RF Power Flow Analysis Probe for Semiconductor Plasma
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods fail to accurately measure the fundamental and harmonic amplitude and phase relationships of RF voltage and current signals in semiconductor plasma generators, leading to process uncertainty and inefficiency in plasma processing.
Innovation Solution
A measuring probe system with voltage and current sensors connected to a measuring receiver that converts RF signals into digital representations, allowing for digital signal processing to extract fundamental and harmonic amplitude and phase information, and provides networked probes for determining impedance match, insertion loss, and power flow efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If V-I probes are inserted to measure fundamental and harmonic signal power, then measurement capability is improved, but measurement precision of phase angle information deteriorates due to inability to directly measure relative phase angles
Solution Approach 1:
The patent replaces indirect electrical measurement methods with optical measurement technology. Photodetectors convert RF voltage and current signals into optical signals, allowing direct and accurate measurement of phase angle information without the limitations of traditional electrical probe methods. This substitution enables precise simultaneous measurement of amplitude and phase characteristics.
2Productivity
If multiple RF signal frequencies are introduced to enhance process performance, then productivity is improved, but reliability deteriorates due to increased process uncertainty from intermodulation frequency components
Solution Approach 1:
The patent implements a feedback control system that continuously monitors the RF power transmission characteristics and processes. The measured data on fundamental and harmonic frequency components, including their amplitudes and phase angles, is fed back to control the RF generator. This allows real-time adjustment to maintain process stability and reduce uncertainty even when multiple frequencies are used to enhance productivity.
3Device complexity
If indirect derivation methods are used to calculate phase angle information from sensed signals, then device complexity is reduced, but measurement precision of phase angle relationships deteriorates
Solution Approach 1:
The patent introduces optical signals as an intermediary medium between the RF voltage and current sensors and the measurement system. Photodetectors convert electrical RF signals into optical signals, which then serve as intermediaries for precise phase angle measurement. This intermediary approach enables direct measurement of phase relationships without complex indirect calculation methods, achieving high precision while maintaining manageable 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
Enables precise monitoring and control of power flow, improving manufacturing yields and process repeatability by characterizing frequency content of RF excitation signals, and can be applied to various power transmission systems.
Implementation Method 1
by sampling-based frequency converters that bring the RF voltage and current signals to a fixed intermediate frequency (IF) before digital conversion
Implementation Method 2
RF voltage and current signals are converted into digital representations of the RF waveforms
Implementation Method 3
Digital signal processing circuitry manages data capture, mathematical transforms, signal filters, scaling, and creation of mathematically alterable analog outputs
Data Source
AI summary
A system and method for measuring and analyzing power flow parameters in RF-based excitation systems for semi-conductor plasma generators. A measuring probe (8) is connected to an RF transmission line for receiving and measuring voltage (10) and current signals (12) from the transmission line (4). A high-speed sampling process converts the measured RF voltage and current signals into digital signals. The digital signals are then processed so as to reveal fundamental and harmonic amplitude and phase information corresponding to the original RF signals. Multiple measuring probes may be inserted in the power transmission path to measure two-port parameters, and the networked probes may be interrogated to determine input impedance, output impedance, insertion loss, internal dissipation, power flow efficiency, scattering, and the effect of plasma non-linearity on the RF signal.