DocumentCode :
787432
Title :
Front-to-backside alignment using resist-patterned etch control and one etching step
Author :
Kim, Eun Sok ; Muller, Richard S. ; Hijab, Raif S.
Author_Institution :
Dept. of Electr. Eng., Univ. of Hawaii at Manoa, Honolulu, HI, USA
Volume :
1
Issue :
2
fYear :
1992
fDate :
6/1/1992 12:00:00 AM
Firstpage :
95
Lastpage :
99
Abstract :
A processing technique that aligns features on the front side of a wafer to those on its backside has been developed for bulk micromachining. A 30 μm-square and 1.6 μm-thick diaphragm serves as an alignment pattern. At the same time that the alignment diaphragm is made, much thicker, large-area diaphragms can be partially etched using `mesh´ masking patterns in these areas. The mesh-masking technique exploits the etch-rate differences between (100) and (111) planes to control the depths reached by etch pits in selected areas. The large partially etched diaphragms (2 to 3 mm2, roughly 100 μm thick) are sufficiently robust to survive subsequent IC-processing steps in a silicon-foundry environment. The thin alignment diaphragm can be processed through these steps because of its very small area. The partially etched diaphragms can be reduced to useful thicknesses in a final etch step after the circuits have been fabricated
Keywords :
etching; semiconductor technology; 1.6 micron; 100 micron; 30 micron; Si wafers; alignment diaphragm; alignment pattern; bulk micromachining; etch pits; etch-rate differences; features alignment; front-to-backside alignment; mesh-masking technique; one etching step; partially etched diaphragms; resist-patterned etch control; Anisotropic magnetoresistance; Circuits; Crystals; Etching; Fabrication; Fixtures; Microchannel; Micromachining; Robustness; Silicon;
fLanguage :
English
Journal_Title :
Microelectromechanical Systems, Journal of
Publisher :
ieee
ISSN :
1057-7157
Type :
jour
DOI :
10.1109/84.157364
Filename :
157364
Link To Document :
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