Microwave Resonator Plasma Diagnostics Using Chirped Signal Measurement
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Solution Overview
Problem
Existing metrology tools struggle with real-time measurement of high-density plasmas in semiconductor processing, leading to inaccurate process control and invasiveness in high volume manufacturing environments.
Innovation Solution
A system utilizing a signal generator to produce chirped signals, mixed with a circulator and resonator, and converted by mixers to measure plasma properties in real-time, enabling rapid monitoring through chirped pulse techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing metrology tools are used to measure plasma properties, then measurement capability is provided, but real-time measurement capability is insufficient and time resolution is poor
Solution Approach 1:
The patent employs periodic chirped pulse carrier signals to interrogate the resonator at regular intervals, enabling repeated measurements of plasma properties over time. This periodic excitation allows the system to capture temporal variations in plasma conditions while maintaining high time resolution through the short duration of each pulse cycle
Solution Approach 2:
The patent utilizes changes in the resonant frequency of the resonator caused by plasma interaction as the key measurement parameter. By monitoring how the plasma modifies the resonant frequency of the resonator, the system achieves real-time plasma diagnostics without requiring direct contact with the plasma, thereby improving both measurement capability and time resolution
2Measurement precision
If existing measurement tools are deployed in high volume manufacturing, then plasma measurement is achieved, but the tools are invasive and unsuitable for HVM environments
Solution Approach 1:
The patent introduces a resonator as an intermediary element that indirectly measures plasma properties through frequency modulation. Instead of placing measurement probes directly in the plasma environment (which would be invasive), the resonator couples to the plasma and translates plasma conditions into measurable frequency shifts, eliminating the need for direct plasma contact while maintaining measurement accuracy
Solution Approach 2:
The patent replaces traditional mechanical or direct-contact plasma measurement probes with an electromagnetic field-based resonator system. This substitution eliminates the mechanical invasiveness of physical probes while maintaining the ability to measure plasma properties through non-contact electromagnetic interaction
3Manufacturing precision
If real-time plasma measurement is implemented, then process control accuracy is improved, but measurement of high density plasmas becomes particularly difficult
Solution Approach 1:
The patent employs resonant oscillation of the resonator at its natural frequency, which is modified by plasma interaction. By exciting the resonator at its resonant frequency and measuring the frequency shift caused by plasma coupling, the system achieves sensitive detection of high density plasma properties through vibrational resonance rather than direct measurement
Solution Approach 2:
The resonator serves multiple functions simultaneously: it acts as both the measurement sensor and the coupling element to the plasma. This multi-functionality allows the same component to both detect plasma properties and interact with the plasma field, enabling effective measurement of high density plasmas through the universal resonant response
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
Achieves real-time plasma property measurement with improved time resolution of three orders of magnitude, allowing for precise process control and chamber matching in semiconductor manufacturing.
Implementation Method 1
a plasma modified resonant frequency of the resonator is measured by a reflected chirped carrier signal
Implementation Method 2
providing the chirped signal to a resonator for interaction with a plasma
Data Source
AI summary
Embodiments disclosed herein include an apparatus that comprises a board with a signal generator for generating chirped signals on the board. In an embodiment, a first mixer is on the board and electrically coupled to the signal generator, and a circulator is on the board. In an embodiment, the circulator comprises a first port that is electrically coupled to the mixer, a second port that is electrically coupled to a connector, and a third port. In an embodiment, a second mixer is on the board and electrically coupled to the third port of the circulator. In an embodiment, an analog to digital converter (ADC) is on the board and electrically coupled to the second mixer.