Source
AI summary
An image sensor configured to provide improved reliability may include a charge passivation layer that includes a multiple different elements, each element of the different elements being a metal element or a metalloid element. The different elements may include a first element of a first group of periodic table elements and a second element of a second, different group of periodic table elements. The charge passivation layer may include an amorphous crystal structure.