High Power Impulse Plasma Source for Low-Temperature Surface Treatment
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Solution Overview
Problem
Current vapor deposition processes face limitations such as high processing temperatures, substrate degradation, and restricted source-to-substrate distance due to coil or electrode geometry, which hinder efficient surface treatment and film deposition.
Innovation Solution
A high power impulse plasma source system utilizing a pulsed DC generator with a power conducting electrode, delivering power pulses in the range of 40 kW to 100 kW at frequencies from 0.1 Hz to 62.5 kHz, generating a non-thermal plasma with high flux of reactive species at atmospheric pressure, allowing for surface modification, cleaning, and etching while maintaining low substrate temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If radio frequency plasma is generated using coils or electrodes, then plasma is formed for surface treatment, but the processing chamber must be maintained at low pressures (1-50 mTorr) and the source-to-substrate distance is limited by geometry
Solution Approach 1:
The patent applies parameter changes by transitioning from radio frequency plasma generation to pulsed direct current plasma generation. This fundamental parameter change enables atmospheric pressure operation and eliminates geometric constraints on source-to-substrate distance, as the pulsed DC mechanism does not rely on resonant coupling or electrode geometry for plasma sustainment
Solution Approach 2:
The patent employs periodic action through pulsed direct current delivery to the power conducting electrode. The pulsed nature of the power delivery (with pulse widths from microseconds to milliseconds) enables plasma generation at atmospheric pressure by providing high peak power in short bursts, allowing the plasma to be sustained without continuous high power input that would otherwise require vacuum conditions
2Quantity of substance
If high power is applied continuously to generate plasma, then plasma density increases, but substrate temperature rises above 300°C causing degradation
Solution Approach 1:
The patent resolves this contradiction by using periodic pulsed power delivery instead of continuous power application. The pulsed DC generator delivers high peak power (40-100 kW) in short pulses to achieve high plasma density, followed by off-periods that allow the substrate to cool. This temporal separation enables high plasma density during treatment while maintaining substrate temperature below 300°C
Solution Approach 2:
The system dynamically adjusts the pulse parameters (pulse width, frequency, duty cycle) to optimize the balance between plasma density and substrate temperature. By making the power delivery dynamic rather than static, the system can deliver high power when plasma generation is needed and reduce power when substrate heating becomes excessive
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
The system achieves increased ionization and plasma density, resulting in denser, lower-stress films with improved durability and adherence, and maintains substrate temperatures around 30°C to 150°C, outperforming RF and AC systems in terms of ionization and flux.
Implementation Method 1
Power pulses may be applied to the power conducting electrode with a DC generator in the range of 40 kW to 100 kW at a frequency in the range of 0.1 Hz to 62.5 kHz, and with an individual pulse duration in the range of 0.1 microseconds to 3,000 microseconds, providing peak currents in the range of 100 Amps to 400 Amps and forming a plasma from the gas
Implementation Method 2
The gas may then be ionized and form a plasma. However, the processing chamber may need to be maintained at pressures of 1 mTorr to 50 mTorr. Further, the coil or electrode geometry may limit the source to substrate distance
Data Source
AI summary
A method and system for generating a surface treating plasma. Gas is provided to a power conducting electrode and flows through the power conducting electrode. Power pulses are applied to the power conducting electrode in the range of 40 kW to 100 kW with a DC generator, at a frequency in the range of 1 Hz to 62.5 kHz, and with a pulse duration in the range of 0.1 microseconds to 3,000 microseconds. Peak currents in the range of 100 Amps to 400 Amps are produced and plasma is formed from the gas. A substrate surface may then be treated with the plasma.