3D Plasma Parameter Mapping Using Spatially Resolved OES
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Solution Overview
Problem
Existing plasma characterization techniques, such as Langmuir probe and Wise-probe, are intrusive and have limited spatial resolution, making it challenging to accurately characterize plasma parameters during semiconductor manufacturing, especially for advanced 3D features, and existing OES techniques are limited to chemical species analysis.
Innovation Solution
Utilizing spatially-resolved optical emission spectroscopy (OES) with tomographic techniques and actinometry, combined with a trace amount of probe gas, to non-intrusively map electron temperature, neutral gas temperature, and sheath electrical field in 2D or 3D, enabling time-resolved plasma parameter monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If intrusive probe techniques (Langmuir probe, Wise-probe) are used to measure plasma parameters, then measurement capability is provided, but plasma disturbance occurs and spatial resolution is limited
Solution Approach 1:
The patent replaces intrusive mechanical probe measurements with non-intrusive optical emission spectroscopy (OES) measurements. Instead of physically inserting probes into the plasma that disturb it, the system uses optical detectors to measure plasma parameters remotely through emission spectra analysis, eliminating plasma disturbance while maintaining measurement capability
Solution Approach 2:
The patent introduces a probe gas (such as neon, argon, or nitrogen) as an intermediary substance that emits characteristic optical signals when exposed to plasma. This intermediary allows indirect measurement of plasma parameters through OES without direct probe insertion, avoiding plasma disturbance while enabling precise spatially-resolved measurements
2Loss of information
If traditional OES techniques are used for plasma analysis, then chemical species information is obtained, but spatial distribution mapping capability is insufficient
Solution Approach 1:
The patent segments the plasma measurement space into multiple discrete measurement points by using multiple optical detectors positioned at different locations. Each detector captures OES signals from a specific spatial region, and the system reconstructs the complete spatial distribution by combining these segmented measurements, achieving high-resolution 2D/3D mapping while preserving chemical species information
Solution Approach 2:
The patent transitions from traditional one-dimensional spectral analysis to multi-dimensional spatial mapping by adding spatial coordinates to the OES measurements. The system measures plasma parameters not only in terms of wavelength/intensity but also across two or three spatial dimensions, enabling comprehensive spatial distribution mapping while maintaining chemical species analysis capability
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
Provides precise, non-intrusive 2D/3D mapping of plasma parameters without disturbing the plasma, facilitating in-situ process monitoring and optimization, and improving plasma reactor performance.
Implementation Method 1
a plasma optical emission spectroscopy (OES) system configured to measure optical emissions from the plasma
Implementation Method 2
flowing a probe gas through the plasma processing chamber; obtaining spatially-resolved OES signals at a wavelength of an optical emission line of the probe gas
Data Source
AI summary
A method of characterizing a plasma in a plasma processing chamber that includes: sustaining a plasma generated from a process gas in a plasma processing chamber; flowing a probe gas through the plasma processing chamber; obtaining spatially-resolved OES signals at a wavelength of an optical emission line of the probe gas within the plasma processing chamber, signal intensities of the spatially-resolved OES signals being correlated to a plasma parameter of the plasma, the plasma parameter having a spatial distribution within the plasma processing chamber; and based on the spatially-resolved OES signals, constructing a 3D map of OES signals by data fitting of the spatially-resolved OES signals with a computation model; and converting the 3D map of OES signals into a 3D map of the plasma parameter, the 3D map of the plasma parameter including information about the spatial distribution.