Electrostatic Chuck with Embedded Bias Electrodes for Discharge Suppression
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Solution Overview
Problem
In plasma processing, abnormal discharge occurs within the electrostatic chuck due to the potential difference generated by low-frequency, high-power bias power, leading to discharge marks on substrates and process malfunctions, which is difficult to suppress with existing designs, especially when a heating mechanism is integrated.
Innovation Solution
The plasma processing apparatus incorporates a ceramic member with embedded electrostatic and bias electrode layers, and conductive vias that surround vertical holes to maintain an equivalent potential, reducing the potential difference and suppressing abnormal discharge, while allowing for increased ceramic thickness to accommodate heating mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If low-frequency, high-power bias power is applied for plasma processing, then processing effectiveness is improved, but abnormal discharge occurs inside the electrostatic chuck causing discharge marks and process malfunctions
Solution Approach 1:
The electrostatic chuck is divided into multiple electrode layers (first and second bias electrode layers, electrostatic electrode layer) separated by insulating ceramic members. This segmentation allows independent control of electrostatic attraction and bias power functions, preventing abnormal discharge while maintaining processing effectiveness.
Solution Approach 2:
An insulating ceramic member is introduced as an intermediary between the electrode layers and the substrate. This ceramic member prevents direct discharge paths while allowing electrical connections through conductive vias, thereby suppressing abnormal discharge marks on substrates.
2Temperature
If ceramic member thickness is increased to accommodate heating mechanisms, then mechanical characteristics and heating capability are improved, but potential difference increases leading to abnormal discharge
Solution Approach 1:
Conductive vias are provided to electrically connect the first and second bias electrode layers through the ceramic member, creating equipotential regions. This eliminates potential differences across the thick ceramic member, preventing abnormal discharge while maintaining heating capability.
Solution Approach 2:
The electrode layers and conductive vias are embedded within the ceramic member structure, with the ceramic member nesting the electrical components. This allows thick ceramic construction for heating while integrating electrical connections to prevent discharge.
3Reliability
If multiple electrode layers and conductive vias are embedded in the ceramic member, then abnormal discharge is suppressed, but manufacturing complexity increases
Solution Approach 1:
The ceramic member serves multiple functions simultaneously: it provides electrical insulation between electrode layers, supports mechanical heating structures, and contains embedded conductive vias for electrical connections. This multi-functionality reduces the need for separate components, simplifying overall manufacturing.
Solution Approach 2:
The insulating ceramic member and conductive vias are combined into a single integrated component. The vias are formed directly within the ceramic member during manufacturing, merging the insulation and electrical connection functions into one element, thereby reducing assembly steps and 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
This configuration effectively suppresses abnormal discharge, enhances the mechanical characteristics of the electrostatic chuck, and simplifies maintenance by eliminating the need for separate discharge measures, while maintaining cost-effectiveness and allowing for uniform temperature control of substrates.
Implementation Method 1
an electrostatic electrode layer embedded into the ceramic member and disposed below the substrate support surface
Implementation Method 2
first and second central bias electrode layers embedded into the ceramic member and disposed below the electrostatic electrode layer... each first vertical connector electrically connecting the first central bias electrode layer and the second central bias electrode layer
Data Source
AI summary
A plasma processing apparatus comprises a plasma processing chamber and a substrate support disposed in the plasma processing chamber. The substrate support includes a base, a ceramic member having a plurality of first vertical holes and a plurality of second vertical holes, at least one annular member, an electrostatic electrode layer, first and second central bias electrode layers, a plurality of first vertical connectors to surround the first vertical hole and to connect the first central bias electrode layer and the second central bias electrode layer, first and second annular bias electrode layers, a plurality of second vertical connectors to surround the second vertical hole and to connect the first annular bias electrode layer and the second annular bias electrode layer.