Title :
Overlay stability improvement at metal layers using combination of feedforward and feedback run-to-run control
Author :
Higashi, T. ; Murakami, Kazuki ; Oikawa, A.
Author_Institution :
FASL, LLC, Fukushima, Japan
fDate :
30 Sept.-2 Oct. 2003
Abstract :
We had to rework many lots at metal layers for the overlay instability. We found that the wafer rotation in overlay components related at the number of wafers from the change of CMP PAD at Tungsten CMP process and then improved overlay stability by using the feedforward run-to-run control as utilizing above correlation and confirmed the advantage for using the combination of feedforward and feedback run-to-run control.
Keywords :
chemical mechanical polishing; feedforward; integrated circuit manufacture; process control; tungsten; W; metal layers; overlay instability; overlay stability; run-run control; tungsten CMP; wafer rotation; Atherosclerosis; Controllability; Feedback control; Position measurement; Semiconductor device modeling; Stability; Tungsten;
Conference_Titel :
Semiconductor Manufacturing, 2003 IEEE International Symposium on
Print_ISBN :
0-7803-7894-6
DOI :
10.1109/ISSM.2003.1243242
