Branched Additive for Copper Electroplating Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electroplating methods result in uneven metal deposits on substrates with irregular surfaces, particularly leading to underplating in holes, which affects conductivity and quality.
Innovation Solution
A new additive compound with a branched structure and high charge density, represented by formula (I), is used in the electroplating process, allowing for adjustable nitrogen to oxygen ratios, which acts as a leveler to enhance copper electrochemical deposition, especially in 3D-IC integration, providing high filling power and thin surface plating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional electroplating process is used without additives, then the process is simple and cost-effective, but the metal deposit becomes uneven on irregular substrate surfaces with holes
Solution Approach 1:
The patent introduces a leveler additive as an intermediary substance in the electroplating bath. This additive mediates between the irregular substrate surface and the metal deposit by adsorbing preferentially on high-current-density areas (protrusions, hole edges) and suppressing deposition there, thereby achieving uniform metal coverage on complex geometries without fundamentally changing the electroplating process
Solution Approach 2:
The patent modifies the electroplating bath composition by adding specific chemical substances (levelers) and adjusting their concentrations. This changes the electrochemical parameters of the system, particularly the distribution of current density and deposition rate, enabling uniform plating on irregular surfaces while maintaining process simplicity
2Manufacturing precision
If conventional levelers are added to achieve uniform metal deposit, then the deposit quality improves, but the filling power in holes remains insufficient
Solution Approach 1:
The patent employs levelers with specific molecular structures (positively charged nitrogen moieties, hydrophobic groups) that provide different functional properties at different locations. The additive exhibits local quality by preferentially adsorbing on specific surface features (protrusions vs. recesses) and providing spatially varying deposition control, enabling both uniformity and effective hole filling
Solution Approach 2:
The patent uses composite-leveler molecules that combine multiple functional groups (positively charged nitrogen, hydrophobic chains, oxygen-containing groups) within a single additive structure. This composite molecular design enables the additive to simultaneously provide leveling action and enhance hole filling capability that conventional single-function levelers cannot achieve
3Adaptability or versatility
If the substrate has holes with irregular geometry, then the substrate functionality is maintained, but the edge becomes overplated while inner walls remain underplated
Solution Approach 1:
The leveler additive acts as an intermediary that bridges the gap between irregular substrate geometry and uniform plating requirements. It adsorbs on the substrate surface and modifies the local electrochemical environment, mediating the deposition process to achieve controlled thickness distribution on complex geometries including holes, protrusions, and recesses
Solution Approach 2:
The patent changes the electrochemical parameters at the substrate surface through additive adsorption. The leveler modifies the double-layer structure, hydrogen bonding, and surface tension locally, thereby changing the deposition rate and current efficiency parameters to achieve uniform plating on irregular substrates
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 additive compound achieves uniform metal deposition, ensuring proper filling of holes and improved conductivity by providing a high-quality plating with thin thickness and minimal dimples, surpassing conventional levelers in performance.
Implementation Method 1
electroplating a substrate by submerging it into an electroplating bath
Implementation Method 2
The additive compound achieves uniform metal deposition, ensuring proper filling of holes
Implementation Method 3
applying an electric current to the substrate for a predetermined period of time such that a plating is formed on the substrate
Data Source
AI summary
This invention relates to a new compound represented by formula (I). Particularly, the new compound is used as an additive in copper electroplating. A chemical structure for the leveler, an electroplating bath containing the same, a method of preparing the additive and a method of electroplating a substrate with the electroplating bath containing the additive are disclosed. The additive compound/molecule of the present invention provides a branched structure at each ends, wherein each of the branches comprises a positively charged nitrogen moiety. The additive compound/molecule is formed by linking the branches having the positive charged nitrogen moieties to the backbone of the additive compound/molecule. This leads to a high charge density novel additive compound/molecule.