Plating Apparatus Film Thickness Detection Electrode
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Solution Overview
Problem
In a plating apparatus, variations in film thickness of the plating film formed on substrates can occur due to dimensional tolerance of the substrates, changes in the state of the plating solution, and variations in film thickness across different locations on the same substrate.
Innovation Solution
A plating apparatus is designed with a plating tank, a substrate holder, an anode, a resistor to adjust the electric field, a first detection electrode inside the resistor, a second detection electrode at a position with minimal potential change, and a controller that measures the potential difference between the first and second detection electrodes to estimate the film thickness of the plating film during the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If film thickness is measured after plating using a separate device, then measurement accuracy is improved, but productivity deteriorates due to transfer time and process interruption
Solution Approach 1:
The measurement function is merged with the plating apparatus by integrating detection electrodes directly into the plating tank structure. The first detection electrode is positioned inside the resistor between the substrate and anode, while the second detection electrode is positioned at a location with minimal potential change, allowing film thickness measurement to occur simultaneously with the plating process without requiring separate measurement equipment or process interruption.
Solution Approach 2:
The film thickness measurement is performed continuously during the plating process rather than after completion. The controller measures the potential difference between the two detection electrodes in real-time, enabling continuous monitoring of film thickness formation and allowing for immediate process adjustments to maintain uniformity.
2Productivity
If plating is performed on multiple wafers with the same recipe, then productivity is improved, but manufacturing precision deteriorates due to variations in film thickness across different substrates
Solution Approach 1:
The system implements feedback control by continuously measuring the potential difference between the two detection electrodes during plating and using this information to monitor film thickness in real-time. This allows for detection of thickness variations across substrates in the batch, enabling process adjustments to be made while plating is still in progress to correct non-uniformity issues.
Solution Approach 2:
The measurement system captures dynamic changes in film thickness during the plating process rather than only final thickness. By monitoring the potential difference continuously, the system can detect variations in thickness development across different substrates and locations, providing dynamic information for process control.
3Measurement precision
If detection electrode is placed inside the resistor, then measurement capability is improved, but device complexity increases
Solution Approach 1:
The resistor serves multiple functions: it adjusts the electric field during plating and simultaneously houses the first detection electrode for film thickness measurement. This multi-functionality reduces the need for separate components and simplifies the overall device structure while maintaining measurement capability.
Solution Approach 2:
The first detection electrode is nested within the resistor structure, with its electrode end disposed at a position inside the resistor between the substrate and anode. This nesting arrangement allows the detection electrode to be integrated into the existing electric field adjustment component without requiring additional space or complex external positioning mechanisms.
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 allows for real-time detection and estimation of film thickness variations, enabling adjustments to the plating conditions to achieve uniform film thickness distribution across substrates.
Implementation Method 1
a controller that measures a potential difference between the first detection electrode and the second detection electrode, to estimate a thickness of a plating film on the substrate based on the potential difference during a plating process
Implementation Method 2
a resistor disposed between the substrate and the anode to adjust an electric field
Implementation Method 3
a voltage is applied between the substrate and an anode, thereby precipitating a conductive film on a substrate surface
Data Source
AI summary
Proposed is a plating apparatus capable of detecting a film thickness of a plating film formed on a substrate during a plating process. The plating apparatus includes a plating tank, a substrate holder configured to hold a substrate, an anode disposed in the plating tank to oppose the substrate held by the substrate holder, a resistor disposed between the substrate and the anode to adjust an electric field, a first detection electrode disposed in a region between a surface to be plated of the substrate and the anode and having an electrode end disposed at a first position inside the resistor, a second detection electrode disposed at a second position where there is less change in potential as compared with the first position in the plating tank, and a controller that measures a potential difference between the first detection electrode and the second detection electrode, to estimate a thickness of a plating film on the substrate based on the potential difference.