Stacked Imaging Element Polishing Layout for Bonding Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The reliability of stacked imaging devices is compromised due to defects during manufacturing, primarily caused by excessive polishing of semiconductor substrates, which can lead to contamination and bonding failures.
Innovation Solution
Incorporating a polishing adjustment section with a lower polishing rate material, such as silicon nitride or silicon oxide, in the peripheral regions of the semiconductor elements to prevent excessive polishing and ensure even surface flatness during the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the semiconductor substrate is polished to improve surface flatness, then bonding reliability is improved, but excessive polishing causes contamination and defects
Solution Approach 1:
The polishing adjustment section is provided only in the peripheral region of the semiconductor substrate, not in the entire substrate. This local modification allows the peripheral area to be polished at a different rate than the central wiring region, preventing excessive polishing at edges while maintaining overall surface flatness and avoiding contamination
Solution Approach 2:
The polishing adjustment section is formed in advance before the bonding process. By pre-forming this section with material having different polishing characteristics, the substrate is prepared to resist excessive polishing during subsequent manufacturing steps, preventing contamination before it can occur
2Manufacturing precision
If the polishing process is extended to ensure even flatness, then surface quality is improved, but manufacturing time and risk of defects increase
Solution Approach 1:
By localizing the polishing adjustment section to the peripheral region, the polishing process can be optimized to focus on achieving flatness without requiring extended polishing time across the entire substrate. The adjusted section controls the polishing rate locally, enabling faster overall processing while maintaining surface quality
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 solution effectively suppresses excessive polishing and contamination, enhancing the reliability and quality of the imaging device by maintaining flatness and preventing bonding failures, thus reducing defects during manufacture.
Implementation Method 1
a polishing adjustment section including a material that is lower in polishing rate than a constituent material of the semiconductor substrate
Data Source
AI summary
Provided is an imaging device (1) including: an imaging element (10); and a semiconductor element (20, 30) provided to be opposed to the imaging element and electrically coupled to the imaging element. The semiconductor element includes: a wiring region (20A, 30A) provided in a middle portion and a peripheral region (20B, 30B) outside the wiring region; a wiring layer (22, 32) having a wiring line in the wiring region; a semiconductor substrate (21, 31) opposed to the imaging element with the wiring layer interposed therebetween and having a first surface (Sa, Sc) and a second surface (Sb, Sd) in order from a side of the wiring layer; and a polishing adjustment section (23, 33) including a material that is lower in polishing rate than a constituent material of the semiconductor substrate, the polishing adjustment section being disposed in at least a portion of the peripheral region and provided in a thickness direction of the semiconductor substrate from the second surface.