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:
Oct. 29, 1991
Filed:
Apr. 22, 1988
Applicant:
Inventors:
John S Batchelder, Tarrytown, NY (US);
Donald M DeCain, New York, NY (US);
Marc A Taubenblatt, Tarrytown, NY (US);
Hermantha K Wickramasinghe, Chappaqua, NY (US);
Clayton C Williams, Peekskill, NY (US);
Assignee:
International Business Machines Corporation, Armonk, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01B / ;
U.S. Cl.
CPC ...
356345 ; 356351 ; 356353 ;
Abstract
A method and apparatus for monitoring process fluids used in the manufacture of semiconductor components and other microelectronic devices relies upon detection of the phase shift of a pair of optical energy beams encountering a bubble or particle in the fluid. The system distinguishes between bubbles and particles having indices of refraction greater than the surrounding fluid and between different types and sizes of particles.