Electrostatic Chuck Preheating to Prevent Attraction Loss in Plasma Processing
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Solution Overview
Problem
In plasma processing, prolonged exposure at high temperatures leads to a decrease in the attraction force of an electrostatic chuck due to electric charge migration, affecting the stability of the substrate's attraction.
Innovation Solution
A plasma processing method that involves placing a substrate on an electrostatic chuck at a first temperature, monitoring the flow rate or pressure of a heat transfer gas, and adjusting the chuck's temperature to a higher second temperature to prevent charge migration and maintain attraction force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the electrostatic chuck is maintained at a high temperature for prolonged plasma processing, then the processing can be continued, but the attraction force of the electrostatic chuck decreases due to electric charge migration
Solution Approach 1:
The patent applies preliminary action by pre-heating the electrostatic chuck to a high temperature (e.g., 200°C to 400°C) before starting plasma processing. This preliminary heating establishes a temperature condition that prevents charge migration during the subsequent plasma processing, thereby maintaining attraction force throughout the processing duration without degradation.
Solution Approach 2:
The patent changes the temperature parameter of the electrostatic chuck from a low initial state to a specifically controlled high temperature state (within a predetermined range such as 200°C to 400°C). This parameter change fundamentally alters the electrical properties of the dielectric material, suppressing charge migration and maintaining stable attraction force during prolonged plasma processing.
2Reliability
If the temperature of the electrostatic chuck is raised to prevent charge migration, then attraction force is maintained, but additional heating control mechanisms are required
Solution Approach 1:
The patent implements feedback control by continuously monitoring the temperature of the electrostatic chuck using temperature sensors and adjusting the heating power accordingly. The control system maintains the chuck temperature within a predetermined range (e.g., 200°C to 400°C) by comparing actual temperature readings with target values and dynamically adjusting heating intensity, ensuring reliable suppression of charge migration while preventing overheating.
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 method effectively suppresses the decrease in attraction force by controlling the electrostatic chuck's temperature, ensuring stable substrate attraction during plasma processing.
Implementation Method 1
electrostatically attracting the substrate to the electrostatic chuck
Implementation Method 2
supply of a heat transfer gas between the substrate and the electrostatic chuck
Implementation Method 3
generating plasma in the plasma processing chamber
Data Source
AI summary
A plasma processing method is disclosed that includes (a) placing a substrate on an electrostatic chuck at a first temperature, the electrostatic chuck being disposed in a plasma processing chamber; (b) electrostatically attracting the substrate to the electrostatic chuck; (c) starting supply of a heat transfer gas between the substrate and the electrostatic chuck; (d) detecting a flow rate of the heat transfer gas or a pressure between the substrate and the electrostatic chuck; (e) determining whether the flow rate or the pressure exceeds a predetermined threshold value; (f) raising the temperature of the electrostatic chuck until the temperature of the electrostatic chuck becomes a second temperature, the second temperature being higher than the first temperature; and (g) generating plasma in the plasma processing chamber.