We studied the erosion and feature stability of fused silica patterns under different template cleaning conditions. The conventional SPM cleaning is compared with an advanced non-acid process. Spectroscopic ellipsometry optical critical dimension (SE-OCD) measurements were used to characterize the changes in pattern profile with good sensitivity. This study confirmed the erosion of the silica patterns in the traditional acid-based SPM cleaning mixture (H2SO4+H2O2) at a rate of ~0.1nm per cleaning cycle. The advanced non-acid clean process however only showed CD shift of ~0.01nm per clean. Contamination removal & pattern integrity of sensitive 20nm features under MegaSonic assisted cleaning is also demonstrated.

Date Published: 21 March 2012
PDF: 6 pages
Proc. SPIE 8323, Alternative Lithographic Technologies IV, 832317 (21 March 2012); doi: 10.1117/12.916294

Published in SPIE Proceedings Vol. 8323:
Alternative Lithographic Technologies IV
William M. Tong, Editor(s)