Adjustable Plasma Electrode for Uniform Etching
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Solution Overview
Problem
Plasma etching in semiconductor fabrication often faces challenges with non-uniform etching across the surface of wafers, leading to inconsistent feature dimensions and reduced yields due to non-uniform plasma charge density.
Innovation Solution
The implementation of a plasma reactor with an adjustable plasma electrode that can dynamically adjust its shape and position to maintain uniform plasma distribution, using actuators and a controller to monitor and adjust plasma parameters, ensuring consistent etching across the wafer surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional plasma reactor with fixed electrodes is used, then the device structure is simple, but the etching uniformity across the wafer surface deteriorates due to non-uniform plasma charge density
Solution Approach 1:
The patent applies the dynamics principle by making the plasma electrode adjustable rather than fixed. The electrode can be repositioned and reconfigured during operation to maintain uniform plasma distribution across the wafer surface, directly addressing the etching uniformity problem while managing device complexity through controlled adaptability
Solution Approach 2:
The patent implements parameter changes by allowing the plasma electrode to modify its position, shape, and configuration parameters. These dynamic parameter adjustments enable the system to compensate for non-uniform plasma charge density and achieve consistent etching across different regions of the wafer
2Manufacturing precision
If the plasma electrode is made adjustable to improve plasma uniformity, then etching consistency improves, but the device complexity and control requirements increase
Solution Approach 1:
The patent applies local quality by enabling different regions of the plasma electrode to be independently adjusted. This allows localized compensation for non-uniform plasma distribution in specific areas of the wafer, improving feature dimension consistency while keeping the overall system manageable through region-specific control
Solution Approach 2:
The patent implements feedback control where the system monitors plasma distribution and wafer etching characteristics, then uses this information to dynamically adjust the plasma electrode position and configuration. This closed-loop approach achieves consistent etching results while automating the complexity of controlling multiple actuators
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 significantly improves etching uniformity by dynamically controlling the plasma gap and shape of the electrode, leading to more consistent feature dimensions and enhanced wafer processing outcomes.
Implementation Method 1
The power source 14 creates a bias voltage between the support 12 and the lid 18 to establish and/or to maintain a plasma 24 between the lid 18 and a wafer 28 held on the support 12
Data Source
AI summary
Plasma reactors with adjustable plasma electrodes and associated methods of operation are disclosed herein. The plasma reactors can include a chamber, a workpiece support for holding a microfeature workpiece, and a plasma electrode in the chamber and spaced apart from the workpiece support. The plasma electrode has a first portion and a second portion configured to move relative to the first portion. The first and second portions are configured to electrically generate a plasma between the workpiece support and the plasma electrode.