Solid-State Imaging Element Light-Blocking Film for TSV Gap Isolation
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Solution Overview
Problem
In laminated solid-state imaging elements with three or more substrates, the gaps around through-silicon vias (TSVs) often fail to be adequately blocked from light, allowing it to pass through and potentially affect the CMOS image sensor.
Innovation Solution
A solid-state imaging element design that includes a through electrode connecting substrates, a light-blocking film in the wiring layer with an opening for the electrode, and a contact electrode on the bonded surface to enhance light blocking, along with a manufacturing method that deposits insulation and light-blocking films to form these components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a through-silicon via (TSV) is formed to connect substrates in a laminated structure, then electrical connection between substrates is achieved, but light can pass through the gap around the TSV and enter the CMOS image sensor
Solution Approach 1:
A light-blocking film is introduced as an intermediary element between the TSV structure and the CMOS image sensor. This film specifically targets and blocks light paths that would otherwise reach the sensor, while maintaining the electrical connectivity function of the TSV. The light-blocking film acts as a mediator that resolves the conflict between needing open TSV gaps for electrical connection and needing to prevent light from reaching the sensor.
Solution Approach 2:
The solution segments the TSV structure by introducing a separate light-blocking film layer that is distinct from the electrical connection structure. Instead of trying to make the TSV itself serve both functions, the problem is divided into two separate components: the TSV for electrical connection and the light-blocking film for optical isolation. This segmentation allows each component to optimize its specific function without compromising the other.
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 improves the light-blocking effect, preventing light from entering the sensor substrate and reducing adverse effects from hot carriers, thereby enhancing image quality.
Implementation Method 1
a light-blocking film arranged in a wiring layer included in the second substrate and provided on the third substrate side
Implementation Method 2
depositing an insulation film to be the wiring layer of the second substrate with a predetermined film thickness or less; and depositing the light-blocking film on an entire surface of the insulation film
Data Source
AI summary
Provided is a solid-state imaging element, a manufacturing method, and an electronic apparatus which are capable of further improving a light-blocking effect. The solid-state imaging element has a laminated structure in which a memory substrate, a logic substrate, and a sensor substrate are laminated. The solid-state imaging element includes a through electrode that connects the memory substrate and the sensor substrate in a manner passing through a semiconductor layer of the logic substrate, and a light-blocking metal film arranged in a wiring layer included in the logic substrate and provided on the sensor substrate side, where the light-blocking metal film has an opening opened so as to allow the through electrode to pass through. The solid-state imaging element further includes a contact electrode formed on a bonded surface between the logic substrate and the sensor substrate and used to connect the through electrode to the sensor substrate side.