title: Electron beam lithography with feedback using in situ self-developed resist.
abstract: Due to the lack of feedback, conventional electron beam lithography (EBL) is a 'blind' open-loop process where the exposed pattern is examined only after ex situ resist development, which is too late for any improvement. Here, we report that self-developing nitrocellulose resist, for which the pattern shows up right after exposure without ex situ development, can be used as in situ feedback on the e-beam distortion and enlargement. We first exposed identical test pattern in nitrocellulose at different locations within the writing field; then, we examined in situ at high magnification the exposed patterns and adjusted the beam (notably working distance) accordingly. The process was repeated until we achieved a relatively uniform shape/size distribution of the exposed pattern across the entire writing field. Once the beam was optimized using nitrocellulose resist, under the same optimal condition, we exposed the common resist PMMA. We achieved approximately 80-nm resolution across the entire writing field of 1 mm × 1 mm, as compared to 210 nm without the beam optimization process.
authors.affiliation: Department of Electrical and Computer Engineering, Waterloo Institute for Nanotechnology (WIN), University of Waterloo, 200 University Ave. West, Waterloo, ON N2L 3G1, Canada.
authors.forename: Ripon Kumar
authors.initials: RK
authors.lastname: Dey
authors.affiliation: Department of Electrical and Computer Engineering, Waterloo Institute for Nanotechnology (WIN), University of Waterloo, 200 University Ave. West, Waterloo, ON N2L 3G1, Canada.
authors.forename: Bo
authors.initials: B
authors.lastname: Cui
keywords: Electron beam lithography; Nitrocellulose; Self-developing resist
references.citation: Nano Lett. 2005 Jun;5(6):1157-60
references.pmid: 15943460
references.citation: Nano Lett. 2012 Feb 8;12(2):1018-21
references.pmid: 22229744
references.citation: Nanotechnology. 2012 May 11;23(18):185302
references.pmid: 22498712
references.citation: Adv Mater. 2012 Dec 4;24(46):6136-40
references.pmid: 22965485