Self-Assembled Monolayer Blocking for Low-Resistance Via Contacts
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Solution Overview
Problem
As semiconductor devices shrink, 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 semiconductor structures.
Innovation Solution
The method involves selectively depositing a self-assembled monolayer (SAM) on a metallic surface using a precursor with specific functional groups, followed by selective deposition of a liner on a dielectric surface, and subsequent removal of the SAM to reduce contact resistance, using precursors with functional groups like alkene, alkyne, hydroxyl, or ester, to enhance the electrical resistance at the via contact interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a planar process is used to manufacture interconnect structures, then alignment and connection of metallization layers can be achieved, but via resistance cannot be effectively minimized
Solution Approach 1:
A self-assembled monolayer (SAM) is deposited on the metal surface before the via formation process. This preliminary action modifies the metal surface properties to control subsequent material deposition and prevent unwanted metal migration, ultimately reducing via resistance without complicating the manufacturing process
Solution Approach 2:
The self-assembled monolayer acts as an intermediary between the metal surface and subsequent materials. It provides controlled interaction surfaces that prevent direct unwanted interactions while enabling desired electrical contact, thereby reducing via resistance through controlled interface properties
2Length of moving object
If the via size is reduced to maintain spacing in smaller ICs, then device scaling is achieved, but contact resistance increases
Solution Approach 1:
The self-assembled monolayer provides locally optimized surface properties at the via interface. By modifying only the local metal surface where the via contacts the metal line, it enables reduced via dimensions while maintaining low contact resistance through controlled local interface properties
3Reliability
If cladding is minimized to reduce via resistance, then via resistance improves, but metal surface control becomes difficult
Solution Approach 1:
The self-assembled monolayer serves as an intermediary that enables precise control of metal surface properties without requiring extensive cladding. It provides molecular-level control over surface reactivity and material deposition, achieving via resistance reduction while simplifying surface control
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 blocking the metallic surface while maintaining the dielectric surface integrity, leading to improved performance in semiconductor structures, particularly for 3 nm node and beyond devices.
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, ester, 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, at least one functional group selected from amino groups, hydroxyl groups, ether linkages or combinations thereof to form a self-assembled monolayer (SAM) on metallic surfaces.