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Traceable emissivity measurements in RTP using room temperature reflectometry

By: Hunter, A.; Adams, B.; Ramanujam, R.
Advanced Thermal Processing of Semiconductors, 2003. RTP 2003. 11th IEEE International Conference on RTP
Volume , Issue , 23-26 Sept. 2003 Page(s): 85 – 88
Digital Object Identifier 10.1109/RTP.2003.1249127
Summary:

The design of an integrating reflectometer specific to the optical and spectral requirements of rapid thermal processing (RTP) is discussed. We report reflectance measurements of various materials. These measurements are correlated to in-situ emittance measurements recorded during rapid thermal processing. We also present the design of an optimized emissometer for an RTP chamber. We propose a means for correlating room temperature reflectance measurements to emittance standards for RTP.

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SPECTRAL MEASUREMENTS FIELD GUIDE

This web site gives the executive summary and table of contents for the Field Guide.

Here’s a summary of what the Field Guide is all about in the words of its authors:

EXECUTIVE SUMMARY

“Because of the rapid advance of airborne and satellite sensor technology in providing higher spectral resolution over progressively broader wavelength regions, there is a need for more (and more accurate) field measurements to complement overhead data. The purpose of this field guide is to facilitate such ground-based measurements, first through a review of the environmental factors affecting such measurements, second through an evaluation of the instrumentation involved, and third through a suggested approach to the measurement process.

“In evaluating environmental factors affecting spectral measurements in the field, the sources of radiance from a target are discussed in both the reflectance and emittance regions of the spectrum, as well as how those sources are modified by atmospheric attenuation and scattering, and the presence of clouds and wind.

“Another factor affecting all spectral measurements in the field is the computer typically used for instrument control and data storage. Computers tend to be the universal weak link in field spectrometers, because of their typical low tolerance for bright sunlight, temperature extremes, windblown dust, and rain. Various solutions to the computer problem are discussed, including the acquisition of hardened computers.

“The most commonly used field spectrometers are described, with advice on how to get the most out of each instrument. Then the pros and cons of each instrument are discussed with regard to different applications.

“Finally, how to approach field measurements is described, beginning with a thorough testing of a field instrument (and the field instrument user) in the laboratory. Approaches to data collection, record keeping, data reduction, and data analysis are discussed. A major conclusion is that much greater support for data analysis is necessary to reach the full potential of spectroscopic remote sensing for target identification”.

Infrared Sea Surface Emissivity

“The InfraRed Sea Surface Emissivity (IRSSE) model was developed for use in the Global Data Assimilation System (GDAS) at NCEP/EMC. Previously, the GDAS used an IRSSE model based on Masuda et al (1988).

“The Masuda model doesn’t account for the effect of enhanced emission due to reflection from the sea surface (only an issue for larger view angles) and the implementation was based on coarse spectral resolution emissivity data making its application to high resolution instruments, such as AIRS, problematic.

“The old IRSSE model has been upgraded to use sea surface emissivities derived via the Wu and Smith (1997) methodology as described in van Delst and Wu (2000).

“The emissivity spectra are computed assuming the infrared sensors are not polarised and using the data of Hale for the refractive index of water, Segelstein (1981) for the extinction coefficient, and Friedman (1969) for the salinitiy/chlorinity corrections.

“Instrument spectral response functions (SRFs) are used to reduce the emissivity spectra to instrument resolution. These are the quantities predicted by the IRSSE model.”

ASTM E307-72(2002)

ASTM E307-72(2002):

Standard Test Method for Normal Spectral Emittance at Elevated Temperatures

Developed by Subcommittee: E21.04

Book of Standards Volume: 15.03
“1. Scope

“1.1 This test method describes a highly accurate technique for measuring the normal spectral emittance of electrically conducting materials or materials with electrically conducting substrates, in the temperature range from 600 to 1400 K, and at wavelengths from 1 to 35 ?m.

“1.2 The test method requires expensive equipment and rather elaborate precautions, but produces data that are accurate to within a few percent. It is suitable for research laboratories where the highest precision and accuracy are desired, but is not recommended for routine production or acceptance testing. However, because of its high accuracy this test method can be used as a referee method to be applied to production and acceptance testing in cases of dispute.

“1.3 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.

“1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.”

STANDARDIZATION OF THERMAL EMITTANCE MEASUREMENTS. PART 5

Title: STANDARDIZATION OF THERMAL EMITTANCE MEASUREMENTS. PART 5. NORMAL SPECTRAL EMITTANCE, 800-1400 K (ABSTRACT BELOW)
DOWNLOAD FULL REPORT IN PDF FORMAT


Corporate Author : NATIONAL BUREAU OF STANDARDS GAITHERSBURG MD

Personal Author(s) : Harrison, William N. ; Richmond, Joseph C. ; Shorten, Frederick J. ; Joseph, Horace M.

Handle / proxy Url : http://handle.dtic.mil/100.2/AD426846

Report Date : NOV 1963

Pagination or Media Count : 99

Abstract: Equipment and procedures were developed to measure normal spectral emittance of specimens that can be heated by passing a current through them, at temperatures in the range of 800 to 1400 K, and over the wavelength range of 1 to 15 microns. A data-processing attachment for the normal spectral emittance equipment was designed to (1) automatically correct the measured emittance for ‘100% line’ and ‘zero line’ errors on the basis of previously-recorded calibration tests; (2) record the corrected spectral emittance values and wavelengths at preselected wavelength intervals on punched paper tape in form suitable for direct entry into an electronic digital computer; and (3) to compute during a spectral emittance test on a specimen the total normal emittance, or absorptance for radiant energy of any known spectral distribution of flux, of the specimen. Working standards of normal spectral emittance having low, intermediate and high emittance values, respectively, were prepared and calibrated for use in other laboratories to check the operation of equipment and procedures used for measuring normal spectral emittance.