Rosamond, MC, Batley, J, Burnell, G et al. (2 more authors) (2015) High contrast 3D proximity correction for electron-beam lithography: An enabling technique for the fabrication of suspended masks for complete device fabrication within an UHV environment. Microelectronic Engineering, 143. 5 - 10. ISSN 0167-9317
Abstract
Abstract Many devices, such as lateral spin valves, depend critically on the quality of interfaces formed between different materials, and hence require the entire device to be fabricated within an ultra-high vacuum environment. This is possible using angled deposition with a suspended mask such that, by depositing from specific angles, different patterns form on the substrate beneath. We use a bi-layer of MMA(8.5)MAA copolymer and PMMA patterned by electron-beam lithography (EBL) to form such a mask. It is necessary, though, to perform proximity effect correction (PEC) in EBL to achieve the correct spatial distribution of electrons, and hence produce the desired pattern in the developed resist. For bi-layer processes this is a three-dimensional (3D) correction since we must optimise for two different critical doses (one for the copolymer, the other for the PMMA) at defined 3D positions within the resist stack. We perform this 3D correction using the commercial software BEAMER produced by GenISys GmbH. We show that by applying manual shape segregation and modulation to the exposure pattern, prior to the “3D-PEC” algorithm, it is possible to achieve much higher contrasts in the spatial distribution of absorbed energy and hence significantly increase the processing window, and yield in the fabrication of suspended masks.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2015 Elsevier B.V. All rights reserved. NOTICE: this is the author’s version of a work that was accepted for publication in Microelectronic Engineering. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Microelectronic Engineering, 143, (2015) DOI 1016/j.mee.2015.01.020 |
Keywords: | E-beam lithography; Suspended shadow mask; Angled evaporation; 3D-PEC; GenISys BEAMER; Lateral spin valve |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Electronic & Electrical Engineering (Leeds) > Institute of Communication & Power Networks (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 18 Mar 2015 09:33 |
Last Modified: | 15 Jan 2018 18:55 |
Published Version: | http://dx.doi.org/10.1016/j.mee.2015.01.020 |
Status: | Published |
Publisher: | Elsevier |
Refereed: | Yes |
Identification Number: | 10.1016/j.mee.2015.01.020 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:83485 |