Minute step measuring method

Details Minute step measuring method Minute step measuring method

1995-10-10

1997-12-02

Pham, Hoa Q.

Optics: measuring and testing

By polarized light examination

With light attenuation

356 401, 356359, G01B 1100

Patent

active

056942206

ABSTRACT:
A minute step measuring method comprises forming a laser spot on an object by condensing light from a laser light source, condensing light beams from the object on an end face of a double-mode waveguide, branching light propagating in the double-mode waveguide into two channel waveguides, detecting light beams emerging from the two channel waveguides, and measuring a minute step existing on the object, using a signal of a difference and a signal of a sum between two signals according to the two light beams detected, wherein measurement is conducted of a signal W.sub.a of the sum when the laser spot is located on one of two flat portions existing before and after the step, and of a signal W.sub.b of the sum when the laser spot is located on the other flat portion, and wherein the step is measured by correcting a difference between reflectivities of the two flat portions existing before and after the step in measuring the minute step, using the signals W.sub.a and W.sub.b.

REFERENCES:
patent: 4679941 (1987-07-01), Fujita
patent: 4770532 (1988-09-01), Ito
patent: 4900940 (1990-02-01), Nakamura
patent: 5087121 (1992-02-01), Kakuchi et al.
patent: 5315373 (1994-05-01), Kubo et al.
patent: 5581345 (1996-12-01), Oki et al.
Ooki, Hiroshi et al, "A novel type of laser scanning microscope: theoretical considerations", Optics Communications, vol. 85, No. 2, 3, Sep., 1991 pp. 177-182.
Ooki, Hiroshi et al, "A Novel Super Resolution Technique for High-Density Optical Data Storage Using Mode Interference in Channel Waveguides", Japanese Journal of Applied Physics, vol. 32, Part 1, No. 4, Apr. 1993, pp. 1668-1671.
Ooki, Hiroshi et al, "Laser Scanning Mode Interference Contrast Microscope and Its Application to Step Height Measurement", Japanese Journal of Applied Physics, vol. 32, Part 1, No. 11A, Nov., 1993, pp. 4998-5001.
Arimoto, Rieko et al, "Laser Scanning Mode Interference Contrast Microscope", Contemporary Optics & Optics Design, Oct. 21, 1994, pp. 40-45 (in Japanese with English translation).
Jungerman, R.L. et al., "Phase Sensitive Scanning Optical Microscope," Applied Physics Letters; vol. 45, No. 8, Oct. 1984; pp. 846-848.

Affiliated with

Also associated with

Rating

Minute step measuring method does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Minute step measuring method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Minute step measuring method will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-805898