Plasma Processing Method Using Bias Power to Suppress Arcing
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Solution Overview
Problem
In plasma processing apparatuses, arcing and particle entry into the substrate gap occur due to reduced electrostatic attraction force caused by potential differences between the substrate and electrostatic chuck, especially when DC voltage is applied with high frequency power excitation.
Innovation Solution
Applying a high frequency bias power with a lower frequency than the high frequency excitation power to the mounting table before applying the DC voltage to the electrostatic chuck, thereby reducing particle attraction and maintaining a stronger electrostatic attraction force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a DC voltage is applied to the electrostatic chuck to attract the substrate, then the electrostatic attraction force is improved, but particles are drawn toward the substrate due to potential difference
Solution Approach 1:
A high frequency bias power is applied to the mounting table before applying the DC voltage to the electrostatic chuck. This preliminary action creates a potential distribution that prevents particles from being drawn toward the substrate when the DC voltage is subsequently applied, while still maintaining the electrostatic attraction force needed to hold the substrate.
Solution Approach 2:
The invention changes the frequency parameter by applying a high frequency bias power (lower frequency than plasma excitation power) to the mounting table before applying DC voltage. This frequency-based parameter change modifies the electrical environment to suppress particle attraction while preserving electrostatic chuck functionality.
2Reliability
If a DC voltage is applied to the electrostatic chuck, then the substrate adhesion is improved, but arcing occurs due to charge discharge toward the plasma
Solution Approach 1:
The high frequency bias power is applied to the mounting table before the DC voltage is applied to the electrostatic chuck. This preliminary action prepares the electrical environment by creating a favorable potential distribution that prevents charge discharge and arcing when the DC voltage is subsequently applied, while maintaining substrate adhesion.
3Power
If high frequency power is applied to the mounting table with DC voltage, then the plasma excitation is improved, but the Coulomb force is reduced causing gap enlargement
Solution Approach 1:
The invention separates the frequency parameters by applying a high frequency bias power at a lower frequency than the plasma excitation power to the mounting table. This parameter separation allows the plasma excitation to occur at the higher frequency while the lower frequency bias power maintains the Coulomb force and prevents gap enlargement between the substrate and electrostatic chuck.
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 approach effectively suppresses arcing and particle entry into the substrate gap by maintaining a stable electrostatic attraction force and reducing the likelihood of electric discharge, ensuring efficient plasma processing.
Implementation Method 1
a plasma processing method includes a step of loading a substrate into a chamber where a plasma process is to be executed, a step of applying a high frequency bias power that has a lower frequency than a high frequency excitation power for plasma excitation to a mounting table
Implementation Method 2
a step of applying a DC voltage to an electrostatic chuck configured to electrostatically attract the substrate that is mounted on the mounting table
Implementation Method 3
a high frequency excitation power for plasma excitation to a mounting table on which the substrate is mounted
Data Source
AI summary
A plasma processing method is provided that includes a step of loading a substrate into a chamber where a plasma process is to be executed, a step of applying a high frequency bias power that has a lower frequency than a high frequency excitation power for plasma excitation to a mounting table on which the substrate is mounted, and a step of applying a DC voltage to an electrostatic chuck configured to electrostatically attract the substrate that is mounted on the mounting table. The step of applying the DC voltage is performed after the step of applying the high frequency bias power.