Edge Ring Bias Timing for Uniform Ion Incidence in Plasma Processing
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Solution Overview
Problem
In plasma processing apparatuses, there is a challenge in ensuring that ions travel vertically towards the entire surface of the substrate, as existing techniques struggle to eliminate differences in the boundary positions between the plasma and the sheath above the edge ring and the substrate.
Innovation Solution
A plasma processing apparatus is designed with a correction power supply that applies a negative voltage to the edge ring during specific periods when radio-frequency power is supplied, thereby correcting the traveling direction of ions with respect to the substrate edge inwardly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the negative voltage is applied to the edge ring, then the ion traveling direction inwardly with respect to the substrate is corrected, but the complexity of the power supply system increases
Solution Approach 1:
The correction power supply is designed to perform multiple functions: it applies negative voltage to the edge ring for ion direction correction, operates in synchronization with the radio-frequency power supply cycles, and can be integrated into the existing plasma processing apparatus power supply architecture. This multi-functionality reduces the need for completely separate dedicated correction systems, thereby limiting the increase in overall system 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 solution effectively corrects the traveling direction of ions inwardly with respect to the substrate, improving the uniformity of ion distribution across the substrate surface, and allows for adjustable correction based on the ratio of first periods to the total ON period.
Implementation Method 1
The correction power supply is configured to apply a negative voltage to the edge ring
Implementation Method 2
The one or more radio-frequency power supplies are configured to supply one or more radio-frequency powers in an ON period in which plasma is generated from a gas in the chamber
Data Source
AI summary
A plasma processing apparatus disclosed herein includes a chamber, a substrate support, one or more radio-frequency power supplies, and a correction power supply. The one or more radio-frequency power supplies supply one or more radio-frequency powers to the chamber in an ON period in which plasma is generated from a gas in the chamber. The correction power supply applies the negative voltage to the edge ring in one or more first periods in the ON period. Each of the one or more first periods corresponds to a plurality of times of a longest waveform cycle among waveform cycles of the one or more radio-frequency powers. The correction power supply stops the application of the negative voltage to the edge ring in a one or more second periods in the ON period. Each of the one or more second periods corresponds to the plurality of times of the longest waveform cycle.