Wafer Electroplating Edge Bevel Control With Multi-Nozzle Flow Regulation
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Solution Overview
Problem
In electrochemical plating processes for semiconductor wafers, achieving uniform and defect-free metal deposition is challenging due to issues with bubble formation and by-products in the plating solution, which affect the quality and reliability of the deposited metal layer.
Innovation Solution
The electrochemical plating system incorporates a substrate holder with a rotatable spindle and apertures to direct the plating solution radially outward, removing gas bubbles and using a recirculation system with filtration and replenishment to maintain solution quality, along with an edge bevel removal process utilizing multiple nozzles to control the tap width and edge profile of the plated metal film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the wafer contacts the plating solution horizontally in a parallel manner, then the uniformity of metal deposition is improved, but gas bubbles and by-products form on the wafer surface causing defects
Solution Approach 1:
The wafer back surface is segmented with multiple apertures that divide and redirect the plating solution flow. This segmentation allows the solution to be distributed across multiple exit points, creating numerous small flow paths that effectively sweep away bubbles and by-products while maintaining horizontal contact for uniform deposition.
Solution Approach 2:
The invention uses hydraulic flow through the apertures in the wafer back surface to create a sweeping action that removes gas bubbles and by-products from the wafer surface. The controlled liquid flow through the aperture array creates a pneumatic-hydraulic effect that prevents bubble accumulation while maintaining deposition uniformity.
2Object-affected harmful factors
If the plating solution flows directly over the wafer surface, then bubble removal is improved, but the edge bevel and tap width control become difficult
Solution Approach 1:
The aperture array is strategically positioned and sized to create different flow characteristics in different regions of the wafer. The apertures near the edge are configured to provide gentle flow for better edge bevel control, while central apertures provide stronger flow for effective bubble removal, achieving local optimization of both functions.
Solution Approach 2:
The system dynamically controls the plating solution flow rate and distribution through the apertures to adapt to different processing stages. The flow characteristics are adjusted to balance bubble removal effectiveness with edge bevel and tap width control requirements throughout the deposition process.
3Manufacturing precision
If multiple nozzles are used for edge bevel removal, then the tap width control is improved, but the device complexity increases
Solution Approach 1:
The aperture array in the wafer back surface serves multiple functions simultaneously: it distributes plating solution for uniform deposition, removes bubbles and by-products through controlled flow, and enables edge bevel removal. This multi-functionality eliminates the need for separate nozzle systems, reducing device complexity while maintaining precise tap width control.
Solution Approach 2:
The invention merges the bubble removal function and edge bevel removal function into a single integrated aperture array system. The same structure that distributes plating solution also performs edge treatment, combining multiple functions into one component and simplifying the overall device architecture.
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 ensures a uniform, defect-free metal deposition with improved reliability and reduced processing time, enhancing the yield and throughput of semiconductor manufacturing by minimizing unwanted metal layers at the wafer edges.
Implementation Method 1
Electrochemical plating (ECP) is a common manufacturing process that applies a thin layer of one metal onto another
Implementation Method 2
a substrate holder configured to hold a substrate on which a conductive layer is formed, and to rotate the substrate. The two or more nozzles are configured to eject an edge bevel removal (EBR) solution
Data Source
AI summary
An electrochemical plating apparatus for performing an edge bevel removal process on a wafer includes a cell chamber. The cell chamber includes two or more nozzles located adjacent to the edge of the wafer. A flow regulator is arranged with each of the two or more nozzles, which is configured to regulate a tap width of a deposited film flowing out through the each of the two or more nozzles. The electrochemical plating apparatus further includes a controller to control the flow regulator such that tap width of the deposited film includes a pre-determined surface profile. The two or more nozzles are located in radially or angularly different dispensing positions above the wafer.