Edge Ring Line Contact for Electrostatic Chuck Heat Leakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional edge rings in substrate processing apparatuses experience increased leakage of heat transfer gas due to surface contact with electrostatic chucks, leading to reduced attractive force and non-uniform temperature control, which affects substrate processing quality.
Innovation Solution
The edge ring is designed with a lower surface that maintains line contact with the electrostatic chuck, reducing electric charge movement and minimizing heat transfer gas leakage by using ring-shaped contact portions that avoid heat transfer gas supply grooves, thereby stabilizing the attractive force and improving heat transfer characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the edge ring contacts the electrostatic chuck surface, then the edge ring is held in position, but heat transfer gas leaks through the contact area
Solution Approach 1:
The lower surface of the edge ring is divided into multiple contact portions arranged in a circular pattern. Each contact portion makes line contact with the electrostatic chuck at discrete locations, avoiding continuous surface contact and preventing heat transfer gas leakage paths while maintaining positioning stability.
Solution Approach 2:
The contact portions are positioned at the outer peripheral side of the heat transfer gas supply grooves in the radial direction. This spatial arrangement in the radial dimension allows the contact portions to avoid the groove openings, preventing gas leakage while maintaining attractive force.
2Force
If surface contact is used between edge ring and electrostatic chuck, then large contact area provides strong attraction, but electric charge moves easily causing reduced attractive force over time
Solution Approach 1:
The contact area is segmented into multiple discrete contact portions rather than a continuous surface. This segmentation reduces the total contact area to minimal line contacts, limiting electric charge movement paths and preventing the gradual reduction of attractive force that occurs with large surface contact areas.
Solution Approach 2:
Different regions of the edge ring lower surface have different contact characteristics. The contact portions are specifically designed to make line contact at the outer peripheral side of the grooves, creating localized contact zones that provide sufficient attraction while minimizing charge transfer. The central region with grooves remains non-contacting to prevent gas leakage.
3Loss of substance
If the edge ring is positioned to avoid heat transfer gas supply grooves, then gas leakage is reduced, but contact area with electrostatic chuck is limited
Solution Approach 1:
The contact portions are positioned in the radial dimension at the outer peripheral side of the heat transfer gas supply grooves. This radial positioning allows the contact portions to bypass the groove openings without requiring vertical offset, achieving gas leakage prevention while maintaining adequate contact for attractive force through line contact at the groove peripheries.
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 maintains a consistent attractive force over time, reduces heat transfer gas leakage, and enhances temperature control uniformity, leading to improved substrate processing consistency and efficiency.
Implementation Method 1
an edge ring 30 placed on an electrostatic chuck 25
Implementation Method 2
heat transfer gas supplied between an edge ring (also referred to as a focus ring) and a mounting surface of an electrostatic chuck
Data Source
AI summary
An edge ring that is placed on an electrostatic chuck of a substrate processing apparatus so as to surround a periphery of a substrate is provided. Multiple contact portions are provided on a lower surface of the edge ring, and each of the contact portions is of a ring shape. Each of the contact portions is in line contact with a mounting surface of the electrostatic chuck.