Semiconductor Device Through Holes Reduce Parasitic Capacitance
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Solution Overview
Problem
In semiconductor devices used in electronic apparatuses like digital cameras and video cameras, parasitic capacitance caused by a low-refractive-index film covering the peripheral circuit region reduces the electrical signal level and image quality.
Innovation Solution
The semiconductor device incorporates through holes in the low-refractive-index film above the amplifier circuits in the peripheral circuit region, reducing parasitic capacitance and improving image quality by using air as a dielectric substance and a transparent adhesive layer that forms a spherical surface to attenuate stray light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a low-refractive-index film is formed to cover the peripheral circuit region, then stray light is reduced and imaging performance is improved, but parasitic capacitance increases and electrical signal level decreases
Solution Approach 1:
The patent applies local quality by differentiating the treatment of different regions on the semiconductor substrate. The low-refractive-index film is selectively formed only on the imaging region containing photoreceptors and microlenses, while intentionally excluding the peripheral circuit region containing amplifier circuits. This localized application allows the film to reduce stray light in the imaging area without introducing parasitic capacitance in the circuit area, thus resolving the contradiction between optical performance and electrical signal integrity.
2Illumination intensity
If the low-refractive-index film covers the amplifier circuit, then optical performance is improved, but parasitic resistance increases
Solution Approach 1:
The patent implements local quality by precisely controlling the deposition area of the low-refractive-index film. The film is applied exclusively to the imaging region where photoreceptors and microlenses are located, while the peripheral circuit region containing amplifier circuits remains uncovered. This spatial differentiation ensures that the optical benefits of the low-refractive-index film are realized without the electrical penalty of increased parasitic resistance in the amplifier circuits.
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 significantly reduces parasitic capacitance, suppresses the decrease in electronic signal levels, and enhances the quality of the final image information by minimizing stray light entry into photoreceptors.
Implementation Method 1
parasitic capacitance in an amplifier circuit, and therefore finally obtained image information is decreased in quality
Implementation Method 2
a transparent adhesive layer that forms a spherical surface to attenuate stray light
Data Source
AI summary
A semiconductor device includes: a semiconductor substrate having an imaging region in which a plurality of photoreceptors are arranged, and a peripheral circuit region arranged around the imaging region; a plurality of microlenses formed on the imaging region; a low-refractive-index film formed on the semiconductor substrate to cover the plurality of microlenses and part of the peripheral circuit region; and a transparent substrate formed on part of the low-refractive-index film above the imaging region. A through hole is formed in part of the low-refractive-index film above an amplifier circuit arranged in the peripheral circuit region.