Electroplating Electrolyte Control for Acid-Metal Ion Partition
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Solution Overview
Problem
The concentration of electroplating solutions in electrochemical plating apparatuses for semiconductor substrates fluctuates due to the acid/metal ion partition effect, leading to undesirable side effects such as crystallization and membrane damage, which affects electroplating process performance.
Innovation Solution
A method involving the controlled addition of a secondary electroplating solution with components at concentrations that significantly deviate from the target concentrations to counteract these fluctuations, ensuring precise control over the electroplating solution composition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If make-up solution is supplied to replenish electroplating solution components, then the target concentration of components is maintained, but the acid/metal ion partition effect causes concentration fluctuations and crystallization
Solution Approach 1:
The patent changes the concentration parameters of the secondary electroplating solution to significantly deviate from target concentrations (e.g., acid at 10-100x higher, metal ions at 0.1-10x lower). This parameter transformation allows the system to counteract concentration fluctuations caused by the acid/metal ion partition effect during normal electroplating operations, preventing crystallization and membrane damage while maintaining stable plating conditions.
Solution Approach 2:
The patent applies preliminary anti-action by adding secondary electroplating solution with deliberately inverted concentration ratios before the acid/metal ion partition effect can cause harmful crystallization. The high acid and low metal ion concentrations in the secondary solution preemptively counterbalance the partition effect, preventing the formation of harmful conditions rather than reacting to them after they occur.
2Reliability
If secondary electroplating solution is added frequently to maintain concentration, then optimal electroplating performance is maintained, but operational complexity and cost increase
Solution Approach 1:
The patent makes the secondary electroplating solution multi-functional by designing it to simultaneously address multiple issues: counteracting the acid/metal ion partition effect, preventing crystallization, maintaining pH balance, and stabilizing metal ion concentrations. This universal solution reduces the need for multiple separate chemical additions and complex solution management procedures, simplifying the overall system while maintaining reliable electroplating performance.
3Quantity of substance
If traditional make-up solution is used to replenish electroplating solution, then component concentrations are maintained, but acid and metal ion concentrations fluctuate due to partition effect
Solution Approach 1:
The patent creates a composite electroplating system by combining traditional make-up solution with secondary electroplating solution having fundamentally different concentration characteristics. The make-up solution replenishes volume and base components at target concentrations, while the secondary solution with inverted concentration ratios (high acid, low metal ions) stabilizes the acid/metal ion balance. This composite approach maintains both volume and compositional stability despite the partition effect.
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 stabilizes the electroplating solution concentrations, maintaining optimal performance and reducing the need for frequent replenishment, thereby minimizing waste and operational costs while preventing membrane damage.
Implementation Method 1
The concentration of electroplating solutions in electrochemical plating apparatuses for semiconductor substrates fluctuates due to the acid/metal ion partition effect
Implementation Method 2
A method involving the controlled addition of a secondary electroplating solution with components at concentrations that significantly deviate from the target concentrations to counteract these fluctuations
Implementation Method 3
The features (vias and trenches) are then filled electrochemically with Cu through an electrochemical deposition process, during which the copper cation is reduced electrochemically to copper metal
Data Source
AI summary
Methods and electroplating systems for controlling plating electrolyte concentration on an electrochemical plating apparatus for substrates are disclosed. A method involves: (a) providing an electroplating solution to an electroplating system; (b) electroplating the metal onto the substrate while the substrate is held in a cathode chamber of an electroplating cell of electroplating system; (c) supplying the make-up solution to the electroplating system via a make-up solution inlet; and (d) supplying the secondary electroplating solution to the electroplating system via a secondary electroplating solution inlet. The secondary electroplating solution includes some or all components of the electroplating solution. At least one component of the secondary electroplating solution has a concentration that significantly deviates from its target concentration.