Radiant energy – Photocells; circuits and apparatus – Optical or pre-photocell system
Patent
1989-01-26
1990-06-12
Nelms, David C.
Radiant energy
Photocells; circuits and apparatus
Optical or pre-photocell system
356369, 356430, 250225, G01N 2101
Patent
active
049335677
ABSTRACT:
A method and apparatus are disclosed for nondestructively measuring the density and orientation of crystalline and other micro defects directly below the surface of a properly prepared material such as a semiconductor wafer. The material surface is illuminated with a probe beam of electromagnetic radiation which is limited to a nondestructive power level and with a wavelength, or wavelengths, selected according to certain characteristics of the material so that penetration depth is controlled. Specific orientation of the material with respect to the probe beam and the detector is required to detect that portion of the probe beam scattered from the subsurface region without interference from the surface scatter and to identify the orientation of the defects. Maps of scatter intensity versus position are made according to the density of the defects in the subsurface.
REFERENCES:
patent: 3574470 (1971-04-01), Vukelich et al.
patent: 3652863 (1972-03-01), Gaskell et al.
patent: 3904293 (1975-09-01), Gee
patent: 4015127 (1977-03-01), Sharkins
patent: 4314763 (1982-02-01), Steigmeier et al.
patent: 4342515 (1982-08-01), Akiba et al.
patent: 4352016 (1982-09-01), Duffy et al.
patent: 4352017 (1982-09-01), Duffy et al.
patent: 4391524 (1983-07-01), Steigmeier et al.
patent: 4395122 (1983-07-01), Southgate et al.
patent: 4575249 (1986-03-01), Grieger
F. D. Orazio, Jr., W. K. Stowell and R. M. Silva, Instrumentation of a Variable Angle Scatterometer (VAS), Aug. 1982.
W. K. Stowell, R. M. Silva and F. D. Orazio, Jr., Damage Susceptibility of Ring Laser Gyro Class Optics, Aug. 1982.
R. M. Silva, F. D. Orazio, Jr. and W. K. Stowell, Scatter Evaluation of Supersmooth Surfaces, Aug. 1982.
IBM Technical Disclosure Bulletin, vol. 20, No. 8, Jan. 1978, Automatic Brewster's Angle Thin Film Thickness Measurement Spectrophotometer, Chwalow et al.
Orazio, Jr. Fred D.
Silva, deceased Robert M.
Sledge, Jr. Robert B.
Allen Stephone B.
Nelms David C.
VTI, Inc.
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