Solid-State Imaging Device Light Shielding Film Segmentation

Solution Overview

Problem

Existing solid-state imaging devices with organic photoelectric conversion films face property fluctuations and white defects due to film stress from upper electrodes, which are not adequately alleviated by existing techniques, especially when a light shielding film is formed above the upper electrode.

Innovation Solution

The implementation of two or more light shielding films positioned higher than the photoelectric conversion film with respect to the semiconductor substrate helps reduce the film stress generated in the upper electrode, thereby minimizing its impact on the photoelectric conversion film.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a light shielding film is formed as a higher layer than the upper electrode, then light shielding performance is improved, but film stress concentration on the photoelectric conversion film increases

Engineering Contradiction:

Improvelight shielding performanceVSAvoidfilm stress concentration

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The light shielding film is divided into multiple segments (first light shielding film and second light shielding film) separated by insulating films. This segmentation reduces the continuous stress that would be applied to the photoelectric conversion film, while still achieving the required light shielding performance. Each segment can be independently optimized for thickness and material properties.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Insulating films are introduced as intermediary layers between the light shielding film segments and between the light shielding films and the upper electrode. These intermediary layers act as stress buffers that prevent direct stress transmission to the photoelectric conversion film, while allowing the light shielding function to be maintained.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If a single light shielding film is formed above the upper electrode, then manufacturing process is simplified, but film stress cannot be adequately reduced

Engineering Contradiction:

Improvemanufacturing process complexityVSAvoidfilm stress influence

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The light shielding film is divided into multiple segments (first light shielding film and second light shielding film) separated by insulating films. This segmentation reduces the continuous stress that would be applied to the photoelectric conversion film, while still achieving the required light shielding performance. Each segment can be independently optimized for thickness and material properties.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Insulating films are introduced as intermediary layers between the light shielding film segments and between the light shielding films and the upper electrode. These intermediary layers act as stress buffers that prevent direct stress transmission to the photoelectric conversion film, while allowing the light shielding function to be maintained.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS10868068B2Solid-state imaging device, method of manufacturing the same, and electronic apparatus

Publication Date: 2020.12.15 SONY GROUP CORP

AI summary

The present technology relates to a solid-state imaging device that can further reduce the influence the film stress generated in an upper electrode has on a photoelectric conversion film, a method of manufacturing the solid-state imaging device, and an electronic apparatus.A solid-state imaging device includes: a photoelectric conversion film formed on the upper side of a semiconductor substrate; and two or more light shielding films formed at positions higher than the photoelectric conversion film with respect to the semiconductor substrate. The present technology can be applied to solid-state imaging devices, electronic apparatuses, and the like, for example.