Solid-State Imaging Device With Island-Shaped Semiconductors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current solid-state imaging devices face limitations in achieving high pixel density, high sensitivity, and wide dynamic range due to the inability to apply advanced CMOS micromachining technology to color filters, leading to increased costs and light absorption issues that hinder light transmittance and sensitivity.
Innovation Solution
A solid-state imaging device with island-shaped semiconductors having different thicknesses for each color, where the third semiconductor region absorbs incident light and allows for the formation of color filters over the island-shaped semiconductors, enabling photoelectric conversion and signal charge accumulation without the need for RGB color filters, thus increasing pixel density and sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If color filters are formed using photolithography technology, then color imaging is achieved, but pixel density is limited due to larger micromachinable dimensions
Solution Approach 1:
The patent replaces the photolithography-based color filter formation with a micromachining-based approach. Island-shaped semiconductors are formed using advanced CMOS micromachining technology, and color filters are subsequently formed using the same micromachining process, enabling higher pixel density while maintaining manufacturing feasibility through process integration
Solution Approach 2:
The micromachining process is made universal by applying it to both the formation of island-shaped semiconductors and color filters. This multi-functional approach allows a single manufacturing process to handle multiple critical components, achieving high pixel density without compromising ease of manufacture
2Manufacturing precision
If color filters are formed using photolithography technology, then color imaging is achieved, but manufacturing cost increases due to different processes and apparatus
Solution Approach 1:
The patent merges the color filter formation process with the island-shaped semiconductor formation process by using the same advanced CMOS micromachining technology for both. This consolidation eliminates the need for separate photolithography processes and apparatus, reducing manufacturing cost while maintaining color imaging capability
3Manufacturing precision
If conventional color filters are used, then color separation is achieved, but light transmittance is reduced due to light absorption
Solution Approach 1:
The patent applies local quality by forming color filters with specific optical properties directly on the island-shaped semiconductors. The color filters are designed to transmit specific wavelength ranges while blocking others, achieving color separation with optimized light transmittance characteristics tailored to each pixel location
Solution Approach 2:
The patent replaces conventional photolithography-formed color filters with micromachining-formed color filters on island-shaped semiconductors. This substitution enables better control over filter thickness and material composition, improving light transmittance while maintaining color separation capability
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 allows for high pixel density, high sensitivity, and a wide dynamic range without the need for RGB color filters, reducing costs and improving light transmittance, enabling effective color imaging.
Implementation Method 1
The third semiconductor regions have a conductivity type opposite to a conductivity type of the second semiconductor regions. The third semiconductor region includes a sufficient quantity of acceptor or donor impurities that signal charges generated by absorption of incident light incident on top surfaces of upper ends of the island-shaped semiconductors in the third semiconductor regions are recombined and disappear in the third semiconductor regions.
Implementation Method 2
Incident light (electromagnetic energy waves) incident on the upper surfaces of the N regions 102a to 102c undergoes photoelectric conversion in the N regions 102a to 102c and the P-region substrate 100 located below the N regions 102a to 102c, and signal charges (in this case, free electrons) are generated.
Data Source
AI summary
In a solid-state imaging device, N regions serving as photoelectric conversion diodes are formed on outer peripheries of P regions in upper portions of island-shaped semiconductors formed on a substrate, and P+ regions connected to a pixel selection line conductive layer are formed on top layer portions of upper ends of the island-shaped semiconductors so as to adjoin the N regions and the P regions. In the P+ regions, a first P+ region has a thickness less than a second P+ region, and the second P+ region has a thickness less than a third P+ region.