scholarly journals Calibration of the apparent temperature of silicon single crystals as a function of their true temperature and their thickness as determined by infrared measurements

1993 ◽  
Author(s):  
R.K. Smither ◽  
P.B. Fernandez
1996 ◽  
Vol 8 (2) ◽  
pp. 136-143
Author(s):  
Minoru Inamura ◽  

A thermal infrared image is a visualized image of the thermal energy radiated from an object. Thermal radiation energy is dependent on the absolute temperature and the effective emissivity of an object, so that a thermal infrared image does not give the temperature distribution of an object but, rather, is a superimposed image of, so to speak, the temperature pattern and the emissivity pattern. In other words, a emissivity pattern is an apparent temperature pattern superimposed on a true temperature pattern. However, this paper points out that a thermal infrared image obtained with a sensor having an instantaneously large field of view, like a remotely sensed image, has additionally a third pattern due to the size of the field of view superimposed and that this appears as an apparent temperature change on the thermal infrared image. Moreover, the paper stresses the fact that in order to obtain correct information on temperature, it is necessary to remove these patterns and, at the same time, points out that these can be removed if effective use is made of visible, multispectral images.


1991 ◽  
Vol 113 (3) ◽  
pp. 286-293 ◽  
Author(s):  
S. Heng ◽  
W. Z. Black

This paper describes the use of digital image processing in conjunction with an infrared imaging apparatus to locate and quantify “micro” hot spot temperatures on the surface of energized microelectronic chips. Briefly, the temperature mapping/processing procedure creates emissivity maps for the surface of the chip at different isothermal conditions. The emissivity map images are digitized and stored as a 512 × 512 pixel array, of which 400 lines contain IR information. Apparent temperature measurements are then collected with the chip energized in its normal operating environment. These apparent temperature data are digitized and stored as a 512 × 512 integer array using the same format as the digitized emissivity data. Before correcting for emissivity variations, the apparent temperature images are rectified using digital image processing to precisely overlay the spatial coordinates of the emissivity map. Finally, actual temperature maps are obtained by correcting the apparent temperature data for the local emissivity variations and background reflections. The computer driven measurement technique has been applied to the task of measuring localized temperatures on areas as small as 30 μm on the surface of an energized chip to an accuracy of ±1°C once the surface emissivity is accurately known. The infrared equipment, image processing hardware and supporting software are used to measure the temperature distribution on the surface of a 4.7 mm × 4.7 mm energized chip. IR measured temperatures at isolated locations on the chip are compared with results obtained by the resistance-temperature technique. Since the resistance-temperature technique provides an area-averaged temperature for the energized region, the result obtained from the high resolution IR measurements yields higher localized temperatures. Results are presented for peak surface temperatures up to 100°C and maximum heat flux values of 7.9x106 W/m2. A separate set of infrared measurements are used to predict the influence of surface emissivity on the accuracy of the temperature measurements.


1996 ◽  
Vol 441 ◽  
Author(s):  
Z. Yina ◽  
Z. L. Akkerman ◽  
W. Smith ◽  
R. Gat

AbstractA model for the infrared radiation emitted by a film/substrate system has been developed which includes both the effects of interference in the growing film and of scattering from its rough growth surface. Predictions of the model for the time-dependence of the apparent temperature Tapp of the film/substrate system measured in-situ by both one-color and two-color infrared pyrometers are presented for the case of diamond growth on Si. Using this model, the following information can be obtained from in-situ pyrometric results in real time: the true temperature of the film/substrate system, the instantaneous film growth rate, and the rms surface roughness σ of the film.


1987 ◽  
Vol 99 ◽  
Author(s):  
T. W. Noh ◽  
P. E. Sulewski ◽  
S. G. Kaplan ◽  
A. J. Sievers ◽  
D. K. Lathrop ◽  
...  

ABSTRACTWe report measurements of the reflectivity of bulk samples, films and single crystals of high Tc materials. The data are fitted with the Mattis-Bardeen theory to obtain gap values. For sintered samples we find 2Δ/kTc = 2.6, while for YBa2Cu3O7-y films and single crystals 2Δ/kTc = 6.4 and 7.7 respectively.


