Cross Flow Manifold for Electroplating Uniformity
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Solution Overview
Problem
Electroplating processes for semiconductor substrates face challenges in achieving uniformity and efficient mass transfer of metal ions at higher plating rates, particularly in wafer level packaging and through silicon via applications, where feature sizes and aspect ratios are larger and plating speeds are faster, leading to non-uniform electrodeposited layers.
Innovation Solution
The introduction of a cross flow manifold with a channeled plate and a compressible sealing member to increase electrolyte velocity across the substrate surface, creating a sealed cross flow environment that enhances mass transfer and plating uniformity by directing electrolyte flow parallel to the substrate and preventing leakage, thereby increasing the velocity of electrolyte flow and maintaining uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If plating rate is increased to improve productivity, then plating speed increases, but plating uniformity deteriorates
Solution Approach 1:
The patent introduces a cross-flow manifold system that delivers electrolyte to the substrate surface using hydraulic flow principles. By controlling electrolyte flow rates and creating cross-flow patterns, the system maintains mass transfer efficiency at high plating rates while ensuring uniform metal deposition across the substrate surface, thereby resolving the contradiction between productivity and manufacturing precision
2Manufacturing precision
If cross flow velocity is increased to improve mass transfer, then plating uniformity improves, but device complexity increases
Solution Approach 1:
The cross-flow manifold is designed to serve multiple functions simultaneously: it distributes electrolyte uniformly across the substrate, creates controlled cross-flow patterns to enhance mass transfer, and can be integrated with the substrate holder structure. This multi-functionality reduces the need for separate components, thereby improving plating uniformity while limiting the increase in device complexity
3Productivity
If electrolyte flow rate is increased to improve mass transfer, then plating speed increases, but energy consumption increases
Solution Approach 1:
The patent optimizes electrolyte flow parameters by introducing cross-flow components that create more efficient flow patterns. By changing the flow direction and distribution parameters rather than simply increasing flow rate, the system achieves improved mass transfer and higher plating speeds with lower energy consumption, as the cross-flow pattern reduces turbulence and improves contact efficiency between electrolyte and substrate surface
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 solution significantly improves plating uniformity and efficiency by maintaining high electrolyte velocity and preventing leakage, ensuring uniform deposition across larger features and higher plating rates, enhancing the quality of electroplated layers on semiconductor substrates.
Implementation Method 1
increasing the velocity of cross flow of electrolyte in the immediate vicinity of the surface of the substrate
Implementation Method 2
Electrochemical deposition processes are well-established in modern integrated circuit fabrication
Implementation Method 3
electroplating the metal into very thin, high-aspect ratio trenches and vias
Implementation Method 4
sealing the cross flow near the substrate by blocking electrolyte outlets that could lead to reduced cross flow velocity
Data Source
AI summary
The embodiments herein relate to methods and apparatus for electroplating one or more materials onto a substrate. Typically, the embodiments herein utilize a channeled plate positioned near the substrate, creating a cross flow manifold between the channeled plate and substrate, and on the sides by a flow confinement ring. A seal may be provided between the bottom surface of a substrate holder and the top surface of an element below the substrate holder (e.g., the flow confinement ring). During plating, fluid enters the cross flow manifold through channels in the channeled plate, and through a cross flow inlet, then exits at the cross flow exit, positioned opposite the cross flow inlet. The apparatus may switch between a sealed state and an unsealed state during electroplating, for example by lowering and lifting the substrate and substrate holder as appropriate to engage and disengage the seal.