Pulsed Plasma Diagnosis System Using Optical Emission Sensor
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Solution Overview
Problem
Current facilities lack a diagnosis system capable of monitoring the characteristics of pulsed plasma formed by pulsed RF power supplies, hindering the determination of basic plasma characteristics in semiconductor processes.
Innovation Solution
A diagnosis system comprising a chamber with a first pulsed RF power supply, an optical emission sensor (OES) to convert light into electrical signals, a digitizer to synchronize these signals with pulse signals, and an analyzer to analyze the synchronized signals, allowing for the determination of plasma characteristics such as magnitude, time resolution, and duty ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a pulsed RF power supply is used to form pulsed plasma, then the selection ratio and profile in deposition or etching process are improved, but the basic characteristics of pulsed plasma cannot be determined due to lack of diagnosis system
Solution Approach 1:
The patent replaces traditional electrical measurement methods with optical measurement using an optical emission sensor (OES). The OES detects light emitted by excited species in the pulsed plasma and converts it to electrical signals, enabling non-intrusive measurement of plasma characteristics during pulsed RF operation without interfering with the plasma process
Solution Approach 2:
The patent introduces an optical emission sensor as an intermediary between the pulsed plasma and the measurement system. The sensor converts optical information from the plasma into electrical signals that can be processed and analyzed, bridging the gap between the plasma state and diagnostic capabilities
2Measurement precision
If continuous wave RF power supply is used, then the diagnosis system can monitor plasma characteristics, but the selection ratio and profile in deposition or etching process cannot be improved
Solution Approach 1:
The patent implements periodic action by using pulsed RF power supply to create time-varying plasma conditions. The system applies RF power in discrete pulses rather than continuously, creating distinct pulse-on and pulse-off periods that enable better control over plasma chemistry and process outcomes while the diagnostic system captures characteristics during each phase
3Measurement precision
If optical emission sensor is used to sense light from pulsed plasma, then plasma characteristics can be monitored, but the system complexity increases
Solution Approach 1:
The optical emission sensor serves multiple functions: it detects light from the plasma, converts it to electrical signals, and provides time-resolved measurements of plasma characteristics. This multi-functionality reduces the need for separate diagnostic components and simplifies the overall system architecture despite the advanced measurement capabilities
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 accurate monitoring and analysis of pulsed plasma characteristics, improving process stability and reproducibility in semiconductor processes by distinguishing pulse-on and pulse-off periods with high time resolution, thereby enhancing wafer yield.
Implementation Method 1
an optical emission sensor (OES) to sense and convert the generated light into an electrical signal
Data Source
AI summary
A diagnosis system for pulsed plasma includes an optical emission sensor (OES) to receive light generated the pulsed plasma, the pulsed plasma having been generated in accordance with a pulse signal, a digitizer to synchronize the electrical signal with the pulse signal, and an analyzer to analyze the synchronized electrical signal.