The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 17, 1996
Filed:
Oct. 13, 1994
Michael Downer, Austin, TX (US);
Jerry I Dadap, Austin, TX (US);
John K Lowell, Round Rock, TX (US);
Advanced Micro Devices Inc., Sunnyvale, CA (US);
Abstract
A non-destructive, non-intrusive characterization of angstrom-level roughness characteristics of subsurface interfaces is performed by applying femtosecond light pulses from a laser onto a surface, and analyzing the contents of the reflected pulses. After impinging on the surface being analyzed, the pulses pass through optical filters, which attenuate the fundamental and third harmonic frequencies of the pulses, but keep a substantial portion of the second harmonic. Analysis of the second harmonic signals provides rapid, non-contact, interface-specific characterization of the angstrom-level interfacial microroughness of the subsurface. For semiconductor devices, the second harmonic signals can be used to detect strain, contamination, and trapped charges in the Si/Si(O.sub.2) interface.