Copper Electroplating Bath Nitrate Additive Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional copper or copper alloy electroplating baths struggle to form high-aspect bump electrodes with uniform height and thickness at high speeds, particularly for three-dimensional semiconductor components like PoP, due to limitations in solubility and performance of conventional electrolytes such as sulfuric acid and methanesulfonic acid.
Innovation Solution
A copper or copper alloy electroplating bath comprising two or more electrolytes, including at least one nitrate and optionally other acids, chlorides, carbonates, phosphates, or perchlorates, with specific nitrates like sodium nitrate and copper(II) nitrate, and copper ion-supplying compounds, to achieve uniform electrodeposition and reduce abnormal precipitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional electrolytes (sulfuric acid, methanesulfonic acid) are used in copper electroplating baths, then the plating bath can maintain basic operation, but it cannot form high-aspect bump electrodes with uniform height at high speed due to solubility limitations
Solution Approach 1:
The patent changes the chemical parameters of the electrolyte by introducing nitric acid and nitrates, which fundamentally alter the solubility characteristics and electrochemical behavior of the plating bath, enabling high-speed plating with uniform deposit formation
Solution Approach 2:
The patent creates a composite electrolyte system combining nitric acid, nitrates, and conventional electrolytes (sulfuric acid, methanesulfonic acid), where the synergistic interaction of multiple components achieves both high plating speed and uniform deposit quality that neither component could achieve alone
2Manufacturing precision
If conventional electrolytes are used, then the plating bath composition is simple, but abnormal precipitation occurs frequently and uniform height cannot be achieved
Solution Approach 1:
The patent modifies the chemical composition parameters by adding specific concentrations of nitric acid (1-50 g/L) and nitrates (1-100 g/L), which change the electrochemical environment to suppress abnormal precipitation and enable uniform deposit formation
Solution Approach 2:
The nitrate ions act as intermediary species that mediate between the copper ion supply and the electrodeposition process, controlling the release and deposition rate of copper to achieve uniform bump electrode formation while preventing abnormal precipitation
3Productivity
If high plating speed is pursued with conventional electrolytes, then productivity increases, but abnormal precipitation occurs and uniformity is lost
Solution Approach 1:
The patent changes the electrochemical parameters of the bath by introducing nitric acid and nitrates, which modify the deposition kinetics to maintain uniformity even at high plating speeds, thereby improving productivity without sacrificing reliability
Solution Approach 2:
The patent creates a dynamic equilibrium in the plating bath where nitrate ions continuously regulate copper ion availability, allowing the system to adapt to high current densities while maintaining controlled, uniform deposition and preventing abnormal precipitation
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 solution enables the formation of high-aspect bump electrodes with uniform height and thickness at high speeds, significantly reducing abnormal precipitation and improving the productivity of electronic components, particularly for three-dimensional semiconductor structures.
Implementation Method 1
a copper or copper alloy electroplating bath comprising two or more electrolytes, wherein the electrolytes include at least one selected from nitric acid and a nitrate
Implementation Method 2
can form electrodeposits, such as a group of high-aspect bump electrodes, having a uniform height or thickness at high speed
Data Source
AI summary
A copper or copper alloy electroplating bath has two or more electrolytes. The two or more electrolytes include at least one selected from nitric acid and a nitrate. The two or more electrolytes can form electrodeposits, such as a group of high-aspect bump electrodes, that have a uniform height or thickness at high speed.