Ureylene Additive for Void-Free Copper Plating
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Solution Overview
Problem
Current copper plating baths in the electronics and semiconductor industry face challenges in achieving complete and void-free filling of recessed structures with copper, particularly in advanced printed circuit boards, IC substrates, and glass substrates, due to limitations in the selectivity and reactivity of isocyanate-based additives.
Innovation Solution
The use of ureylene additives with specific structural units in copper or copper alloy deposition compositions as levelers and suppressors, which enhance plating rates and ensure uniform deposition by minimizing voids and dimples, is proposed. These additives are synthesized through a method involving isocyanates, monoamines, and multifunctional starting materials, avoiding halide functional groups to prevent side reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional additives containing isocyanate groups are used in copper plating baths, then the additives can participate in the deposition process, but they lack sufficient selectivity and reactivity control, leading to incomplete filling of recessed structures and formation of voids
Solution Approach 1:
The invention modifies the chemical structure of the additive by changing the isocyanate group (-NCO) to a ureylene group (-NH-CO-NH-). This parameter change in molecular structure provides better selectivity and reactivity control, enabling complete filling of recessed structures without voids while maintaining uniform copper deposition.
Solution Approach 2:
The invention uses a composite approach by combining the ureylene group with specific polyether chains and aromatic or aliphatic structures to create a multifunctional additive that simultaneously achieves complete recessed structure filling and uniform deposition across different surface topographies.
2Productivity
If isocyanate-based additives are used in plating baths, then they can function as suppressors or levelers, but they exhibit insufficient selectivity in their reactivity, resulting in side reactions and poor deposition control
Solution Approach 1:
The chemical parameter change from isocyanate to ureylene groups fundamentally alters the reactivity profile. The ureylene group provides controlled selectivity that enables high plating rates while maintaining precise control over deposition uniformity, eliminating the side reactions associated with isocyanate groups.
3Productivity
If conventional additives are used to achieve fast plating rates, then productivity increases, but the filling of recessed structures becomes incomplete and voids form
Solution Approach 1:
By changing the functional group parameter from isocyanate to ureylene, the invention achieves a synergistic effect where fast plating rates and complete void-free filling of recessed structures are simultaneously accomplished, resolving the trade-off between productivity and manufacturing precision.
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
The ureylene additives enable improved plating rates and complete filling of recessed structures without voids or dimples, enhancing the uniformity and quality of copper deposits, which is critical for advanced electronic and semiconductor applications.
Implementation Method 1
electrolytic copper deposition, this being fast and cost-efficient
Implementation Method 2
a combination of various additives is used in such plating bath compositions... levelers, suppressors (also referred to as carriers in the art) and accelerators
Data Source
Figure 1A~1B
AI summary
The present invention relates to ureylene additives, a method for their preparation, a use of said ureylene additives favorably as additive in metal or metal alloy deposition composition, preferably in a copper or copper alloy deposition composition, more preferably as leveler and/or suppressor therein, metal or metal alloy deposition composition comprising said ureylene additive and the use of such composition, a method for electrolytically depositing a metal or metal alloy layer, preferably a copper or copper alloy layer, onto at least one surface of a substrate and metal or metal alloy layers formed from above metal or metal alloy deposition composition. The ureylene additives allow for example in the case of copper plating for very levelled copper deposits without voids, in particular when filling recesses.