Semiconductor Through Electrode Void Prevention via Via Insulating Film Level Difference
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Solution Overview
Problem
Conventional semiconductor devices with through electrodes often suffer from void formation and reduced reliability due to etching processes that fail to effectively manage the level differences in insulating films, leading to inadequate seed film coating and increased void occurrence.
Innovation Solution
The semiconductor device incorporates a damascene structure with a surface electrode and interlayer insulating film, where a via insulating film is formed with a level difference to prevent etching of the between-wiring-lines insulating film, ensuring excellent seed film coating and reducing void formation by maintaining a flush connection with the through electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching processes are used to form through holes, then through electrodes can be formed, but voids occur in the through electrodes due to inadequate seed film coating
Solution Approach 1:
The patent forms a via insulating film with a predetermined level difference before forming the through electrode. This preliminary action creates a stepped structure that ensures the seed film can be properly coated on the inner wall of the through hole, preventing void formation and improving electrode quality and device reliability.
Solution Approach 2:
The via insulating film is formed with different thicknesses in different regions: a first thickness in the region to be etched and a second thickness (greater than the first) in the region to remain. This local quality differentiation creates the necessary level difference for proper seed film coating while maintaining the integrity of the between-wiring-lines insulating film.
2Manufacturing precision
If the interlayer insulating film is etched to expose the wiring line, then the through electrode can be formed, but the between-wiring-lines insulating film is improperly etched due to level differences
Solution Approach 1:
The via insulating film acts as an intermediary structure with a level difference that mediates the etching process. The stepped structure allows the etching to proceed to the correct depth to expose the wiring line while preventing over-etching of the between-wiring-lines insulating film, thus eliminating etching defects.
Solution Approach 2:
The via insulating film is formed with a predetermined level difference before the etching process. This preliminary structuring creates a physical stop that prevents the etching from damaging the between-wiring-lines insulating film while still allowing adequate exposure of the wiring line for through electrode formation.
3Manufacturing precision
If the seed film is coated on the inner wall of the through hole, then the through electrode can be formed, but voids occur due to poor coating quality
Solution Approach 1:
The via insulating film creates a local stepped structure with different thicknesses in different regions. This local quality differentiation provides an optimal surface geometry for seed film coating, ensuring uniform coverage on the inner wall of the through hole and preventing void formation, which directly improves through electrode reliability.
Solution Approach 2:
The via insulating film with predetermined level difference is formed as a preliminary structure before seed film coating. This preliminary action creates the ideal surface geometry that enables proper seed film adhesion and uniform coating, eliminating the root cause of void formation and improving electrode reliability.
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 approach prevents voids in through electrodes, enhancing the reliability of semiconductor devices by ensuring proper seed film formation and reducing etching-induced defects, resulting in improved manufacturing outcomes.
Implementation Method 1
a via insulating film disposed between the through electrode and the semiconductor substrate
Implementation Method 2
forming a through electrode so as to be electrically connected to the surface electrode by plating an electrode material on the inner side of the via insulating film on the through hole
Data Source
AI summary
An electrode layer is formed on a gate insulating film. An interlayer insulating film is formed on the gate insulating firm. A lower pad is formed by a damascene method. Next, a through hole is formed, and a first interlayer insulating film, which is provided with a projected portion that is in the same pattern as a lower insulating film, is exposed within the through hole at the same time. After etching the first interlayer insulating film so that a part of the projected portion remains as an etching residue, a via insulating film is formed and the via insulating film at the bottom of the through hole is etched. After that, a through electrode is formed by plating an electrode material on the inner side of the via insulating film on the through hole.