Electrochemical Plating Flow Regulators for Uniform Wafer Deposition
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Solution Overview
Problem
In electrochemical plating processes for semiconductor wafers, achieving uniform thickness and defect-free deposition of metal layers is challenging due to issues with bubble entrapment and non-uniform plating solution flow, which affects the quality and yield of the metal film.
Innovation Solution
The electrochemical plating system incorporates a cell chamber with a leveling assembly and flow regulators to ensure a horizontally parallel contact between the wafer and the plating solution, utilizing a recirculation system with filters and a feedback controller to maintain radially uniform overflow and remove bubbles and by-products, thereby ensuring consistent deposition quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional electrochemical plating is performed without flow regulation, then the process is simple, but the plating solution flow is non-uniform causing defects and poor deposition quality
Solution Approach 1:
The cell chamber is divided into multiple zones with different flow regulator configurations. Flow regulators are positioned at specific locations (e.g., at angles of 0°, 45°, 90°, 135°) to segment the flow control function across different regions of the wafer, ensuring uniform plating solution distribution without requiring complete redesign of the entire chamber.
Solution Approach 2:
Different flow regulator settings are applied to different regions of the cell chamber based on local flow requirements. The flow regulators can be independently adjusted to provide tailored flow rates and angles for specific areas, compensating for local variations in solution distribution and ensuring uniform deposition across the entire wafer surface.
2Reliability
If flow regulators are added to control plating solution flow, then uniform overflow and defect-free deposition are achieved, but the device complexity increases
Solution Approach 1:
A feedback control system is implemented where flow rate sensors monitor the actual plating solution flow rate, and this information is fed back to a controller that adjusts the flow regulator accordingly. This closed-loop feedback mechanism maintains consistent flow rates and uniform overflow patterns, ensuring reliable deposition quality while automating the complexity of flow management.
3Manufacturing precision
If recirculation system with filters is implemented, then bubbles and by-products are removed improving film quality, but the system complexity and maintenance requirements increase
Solution Approach 1:
The recirculation system operates continuously throughout the electrochemical plating process, constantly filtering bubbles and by-products from the plating solution. This continuous action ensures that the solution remains clean and free of defects throughout the entire deposition process, maintaining high film quality without requiring intermittent intervention or complex batch processing.
Solution Approach 2:
The recirculation system with filters is designed to automatically remove bubbles and by-products without requiring manual intervention. The system self-regulates the filtration process, continuously cleaning the plating solution and maintaining its quality throughout the operation, reducing the need for manual maintenance while ensuring consistent film 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 results in a uniform and defect-free metal film deposition, enhancing the yield and throughput of semiconductor manufacturing while reducing maintenance costs by maintaining consistent plating solution circulation and flow.
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 recirculation system with filters and a feedback controller to maintain radially uniform overflow and remove bubbles and by-products
Data Source
AI summary
An electrochemical plating apparatus for depositing a conductive material on a wafer includes a cell chamber. The plating solution is provided from a bottom of the cell chamber into the cell chamber. A plurality of openings passes through a sidewall of the cell chamber. A flow regulator is arranged with each of the plurality of openings configured to regulate an overflow amount of the plating solution flowing out through the each of the plurality of openings. The electrochemical plating apparatus further comprises a controller to control the flow regulator such that overflow amounts of the plating solution flowing out through the plurality of openings are substantially equal to each other.