Plasma Processing Apparatus RF Power Modulation
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Solution Overview
Problem
Existing plasma processing technologies face challenges in achieving high precision etching due to limitations in controlling the temporal modulation of radio-frequency bias power, particularly in terms of resolution and frequency range, which affects the precision of etching shape control and reaction product concentration.
Innovation Solution
A plasma processing apparatus and method utilizing a radio-frequency power supply that generates temporally modulated intermittent radio-frequency power with multiple frequency bands, allowing for precise control of the repetition frequency and duty ratio, thereby improving the resolution and controllability of the etching process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the repetition frequency of radio-frequency bias is increased to reduce reaction product concentration, then etching precision is improved, but the resolution of frequency control deteriorates due to analog signal noise
Solution Approach 1:
The frequency control is segmented into multiple discrete bands (first frequency band with higher resolution and second frequency band with lower resolution). The D/A converter is divided into multiple units, each handling a specific frequency band with appropriate resolution, thereby resolving the conflict between high frequency and high resolution requirements.
Solution Approach 2:
Different resolution qualities are applied to different frequency bands. The first frequency band (lower repetition frequencies) uses higher resolution D/A conversion to maintain precision when reaction product concentration control is most sensitive, while the second frequency band (higher repetition frequencies) uses lower resolution, optimizing overall system performance.
2Manufacturing precision
If the gas flow Q is increased to shorten reaction product stay time, then etching precision is improved, but the trade-off with processing pressure P and chamber volume V limits further enhancement
Solution Approach 1:
The system changes the temporal parameters of radio-frequency bias (repetition frequency and duty ratio) to control reaction product concentration dynamically during the etching process. This allows precision control without being limited by the static trade-off relationships among gas flow, pressure, and chamber volume.
Solution Approach 2:
The radio-frequency bias is applied periodically with variable repetition frequencies and duty ratios. This periodic modulation allows control of reaction product concentration by adjusting the on/off cycles, providing an additional degree of freedom independent of gas flow, pressure, and chamber volume parameters.
3Manufacturing precision
If the processing pressure P is lowered to shorten reaction product stay time, then etching precision is improved, but the trade-off with gas flow Q and chamber volume V limits further enhancement
Solution Approach 1:
The system changes the temporal parameters of radio-frequency bias (repetition frequency and duty ratio) to control reaction product concentration dynamically during the etching process. This allows precision control without being limited by the static trade-off relationships among gas flow, pressure, and chamber volume.
Solution Approach 2:
The radio-frequency bias is applied periodically with variable repetition frequencies and duty ratios. This periodic modulation allows control of reaction product concentration by adjusting the on/off cycles, providing an additional degree of freedom independent of gas flow, pressure, and chamber volume parameters.
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 enables high-precision etching by enhancing the resolution of the low-frequency band and widening the usable frequency range, allowing for precise control of the reaction product concentration and etching shape, even in varied etching processes.
Implementation Method 1
a radio-frequency power supply for generating plasma in the vacuum vessel and applying the plasma to the sample, wherein the radio-frequency power supply supplies temporally modulated intermittent radio-frequency power
Implementation Method 2
the plasma is generated by microwaves in a vacuum vessel applying a magnetic field from the outside. Electrons perform cyclotron motion by the magnetic field and the plasma can be efficiently generated by resonating a frequency of the magnetic field and a frequency of the microwaves
Implementation Method 3
Electrons perform cyclotron motion by the magnetic field and the plasma can be efficiently generated by resonating a frequency of the magnetic field and a frequency of the microwaves
Implementation Method 4
the plasma can be efficiently generated by resonating a frequency of the magnetic field and a frequency of the microwaves
Implementation Method 5
In order to accelerate ions incident in the semiconductor device, radio-frequency power is applied to a sample as sequential waveforms substantially in a sinusoidal waveform
Implementation Method 6
as gas forming plasma, halogen gas such as chlorine or fluorine is widely used
Data Source
AI summary
Provided are a plasma processing apparatus with a radio-frequency power supply supplying temporally modulated intermittent radio-frequency power which can be controlled with high precision in a wide repetition frequency band, and a plasma processing method using the plasma processing apparatus.A plasma processing apparatus includes: a vacuum vessel; a plasma generating section plasma in the vacuum vessel; a stage installed in the vacuum vessel and mounted with a sample; and a radio-frequency power supply applying temporally modulated intermittent radio-frequency power to the stage, wherein the radio-frequency power supply has two or more different frequency bands and temporally modulates the radio-frequency power by a repetition frequency which has the same range of analog signals used in each of the frequency band.