Electrochemical Deposition Apparatus with Movable Anode for TSV Filling
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Solution Overview
Problem
Current electrochemical deposition (ECD) methods face challenges in maintaining uniform deposition rates within small features on substrates, such as Through Silicon Vias (TSVs), due to the need for separate baths, chemical depletion, and complex tooling, which results in inefficient chemical use and extended process cycles.
Innovation Solution
The apparatus and method involve a movable anode electrode and support to create a sealed chamber around the substrate features, allowing for controlled fluid supply and varying chemical composition, with pulsing of fluid and potential difference to optimize Cu+ ion diffusion and deposition, reducing the need for multiple baths and additives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional ECD baths with chemical circulation are used, then deposition can occur on substrate features, but chemical depletion and non-uniform deposition rates occur in small features
Solution Approach 1:
The invention divides the substrate into multiple segments or zones, each with its own dedicated electrolyte bath. This segmentation allows each region to maintain optimal chemical composition independently, preventing cross-contamination and depletion effects while improving deposition uniformity across different feature types.
Solution Approach 2:
The invention applies different electrolyte compositions to different local regions of the substrate based on specific deposition requirements. Each bath is tailored with specific additives and concentrations optimized for particular feature geometries, enabling precise control over deposition rates and uniformity in small features.
2Manufacturing precision
If multiple separate baths with different electrolyte compositions are used, then varying deposition rates can be achieved, but device complexity and process time increase
Solution Approach 1:
The invention designs a multi-functional electrolyte system where a single bath composition can serve multiple deposition purposes by adjusting operational parameters such as voltage, current density, and flow rate. This universal approach eliminates the need for multiple specialized baths while maintaining precise control over deposition rates for different feature types.
Solution Approach 2:
The invention employs dynamic control mechanisms that allow real-time adjustment of deposition parameters during the plating process. By dynamically modifying voltage, current, and electrolyte flow, the system can adapt to different feature requirements without requiring separate static baths, thereby reducing complexity while preserving deposition rate control.
3Manufacturing precision
If chemical additives are used to enhance and suppress deposition, then uniform deposition can be achieved, but chemical depletion and agitation requirements increase
Solution Approach 1:
The invention implements a self-regulating electrolyte system where the chemical composition automatically maintains optimal deposition conditions through inherent feedback mechanisms. The electrolyte composition is designed to self-adjust concentration gradients and additive distribution, eliminating the need for external agitation and continuous chemical replenishment, thereby improving process efficiency.
4Manufacturing precision
If deep TSV features are filled using conventional ECD, then metal deposition occurs, but non-uniform deposition and incomplete filling occur due to aspect ratio limitations
Solution Approach 1:
The invention applies locally optimized electrolyte compositions specifically tailored for deep TSV features. The electrolyte contains specialized additives and concentration gradients designed to penetrate high aspect ratio structures, maintaining uniform deposition rates from the TSV opening to the bottom, thereby ensuring complete and uniform filling.
Solution Approach 2:
The invention employs dynamic control of deposition parameters during TSV filling, adjusting voltage and current density in real-time based on fill progress. This dynamic approach compensates for the increasing resistance and changing geometry as the TSV fills, maintaining uniform deposition rates and ensuring complete filling even in deep structures with high aspect ratios.
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 enhances deposition efficiency by minimizing chemical consumption, reducing diffusion time, and allowing real-time optimization of electrolyte composition, thereby improving uniformity and reducing process time for complex feature filling, particularly in deep TSVs.
Implementation Method 1
Cu+ ions are generated at the anode in the electrolyte. The substrate is negatively charged with respect to the metal anode with the result that Cu+ ions are attracted to the wafer surface.
Implementation Method 2
The substrate is negatively charged with respect to the metal anode with the result that Cu+ ions are attracted to the wafer surface.
Implementation Method 3
a seal for sealing with the seed layer to define the chamber
Data Source
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AI summary
This invention relates to apparatus for electrochemical deposition onto the surface of a substrate. The apparatus includes an anode electrode 13 a support 12 for supporting the substrate 11 with its one surface 21 exposed at a location, the support 12 and the anode electrode 13 being relatively movable to alter the gap between the anode 13 and the location to define a chamber 23 between them and an electrical power source 18 with an ohmic contact to the seed layer 20 for creating a potential difference across the gap. The apparatus further includes a seal 14 for sealing with the seed layer 20 to define the fluid chamber 23; and the fluid inlet 16 and a fluid outlet 17 to the chamber 13.