Electroplating Wafer Rinsing Stages to Recover Bath Fluid
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor processing techniques face issues during rinsing operations in electroplating systems, leading to bath dilution, contamination, and loss of plating solution, which increases costs and reduces the efficiency of the process.
Innovation Solution
A staged cleaning system is implemented, utilizing a first nozzle to recover residual bath fluid back into the plating bath and a second nozzle to deliver a cleaning fluid that minimizes fluid delivery into the bath, with the first fluid being compatible and the second fluid being separate, to reduce dilution and contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If water is sprayed across the substrate surface during rinsing, then the substrate is cleaned, but bath fluid is diluted and lost
Solution Approach 1:
The rinsing process is segmented into multiple stages: a first rinse stage that delivers water to the substrate to remove bulk bath fluid, and a second rinse stage that delivers additional water to remove residual bath fluid. This segmentation allows optimized fluid delivery at each stage, reducing overall bath fluid loss while maintaining cleaning quality.
Solution Approach 2:
The system changes parameters such as water flow rate, water pressure, and rinse stage timing to optimize the balance between substrate cleaning and bath fluid conservation. By adjusting these parameters, the system achieves effective rinsing while minimizing the volume of water that mixes with and dilutes the bath fluid.
2Manufacturing precision
If rinse time is extended to improve cleaning, then substrate quality improves, but bath dilution increases
Solution Approach 1:
The first rinse stage performs preliminary cleaning by removing the bulk of bath fluid from the substrate surface before the second rinse stage. This preliminary action reduces the need for extended rinse times in subsequent stages, thereby limiting overall bath dilution while achieving thorough cleaning.
Solution Approach 2:
The rinsing process uses periodic action with distinct rinse stages separated by substrate rotation or position changes. This periodic delivery of water in controlled stages improves cleaning efficiency without requiring continuous extended rinsing that would increase bath dilution.
3Manufacturing precision
If plating solution is splashed onto the wafer during rinsing, then the wafer is cleaned, but staining occurs
Solution Approach 1:
The system uses an intermediary mechanism where water is delivered in a controlled manner through nozzles positioned to rinse the wafer surface without allowing plating solution to splash onto the wafer during the rinsing process. This intermediary water delivery method prevents direct contact between plating solution and wafer surface that would cause staining.
Solution Approach 2:
The rinsing process applies preliminary anti-action by delivering water to the wafer surface before plating solution can splash onto it during substrate movement. This preemptive rinsing creates a protective water barrier that prevents staining while still achieving cleaning objectives.
4Manufacturing precision
If residual bath fluid is drained from the substrate, then cleaning is improved, but processing costs increase
Solution Approach 1:
The system applies discarding and recovering by collecting residual bath fluid that drains from the substrate during rinsing and returning it to the plating bath. This recovery process reduces the volume of bath fluid that must be discarded and replaced, thereby reducing processing costs while maintaining substrate cleaning quality.
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 reduces bath loss, limits dilution, and maintains bath fluid quality, allowing for more efficient and economic cleaning processes while protecting the substrate and plating bath.
Implementation Method 1
rotating the head for a first period of time to sling bath fluid back into the plating bath
Implementation Method 2
delivering a first fluid to the substrate from a first fluid nozzle to at least partially expel the residual amount of bath fluid back into the plating bath
Implementation Method 3
delivering a second fluid across the substrate from a second fluid nozzle
Data Source
AI summary
Exemplary electroplating apparatuses may include a system head operable to clamp a substrate. The system head may be operable to raise and lower the substrate between a plating bath, a first position above the plating bath, and a second position above the first position. The electroplating apparatuses may include a plating bath vessel adapted to hold the plating bath for electroplating on the substrate. The electroplating apparatuses may include a weir extending about the plating bath vessel. The electroplating apparatuses may include a first nozzle extending through the weir at a first radial position, and positioned to deliver fluid to the substrate at the first position above the plating bath. The electroplating apparatuses may include a second nozzle extending through the weir at a second radial position, and positioned to deliver fluid to the substrate at the second position above the plating bath.