Arbitrary Shape Microcomponents for Photodetector Light Collection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing focal plane array (FPA) technologies face challenges in achieving high sensitivity and large angle-of-view (AOV) with defect-free large-scale arrays of microspheres, and aligning microspheres with photodetector mesas for efficient light coupling, resulting in unacceptable pixel defect rates and limited AOV.
Innovation Solution
The use of microcomponents with arbitrary shapes, such as microcones, cuboids, and pyramids, that operate based on waveguiding and light scattering effects, allowing for efficient light collection and focusing into photodetector mesas without the need for individual alignment, and can be fabricated using established large-scale planar technologies like lithography and etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If microspheres are used to enhance light collection efficiency and sensitivity, then sensitivity is improved, but manufacturing precision and alignment accuracy deteriorate due to difficulty in achieving defect-free large-scale arrays
Solution Approach 1:
The system segments the light collection function by introducing separate microcomponent elements (microspheres, microcylinders, microfibers, or arbitrary shape microcomponents) that are positioned above photodetector mesas. Each microcomponent independently collects and focuses light onto its corresponding mesa, allowing individual optimization of light gathering while maintaining array scalability.
Solution Approach 2:
The patent introduces microcomponents as intermediary elements between the incident light and the photodetector mesas. These intermediaries perform the light collection and focusing function, decoupling the light gathering area from the detector size and enabling improved sensitivity without compromising alignment precision.
2Manufacturing precision
If photodetector mesa size is reduced to improve resolution, then area fill factor is improved, but light collection efficiency deteriorates
Solution Approach 1:
The patent extends the light collection problem from two dimensions (mesa surface area) to three dimensions by introducing vertical microcomponent structures. These microcomponents have characteristic dimensions much larger than the mesa diameter, collecting light from a larger volumetric region and focusing it onto the smaller mesa area, thereby decoupling collection efficiency from mesa size.
Solution Approach 2:
The system employs composite structures combining microcomponents (with high refractive index materials such as silicon, germanium, or semiconductors) with the photodetector mesas. The microcomponents act as optical antennas or waveguides that enhance light-matter interaction, enabling efficient light collection from larger effective areas onto smaller detector regions.
3Ease of manufacture
If standard fabrication methods are used for microspheres, then ease of manufacture is improved, but manufacturing precision deteriorates due to alignment defects in large-scale arrays
Solution Approach 1:
The patent employs preliminary self-assembly of microcomponents into ordered arrays before final integration with the photodetector substrate. Microcomponents are first formed into suspensions or deposited onto temporary substrates where they self-organize into ordered patterns, and then transferred to their final positions. This preliminary organization reduces defects and improves alignment accuracy in large-scale arrays.
Solution Approach 2:
The system utilizes self-assembly mechanisms where microcomponents spontaneously organize into ordered arrays through physical or chemical interactions. This self-service approach enables large-scale array formation with high precision without requiring complex external manipulation, thereby maintaining ease of manufacture while improving manufacturing precision.
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
This approach enhances light collection efficiency, reduces photodetector mesa size without sacrificing sensitivity, and achieves higher AOVs, enabling improved imaging capabilities in surveillance and sensor applications while reducing dark current and increasing operation temperature.
Implementation Method 1
The microcomponent has an ability to collect the incident radiation from a wider area and concentrate it into the smaller area of the associated photosensitive region, operating based not only on the refraction of radiation (like a lens), but also on waveguiding and/or light scattering effects
Implementation Method 2
The microcomponent has an ability to collect the incident radiation from a wider area and concentrate it into the smaller area of the associated photosensitive region, operating based not only on the refraction of radiation (like a lens), but also on waveguiding and/or light scattering effects
Implementation Method 3
The microcomponent has an ability to collect the incident radiation from a wider area and concentrate it into the smaller area of the associated photosensitive region, operating based not only on the refraction of radiation (like a lens), but also on waveguiding and/or light scattering effects
Data Source
AI summary
A photodetector focal plane array system having enhanced sensitivity and angle-of-view, including: a substrate including a plurality of photosensitive regions; and a microcomponent disposed adjacent to each of the plurality of photosensitive regions operable for receiving incident radiation from a relatively wider area and directing the incident radiation into a relatively smaller area of the associated photosensitive region by, in part, one or more of waveguiding and scattering; wherein each of the microcomponents is centered with respect to a photodetector mesa of each of the plurality of photosensitive regions. Each of the microcomponents includes one of a microcone, a microcuboid, a micropillar, a core-shell micropillar, a microtubule, a pyramid, an inverted pyramid, and an arbitrary shape microcomponent—with a top surface having a a selected or arbitrary cross-sectional shape and a selected or arbitrary profile.