Cross-linked Hydrophobic Coating for Plasma-Resistant Die Self-Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current hybrid bonding techniques for forming 3D die stacks face challenges in preserving hydrophobic coatings during pre-bonding plasma processing, leading to misalignment and bond failures.
Innovation Solution
The use of cross-linkable hydrophobic materials with high cross-link density and tunable thickness to surround hybrid bonding regions, which remain intact and functional even after plasma processing, ensuring effective liquid droplet confinement and self-alignment during bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If plasma processing is performed to clean and activate hybrid bond regions, then bonding quality is improved, but hydrophobic coatings are damaged or removed leading to misalignment
Solution Approach 1:
The patent applies parameter changes by modifying the chemical structure of hydrophobic coatings through cross-linking. The cross-linked hydrophobic coating resists plasma etching and damage, maintaining its integrity during plasma processing. This allows the coating to survive the plasma treatment that is necessary for cleaning and activating bond regions, thereby resolving the contradiction between improving bonding quality and maintaining alignment accuracy.
Solution Approach 2:
The patent uses composite materials by combining hydrophobic coating materials with cross-linking agents to create a cross-linked hydrophobic coating system. This composite structure provides both the hydrophobic properties needed for liquid droplet confinement and the plasma resistance needed to survive processing, simultaneously addressing both bonding quality and alignment accuracy requirements.
2Manufacturing precision
If hydrophobic coatings are used for liquid droplet confinement, then self-alignment is enabled, but plasma processing removes or damages the coatings
Solution Approach 1:
The patent changes the physical and chemical parameters of the hydrophobic coating by introducing cross-links. This cross-linking increases the coating's resistance to plasma etching and damage while preserving its hydrophobicity. The cross-linked structure maintains the coating's integrity during plasma processing, enabling it to continue functioning as a liquid droplet confinement layer for self-alignment.
Solution Approach 2:
The patent applies preliminary action by forming the cross-linked hydrophobic coating before plasma processing. The cross-linking is performed in advance to create a plasma-resistant protective layer that will survive subsequent plasma treatment. This preliminary preparation ensures the coating remains intact during the necessary plasma cleaning and activation steps, maintaining both self-alignment capability and coating integrity.
3Reliability
If cross-link density is increased to improve plasma resistance, then coating durability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent uses parameter changes by adjusting cross-link density as a controllable variable. By optimizing the cross-link density parameter, the patent achieves sufficient plasma resistance and coating durability without excessive complexity. The cross-link density can be controlled through deposition conditions, exposure time, and chemical composition, allowing for practical implementation while maintaining high 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 enhances the compatibility of hydrophobic coatings with plasma treatments, maintaining wettability contrast and achieving high accuracy and reliability in self-aligned hybrid bonding processes.
Implementation Method 1
cross-linked hydrophobic material-based structures extending around an outer perimeter of the inorganic dielectric material... effective liquid droplet confinement
Implementation Method 2
prior to bonding, the surface of each die may be controlled to promote bonding... the hybrid bond regions may be cleaned and activated using plasma processing
Implementation Method 3
self-alignment assisted assembly... effective liquid droplet confinement and self-alignment during bonding
Implementation Method 4
material comprising a plurality of polymer chains cross-linked by a plurality of covalent bonds between the polymer chains... high cross-link density
Data Source
AI summary
Hybrid bonded die stacks, related apparatuses, systems, and methods of fabrication are disclosed. One or both of an integrated circuit (IC) die hybrid bonding region and a base substrate hybrid bonding region surrounded by hydrophobic structures that include a cross-linked material. The hybrid bonding regions are brought together with a liquid droplet therebetween, and capillary forces cause the IC die to self-align. A hybrid bond is formed by evaporating the droplet and a subsequent anneal. The cross-linked material hydrophobic structures contain the liquid droplet for alignment and are resistant to plasma treatment prior to bonding.