Method of checking alignment accuracy in photolithography

Details Method of checking alignment accuracy in photolithography Method of checking alignment accuracy in photolithography

1996-03-28

1997-09-30

Chaudhari, Chandra

Fishing, trapping, and vermin destroying

437229, 437924, H01L 2166

Patent

active

056725205

ABSTRACT:
In a photolithographic step in the fabrication of semiconductor integrated circuits, alignment of the photomask pattern with two patterns defined on the wafer in two previous steps is checked simultaneously. Each of the two patterns on the wafer is provided with an alignment check pattern consisting of a plurality of rectangular pattern elements arranged parallel to each other in a row at a first constant pitch. The pattern elements of one check pattern are respectively opposite to the pattern elements of the other check pattern. On the photomask there is an alignment check pattern consisting of a plurality of rectangular and relatively long pattern elements arranged parallel to each other in a row at a second constant pitch. In the composite layout of the three alignment check patterns, each pattern element of the check pattern on the photomask partly ovelaps a pattern element of each of the two check patterns on the wafer. Alignment accuracy is checked by examining which pattern element of the check pattern on the photomask is in accurate alignment with a pattern element of each check pattern on the wafer. Alignment of the photomask pattern with more than two patterns on the wafer can be checked in the same manner.

REFERENCES:
patent: 5376589 (1994-12-01), Thienel
patent: 5405810 (1995-04-01), Mizuno et al.
patent: 5407763 (1995-04-01), Pai
patent: 5545593 (1996-08-01), Watkins et al.

Affiliated with

Also associated with

Rating

Method of checking alignment accuracy in photolithography does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of checking alignment accuracy in photolithography, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of checking alignment accuracy in photolithography will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2256214