An alignment system for align first and second objects using ali

Details An alignment system for align first and second objects using ali An alignment system for align first and second objects using ali

1989-09-28

1991-07-02

Nelms, David C.

Radiant energy

Photocells; circuits and apparatus

Photocell controls its own optical systems

250557, 356401, G01N 2186

Patent

active

050287974

ABSTRACT:
An alignment system for aligning a mask and a wafer into a predetermined positional relationship uses alignment marks provided on the mask and the water. In this system, light from a light source is directed to the alignment marks of the mask and the wafer and, then, the light from these alignment marks is detected by an accumulation type photoelectric converting device, for alignment of the mask and the wafer. The accumulation time of the photoelectric converting device is controlled to be sufficiently longer than or to be equal to a multiple, by an integral number, of the period of relative and natural vibration of the mask and the wafer. This makes it possible to reduce the effect of the relative vibration of the mask and the wafer upon the alignment result and, therefore, makes it possible to enhance the alignment precision.

REFERENCES:
patent: 4398824 (1983-08-01), Feldman et al.
patent: 4634876 (1987-01-01), Ayata
patent: 4725737 (1988-02-01), Nakata et al.
patent: 4815854 (1989-03-01), Tanaka et al.
patent: 4818879 (1989-04-01), Kajikawa
patent: 4838693 (1989-06-01), Uchida et al.
patent: 4880308 (1989-11-01), Shirasu

Affiliated with

Also associated with

Rating

An alignment system for align first and second objects using ali does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with An alignment system for align first and second objects using ali, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and An alignment system for align first and second objects using ali will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1248931