DocumentCode
785007
Title
Automatic mask alignment without a microscope
Author
Kanjilal, Alok Kumar ; Narain, Ram ; Sharma, Rina ; Chitnis, Vijay T. ; Singh, Brahm Pal ; Liu, Jingnan ; Yamada, Jun ; Uchida, Yoshiyuki
Author_Institution
Stand. Div., Nat. Phys. Lab., New Delhi, India
Volume
44
Issue
3
fYear
1995
fDate
6/1/1995 12:00:00 AM
Firstpage
806
Lastpage
809
Abstract
A novel method for automatic mask alignment without using a microscope is reported. This method relies on the moire technique, and alignment marks are used in the form of gratings. The alignment is done in two steps with coarse and fine pitch gratings. The mask-to-wafer placement accuracy is estimated to be ±40 μm. The mask alignment accuracy with present experimental conditions is demonstrated to be better than ±50 nm. New alignment marks for the actual mask aligner are also proposed
Keywords
integrated circuit technology; masks; semiconductor technology; IC fabrication; automatic mask alignment; coarse pitch gratings; fine pitch gratings; gratings; mask-to-wafer placement accuracy; moire technique; Costs; Energy consumption; Equations; Error correction; Gratings; Instruments; Laser beams; Microcomputers; Microscopy; Signal generators;
fLanguage
English
Journal_Title
Instrumentation and Measurement, IEEE Transactions on
Publisher
ieee
ISSN
0018-9456
Type
jour
DOI
10.1109/19.387338
Filename
387338
Link To Document