Static states and dynamic behaviour of charges: observation and control by scanning probe microscopy

Abstract

This paper reviews charges that locally functionalize materials. Microscopic analyses and operation of charges using various scanning probe microscopy (SPM) techniques have revealed static, quasi-static/quasi-dynamic and dynamic charge behaviours. Charge-sensitive SPM has allowed for the visualization of the distribution of functionalized charges in electronic devices. When used as bit data in a memory system, the charges can be operated by SPM. The behaviour of quasi-static/quasi-dynamic charges is discussed here. In the data-writing process, spatially dispersive charges rather than a fast injection rate are introduced, but the technical problems can be solved by using nanostructures. Careful charge operations using SPM should realize a memory with a larger density than Tbit/inch(2). Dynamic charges have been introduced in physical analyses and chemical processes. Although the observable timescale is limited by the SPM system response time of the order of several seconds, dynamics such as photon-induced charge redistributions and probe-assisted chemical reactions are observed.

Multi-dimensional modelling of electrostatic force distance curve over dielectric surface: Influence of tip geometry and correlation with experiment

“…The use of Atomic Force Microscopy (AFM), 2 and techniques derived from it, such as Electrostatic Force Microscopy (EFM) or Kelvin Force Microscopy (KFM), provides a considerable advantage allowing the acquisition of new information down to nanoscale, such as the charge state of dielectric materials and their ability to store and dissipate charges. [3][4][5][6] They complement the available methods such as Laser Induced Modulation Method (LIMM) 7 or Pulsed Electro-Acoustic method (PEA) 8 for charge detection in dielectrics, which work at the micro-scale (spatial resolution close to few micrometres) and on relatively thick layers (several tens of lm). However, KFM and EFM exhibit some limitations for space charge measurement in terms of experimental setup [9][10][11] and modelling to extract quantitative results.…”

Interface properties in dielectrics: A cross-section analysis by atomic force microscopy

“…As far as dielectric materials are concerned, probing at nanoscale processes at interfaces between dielectric and electrode or in nanocomposite is crucial. Electrical modes derivate from Atomic Force Microscopy (AFM) such as Electric Force Microscopy (EFM) or Kelvin Probe Force Microscopy (KPFM) are ideal to probe free surface properties, a typical application being the charging of the surface using a biased AFM tip in 'writing mode', followed by probing electrostatic force or surface potential [5,6]. However, quantifying charges under these conditions is not straightforward, mainly because the behaviour of deposited charges is controlled both by surface and in-volume processes which are not included in electrostatic models [7].…”

Handling Geometric Features in Nanoscale Characterization of Charge Injection and Transport in thin Dielectric Films

“…Due to the nanomaterials attractiveness for electronic and energy applications [3] and the scaling down of the dimension of electronic devices [4], these mechanisms need to be characterized at local scale. To that end electrical modes, derived from Atomic Force Microscopy (AFM), as Kelvin Probe Force Microscopy (KPFM), Electrostatic Force Microscopy (EFM) and Conductive AFM (C-AFM) are more and more frequently used for characterization of thin dielectric layers [5][6][7]. However, the results provided by such techniques rely strongly on the tipplane geometry involved in either charge injection or measurement configurations.…”