Solid-State Imaging Element Noise Isolation via Segmented Wells
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Solution Overview
Problem
Conventional solid-state imaging elements with a triple-well structure face challenges in reducing noise-induced malfunctions while maintaining area efficiency, as noise can be transmitted between adjacent N-wells, leading to circuit malfunctions and decreased area efficiency.
Innovation Solution
The implementation of a solid-state imaging element with first and second wells having impurities with the same polarity as the substrate, where the first circuit generates noise in a predetermined period and the second circuit generates noise in a different period, along with a time code generation unit and memory, dispersedly disposed on multiple chips to reduce noise interference and improve area efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple N-wells are disposed adjacent to each other on the substrate to reduce circuit area, then area efficiency is improved, but noise is transmitted from one side to the other side of circuits on the N-wells causing malfunction
Solution Approach 1:
The patent divides adjacent N-wells into separate operational groups by inserting P-wells between them. This segmentation prevents noise transmission between N-wells while maintaining compact area utilization. The P-well acts as a noise isolation barrier, allowing N-wells to be placed close together without causing mutual interference that would lead to circuit malfunction.
Solution Approach 2:
The P-well serves as an intermediary structure between adjacent N-wells. It physically separates the N-wells and electrically isolates them, preventing noise from propagating from one N-well to another. This intermediary P-well layer enables dense packing of N-wells while maintaining signal integrity and preventing circuit malfunction caused by noise coupling.
2Reliability
If N-wells are removed from the substrate to prevent noise transmission, then noise-induced malfunction is reduced, but area efficiency of the circuit decreases
Solution Approach 1:
Instead of removing N-wells entirely, the patent segments the substrate into isolated N-well regions separated by P-wells. This segmentation maintains the area efficiency benefits of having N-wells on the substrate while preventing noise transmission between them. The P-well segments create electrical isolation zones that block noise propagation paths.
Solution Approach 2:
The P-well acts as an intermediary noise-blocking layer that allows N-wells to remain on the substrate without direct noise coupling. This intermediary structure provides the noise isolation function that would otherwise require complete N-well removal, thereby preserving area efficiency while achieving noise reduction and preventing circuit malfunction.
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 configuration effectively reduces circuit malfunctions caused by noise and enhances area efficiency by separating noise-generating periods and dispersing circuits across multiple chips, thereby improving the performance of the solid-state imaging element.
Implementation Method 1
a first circuit that is disposed on the first well and generates noise in a predetermined period, and a second circuit that is disposed on the second well and generates noise in a period different from the predetermined period
Data Source
AI summary
A solid-state imaging element including a well improves area efficiency while reducing malfunction of a circuit on the well. The solid-state imaging element includes a first well, a second well, a first circuit, and a second circuit. The first well contains an impurity having a polarity identical to a polarity of an impurity in a substrate. The second well contains an impurity having a polarity identical to the polarity of the impurity in the substrate and is disposed adjacent to the first well. The first circuit is disposed on the first well and generates noise in a predetermined period. The second circuit is disposed on the second well and generates noise in a period different from the predetermined period.