Solid-State Imager Groove Structure for Film Thickness Control
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Solution Overview
Problem
Existing solid-state imaging devices face challenges in improving reliability and reducing manufacturing costs, particularly when using silicon on insulator (SOI) substrates, which increase costs and do not adequately enhance device characteristics.
Innovation Solution
A solid-state imaging device design that includes a groove on the semiconductor substrate with oblique side walls, embedded with insulating material, allowing for precise control of film thickness and reducing manufacturing costs by using a normal semiconductor substrate instead of SOI, and a manufacturing method involving the formation and exposure of such grooves to facilitate bonding and element separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a silicon on insulator (SOI) substrate is used to prevent variations in film thickness, then manufacturing precision is improved, but manufacturing cost increases
Solution Approach 1:
The invention divides the semiconductor substrate into multiple regions: a first region with a groove for forming thin-film transistors and a second region without the groove for forming thick-film transistors. This segmentation allows different film thicknesses in different regions, enabling precise thickness control where needed while avoiding the cost of SOI substrates across the entire wafer.
Solution Approach 2:
The groove is formed only in specific regions where thin-film transistor precision is required, rather than uniformly across the entire substrate. This local application of the thickness control mechanism achieves the necessary manufacturing precision only where it impacts device performance, reducing overall manufacturing costs.
2Reliability
If a groove with oblique side walls is formed on the semiconductor substrate, then reliability is improved through precise film thickness control, but device complexity increases
Solution Approach 1:
The groove with oblique side walls is formed in advance during the substrate preparation stage, before transistor fabrication begins. This preliminary action ensures that the correct film thickness is established upfront, preventing defects during subsequent processing steps and improving device reliability without adding complexity to the transistor fabrication process itself.
Data Source
AI summary
Provided is a solid-state imaging device capable of further improving reliability of a solid-state imaging device and further reducing manufacturing cost. Provided is a solid-state imaging device including a second semiconductor substrate provided with a photoelectric conversion unit and a second element, a second insulating layer, a first semiconductor substrate provided with a first element, and a first insulating layer arranged in this order from a light incident side, and including a groove formed on the first semiconductor substrate, in which the groove has a first side wall and a second side wall, and a part of at least one side wall of the first side wall or the second side wall extends in an oblique direction with respect to a surface of the first semiconductor substrate on the light incident side.