Exploring the Surface Oxidation and Environmental Instability of 2H‐/1T’‐MoTe₂ Using Field Emission‐Based Scanning Probe Lithography

Abstract

An unconventional approach for the resistless nanopatterning 2H‐ and 1T’‐MoTe2 by means of scanning probe lithography is presented. A Fowler‐Nordheim tunneling current of low energetic electrons (E = 30‐60 eV) emitted from the tip of an atomic force microscopy (AFM) cantilever is utilized to induce a nanoscale oxidation on a MoTe2 nanosheet surface under ambient conditions. Due to the water solubility of the generated oxide, a direct pattern transfer into the MoTe2 surface can be achieved by a simple immersion of the sample in deionized water. The tip‐grown oxide was characterized using Auger electron and Raman spectroscopy, revealing it consists of amorphous MoO3/MoOx as well as TeO2/TeOx. With the presented technology in combination with subsequent AFM imaging it was possible to demonstrate a strong anisotropic sensitivity of 1T’‐/(Td)‐MoTe2 to aqueous environments. We finally used the discussed approach to structure a nanoribbon field effect transistor out of a few‐layer 2H‐MoTe2 nanosheet.This article is protected by copyright. All rights reserved

Investigations on tip-based large area nanofabrication and nanometrology using a planar nanopositioning machine (NFM-100)

“…Experience and knowledge regarding the fabrication of the used active microcantilevers as well as the use of special resist types or additionally resistless nanopatterning through nanoscale oxidation could be gained to further improve the process and ultimately fabricate structures in the sub-5 nm range [14,[16][17][18][19]. The fact that the SPL systems can also be used as an ordinary AFM system means that the result can be inspected directly after the fabrication step.…”

“…The possibility of measuring the sample surface before and after the structuring step and the requirement to find the fabricated structures again also allows alignment with existing structures at the same time. Moreover, the tip-based SPM lithography with active is capable to be employed in diverse modes like STM Mode at UHV on hydrogen in the voltage range of 0.3-3 V [18], or as local anodic oxidation of 2D-Materials in the voltage range of 4-25 V [19,20] and FN FE lithography on resist in the voltage range of 35-110 V [21].…”

Anisotropic Effects in Local Anodic Oxidation Nanolithography on Silicon Surfaces: Insights from ReaxFF Molecular Dynamics

“…6 Compared with other nanomanufacturing techniques, such as optical lithography, electron beam lithography, and nanoimprint lithography, LAO has advantages in atomiclevel resolution, direct surface patterning ability, and low instrument cost. 7,8 It has found broad applications in the manufacturing of quantum devices, 9 synaptic devices, 10 metasurfaces, 11 memristors, 12 transistors, 13 Schottky junctions, 14 gas sensors, 15 photoluminescence enhancement, 16 and optical devices. 17 Despite the promise of this approach, several challenges impede its further development and industrial implementations.…”

“…Local anodic oxidation (LAO) nanolithography is a promising nanofabrication technique to accommodate fast and flexible prototyping of functional nanostructures. − It relies on the controlled oxidation of conductive surfaces in anodic solutions, which is induced by an enhanced local electric field created by applying a bias between the nanoscale probes/electrodes and substrate . Compared with other nanomanufacturing techniques, such as optical lithography, electron beam lithography, and nanoimprint lithography, LAO has advantages in atomic-level resolution, direct surface patterning ability, and low instrument cost. , It has found broad applications in the manufacturing of quantum devices, synaptic devices, metasurfaces, memristors, transistors, Schottky junctions, gas sensors, photoluminescence enhancement, and optical devices …”