Plating Apparatus with Nested Shielding for Uniform Film Thickness
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Solution Overview
Problem
Existing cup type electroplating apparatuses face challenges in achieving uniform film-thickness distribution due to the placement of an ionically resistive element and a shielding member, which can lead to increased plating film-thickness at the outer edge of the substrate.
Innovation Solution
A plating apparatus is designed with an ionically resistive element positioned close to the substrate's surface to be plated, featuring a first and second opposed surface where the second surface is further apart from the substrate, allowing a shielding member to be placed in a depressed region formed by the second surface, thereby enhancing film-thickness uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the ionically resistive element is disposed close to the surface to be plated of the substrate, then the uniformity of plating film-thickness distribution is improved, but the shielding member cannot be properly disposed due to interference
Solution Approach 1:
The shielding member is disposed within the depressed region formed by the second opposed surface of the ionically resistive element, effectively nesting one component within another. This allows the shielding member to be positioned without interfering with the ionically resistive element's close proximity to the substrate surface, thereby maintaining uniform plating film-thickness distribution while accommodating both components.
Solution Approach 2:
The ionically resistive element is designed with a three-dimensional structure including a depressed region, transforming a two-dimensional placement problem into a three-dimensional solution. By creating vertical depth variation through the depressed region, the shielding member can be positioned in a different spatial layer, eliminating interference while maintaining the ionically resistive element's effectiveness in controlling plating uniformity.
2Device complexity
If the ionically resistive element is disposed apart from the surface to be plated of the substrate, then the shielding member can be disposed between them, but the uniformity of plating film-thickness distribution is diminished
Solution Approach 1:
The shielding member is nested within the depressed region of the ionically resistive element, allowing both components to coexist in a compact arrangement. This nesting enables the shielding member to be disposed without forcing the ionically resistive element away from the substrate surface, thereby maintaining uniform plating film-thickness distribution while accommodating the shielding requirement.
Solution Approach 2:
The ionically resistive element exhibits spatially varying properties through its depressed region structure. The local geometry of the depressed region provides a specific zone for the shielding member while the rest of the ionically resistive element maintains its effectiveness in controlling the electric field distribution, ensuring uniform plating across the substrate surface.
3Manufacturing precision
If the ionically resistive element is disposed close to the substrate surface, then film-thickness uniformity is improved, but the electric field may concentrate at the outer edge portion of the substrate
Solution Approach 1:
The shielding member acts as an intermediary between the ionically resistive element and the substrate, positioned within the depressed region. This intermediary configuration helps distribute the electric field more evenly across the substrate surface, preventing concentration at the outer edge while allowing the ionically resistive element to remain close to the substrate for uniform plating control.
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 configuration improves the uniformity of the plating film-thickness distribution by allowing the ionically resistive element to be closer to the substrate without interference from the shielding member, reducing the concentration of the electric field at the substrate's edges.
Implementation Method 1
an ionically resistive element disposed between the substrate and the anode
Implementation Method 2
a shielding member disposed in a depressed region of the ionically resistive element, the shielding member for shielding an electric field
Implementation Method 3
applies a voltage between the substrate and an anode, thereby depositing a conductive film on a surface to be plated of the substrate
Data Source
AI summary
In a plating apparatus including a shielding member, an ionically resistive element is disposed to be close to a surface to be plated of a substrate to improve uniformity of a distribution of plating film-thickness.A plating apparatus includes: a plating tank 410 configured to house a plating solution; a substrate holder 440 configured to hold a substrate Wf with a surface to be plated Wf-a facing downward; an anode 430 disposed in the plating tank 410; an ionically resistive element 450 disposed between the substrate Wf and the anode 430 and including an opposed surface 450-a opposed to the surface to be plated Wf-a, the opposed surface 450-a including a first opposed surface 450-a1 and a second opposed surface 450-a2 apart from the surface to be plated Wf-a more than the first opposed surface 450-a1; and a shielding member 481 disposed in a depressed region β of the ionically resistive element 450, the depressed region β being formed by the second opposed surface 450-a2. The shielding member 481 is for shielding an electric field.