Segmented Antenna for Inductively Coupled Plasma
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional antennas for generating inductively coupled plasma in vacuum chambers face issues with impedance increase as they are lengthened to accommodate larger substrates, leading to poor plasma uniformity and inefficient high-frequency current flow, particularly due to the external antenna's longer inductive coupling path through dielectric windows and the internal antenna's potential for two-dimensional plasma distribution.
Innovation Solution
An internal antenna design featuring a metal pipe structure with a hollow insulator and a layered condenser configuration, where metal pipes are connected in series with hollow insulators, and the condenser is electrically connected in series with the metal pipes, reducing impedance and maintaining plasma uniformity even when the antenna is lengthened.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the antenna is lengthened to accommodate larger substrates, then the substrate processing area is improved, but the impedance of the antenna increases
Solution Approach 1:
The antenna is divided into multiple sections with insulators positioned at intervals along its length. This segmentation creates multiple smaller conductive segments rather than one long continuous conductor, which reduces the overall impedance while maintaining the extended length needed for large substrate processing
Solution Approach 2:
Insulators are introduced as intermediary elements between adjacent conductive sections of the antenna. These insulators prevent unwanted electrical coupling between segments while allowing the antenna to maintain its extended structure for covering larger substrate areas without excessive impedance
2Area of stationary object
If the antenna is lengthened to accommodate larger substrates, then the substrate processing area is improved, but the plasma uniformity deteriorates
Solution Approach 1:
By dividing the long antenna into multiple segmented sections separated by insulators, the current distribution along the antenna is more evenly controlled. This segmentation prevents excessive potential differences between different parts of the antenna, thereby maintaining uniform plasma generation across the entire substrate processing area
Solution Approach 2:
The insulator placement is designed to create more equipotential regions along the antenna structure. By reducing potential differences between adjacent sections, the plasma density and temperature distribution becomes more uniform across the substrate, even when processing large areas
3Area of stationary object
If the antenna is lengthened to accommodate larger substrates, then the substrate processing area is improved, but the high frequency current flow becomes difficult
Solution Approach 1:
The antenna structure is segmented into multiple conductive sections separated by insulators. This segmentation reduces the overall impedance by creating multiple current paths and reducing the inductive reactance of the long antenna structure, making it easier for high frequency current to flow while maintaining the extended length for large substrate processing
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 suppresses impedance increase and maintains plasma uniformity, enabling efficient inductive coupling and improved substrate processing, particularly by reducing potential differences and enhancing the flow of high-frequency current, thus improving plasma generation and processing efficiency.
Implementation Method 1
an antenna to be applied with a high frequency current for generating an inductively coupled plasma in a vacuum chamber
Implementation Method 2
a hollow insulator and a layered condenser configuration, where metal pipes are connected in series with hollow insulators, and the condenser is electrically connected in series with the metal pipes, reducing impedance
Data Source
AI summary
Provided are an antenna, which is disposed in a vacuum chamber for generating an inductively coupled plasma, and a plasma processing device. The antenna and the plasma processing device suppress increase of the impedance even if the antenna is lengthened. An antenna 20 is disposed in a vacuum chamber 2 for generating an inductively coupled plasma 16 in the vacuum chamber 2 by applying a high frequency current. The antenna 20 includes an insulating pipe 22 and a hollow antenna body 24 which is disposed in the insulating pipe 22 and in which cooling water flows. The antenna body 24 has a structure that a plurality of metal pipes 26 are connected in series with a hollow insulator 28 interposed between the adjacent metal pipes 26, and each connecting portion has a sealing function with respect to vacuum and the cooling water.