Self-Assembly Pad Wettability Control via UV-Ozone and Fluorocarbon
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Solution Overview
Problem
Existing methods for manufacturing self-assembly pads struggle to achieve a significant difference in wettability between the pads and the surrounding substrate, leading to errors in liquid confinement during the self-assembly process of integrated circuits.
Innovation Solution
The method involves creating pads with high wettability using ultraviolet radiation in the presence of ozone, while surrounding regions with low wettability are treated with a fluorocarbon layer to maintain their low wettability, resulting in a substantial difference in wettability that ensures effective liquid confinement. Additionally, protuberances with inclined sides are used to enhance the anchoring effect, keeping the liquid on the pad.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pad is made with high wettability material to enable liquid confinement, then the liquid drop can be confined on the pad, but the difference in wettability between the pad and surrounding substrate may not be significant enough, causing the drop to leave the pad during self-assembly
Solution Approach 1:
The patent applies local quality by creating distinct wettability zones: the pad area is treated to have high wettability (contact angle ≤15°) while the surrounding substrate maintains low wettability (contact angle ≥100°). This is achieved through selective UV-ozone treatment of the pad region and fluorocarbon coating of the surrounding areas, creating a sharp local contrast in surface properties that ensures reliable liquid confinement during self-assembly
Solution Approach 2:
The patent changes the wettability parameter of the pad surface by exposing it to UV radiation in the presence of ozone, which modifies the surface chemistry to achieve high wettability (contact angle ≤15°). Simultaneously, the surrounding substrate is coated with fluorocarbon material to maintain low wettability (contact angle ≥100°), creating a controlled parameter difference that ensures drop confinement
2Reliability
If ultraviolet treatment is applied to create high wettability pads, then the pad wettability is improved, but the surrounding substrate may also be affected, reducing the wettability difference needed for effective liquid confinement
Solution Approach 1:
The patent applies preliminary action by first forming a fluorocarbon coating on the entire substrate surface to establish low wettability regions, then selectively removing the fluorocarbon coating from the pad area through UV-ozone treatment. This sequence ensures that the surrounding substrate maintains its low wettability (contact angle ≥100°) while the pad achieves high wettability (contact angle ≤15°), preventing unintended wettability changes in the surrounding areas
Solution Approach 2:
The patent extracts the fluorocarbon coating from the pad region by applying UV-ozone treatment selectively to that area. The fluorocarbon material is removed from the pad surface through this treatment, exposing the underlying high-wettability substrate, while the surrounding fluorocarbon-coated areas retain their low wettability properties, thus creating the desired wettability contrast
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 significantly improves the confinement of drops on the pads, ensuring accurate alignment and attachment of integrated circuits during self-assembly, while being compatible with conventional integrated circuit manufacturing techniques.
Implementation Method 1
exposing the pad and of the fluorocarbon material to ultraviolet treatment in the presence of ozone
Implementation Method 2
exposing the pad and of the fluorocarbon material to ultraviolet treatment in the presence of ozone
Implementation Method 3
The support 11 comprises a substrate 12 made of a material with low wettability, for example silicon, and includes, on the surface of the substrate 12, a pad 14 made of a material with high wettability
Data Source
Figure 1A~2C
Figure 3A~4
Figure 5A~5G
AI summary
The invention concerns a method for producing at least one pad assembly (32, 50) on a support (19, 43) intended for the implementation of a method for self-assembling at least one element (10) on the support (19, 43), and a corresponding device. The production method comprises the following successive steps: (a) forming, on the support (19, 43), a layer (28, 48) of at least one fluorinated material around the location (30, 44) of the pad assembly (32, 50), the layer (28, 48) having a thickness greater than 10 nm; and (b) exposing the layer (28, 48) and the location (30, 44) to an ultraviolet treatment in the presence of ozone to form the pad assembly (32, 50) at said location (30, 44), a drop of liquid (16) having a static contact angle on the pad assembly (32, 50) less than or equal to 15°, the drop of liquid (16) having, after step (b), a static contact angle on the layer (28, 48) greater than or equal to 100°.