MEMS Resonator Substrate for Spatial Plasma Parameter Mapping
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Solution Overview
Problem
Current methods for measuring plasma parameters in plasma chambers, such as optical emission spectroscopy and Langmuir probes, are limited in their ability to accurately determine electron density, temperature, and spatial variations within the plasma, and cannot provide real-time measurements during plasma processes.
Innovation Solution
The use of diagnostic substrates with arrays of resonators, including MEMS sensors and RF resonators, which are capable of measuring plasma parameters like electron density and temperature in real-time by detecting changes in resonance frequencies, and can be integrated across the surface of a substrate with varying geometries and guard ring biases to enhance sensitivity and spatial information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical emission spectroscopy (OES) is used to monitor plasma, then plasma composition can be determined, but electron density, plasma temperature, and spatial differences in these properties cannot be measured
Solution Approach 1:
The plasma diagnostic function is segmented across multiple resonators with different geometries positioned at various locations on the substrate. Each resonator measures specific plasma parameters at its location, collectively providing comprehensive spatial and parametric information that no single sensor could provide alone.
Solution Approach 2:
The resonator array serves multiple diagnostic functions simultaneously - measuring electron density, plasma temperature, and spatial variations across the substrate. This multi-functional approach replaces the need for separate specialized instruments for each measurement type.
2Measurement precision
If Langmuir probes are used to measure plasma properties, then plasma parameters can be measured, but they are macro scale and large numbers cannot be easily integrated across the substrate surface
Solution Approach 1:
The measurement capability transitions from macro-scale point measurements to a two-dimensional array of micro-scale resonators distributed across the substrate surface. This dimensional transformation enables comprehensive spatial mapping while maintaining measurement precision through the distributed sensor network.
Solution Approach 2:
The resonators are designed with varying geometrical parameters (size, shape, orientation) to optimize sensitivity to different plasma parameters and spatial locations. This parameter variation allows the array to extract multiple plasma properties from collective resonance frequency measurements.
3Manufacturing precision
If end-result metrology is used to quantify plasma processes, then material addition or removal can be determined, but real-time plasma parameter monitoring during the process cannot be achieved
Solution Approach 1:
The resonators continuously monitor plasma parameters in real-time during the deposition or etching process, enabling preliminary detection of process deviations before they affect the final material thickness or quality. This allows for real-time process adjustment rather than post-process inspection.
Solution Approach 2:
The real-time resonance frequency measurements from the resonator array provide continuous feedback on plasma conditions (electron density, temperature) that directly influence deposition or etching rates. This feedback enables dynamic process control to achieve precise material addition or removal.
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 real-time characterization of plasma and surface properties, providing accurate measurements of electron density, temperature, and other parameters during plasma processes, overcoming the limitations of existing technologies.
Implementation Method 1
measuring a baseline response from the first resonator and the second resonator in a vacuum without a plasma... measuring a first resonance frequency of the first resonator and a second resonance frequency of the second resonator
Data Source
AI summary
Embodiments disclosed herein include diagnostic substrates and methods of using the diagnostic substrates to extract plasma parameters. In an embodiment, a diagnostic substrate comprises a substrate and an array of resonators across the substrate. In an embodiment, the array of resonators comprises at least a first resonator with a first structure and a second resonator with a second structure. In an embodiment, the first structure is different than the second structure.