2000 ◽  
Vol 33 (1) ◽  
pp. 2-9 ◽  
Author(s):  
Krishan Lal ◽  
R. R. Ramanan ◽  
G. Bhagavannarayana

High-resolution X-ray diffractometry, absolute integrated intensity (ρ) measurements, diffuse X-ray scattering (DXS) and infrared (IR) absorption techniques were used to investigate the influence of oxygen on the structural perfection of high purity (resistivity of the order of 4 kΩ cm) float zone (FZ) grown (111) silicon single crystals. A multicrystal diffractometer set in (+,-,-,+) geometry, with Mo Kα1radiation, was employed. From the infrared measurements, the oxygen concentration in the sample was determined to be 1.3 × 1017 atoms cm^{-3}. High-resolution X-ray diffraction curves of the as-grown crystal had half-widths of ∼11 arcsec; the ρ value was 3.5 × 10^{-5} rad. To incorporate oxygen in a controlled manner into the specimens, they were annealed under dry oxygen ambient for 8 h in the temperature range 573–1373 K (in eight steps). Up to 723 K there was no appreciable change in oxygen content or in the degree of perfection. Annealing at temperatures (AT) > 873 K resulted in considerable increases in the oxygen content, as well as significant improvements in the degree of perfection. For example, as the level of oxygen increased from 1.3 × 1017to 3.6 × 1017 atoms cm^{-3} for A_T=873 K, the values of half-widths and ρ decreased to ∼7 arcsec and 2.4 × 10^{-5} rad, respectively. However, annealing above 1273 K produced deterioration in lattice perfection. DXS measurements showed remarkable changes in the nature of point defects and their clusters with change inAT. Up to A_T=973 K, the defects were predominantly vacancy clusters. However, withATin the range 1073–1273 K, the predominent defects were isolated interstitials. Further increase inATled to interstitial cluster formation, which deteriorated the lattice perfection. This study clearly demonstrates that oxygen concentration in the range ∼3 × 1017to 13 × 1017atoms cm^{-3} leads to significant improvement in structural perfection of silicon single crystals.


Author(s):  
Lucien F. Trueb

A new type of synthetic industrial diamond formed by an explosive shock process has been recently developed by the Du Pont Company. This material consists of a mixture of two basically different forms, as shown in Figure 1: relatively flat and compact aggregates of acicular crystallites, and single crystals in the form of irregular polyhedra with straight edges.Figure 2 is a high magnification micrograph typical for the fibrous aggregates; it shows that they are composed of bundles of crystallites 0.05-0.3 μ long and 0.02 μ. wide. The selected area diffraction diagram (insert in Figure 2) consists of a weak polycrystalline ring pattern and a strong texture pattern with arc reflections. The latter results from crystals having preferred orientation, which shows that in a given particle most fibrils have a similar orientation.


Author(s):  
E. L. Thomas ◽  
S. L. Sass

In polyethylene single crystals pairs of black and white lines spaced 700-3,000Å apart, parallel to the [100] and [010] directions, have been identified as microsector boundaries. A microsector is formed when the plane of chain folding changes over a small distance within a polymer crystal. In order for the different types of folds to accommodate at the boundary between the 2 fold domains, a staggering along the chain direction and a rotation of the chains in the plane of the boundary occurs. The black-white contrast from a microsector boundary can be explained in terms of these chain rotations. We demonstrate that microsectors can terminate within the crystal and interpret the observed terminal strain contrast in terms of a screw dislocation dipole model.


Author(s):  
M.P. Thomas ◽  
A.R. Waugh ◽  
M.J. Southon ◽  
Brian Ralph

It is well known that ion-induced sputtering from numerous multicomponent targets results in marked changes in surface composition (1). Preferential removal of one component results in surface enrichment in the less easily removed species. In this investigation, a time-of-flight atom-probe field-ion microscope A.P. together with X-ray photoelectron spectroscopy XPS have been used to monitor alterations in surface composition of Ni3Al single crystals under argon ion bombardment. The A.P. has been chosen for this investigation because of its ability using field evaporation to depth profile through a sputtered surface without the need for further ion sputtering. Incident ion energy and ion dose have been selected to reflect conditions widely used in surface analytical techniques for cleaning and depth-profiling of samples, typically 3keV and 1018 - 1020 ion m-2.


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