Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published January 22, 2021 | public
Journal Article

Nanoscale Patterning of Zinc Oxide from Zinc Acetate Using Electron Beam Lithography for the Preparation of Hard Lithographic Masks

Abstract

An approach is presented for nanoscale patterning of zinc oxide (ZnO) using electron beam (e-beam) lithography for future nanoelectronic devices and for hard lithographic masks. Zinc acetate (Zn₄O(CH₃COO)₆) films were exposed using a scanning electron microscope (SEM), causing decomposition of Zn₄O(CH₃COO)₆ into ZnO. The exposure of Zn₄O(CH₃COO)₆ using an electron beam was successfully utilized to fabricate 12 nm zinc oxide lines with a 40 nm pitch on silicon. The chemical composition of zinc acetate (film before e-beam exposure) and ZnO (film after e-beam exposure) was investigated using X-ray spectroscopy (XPS). The Zn 2p shift peaks and the O 1s contribution confirmed the decomposition of zinc acetate into zinc oxide after exposure. To confirm this transformation into ZnO, the optical band gap of the film was determined and the electrical resistivity of the film was measured. The electrical resistivity and the optical band gap results revealed the transformation into a ZnO film with a band gap of 3.31 eV at room temperature and an electrical resistivity of 91.5 Ω cm. The ZnO patterns were used as a hard mask to etch silicon, and it showed a good selectivity of 27:1 for dry etching silicon using SF₆ and C₄F₈.

Additional Information

© 2020 American Chemical Society. Received 14 October 2020. Accepted 3 December 2020. Published online 16 December 2020. This research was supported by the European Research Council through ERC-2017-ADG-786734 awarded to REPW and supporting A.C. The posts occupied by G.A.T. and S.M.L. are supported by EPSRC(UK) (EP/R023158/1 and EP/R011079/1). EPSRC(UK) provides the studentship that supports H.R.A. Innovate UK supports the contribution of C.A.M. and P.T. We also thank BP-ICAM and the EPSRC Centre for Doctoral Training "Materials for Demanding Environments" for a studentship for A.K. We are also grateful to the University of Manchester for support. The authors declare no competing financial interest.

Additional details

Created:
August 22, 2023
Modified:
October 23, 2023