Capacitive Etch Reactor Electrode Layout for Uniform Plasma Distribution
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Solution Overview
Problem
Existing capacitive coupled RF etching reactors face inefficiencies due to limited electrode surface area and plasma distribution issues, leading to suboptimal etching performance and complex workpiece handling.
Innovation Solution
A two-electrode capacitive coupled RF vacuum etching apparatus with a larger first electrode surface area, enhanced by a metal body with through openings and slits, and a second electrode surface on a workpiece carrier, utilizing dual RF frequencies to improve plasma density and etching efficiency while simplifying workpiece handling by keeping the second electrode on ground potential.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the electrode surface area is increased to improve plasma distribution and etching efficiency, then the etching performance is improved, but the device complexity and workpiece handling complexity increase
Solution Approach 1:
The first electrode is segmented into multiple sections (first electrode section and second electrode section) with different surface areas. This segmentation allows each section to serve different functions: the larger first section provides sufficient plasma generation area for efficient etching, while the smaller second section maintains appropriate potential differences for workpiece processing, thus resolving the contradiction between improving etching efficiency and managing device complexity
Solution Approach 2:
Different sections of the first electrode are assigned different local qualities (surface areas) to optimize specific functions. The first electrode section has a larger surface area optimized for plasma generation and etching efficiency, while the second electrode section has a smaller surface area optimized for maintaining potential differences and workpiece handling, thereby improving etching performance without proportionally increasing overall device complexity
2Productivity
If dual RF frequencies are used to enhance plasma density and etching efficiency, then the etching performance is improved, but the device complexity increases
Solution Approach 1:
The RF generator arrangement is designed with multi-functionality to generate both first RF frequency signals and second RF frequency signals. This universal design allows a single integrated RF generation system to provide multiple frequency outputs, enhancing plasma density and etching efficiency while avoiding the need for separate RF generator systems, thus improving productivity without proportionally increasing device complexity
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 significantly enlarges the effective electrode surface area, enhances plasma distribution and etching efficiency, and simplifies workpiece handling by maintaining the second electrode on ground potential, improving overall etching performance and operational ease.
Implementation Method 1
a plasma space is provided which is in contact solely with one electrode arrangement... supplied from an output arrangement of an Rf generator arrangement... generates at least one first plasma supply signal at a very high frequency... and at least one second plasma supply signal at a high frequency
Implementation Method 2
two-electrode capacitive coupled RF vacuum etching apparatus... The first electrode arrangement and of a second electrode arrangement facing the first electrode arrangement... capacitive coupled RF plasma discharge is generated
Implementation Method 3
the smaller electrode surface exposed to the Rf plasma is predominantly sputtered off, in other words etched
Data Source
AI summary
In a capacitive coupled etch reactor, in which the smaller electrode is predominantly etched, the surface of the larger electrode is increased by a body e.g. a plate, which is on the same electric potential as the larger electrode and which is immersed in the plasma space. A pattern of openings in which plasma may burn is provided in the body so as to control the distribution of the etching effect on a substrate placed on the smaller electrode.