Self-Assembled Monolayer Blocking for Low-Resistance Metal Vias
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Solution Overview
Problem
As semiconductor device sizes decrease, reducing via resistance becomes critical for improved performance, but existing methods struggle to effectively minimize contact resistance in interconnect structures, particularly for 3 nm node and beyond technologies.
Innovation Solution
A method involving selective deposition of a self-assembled monolayer (SAM) on a substrate using precursors with specific functional groups, such as alkene, alkyne, ketone, hydroxyl, or aldehyde, to selectively form a metal-containing film on metallic surfaces while maintaining low deposition on dielectric surfaces, thereby reducing contact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional planar processes are used to manufacture interconnect structures, then manufacturing simplicity is maintained, but via resistance cannot be effectively reduced for 3 nm node and beyond technologies
Solution Approach 1:
The patent applies preliminary action by depositing a self-assembled monolayer (SAM) on the metal surface before the main via fill process. This SAM layer serves as a preparatory step that modifies the metal surface properties, enabling subsequent selective deposition processes to achieve lower via resistance. The SAM is formed in advance and then removed after serving its function, representing a temporary preliminary action that enables the main goal of via resistance reduction.
Solution Approach 2:
The self-assembled monolayer (SAM) acts as an intermediary substance between the metal surface and the via fill material. This intermediary layer temporarily modifies the surface properties of the metal, enabling selective deposition processes to occur with enhanced control over via resistance. The SAM mediates the interaction between the metal substrate and subsequent processing steps, allowing achievement of lower via resistance without permanently complicating the manufacturing process.
2Adaptability or versatility
If selective deposition is attempted on both metal and dielectric surfaces, then surface preparation flexibility is improved, but deposition selectivity becomes difficult to achieve
Solution Approach 1:
The patent applies local quality by creating different surface properties on different regions of the substrate through selective SAM deposition. The SAM is deposited only on metal surfaces with specific crystallographic orientations (such as Cu(100)), while dielectric surfaces remain unaffected. This localized modification enables subsequent deposition processes to selectively occur on metal surfaces only, achieving high deposition selectivity while maintaining flexibility in surface preparation for different surface types.
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 effectively reduces contact resistance by selectively forming a metal-containing film on metallic surfaces while preserving dielectric surfaces, enhancing the performance of semiconductor structures beyond the 3 nm node.
Implementation Method 1
selectively depositing a self-assembled monolayer (SAM) on a first surface of a substrate by exposing the substrate to a first precursor
Implementation Method 2
the first precursor comprises at least two functional groups selected from alkene, alkyne, ketone, hydroxyl, aldehyde, or combinations thereof
Data Source
AI summary
Methods for selectively depositing on metallic surfaces are disclosed. Some embodiments of the disclosure utilize a hydrocarbon having at least two functional groups selected from alkene, alkyne, ketone, hydroxyl, aldehyde, or combinations thereof to form a self-assembled monolayer (SAM) on metallic surfaces.