Study of Stresses in Thin Silicon Wafers with Near-infraredphase Stepping Photoelasticity

2002 ◽  
Vol 17 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Tieyu Zheng ◽  
Steven Danyluk
Keyword(s):  
Near Infrared ◽  
Silicon Wafers ◽  
Infrared Transmission ◽  
Orientation Measurement ◽  
Phase Stepping ◽  
Stress Orientation ◽  
Transmission Technique ◽  
Stress Coefficient ◽  
Thin Silicon

This paper reports on a study of stress in thin silicon plates sectioned from wafers by a near-infrared transmission technique. Phase stepping was incorporated to determine the magnitude and orientation of stress from fractional birefringence fringe images. The anisotropic relative optic-stress coefficient of (100) silicon was determined and the limitation of the stress orientation measurement is discussed.

Temperature Measurement of Metallized Silicon Wafers by Infrared Transmission Using Single- and Double-Pass Geometries

1994 ◽  
Vol 342 ◽  
Author(s):  
C.W. Cullen ◽  
J.C. Sturm
Keyword(s):  
Temperature Measurement ◽  
Silicon Wafer ◽  
Silicon Wafers ◽  
Infrared Transmission ◽  
Double Pass ◽  
Wafer Temperature ◽  
Single Pass ◽  
Transmission Technique

ABSTRACTThe infrared transmission technique for the measurement of silicon wafer temperature has been extended to metallized wafers. For wafers with partial metal coverage, a single-pass method has been demonstrated from 200°C to 550°C. For wafers with blanket metal coverage, a novel double-pass infrared transmission technique is presented.

scholarly journals Estimation of composition of quinoa ( Chenopodium quinoa Willd.) grains by Near-Infrared Transmission spectroscopy

LWT ◽  
2017 ◽  
Vol 79 ◽  
pp. 126-134 ◽  
Author(s):  
Christian Encina-Zelada ◽  
Vasco Cadavez ◽  
Jorge Pereda ◽  
Luz Gómez-Pando ◽  
Bettit Salvá-Ruíz ◽  
...  
Keyword(s):  
Near Infrared ◽  
Chenopodium Quinoa ◽  
Infrared Transmission ◽  
Transmission Spectroscopy

Application of near Infrared Transmission Spectroscopy for the Determination of Some Quality Parameters of Apples

1994 ◽  
Vol 2 (4) ◽  
pp. 213-221 ◽  
Author(s):  
T. Lovász ◽  
P. Merész ◽  
A. Salgó
Keyword(s):  
Dry Matter ◽  
Near Infrared ◽  
Matter Content ◽  
Dry Matter Content ◽  
Quality Factors ◽  
Infrared Transmission ◽  
Transmission Method ◽  
Titratable Acid ◽  
Transmission Spectroscopy ◽  
Relative Standard

The acceptability of near infrared (NIR) transmission spectroscopy for the prediction of six quality factors of apples (firmness, refractive index, pH, titratable acid, dry matter and alcohol insoluble solids content) was investigated. The effects of storage conditions, cultivars and season on the accuracy of the NIR transmission method were also studied during the experiment. The accuracy of the calibration of all investigated parameters decreased during storage. The alteration of the characteristics of the spectra is possibly due to changes in the chemical composition and structure of apples between September and April. The calibration method was improved by developing a separate calibration for each cultivar per year. The calibrations of the different parameters are season-dependent except for the dry matter content. Using outlier diagnostics, the prediction accuracy can be generally improved by about 10%. The coefficient of variation for each parameter is compatible with the relative standard deviation for the reference methods except for the titratable acid content, showing the applicability of NIR transmission techniques. A relationship seems to exist between the maturity and the NIR transmission spectra of the apple.

Determination of Wavelength Accuracy in the Near-Infrared Spectral Region Based on NIST's Infrared Transmission Wavelength Standard SRM 1921

2000 ◽  
Vol 54 (3) ◽  
pp. 450-455 ◽  
Author(s):  
Stephen R. Lowry ◽  
Jim Hyatt ◽  
William J. McCarthy
Keyword(s):  
Reference Material ◽  
Standard Reference Material ◽  
Spectral Region ◽  
Near Infrared ◽  
Cost Effective ◽  
Infrared Transmission ◽  
Internal Reference ◽  
Mid Infrared ◽  
Infrared Spectral Region ◽  
Infrared Spectral

A major concern with the use of near-infrared (NIR) spectroscopy in many QA/QC laboratories is the need for a simple reliable method of verifying the wavelength accuracy of the instrument. This requirement is particularly important in near-infrared spectroscopy because of the heavy reliance on sophisticated statistical vector analysis techniques to extract the desired information from the spectra. These techniques require precise alignment of the data points between the vectors corresponding to the standard and sample spectra. The National Institute of Standards and Technology (NIST) offers a Standard Reference Material (SRM 1921) for the verification and calibration of mid-infrared spectrometers in the transmittance mode. This standard consists of a 38 μm-thick film of polystyrene plastic. While SRM 1921 works well as a mid-infrared standard, a thicker sample is required for use as a routine standard in the near-infrared spectral region. The general acceptance and proven reliability of polystyrene as a standard reference material make it a very good candidate for a cost-effective NIR standard that could be offered as an internal reference for every instrument. In this paper we discuss a number of the parameters in a Fourier transform (FT)-NIR instrument that can affect wavelength accuracy. We also report a number of experiments designed to determine the effects of resolution, sample position, and optics on the wavelength accuracy of the system. In almost all cases the spectral reproducibility was better than one wavenumber of the values extrapolated from the NIST reference material. This finding suggests that a thicker sample of polystyrene plastic that has been validated with the SRM 1921 standard would make a cost-effective reference material for verifying wavelength accuracy in a medium-resolution FT-NIR spectrometer.

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