Photodetector Pillar Deflecting Section Oblique Light Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing photodetectors face challenges in maintaining optimal optical characteristics, such as crosstalk and non-uniform sensitivity, particularly at the angle-of-view ends due to oblique incidence of light.
Innovation Solution
A photodetector design that includes multiple pixels arranged in a matrix on a semiconductor substrate, each pixel featuring a photoelectric converting section and a deflecting section with pillars of varying thicknesses, pitches, or shapes. These pillars guide incident light at different angles to the photoelectric converting section, achieving a prism-like effect that improves light bending and distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If on-chip lenses are arranged according to pupil correction to improve light utilization at angle-of-view ends, then light utilization efficiency is improved, but optical characteristics such as crosstalk and non-uniform sensitivity deteriorate due to oblique incidence
Solution Approach 1:
The patent applies local quality by making the deflecting section's pillar structure non-uniform across different pixels. Specifically, the prism angle of the deflecting section is adjusted according to the image height (distance to angle-of-view ends), with different pixels having different prism angles optimized for their specific oblique incidence angles. This local customization allows each pixel to correctly direct obliquely incident light while maintaining uniform optical characteristics across the entire photodetector array.
2Ease of manufacture
If conventional methods are used to control light deflection at pixels, then manufacturing is simpler, but processing difficulty is high and shape stability is poor due to non-linear resist solubility response
Solution Approach 1:
The patent applies parameter changes by transitioning from a conventional single-parameter approach (lens shape only) to a multi-parameter approach that includes prism angle as an additional controllable parameter. By adjusting the prism angle of the deflecting section in addition to lens shape parameters, the system achieves better control over light deflection characteristics. This parameter expansion improves shape stability and manufacturing precision by providing an additional degree of freedom to compensate for non-linear resist solubility effects.
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 optical characteristics by reducing crosstalk and non-uniform sensitivity at angle-of-view ends, improving the overall efficiency of light utilization and sensitivity uniformity across the photodetector.
Implementation Method 1
each of the multiple pixels includes a photoelectric converting section that photo-electrically converts incident light
Implementation Method 2
the pillars guide a principal ray that is incident at a different angle for each image height to the photoelectric converting section at a prism angle at which light is bent relative to the principal ray differently for each pixel
Data Source
AI summary
A photodetector that makes it possible to attempt to improve optical characteristics in terms of oblique incidence of light at angle-of-view ends is provided. A photodetector includes multiple pixels arranged in a matrix on a semiconductor substrate. Each of the multiple pixels includes a photoelectric converting section that photo-electrically converts incident light, and a deflecting section that is arranged on a light-incidence-surface side of the photoelectric converting section, and has multiple pillars with different thicknesses, pitches, or shapes in the pixel. The pillars guide an incident principal ray that is incident at a different angle for each image height to the photoelectric converting section at a prism angle at which light is bent relative to the principal ray differently for each pixel.