Fluid Meniscus Stabilization in Semiconductor Electroplating
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Solution Overview
Problem
In semiconductor fabrication, electroplating processes often result in uneven current distribution around the wafer, leading to non-uniform deposition and prolonged processing times, which are inefficient and costly.
Innovation Solution
An apparatus and method that stabilize a fluid meniscus between a plating head and the substrate using a pre-processing fluid, applied upstream to ensure consistent and efficient electroplating by reducing mechanical resonance and enhancing fluid distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the wafer is rotated during electroplating to facilitate uniform plating, then plating uniformity is improved, but mechanical resonance occurs which destabilizes the fluid meniscus and reduces plating precision
Solution Approach 1:
The patent applies ultrasonic vibration to the plating head at a frequency matching the mechanical resonance of the fluid meniscus system. This controlled vibration stabilizes the meniscus by counteracting disruptive resonance effects, enabling precise electroplating while the wafer rotates. The ultrasonic frequency is specifically selected to match the resonant frequency of the meniscus, transforming harmful resonance into a stabilizing effect.
2Reliability
If discrete contacts on the wafer holder are used to provide plating current, then electrical connection is achieved, but current distribution becomes uneven with stronger current near contacts leading to non-uniform plating
Solution Approach 1:
The patent replaces the mechanical contact-based electrical connection system with a field-based approach. An electric field is applied across the fluid meniscus between the plating head and wafer surface, eliminating the need for discrete mechanical contacts on the wafer holder. This substitution ensures uniform current distribution across the entire wafer surface while maintaining reliable electrical connection for electroplating.
3Power
If the wafer is held at negative potential with respect to a positively charged anode plate, then electroplating reaction is driven, but plating time becomes lengthy reducing productivity
Solution Approach 1:
The patent employs a fluid meniscus system where electrolyte is delivered through capillary action and controlled fluid flow between the plating head and wafer surface. This hydraulic approach enables precise control of electrolyte supply and removal, allowing faster plating rates while maintaining reaction efficiency. The fluid dynamics enable rapid electrolyte exchange and product removal, increasing productivity without sacrificing the electrochemical reaction drive.
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 achieves uniform and efficient electroplating by stabilizing the fluid meniscus, reducing mechanical resonance, and ensuring consistent plating results, thereby improving processing efficiency and reducing costs.
Implementation Method 1
reducing mechanical resonance
Implementation Method 2
electroplating is typically performed
Data Source
AI summary
An apparatus for processing a substrate is provided. The apparatus includes a plating head configured to plate a surface of the substrate with a layer of a material using a fluid meniscus between the plating head and a surface of the substrate. The apparatus also includes a fluid meniscus stabilizing apparatus configured to apply a pre-processing fluid to the surface of the substrate before the fluid meniscus is applied to the surface.