A Nonperturbing Real-Time In Situ Plasma Diagnosis Technique Using an Optical Emission Spectrometer (OES)

2006 ◽  
Vol 34 (4) ◽  
pp. 1052-1058 ◽  
Author(s):  
S. Qin ◽  
A. Mcteer
Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1221
Author(s):  
Jun-Hyoung Park ◽  
Ji-Ho Cho ◽  
Jung-Sik Yoon ◽  
Jung-Ho Song

We present a non-invasive approach for monitoring plasma parameters such as the electron temperature and density inside a radio-frequency (RF) plasma nitridation device using optical emission spectroscopy (OES) in conjunction with multivariate data analysis. Instead of relying on a theoretical model of the plasma emission to extract plasma parameters from the OES, an empirical correlation was established on the basis of simultaneous OES and other diagnostics. Additionally, we developed a machine learning (ML)-based virtual metrology model for real-time Te and ne monitoring in plasma nitridation processes using an in situ OES sensor. The results showed that the prediction accuracy of electron density was 97% and that of electron temperature was 90%. This method is especially useful in plasma processing because it provides in-situ and real-time analysis without disturbing the plasma or interfering with the process.


2017 ◽  
Vol 32 (9) ◽  
pp. 1798-1804 ◽  
Author(s):  
S. Gaiaschi ◽  
S. Richard ◽  
P. Chapon ◽  
O. Acher

We developed an in situ measurement technique implemented on a Glow Discharge Optical Emission Spectrometry (GD-OES) instrument, which provides the depth information during the profiling process.


1999 ◽  
Vol 569 ◽  
Author(s):  
T. Parent ◽  
J. Tie ◽  
A. Madhukar

ABSTRACTElectron cyclotron resonance (ECR) CF4/ 02 plasma etching of silicon nitride (SixNy) deposited by plasma enhanced chemical vapor deposition (PECVD) has been examined in-situ by means of spectroscopic ellipsometry (SE) and optical emission (OE). The observed real-time etchrate and the relative intensity of emission of atomic fluorine at 703.7 nm are measured simultaneously and both are found to change with time during the etch in a reproducible manner. The evolution of the real-time etch rate and the fluorine emission intensity depends on the machine input settings and the extent to which the chamber has been exposed to CF4/ 02 plasma prior to sample introduction. In general the initial 10 to 40 seconds of etching reveal a rapid increase in the etch rate, the remainder of the etch exhibiting an etch rate which typically increases gradually until the etch is stopped. This variation in etch behavior with time during the etch process complicates the task of precisely and reliably etching ultrathin (< 50 nm) films, necessitating real-time control based upon in-situ sensors, the end objective of this work. The dependence of the evolution of the SixNy etch rate on microwave power, chamber pressure, and gas in-flow rate is presented and the implications of these dependencies on the implementation of real-time feedback control are discussed.


2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.


2017 ◽  
Vol 2017 (4) ◽  
pp. 5598-5617
Author(s):  
Zhiheng Xu ◽  
Wangchi Zhou ◽  
Qiuchen Dong ◽  
Yan Li ◽  
Dingyi Cai ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2830
Author(s):  
Sili Wang ◽  
Mark P. Panning ◽  
Steven D. Vance ◽  
Wenzhan Song

Locating underground microseismic events is important for monitoring subsurface activity and understanding the planetary subsurface evolution. Due to bandwidth limitations, especially in applications involving planetarily-distributed sensor networks, networks should be designed to perform the localization algorithm in-situ, so that only the source location information needs to be sent out, not the raw data. In this paper, we propose a decentralized Gaussian beam time-reverse imaging (GB-TRI) algorithm that can be incorporated to the distributed sensors to detect and locate underground microseismic events with reduced usage of computational resources and communication bandwidth of the network. After the in-situ distributed computation, the final real-time location result is generated and delivered. We used a real-time simulation platform to test the performance of the system. We also evaluated the stability and accuracy of our proposed GB-TRI localization algorithm using extensive experiments and tests.


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