Real-Time Diagnosis of Etching and Deposition Processes by Spectroscopic Ellipsometry

1983 ◽  
Vol 29 ◽  
Author(s):  
D. E. Aspnes ◽  
R. P. H. Chang
Keyword(s):  
High Pressure ◽  
Data Analysis ◽  
Laser Beam ◽  
Real Time ◽  
Spectroscopic Ellipsometry ◽  
Chemical Etching ◽  
Polarization State ◽  
Surface Information ◽  
Deposition Processes ◽  
Time Diagnosis

ABSTRACTRecent advances in instrumentation and data analysis have made spectroscopic ellipsometry a routine analytic tool with submonolayer sensitivity for monitoring and controlling cleaning, etching, deposition, or other processes that take place in relatively high-pressure or reactive environments. We discuss representative applications in chemical etching, plasma processing, and MOCVD to illustrate analytical procedures and to indicate other potential uses of the technique. The possibility of extracting surface information already carried in the polarization state of the processing laser beam is also discussed.

In Situ Spectroscopic Ellipsometry for the Real Time Process Control of Plasma Etching of Silicon Nitride

1999 ◽  
Vol 591 ◽  
Author(s):  
I. G. Rosen ◽  
T. Parent ◽  
B. Fidan ◽  
A. Madhukar
Keyword(s):  
Silicon Nitride ◽  
Real Time ◽  
Plasma Etching ◽  
Spectroscopic Ellipsometry ◽  
Etch Rate ◽  
Polarization State ◽  
Non Invasive ◽  
Silicon Nitride Films ◽  
In Situ Sensor

ABSTRACTSpectroscopic ellipsometry (SE) is a commonly used non-destructive, non-invasive in-situ sensor for dry etching. SE measures the change in the polarization state of light reflected from a surface. Sample thickness is obtained by fitting a model to the experimental ellipsometry data. In this paper we describe the design, testing and evaluation of an SE based adaptive real time feedback controller for etch rate regulation in CF4/O2 plasma etching of silicon nitride films. The feedback variable is the current etch rate as determined from the in-situ SE measurements of the film's thickness. The controller compensates for drifts in etch rate which occur during a given etch, and adaptively adjusts for the run-to-run variability inherent to plasma processing. Experimental results are presented and discussed.

Real-time Monitoring of semiconductor growth by Spectroscopic ellipsometry

1997 ◽  
Vol 502 ◽  
Author(s):  
B. Johs ◽  
J. Hale ◽  
C. Herzinger ◽  
D. Doctor ◽  
K. Elliott ◽  
...  
Keyword(s):  
Data Analysis ◽  
Real Time ◽  
Spectroscopic Ellipsometry ◽  
Growth Parameters ◽  
High Surface ◽  
Buffer Layers ◽  
Ex Situ ◽  
Angle Of Incidence ◽  
Time Layer ◽  
Analysis Strategies

ABSTRACTin situ Spectroscopic Ellipsometry (SE) is an optical technique which is well suited for the monitoring of epitaxial semiconductor growth, due to its high surface sensitivity and non-invasive nature. In this work, SE systems were installed on both MBE and MOCVD deposition systems to monitor the epitaxial growth of InxGa1−xAs and InxAl1−xAs compounds on InP substrates. The structures grown include thick lattice matched In0.53Ga0.47As buffer layers (for HBT collectors), and strained RTD structures. SE was used to monitor in real-time layer composition and thickness during growth. To enhance the precision and accuracy of the SE determined growth parameters, it was necessary to optimize the SE data analysis strategies. A methodology to determine the best spectral region for the SE data analysis in the presence of noise and systematic effects (such as angle of incidence uncertainty, detector wavelength shifts, surface roughness, uncertainty in surface temperature, non-ideal growth modes, etc.) is presented. Using the optimized data analysis strategies, long term SE-determined InxGa1−�As composition accuracy (as verified by ex situ x-ray measurements) of ±0.002 in ‘x’ was achieved. SE thickness measurements of ultra-thin (<30Å) strained AlAs barrier layers were also in excellent agreement (±0.5Å) with real-time photo-emission oscillation measurements.

User-centered Requirements for Patient Fluid Intake Monitoring Support

2020 ◽  
Vol 64 (1) ◽  
pp. 736-740
Author(s):  
Ellen J. Bass ◽  
Andrew J. Abbate ◽  
Yaman Noaiseh ◽  
Rose Ann DiMaria-Ghalili
Keyword(s):  
Data Analysis ◽  
Focus Group ◽  
Focus Groups ◽  
Real Time ◽  
Information Needs ◽  
Fluid Intake ◽  
Fluid Consumption ◽  
Registered Dietitians ◽  
Group Data ◽  
Focus Group Data

There is a need to support patients with monitoring liquid intake. This work addresses development of requirements for real-time and historical displays and reports with respect to fluid consumption as well as alerts based on critical clinical thresholds. We conducted focus groups with registered nurses and registered dietitians in order to identify the information needs and alerting criteria to support fluid consumption measurement. This paper presents results of the focus group data analysis and the related requirements resulting from the analysis.

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