Atomic force microscopy deposition

Several striking examples demonstrating the atomically precise control exercised by the STM have been reported. A "quantum corral" of Fe atoms has been fabricated by placing 48 atoms in a circle on a flat Cu(lll) surface at 4K (Fig. 4) (94). Both STM (under ultrahigh vacuum) and atomic force microscopy (AFM, under ambient conditions) have been employed to fabricate nanoscale magnetic mounds of Fe, Co, Ni, and CoCr on metal and insulator substrates (95). The AFM has also been used to deposit organic material, such as octadecanethiol onto the surface of mica (96). New appHcations of this type of nanofabrication ate being reported at an ever-faster rate (97—99). 

In this section, the thin-film formation of OPVs is investigated with optical microscopy and X-ray diffraction (XRD). In the case of Oocl-OPV5, this has been supplemented with surface imaging by means of atomic force microscopy. It is demonstrated how an annealing treatment of the films alter deposition influences... 

The lithium morphology at the beginning of the deposition was measured by in-situ atomic force microscopy (AFM) [42], When lithium was deposited at 0.6 C cm2, small particles 200-1000 nm in size were deposited on the thin lines and grain boundaries in LiC104-PC. Lump-like growth was observed in LiAsF6-PC along the line. 

The formation of SiGe nanocrystals on SiOaat ITorr, 10s was clearly observed by atomic force microscopy (inset of Fig. 2(a)). Fig. 2 shows the mean diameter and the surface density of the nanocrystals formed as a function of deposition time and deposition pressure. The mean diameter of the nanocrystals initially increases then decreases with deposition time whereas the nanocrystal density follows the opposite trend. It is evident that different mechanisms dominate in shorter and longer deposition times. According to Kim et al, the formation of SiGe on a dielectric surface preferentially occurs on nucleated Si through impingement [4]. 

I believe, it is fair to state that scanning tunneling microscopy and related techniques such as atomic force microscopy have a tremendeous potential in metal deposition studies. The inherent nature of the deposition process which is strongly influenced by the defect structure of the substrate, providing nucleation centers, requires imaging in real space for a detailed picture of the initial stages. This is possible with an STM, the atomic resolution being an extra bonus which helps to understand these processes on... 

Resch, R. Prohaska, T. Friedbacher, G. Grasserbauer, M. Kanniainen, T. Lindroos, S. Leskela, M. Niinisto, L. Broekaert, J. A. C. 1998. In-situ investigation of ZnS deposition on mica by successive ionic layer adsorption and reaction method as studied with atomic force microscopy. Fresenius J. Anal. Chem. 353 772-777. 

An ordered antibody array has also been assembled on the solid surface by a combination of Langmuir Blodgett (LB) film method and self-assembling method. An ordered monolayer of protein A is deposited on the solid surface by LB method, which is followed by self-assembling of antibody. Individual antigen molecules which are complexed with the antibody array have been quantitated selectively by atomic force microscopy (AFM). 

The technique of atomic force microscopy (AFM) has permitted the direct observation of single polysilane molecules. Poly[//-decyl-(high molecular weight (4/w = 5,330,000 and Mn = 4,110,000), PSS, helicity, and rigid rod-like structure due to the aliphatic chiral side chains, was deposited from a very dilute (10-10 Si-unit) dm-3] toluene solution onto a (hydrophobic) atomically flat (atomic layer steps only present) sapphire (1012) surface. After drying the surface for a few minutes in a vacuum, AFM images were taken at room temperature in air in the non-contact mode.204,253 An example is shown in Figure 22, in which the polymer chain is evident as a yellow trace. 

Spain, E. CAREER Atomic Force Microscopy Studies of Transition Metal Chalcogenide Deposition using Translationally Hot Atoms, 1997 (NSF CHE 9703345). 

Fig. 3 Pentacene grown by supersonic molecular beam deposition to form near monolayer p-type FETs with thiolate monolayer modified Au source and drain contacts (a) visualized by atomic force microscopy and with well-behaved (b) /d-Eds and (c) -Eg characteristics...

Vandamme N, Snauwaert J, Janssens E, Vandeweert E, Lievens P, Van Haesendonck C (2004) Visualization of gold clusters deposited on a dithiol self-assembled monolayer by tapping mode atomic force microscopy. Surf Sci 558 57-64... 

Fig.5 Atomic Force Microscopy (AFM) picture of platinum deposition (CVD) on activated HOPG...

Immersion of fatty acid films into solutions of metal ions, as already indicated, results in an intercalation of the metal ions into the planes formed by the carboxylate head groups of the fatty acids. This can be accomplished in M-FA films where the FA has been regenerated by exposure to H2S [Eq. (4)] or in FA films deposited without any metal ions. Subsequent exposure of the films to H2S has been shown to result in the formation of the metal sulfide. This intercalation/sulfidation (i/s) cycle can be repeated several times to increase the concentration of the metal sulfide in the film. This process has been investigated forCdS (34,39,42,43), PbS (39,43,44), ZnS (39,43), and HgS (45) produced in M-FA films, using Fourier-transform infrared (FTIR) and UV/visible spectroscopies, QCM gravimetry, and atomic force microscopy (AFM). 

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