ORCID
https://orcid.org/0000-0002-5539-9595
Abstract
Charge or spin-qubits can be realized by using gate-defined quantum dots (QDs) in semiconductors in a similar fashion to the processes used in CMOS for conventional field-effect transistors or more recent fin FET technology. However, to realize a larger number of gate-defined qubits, multiples of gates with ultimately high resolution and fidelity are required. Electron beam lithography (EBL) offers flexible and tunable patterning of gate-defined spin-qubit devices for studying important quantum phenomena. While such devices are commonly realized by a positive resist process using metal lift-off, there are several clear limitations related to the resolution and the fidelity of patterning. Herein, we report a systematic study of an alternative TiN multigate definition approach based on the highest resolution hydrogen silsesquioxane (HSQ) EBL resist and all associated processing modes. The TiN gate arrays formed show excellent fidelity, dimensions down to 15 nm, various densities, and complexities. The processing modes developed were used to demonstrate applicability of this approach to forming multigate architectures for two types of spin-qubit devices prototypic to (i) NW/fin-type FETs and (ii) planar quantum well-type devices, both utilizing epi-grown Ge device layers on Si, where GeSn or Ge is the host material for the QDs.
Disciplines
Physics
DOI
10.1021/acsaelm.4c01499
Full Publication Date
1-2025
Publisher
American Chemical Society (ACS)
Funder Name 1
European Commision
Award Number 1
871130
Funder Name 2
European Commission
Award Number 2
101066761
Funder Name 3
Research Ireland
Award Number 3
21/FFP-A/9257
Funder Name 4
Engineering and Physical Sciences Research Council
Award Number 4
23/ 457 EPSRC/3887).
Funder Name 5
T-Star Centre
Award Number 5
113-2634-F-A49-008
Resource Type
journal article
Resource Version
http://purl.org/coar/version/c_ab4af688f83e57aa
Access Rights
open access
Open Access Route
Green Open Access
License Condition
This work is licensed under a Creative Commons Attribution 4.0 International License.
Deposit Statement
This document is the Accepted Manuscript version of a Published Article that appeared in final form in ACS Applied Electronic Materials, Copyright © 2025 American Chemical Society]. To access the final published article, see ACS Articles on Request.
Published version: https://doi.org/10.1021/acsaelm.4c01499
Recommended Citation
Sinan Bugu, Sheshank Biradar, Alan Blake, CheeWee Liu, Maksym Myronov, Ray Duffy, Giorgos Fagas, and Nikolay Petkov ACS Applied Electronic Materials. Accepted Manuscript. Published online January 15, 2026. https://sword.mtu.ie/dptphysciart/123/
Publication Details
ACS Applied Electronic Materials