Offset Fin Paddle for Uniform Electroplating Mass Transport
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Solution Overview
Problem
Conventional electroplating processes face challenges with limited agitation and non-uniform mass transport in tank plating cells, leading to uneven deposition of electrolytic materials on semiconductor wafers.
Innovation Solution
A modified paddle design with offset fins and channels that create Venturi effects to enhance electrolyte flow and agitation, allowing for direct impingement of electrolyte streams onto the wafer surface, promoting uniform deposition and increased mass transport.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional tank plating cells are used with simple agitation, then the device complexity is low, but the mass transport is non-uniform leading to uneven deposition
Solution Approach 1:
The paddle is segmented into multiple functional components: a body portion with multiple channels running through it, and multiple fins (first fin, second fin, third fin) extending from different surfaces. Each channel and fin serves a specific function in directing electrolyte flow, creating localized high-velocity jets that impinge on the wafer surface to enhance mass transport and deposition uniformity.
Solution Approach 2:
The paddle design creates localized regions of high electrolyte velocity and shear rate at specific impingement zones on the wafer surface through the channel-f fin configuration. The channels direct electrolyte flow to specific locations, creating focused agitation zones that promote uniform deposition in critical areas while maintaining overall system simplicity.
2Manufacturing precision
If vertically oriented paddle is used to allow debris to fall to bottom, then debris deposition on workpiece is reduced, but electrolyte agitation and mass transport are limited
Solution Approach 1:
The paddle utilizes hydraulic principles by channeling electrolyte flow through internal passages and directing it via fins to create high-velocity jets that impinge on the wafer surface. This hydraulic action enhances mass transport and deposition rate without requiring complex external agitation systems, maintaining productivity while improving mass transport uniformity.
Solution Approach 2:
The paddle design creates dynamic electrolyte flow patterns through the interaction of channels and fins, generating variable velocity fields and shear rates during the plating process. This dynamic flow regime enhances mass transport and deposition rate compared to static or simple agitation systems.
3Productivity
If high power is used to achieve high-rate deposition, then productivity increases, but heat dissipation and energy consumption increase
Solution Approach 1:
The paddle design uses the electrolyte flow itself to provide the necessary agitation and mass transport functions. The channel-f fin structure directs electrolyte flow to create self-sustaining high-velocity jets that enhance deposition without requiring additional energy input for separate agitation systems, improving productivity while minimizing energy loss.
Solution Approach 2:
The design changes the flow parameters of the electrolyte by creating high-velocity jets through the channel-f fin configuration. This increases the mass transport rate and deposition rate without proportionally increasing power consumption, as the energy is focused in specific directional flows rather than general turbulence.
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 paddle design achieves uniform and high-rate deposition of materials on the wafer surface by increasing the velocity and shear rate of the electrolyte, reducing power consumption and heat dissipation, and allowing for efficient plating operations with reduced voltage.
Implementation Method 1
A modified paddle design with offset fins and channels that create Venturi effects to enhance electrolyte flow and agitation
Data Source
AI summary
A paddle for a plating system has a housing with a back portion, a front portion, a first side portion, a second side portion, a first end portion, and a second end portion. A first fin is disposed laterally along a first external surface of the first side portion and offset and coupled to the first external surface to define a first passageway between the first external surface of the first side portion and a first internal surface of the first fin for flow of the electrolyte through the first passageway. A second fin is disposed laterally along a second external surface of the second side portion and offset and coupled to the second external surface to define a second passageway between the second external surface of the second side portion and a second internal surface of the second fin for flow of the electrolyte through the second passageway.