Plating Substrate Holder Tapered Fixing Ring
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Solution Overview
Problem
Existing plating apparatuses face challenges in achieving uniform deposition of conductive materials on wafers due to non-uniform electric fields and contamination from particles and by-products generated by substrate holders during the plating process.
Innovation Solution
A substrate holder design featuring a seal ring, support ring, and fixing ring with tapered surfaces and a regulation ring that regulates the electric field and prevents contamination by directing plating solution away from the wafer surface when withdrawn from the plating solution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a regulation plate is provided to regulate the electric field, then the electric field distribution is improved, but non-uniform deposition of conductive material still occurs on the wafer surface
Solution Approach 1:
The substrate holder is segmented into multiple functional components: a base member, a holding member with seal ring, and a regulation member with electric contacts. This segmentation allows each component to perform its specific function - the seal ring prevents contamination while the regulation member controls the electric field, collectively achieving uniform deposition without the drawbacks of a single regulation plate
Solution Approach 2:
The regulation member with electric contacts acts as an intermediary between the holding member and the wafer. It regulates the electric field distribution by making controlled contact with the wafer peripheral portion, thereby achieving uniform conductive material deposition without causing contamination that would result from direct contact by the holding member
2Reliability
If the substrate holder includes sliding parts for locking mechanism, then the holding function is improved, but particles are generated that contaminate the wafer
Solution Approach 1:
The harmful sliding parts that generate particles are extracted from the substrate holder design. Instead of using a locking mechanism with sliding components, the invention employs a pressurizing member that applies pressure to the seal ring to maintain sealing contact, thereby preventing particle generation while preserving the holding function
Solution Approach 2:
The seal ring is designed as a replaceable component that can be easily replaced when worn. This allows the use of simpler materials and structures for the seal ring without concern for long-term durability, as it can be replaced periodically to maintain sealing effectiveness without generating contamination
3Reliability
If the substrate holder uses corrosion-resistant metal components, then the resistance against plating solution is improved, but by-products are generated that contaminate the wafer
Solution Approach 1:
The seal ring is designed as a flexible sealing component that can be made from materials resistant to plating solution corrosion. This flexible sealing structure prevents contact between the plating solution and the substrate holder components, thereby preventing by-product generation and contamination while maintaining corrosion resistance
Solution Approach 2:
The seal ring acts as an intermediary barrier between the plating solution and the substrate holder components. It prevents the plating solution from contacting the substrate holder, thereby eliminating the chemical reactions that would generate contaminating by-products while maintaining the necessary corrosion resistance
4Reliability
If the substrate holder directly contacts the wafer peripheral portion, then the holding function is improved, but contamination of the plated surface occurs from plating solution flow
Solution Approach 1:
The seal ring serves as an intermediary between the holding member and the wafer peripheral portion. It maintains the holding function by sealing against the wafer edge while preventing the plating solution from flowing down onto the plated surface, thereby eliminating contamination without compromising the holding capability
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 design ensures uniform deposition of conductive materials across the wafer surface and minimizes contamination by effectively managing the electric field and preventing the flow of plating solution and particles onto the wafer.
Implementation Method 1
a seal ring which can be brought into contact with a peripheral portion of a substrate
Implementation Method 2
a regulation ring projecting radially inwardly from the seal-ring pressing portion. The regulation ring has an inside diameter which is smaller than an inside diameter of the seal ring
Implementation Method 3
The fixing ring includes an annular portion having an inner circumferential surface and an outer circumferential surface, each of which is constituted by a tapered surface
Implementation Method 4
a plating apparatus is a device for depositing a conductive material on a surface of a wafer by passing an electric current between an anode and the wafer which are immersed in a plating solution
Data Source
AI summary
A substrate holder for holding a substrate, such as a wafer, is disclosed. The substrate holder includes a seal ring which can be brought into contact with a peripheral portion of the substrate, a support ring supporting the seal ring, and a fixing ring pressing the seal ring against the support ring. The fixing ring includes an annular portion having an inner circumferential surface and an outer circumferential surface, each of which is constituted by a tapered surface. The fixing ring further includes a seal-ring pressing portion connected to the annular portion, and a regulation ring projecting radially inwardly from the seal-ring pressing portion. The regulation ring has an inside diameter which is smaller than an inside diameter of the seal ring.