Interferometer system for measuring a height of wafer stage

Details Interferometer system for measuring a height of wafer stage Interferometer system for measuring a height of wafer stage

2005-12-27

2005-12-27

Nguyen, Henry Hung (Department: 2851)

Photocopying

Projection printing and copying cameras

Step and repeat

C355S055000, C355S067000

Reexamination Certificate

active

06980279

ABSTRACT:
An interferometer system for measuring the height of a wafer stage utilizes four beams emitted horizontally parallel to one another and in a same direction from an interferometer and obtained by splitting a single laser beam. Two of these four beams are reference beams and the other two are measurement beams. The reference beams are mutually on opposite sides of the center point of the stage, equally separated therefrom horizontally, and are reflected back from the front surface of the stage. The wafer stage is provided with two mirrors inclined at 45° extending horizontally so as to reflect the measurement beams vertically upward. These two inclined mirrors are disposed in lower front and upper back parts of the stage and the two measurement beams are aimed and reflected at target points on them, diametrically opposite with reference to the center point of the stage. The height of the wafer stage is calculated from measured path lengths of these four beams, independent of small displacements to first degree in other linear and rotational degrees of freedom of motion of the wafer stage.

REFERENCES:
patent: 4999669 (1991-03-01), Sakamoto et al.
patent: 5416562 (1995-05-01), Ota et al.
patent: 5917580 (1999-06-01), Ebinuma et al.
patent: 6020964 (2000-02-01), Loopstra et al.
patent: 6122036 (2000-09-01), Yamasaki et al.
patent: 6208407 (2001-03-01), Loopstra
patent: 6285457 (2001-09-01), Ukaji
patent: 0 077 878 (1983-04-01), None
patent: 0 793 073 (1997-03-01), None
Patent Abstracts of Japan, Publication No. 61-196532,Exposure Device,Tsukamoto Izumi, filed Feb. 26, 1985.
Patent Abstracts of Japan, Publication No. 57-183031,Method For Wafer Exposure And Device Thereof,Iwai Hiroshi, filed May 6, 1981.

Affiliated with

Also associated with

Rating

Interferometer system for measuring a height of wafer stage does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Interferometer system for measuring a height of wafer stage, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Interferometer system for measuring a height of wafer stage will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3499617