Semiconductor Alignment Mark with Cover Insulating Film
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing technique for forming alignment marks on semiconductor substrates results in a margin between the polyimide film and the alignment mark, leading to reduced alignment precision due to the potential for the alignment mark to be viewed as double, causing erroneous recognition during alignment.
Innovation Solution
A semiconductor device configuration featuring a metal alignment mark covered by a transparent insulating film, with a polyimide film having an opening that aligns with the alignment mark's end face, improving contrast and precision by overlapping the level difference contrast with the alignment mark.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the polyimide film is formed with a margin from the alignment mark, then the structure is simpler and easier to manufacture, but alignment precision is lowered due to double imaging
Solution Approach 1:
A transparent cover insulating film is introduced as an intermediary layer between the alignment mark and the polyimide film. This cover film extends beyond the alignment mark boundaries, allowing the polyimide film to be formed with a margin while the cover film's transparent portions provide the necessary contrast for precise alignment. The intermediary cover film thus enables both easy manufacturing and high alignment precision.
2Ease of manufacture
If the polyimide film end face is positioned away from the alignment mark end face, then manufacturing is easier, but the alignment mark may be viewed double causing erroneous recognition
Solution Approach 1:
The transparent cover insulating film serves as a mediator that extends beyond the alignment mark. When the polyimide film is patterned with a margin from the alignment mark, the transparent cover film in these margin regions provides optical contrast that prevents double imaging. This allows the polyimide film to be easily patterned with margins while maintaining accurate alignment mark recognition.
3Device complexity
If no cover insulating film is used, then the device structure is simpler, but the alignment mark is exposed to corrosion
Solution Approach 1:
The cover insulating film is designed with local quality variations: it covers the entire alignment mark to provide corrosion protection, while extending beyond the mark boundaries with transparent portions that provide optical contrast. This localized differentiation of the cover film's function allows simultaneous achievement of corrosion protection and alignment precision without significantly increasing overall device complexity.
Data Source
AI summary
A semiconductor device includes a substrate; an alignment mark formed on the substrate and composed of a metal film; a cover insulating film formed on the alignment mark and covering an entire surface of the alignment mark; and a polyimide film formed on the cover insulating film, and having an opening, which is opened on the alignment mark and has an end face aligning with an end face of the alignment mark, in plan view.