Intermediate-Mask Plating With Auxiliary Anode Current Control
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Solution Overview
Problem
Existing plating technologies face challenges in achieving uniform film thickness distribution across substrates with varying specifications, particularly due to terminal effects, which are exacerbated by limited space and high precision requirements for mechanical mechanisms, and are not suitable for vertically standing substrates or substrates with large dimensions.
Innovation Solution
An apparatus with an anode and an intermediate mask featuring a first center opening and an auxiliary anode within the mask, where the auxiliary anode's area is less than 1/5 of the anode's area, allowing for electric field regulation without mechanical mechanisms, and the auxiliary anode is placed near the substrate to adjust plating current based on substrate specifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the auxiliary electrode is placed on the anode side further from the substrate, then the electric field can be regulated, but the current density becomes suppressed and a large area auxiliary electrode is required
Solution Approach 1:
The auxiliary electrode is repositioned from the traditional anode-side location to a location between the anode and substrate, utilizing the intermediate space dimension. This allows the auxiliary electrode to be closer to the substrate while maintaining effective electric field regulation, thereby reducing the required auxiliary electrode area while preserving regulation precision
2Measurement precision
If the intermediate mask is placed near the substrate, then the plating current can be effectively controlled, but the space for mechanical mechanisms is limited
Solution Approach 1:
The patent replaces mechanical mechanisms for adjusting mask openings with an electrical field regulation approach using an auxiliary electrode. By controlling the auxiliary electrode's position and area, the plating current is regulated without requiring mechanical adjustments, thereby eliminating the need for mechanical mechanisms in the limited space near the substrate
3Power
If the auxiliary electrode has a large area, then the electric current flow is sufficient, but the current density is suppressed and maintenance becomes difficult
Solution Approach 1:
The auxiliary electrode is designed with a controlled, limited area rather than a large area, providing sufficient electric current flow for effective field regulation while avoiding excessive current density that would complicate maintenance. The electrode area is optimized to achieve the necessary power without suppressing current density to problematic levels
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 solution effectively regulates plating current to achieve uniform film thickness distribution across substrates, overcoming spatial and precision limitations, and simplifies maintenance and liquid management, while being applicable to various substrate shapes and orientations.
Implementation Method 1
an auxiliary anode that is placed in an internal space of the intermediate mask to be arranged around the first center opening
Implementation Method 2
apparatus for plating a substrate
Data Source
AI summary
There is provided an apparatus for plating a substrate, comprising: an anode placed to be opposed to the substrate; and an intermediate mask placed between the substrate and the anode to be arranged on a substrate side, provided with a first center opening that causes an electric field from the anode toward the substrate to pass through, and further provided with an auxiliary anode that is placed in an internal space of the intermediate mask to be arranged around the first center opening, wherein the auxiliary anode has an area that is not greater than ⅕ of an area of the anode.