Scanning Probe Microscopy HT12 1

Manipulation with Scanning Force Microscopy

•  Manipulation of nanoparticles and nanostructures •  True atomic manipulation •  Patterning with SFM

Scanning Probe Microscopy HT10 2

Traditional contact-mode manipulation by SFM

Example from IBM: Assembly of a carbon nanotube FET

1.  DFM imaging of the nanostructures 2.  Manipulation by pushing along an (x,y) line

Requires suitable substrates, having a weak interaction with the nanoparticle/nanostructure

Example: manipulation of carbon nanotubes (Sofie Yngman, SPM course HT09)

Scanning Probe Microscopy HT10 3

Veeco Innova SFM

Scanning Probe Microscopy HT10 4

SFM contact mode problems…

Appl. Phys. Lett 66, 3295 (1995)

Scanning Probe Microscopy HT10 5

Nanoparticle manipulation

Nanoparticle manipulation

Scanning Probe Microscopy HT12 6

From Kim et al., Nanotechnology 22, 115301 (2011) Au nanoparticles, 15 nm diameter, on quartz substrate

Tip asymmetry effects

Before

After

Nanoparticle pick-up and drop-off

Scanning Probe Microscopy HT10 7

From Kim et al., Nanotechnology 22, 115301 (2011) Au nanoparticles, 15 nm diameter, on quartz substrate

Some nanoparticle get picked up on the tip, are dropped off by a quick release operation

Manipulation of graphene

Scanning Probe Microscopy HT10 8

From Eilers and Rabe, Phys. Stat. Solidi B 246, 2527 (2009)

SFM imaging and manipulation of biological structures

Scanning Probe Microscopy HT10 9

DNA extraction of human chromosome 2

Single atom manipulation

Scanning Probe Microscopy HT10 10

Moving an adsorbate on a Ge(111)c(2x8) surface N.Oyabu et al. ,Nanotechnology 16 S112 (2005) (Morita group, Osaka, Japan)

Critical parameters: •  Tip-adsorbate interaction •  adsorbate-substrate interaction, adsorption sites, surface potential •  Tip scan procedure

Atom manipulation: examples

Scanning Probe Microscopy HT10 11

Sn atoms on Ge(111): move Sn by Sn-Ge adatom substitution. Y. Sugimoto et al., Nature Mat. 4, 156 (2005)

Measuring the force to move an atom or molecule: Co atoms and CO molecules on metal surfaces

Ternes et al., Science 319, 1066 (2008)

Scanning Probe Microscopy HT10 12

Scanning Probe nano-Lithography Organic nanostructures

•  Local modification induced by probe on continuous organic film (mechanical, electrical or optical interaction)

•  local chemical or topographical modification of a substrate acting as template for growth of molecular assemblies

•  local deposition of molecules or clusters from the probe to the substrate

Lithography tools standard part of SFM control software

Scanning Probe Microscopy HT10 13

Figure 2.5. (a) A schematic representation of the STM patterning of SAMs. (i) Normal STM imaging of the SAM with tip bias Vb; (ii) Removal of SAM by applying a pulse Vp to the gold substrate; (iii) The same as (ii) in solution of conjugated oligomers; (iv) insertion of conjugated oligomers in the patterened sites. (b) STM image of dodecanthiol and conjugated oligomeric patterned SAMs. (i) The STM image after consecutive pulsing at three different locations indicating insertion of molecules (two peaks) and one pit without insertion. (ii) The same region imaged a few minutes later showing adsorption into the remaining pit. (iii) A programmed pattern consisting of circles tracing out a rectangle. (iv) The resulting image of the patterned dodecanthiol SAM after chemisorption of the conjugated oligomers showing the produced rectangular frame. (From Ref. 13 by permission of American Institute of Physics.)

STM patterning in self-assembled monolayers

Scanning Probe Microscopy HT10 14

(a) Schematic representation of dip-pen nanolithography (DPN). A water meniscus formed between SFM tip and the gold substrate directs the thiol molecules onto the substrate. The size of the water meniscus is controlled by the relative humidity that in turn affects the overall resolution of DPN. (b) LFM image of an array of octadecanethiol dots on a gold surface generated by holding an ODT-coated SFM tip in contact with the surface for ca. 20 s. (c) LFM image of a molecule-based grid consisting of eight lines 100 nm in width and 2 µm in length.

Dip-pen nanolithography