Abstract
Nanoimprint lithography is emerging as a viable contender for fabrication of large-scale arrays of 5500 nm features. A fabrication process for the realization of thin nanoporous membranes using thermal nanoimprint lithography is presented. Suspended silicon nitride membranes were fabricated by low-pressure chemical vapor deposition (LPCVD) in conjunction with a potassium hydroxide-based bulk micromachining process. Nanoscale features were imprinted into a commercially available thermoplastic polymer resist using a prefabricated silicon mold. The pattern was reversed and transferred to a thin aluminum oxide layer by means of a novel two-stage lift-off technique. The patterned aluminum oxide was used as an etch mask in a CHF 3/He-based reactive ion etch process to transfer the pattern to silicon nitride. Highly directional etch profiles with near vertical sidewalls and excellent Si 3N 4/Al 2O 3etch selectivity were observed. One micrometer thick porous membranes with varying dimensions of 250x250 νm 2to 450x450 νm 2and a pore diameter of 400 nm have been engineered and evaluated. Results indicate that the membranes have consistent nanopore dimensions and precisely defined porosity, which makes them ideal as gas exchange interfaces in blood oxygenation systems as well as other applications such as dialysis. © 2012 IOP Publishing Ltd.
Recommended Citation
B. P. Nabar et al., "A Nanoporous Silicon Nitride Membrane Using A Two-step Lift-off Pattern Transfer With Thermal Nanoimprint Lithography," Journal of Micromechanics and Microengineering, vol. 22, no. 4, article no. 45012, IOP Publishing, Apr 2012.
The definitive version is available at https://doi.org/10.1088/0960-1317/22/4/045012
Department(s)
Mechanical and Aerospace Engineering
International Standard Serial Number (ISSN)
1361-6439; 0960-1317
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2023 IOP Publishing, All rights reserved.
Publication Date
01 Apr 2012
