Semiconductor Mark Structure Layout for Higher Alignment Contrast
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Solution Overview
Problem
The increasing complexity of chip manufacturing processes, particularly in photoetching, requires improved layer-to-layer alignment and optimization of functional and mark structures to enhance accuracy and efficiency.
Innovation Solution
A semiconductor structure and method where the thickness of a dielectric layer at a mark structure is differentiated from that at a functional structure, enhancing imaging contrast and thereby improving photoetching accuracy and production efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the dielectric layer thickness is made uniform across functional structure and mark structure, then the manufacturing process is simple, but the imaging contrast of the mark structure is low
Solution Approach 1:
The patent applies local quality by making the dielectric layer thickness non-uniform: the first dielectric layer has a first thickness at the functional structure and a second thickness at the mark structure, where the thicknesses are different. This localized thickness variation improves the imaging contrast of the mark structure during photoetching while maintaining functional performance, directly resolving the contradiction between measurement precision and device complexity.
2Measurement precision
If the dielectric layer thickness at mark structure is increased, then the imaging contrast improves, but the manufacturing precision requirement increases
Solution Approach 1:
The patent implements preliminary action by forming the first dielectric layer with different thicknesses at the functional structure and mark structure before the photoetching process. This pre-established thickness differentiation creates favorable conditions for subsequent photoetching by improving mark structure imaging contrast, thereby reducing the actual manufacturing precision requirements during the photoetching step itself.
3Adaptability or versatility
If the photoetching process uses multiple layers, then the functional requirements are met, but the layer-to-layer alignment difficulty increases
Solution Approach 1:
The patent uses the mark structure as an intermediary element for alignment. The mark structure, with its enhanced imaging contrast due to the differentiated dielectric layer thickness, serves as a reference marker that facilitates accurate layer-to-layer alignment during multi-layer photoetching processes, thereby reducing alignment difficulty while meeting functional requirements.
Data Source
AI summary
The examples of the present application disclose a semiconductor structure and a method for manufacturing the same. The semiconductor structure includes: a functional structure and a first mark structure located on a substrate, in which the functional structure and the first mark structure have the same feature size; and a first dielectric layer located at the functional structure and the first mark structure, in which a thickness of the first dielectric layer at the functional structure is different from a thickness of the first dielectric layer at the first mark structure. The examples of the present application can improve the alignment accuracy of the manufacturing process and improve the product yield and production efficiency at the same time.