Microwave Output Device Pulse Power Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing microwave output devices for plasma processing struggle to effectively control pulse-modulated power of microwaves with bandwidth, leading to instability and misfires during low-power operations, and difficulty in accurately managing varying waveforms.
Innovation Solution
A microwave output device comprising a microwave generation unit, an output unit, a first directional coupler, and a measurement unit that pulse-modulates microwaves based on setting frequencies and power levels, averaging power values to control high and low levels, ensuring stable plasma generation and reducing electron temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pulse modulation is applied to microwave power control, then plasma stability is improved and electron temperature is reduced, but control accuracy deteriorates due to waveform variations
Solution Approach 1:
The patent implements a feedback control mechanism where the measurement unit continuously monitors the actual microwave power level, compares it with the target power level, and adjusts the pulse modulation parameters accordingly. This closed-loop feedback system compensates for waveform variations and maintains accurate power control while preserving plasma stability benefits
Solution Approach 2:
The system dynamically adjusts pulse modulation parameters (duty ratio, pulse width, frequency) based on real-time plasma conditions and power measurements. By changing these parameters adaptively, the system maintains both plasma stability and power control accuracy despite waveform variations
2Loss of energy
If microwave power is reduced for low-power operations, then energy consumption is reduced, but plasma stability deteriorates leading to misfires
Solution Approach 1:
The patent employs periodic pulse modulation where microwave power is delivered in controlled pulses rather than continuously. By optimizing the pulse frequency and duty ratio, the system reduces average power consumption while maintaining sufficient peak power to prevent plasma misfires and ensure stable plasma generation during low-power operations
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 solution enables precise control of pulse-modulated microwave power, stabilizing plasma and reducing electron temperature, thereby improving the accuracy and reliability of plasma processing operations.
Implementation Method 1
a microwave generation unit configured to generate a microwave having a center frequency and a bandwidth respectively corresponding to a setting frequency and a setting bandwidth instructed by a controller
Implementation Method 2
a plasma processing apparatus of a type of exciting a gas by using microwaves
Data Source
AI summary
A device includes a microwave generation unit that generates a microwave having a bandwidth, an output unit, a directional coupler, and a measurement unit. The microwave generation unit generates a microwave of which power is pulse-modulated to have a high level and a low level. The measurement unit determines a first high measured value and a first low measured value respectively indicating a high level and a low level of power of travelling waves in the output unit on the basis of parts of the travelling waves output from the directional coupler. The microwave generation unit controls high level power of the pulse-modulated microwave on the basis of and averaged first high measured value and high level setting power, and controls low level power of the pulse-modulated microwave on the basis of an averaged first low measured value and low level setting power.