Copper Electroplating via TSV Additive Control
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Solution Overview
Problem
Current copper electroplating methods for forming through-silicon via (TSV) plugs in semiconductor fabrication face challenges in achieving uniform and void-free copper layers, particularly in high aspect ratio via holes, due to limitations in controlling electroplating speed and surface leveling.
Innovation Solution
A copper electroplating method using a solution containing copper (II) methanesulfonic acid, methanesulfonic acid, chlorine ions, and specific additives such as suppressors, accelerators, and levelers, which include compounds with defined molecular structures and concentrations, applied in an electroplating apparatus with controlled current density and solution circulation, to form a uniform copper layer within TSV plugs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional copper electroplating methods are used to form TSV plugs, then electroplating speed can be maintained, but uniformity and void-free coverage in high aspect ratio via holes cannot be achieved
Solution Approach 1:
The patent applies local quality by using a multi-component additive system where each additive performs a specific localized function: suppressor controls plating rate in deep via regions, accelerator enhances plating rate in accessible regions, and leveler ensures uniform surface deposition. This localized control of plating characteristics enables uniform void-free copper layers while maintaining high plating speed throughout the via structure.
Solution Approach 2:
The patent changes chemical parameters by formulating a specific copper electroplating solution with controlled concentrations of copper (II) methanesulfonic acid (200-500 g/L), methanesulfonic acid (5-20 g/L), and precisely dosed additives (suppressor: 0.5-200 mg/L, accelerator: 10-400 mg/L, leveler: 0.5-200 mg/L). These parameter changes optimize both deposition uniformity and plating rate, resolving the contradiction between manufacturing precision and productivity.
2Productivity
If high current density is applied to increase electroplating speed, then productivity improves, but surface uniformity and void-free deposition deteriorate
Solution Approach 1:
The patent applies preliminary anti-action by incorporating suppressor and leveler additives that preemptively counteract the harmful effects of high current density. The suppressor prevents excessive copper deposition and the leveler maintains surface flatness even when high current density (1.0-100 mA/cm²) is applied, allowing high productivity without sacrificing surface uniformity or creating voids.
Solution Approach 2:
The additive system provides chemical feedback control where the suppressor, accelerator, and leveler dynamically regulate copper deposition based on local conditions within the via. This feedback mechanism ensures that even at high current densities, the deposition remains controlled and uniform, preventing void formation while maintaining high plating speed.
3Manufacturing precision
If additives are added to control electroplating speed and leveling, then manufacturing precision improves, but solution complexity and process control difficulty increase
Solution Approach 1:
The patent merges multiple functional additives (suppressor, accelerator, leveler) into a single integrated electroplating solution formulation. This combined approach simplifies process control compared to sequential additive applications, as all components work synergistically in one bath to achieve uniform void-free copper deposition while maintaining manageable solution and process complexity.
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 method ensures the formation of reliable TSV plugs without seams or voids, maintaining high electroplating speed and productivity while ensuring surface flatness and uniformity, enhancing the manufacturing process for semiconductor devices.
Implementation Method 1
forming a copper electroplating layer on the seed layer, wherein the copper electroplating solution includes water, a copper supply source, an electrolytic material
Implementation Method 2
copper electroplating method including dipping a substrate in a copper electroplating solution... and forming a copper electroplating layer on the seed layer
Data Source
AI summary
A copper electroplating method including dipping a substrate in a copper electroplating solution, the substrate including a seed layer; and forming a copper electroplating layer on the seed layer, wherein the copper electroplating solution includes water, a copper supply source, an electrolytic material, and a first additive, the first additive includes a compound represented by Formula 1, below: