In operando SEM for the accelerated exploration of nanomaterials and their scalable device integration
type: CreativeWork
description: The development of scalable manufacturing and device integration strategies are critical bottlenecks that currently hinder the commercial application of low-dimensional nanomaterials. Bottom-up approaches such as chemical vapour deposition are promising for meeting such needs. However, the reliable production of high-quality electronics-grade material remains non-trivial, owing to the large parameter spaces and complex reaction mechanisms underlying such processes. Traditional ex situ microscopies, which rely on post-mortem characterisation of nanomaterials, offer limited insight. Therefore, there is a need to establish a more suitable in situ microscopy platform that permits (1) operando monitoring of reactions and (2) rapid screening of different process conditions (temperatures and pressures). Herein, the development and implementation of an environmental scanning electron microscope (ESEM) that is suitable for operando imaging of nanoscale dynamics at high temperatures and pressures of reactive gases is outlined. Key to the microscope's operation is a gas injection nozzle that allows high gas pressures to be locally generated at targeted locations on a substrate. Since commercial gas injection systems are incompatible with the requisite high temperatures, this thesis first reports on the fabrication of custom nozzles based on tapered quartz capillaries with opening diameters of ~µms. The spatial confinement of gas fluxes is studied through test particle Monte Carlo simulations and verified experimentally through the localised thermal oxidation of nickel films. The ESEM is subsequently applied to study two low-dimensional nanoscale systems for which manufacturing and/or device integration challenges remain: 1D silicon nanowires and 2D tungsten disulfide. For the former, in situ vacuum annealing is performed to visualise the growth dynamics of nickel-silicide phases into silicon nanowires (`silicidation'), a candidate method for establishing high-quality electrica…
abstract: The development of scalable manufacturing and device integration strategies are critical bottlenecks that currently hinder the commercial application of low-dimensional nanomaterials. Bottom-up approaches such as chemical vapour deposition are promising for meeting such needs. However, the reliable production of high-quality electronics-grade material remains non-trivial, owing to the large parameter spaces and complex reaction mechanisms underlying such processes. Traditional ex situ microscopies, which rely on post-mortem characterisation of nanomaterials, offer limited insight. Therefore, there is a need to establish a more suitable in situ microscopy platform that permits (1) operando monitoring of reactions and (2) rapid screening of different process conditions (temperatures and pressures). Herein, the development and implementation of an environmental scanning electron microscope (ESEM) that is suitable for operando imaging of nanoscale dynamics at high temperatures and pressures of reactive gases is outlined. Key to the microscope's operation is a gas injection nozzle that allows high gas pressures to be locally generated at targeted locations on a substrate. Since commercial gas injection systems are incompatible with the requisite high temperatures, this thesis first reports on the fabrication of custom nozzles based on tapered quartz capillaries with opening diameters of ~µms. The spatial confinement of gas fluxes is studied through test particle Monte Carlo simulations and verified experimentally through the localised thermal oxidation of nickel films. The ESEM is subsequently applied to study two low-dimensional nanoscale systems for which manufacturing and/or device integration challenges remain: 1D silicon nanowires and 2D tungsten disulfide. For the former, in situ vacuum annealing is performed to visualise the growth dynamics of nickel-silicide phases into silicon nanowires (`silicidation'), a candidate method for establishing high-quality electrica…
author: Mizuta, Ryo
language: eng
keywords: low-dimensional nanomaterials, scanning electron microscopy
license: https://www.rioxx.net/licenses/all-rights-reserved/
date published: 2021-06-08
date modified: 2026-07-22T22:24:07Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.80343