Micro Inert Anode Array for Electroplating Thickness Control
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Solution Overview
Problem
Existing electroplating methods face challenges in achieving uniform current distribution across semiconductor wafers with patterned features, leading to non-uniform metal deposition and increased variability in within-die, within-wafer, and within-feature plating uniformity.
Innovation Solution
The use of a micro inert anode array with independently controllable micro anode elements, positioned close to the substrate, allows for a non-uniform current distribution based on the patterned feature layouts, enabling precise control of current distribution to match die layouts and compensate for variations in feature density and design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a uniform current distribution is applied during electroplating, then the simplicity of the plating process is maintained, but the uniformity of metal deposition across the substrate deteriorates
Solution Approach 1:
The anode is divided into multiple independently controllable micro anode elements arranged in an array. Each micro anode element can have its current independently adjusted to compensate for local variations in feature density and achieve uniform metal deposition across different regions of the substrate.
Solution Approach 2:
Different regions of the substrate receive customized current densities tailored to their specific feature density requirements. Areas with higher feature density receive higher current densities, while areas with lower feature density receive lower current densities, ensuring uniform deposition across the entire substrate.
2Measurement precision
If the anode is positioned close to the substrate, then the control precision of current distribution is improved, but the risk of short circuit increases
Solution Approach 1:
The anode structure is segmented into multiple isolated micro anode elements with insulating material between them. This segmentation allows the anode array to be positioned close to the substrate for precise current control while the insulating barriers prevent electrical short circuits between adjacent elements.
Solution Approach 2:
An insulating layer or structure is introduced between the micro anode elements to act as an intermediary that prevents direct electrical contact between adjacent anodes while allowing the array to maintain close proximity to the substrate for effective current distribution 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
This approach results in significantly improved uniformity of metal deposition, reducing within-die, within-wafer, and within-feature variations, enhancing the reliability and consistency of semiconductor manufacturing processes.
Implementation Method 1
electroplating metal on the substrate using a micro inert anode array having a plurality of micro inert anode elements, wherein current is applied to two or more micro inert anode elements
Data Source
AI summary
Metal may be electroplated on a semiconductor substrate in an electroplating chamber with a micro inert anode array positioned proximate to the semiconductor substrate having one or more die. The micro inert anode array includes a plurality of micro inert anode elements that are independently controllable. Current applied to the micro inert anode elements provides a current distribution in the array that may be based at least in part on a die layout in the semiconductor substrate or based at least in part on global within-wafer corrections. The current distribution may achieve uniform plating thickness even with a non-uniform distribution of features in the die of the semiconductor substrate. In some implementations, current distribution may be adjusted in the array during substrate rotation according to a rotational path of the semiconductor substrate.