Nanoscale patterning of a self-assembled monolayer by modification of the molecule–substrate bond

• Cai Shen and
• Manfred Buck

Beilstein J. Nanotechnol. 2014, 5, 258–267, doi:10.3762/bjnano.5.28

• ] this is expected since the growth rate scales with the flux of Cu ions integrated across the defect area. Interestingly, a minimum size of the defect was observed to be required. For defects smaller than 5 nm, it is difficult to trigger the UPD, or even if the UPD starts, the UPD can easily be blocked

En route to controlled catalytic CVD synthesis of densely packed and vertically aligned nitrogen-doped carbon nanotube arrays

• Slawomir Boncel,
• Sebastian W. Pattinson,
• Valérie Geiser,
• Milo S. P. Shaffer and
• Krzysztof K. K. Koziol

Beilstein J. Nanotechnol. 2014, 5, 219–233, doi:10.3762/bjnano.5.24

• key parameters, i.e., growth temperature (660, 760 and 860 °C), composition of the feedstock and time of growth, on morphology and properties of N-CNTs. The presence of nitrogen species in the hot zone of the quartz reactor decreased the growth rate of N-CNTs down to about one twentieth compared to

• the growth rate of multi-wall CNTs (MWCNTs). As revealed by electron microscopy studies (SEM, TEM), the individual N-CNTs (half as thick as MWCNTs) grown under the optimal conditions were characterized by a superior straightness of the outer walls, which translated into a high alignment of dense

• . Optimising the conditions. In order to establish conditions for a high growth rate of N-CNTs and the highest achievable alignment as well as a high density of the N-CNTs arrays, temperature and composition of the feedstock were scanned as variable parameters (Table 2). The parameters used were set

3D-nanoarchitectured Pd/Ni catalysts prepared by atomic layer deposition for the electrooxidation of formic acid

• Loïc Assaud,
• Evans Monyoncho,
• Kristina Pitzschel,
• Anis Allagui,
• Matthieu Petit,
• Margrit Hanbücken,
• Elena A. Baranova and
• Lionel Santinacci

Beilstein J. Nanotechnol. 2014, 5, 162–172, doi:10.3762/bjnano.5.16

• to grow metallic clusters or it is applied to protect those metallic clusters with an ultrathin metal oxide layer (see, e.g., the reviews [18][19][20]). This deposition method is particularly interesting for electrocatalysis because it allows an accurate control of both growth rate and composition of

• regular cyclic variation of the mass vs the number of ALD cycles is observed with an overall linear evolution, which is typical for an ALD process with constant growth rate. An enlarged view of one cycle presented in Figure 2b shows in detail the process during the four successive steps of the NiO ALD

• shown in Figure 8a. Two growth regimes are identified in the curve: before and after 50 cycles. At first, the growth rate of Pd is low and non-linear. It progressively increases and reaches an almost linear growth after 50 ALD cycles. Such behavior has already been observed [36][39]. The initial low

Quantum size effects in TiO₂ thin films grown by atomic layer deposition

• Massimo Tallarida,
• Chittaranjan Das and
• Dieter Schmeisser

Beilstein J. Nanotechnol. 2014, 5, 77–82, doi:10.3762/bjnano.5.7

• spectroscopy. The Ti precursor, titanium isopropoxide, was used in combination with H2O on Si/SiO2 substrates that were heated at 200 °C. The low growth rate (0.15 Å/cycle) and the in situ characterization permitted to follow changes in the electronic structure of TiO2 in the sub-nanometer range, which are

• films Thermal ALD of TiO2 with titanium(IV) isopropoxide (TTIP) and H2O at 200 °C proceeds very slowly [16], with a growth rate of about 0.15 Å/cycle. Indeed, the XAS spectra at the Ti-L2,3 edge in Figure 1 show very small changes with increasing number of ALD cycles. Moreover, various spectral features

STM tip-assisted engineering of molecular nanostructures: PTCDA islands on Ge(001):H surfaces

• Amir A. Ahmad Zebari,
• Marek Kolmer and
• Jakub S. Prauzner-Bechcicki

Beilstein J. Nanotechnol. 2013, 4, 927–932, doi:10.3762/bjnano.4.104

• , current set-point, bias voltages, sample temperature, etc.) may play a role in setting the final growth rate. It is rather expected that in our experiment the scanning probe is coated with molecular material. One could then argue that the direct deposition from the tip should also significantly contribute

In situ growth optimization in focused electron-beam induced deposition

• Paul M. Weirich,
• Marcel Winhold,
• Christian H. Schwalb and
• Michael Huth

Beilstein J. Nanotechnol. 2013, 4, 919–926, doi:10.3762/bjnano.4.103

• enhancement of conductance because of an increasing growth rate of the deposit and/or intrinsic effects, e.g., the increase of the metal content and/or a change of the dielectric matrix. The GA allows for the optimization of the deposition parameters for an arbitrary precursor, without having any additional

• connected in parallel, remains constant if the growth rate and the conductivity do not change. However, if either the conductivity or the growth rate are altered by the variation of deposition parameters, the gradient of is a suitable variable to describe the influence of the deposition parameters on the

• conductance of the deposit. Hence, the gradient of is chosen as the fitness parameter for the GA in order to detect effects that lead to a change of the growth rate and/or the conductivity. Layers with the highest fitness values are selected to generate the next optimization cycle of n parameter sets by

Synthesis of indium oxi-sulfide films by atomic layer deposition: The essential role of plasma enhancement

• Cathy Bugot,
• Nathanaëlle Schneider,
• Daniel Lincot and
• Frédérique Donsanti

Beilstein J. Nanotechnol. 2013, 4, 750–757, doi:10.3762/bjnano.4.85

• long purge time being chosen to ensure a good homogeneity. Figure 1a shows the growth rate of In2S3 thin films at various temperatures. It globally increases with the temperature. An ALD window can be speculatively observed between 160 °C and 200 °C with a mean growth rate of 0.84 Å/cycle. The

• variation of the In2S3 growth rate with different In(acac)3 pulse lengths at a process temperature of 160 °C is illustrated in Figure 1b. This variation only slightly influences the growth rate and a saturation by lengthening the precursor pulse is not observed. The data suggest that the results displayed

• of 2000 cycles was achieved for all samples as described in the previous section. The dependence of the growth rate on the number of In2O3 cycles is shown in Figure 4a. When increasing the ratio from 4.8% to 9.1%, the growth rate increases up to 1.4 Å/cycle and then decreases again. The variation of

Ellipsometry and XPS comparative studies of thermal and plasma enhanced atomic layer deposited Al₂O₃-films

• Jörg Haeberle,
• Karsten Henkel,
• Hassan Gargouri,
• Franziska Naumann,
• Bernd Gruska,
• Michael Arens,
• Massimo Tallarida and
• Dieter Schmeißer

Beilstein J. Nanotechnol. 2013, 4, 732–742, doi:10.3762/bjnano.4.83

• deposited at 200 °C, for the PE-ALD films we varied the substrate temperature range between room temperature (rt) and 200 °C. We show data from spectroscopic ellipsometry (thickness, refractive index, growth rate) over 4” wafers and correlate them to X-ray photoelectron spectroscopy (XPS) results. The 200

• °C T-ALD and PE-ALD processes yield films with similar refractive indices and with oxygen to aluminum elemental ratios very close to the stoichiometric value of 1.5. However, in both also fragments of the precursor are integrated into the film. The PE-ALD films show an increased growth rate and lower

• carbon contaminations. Reducing the deposition temperature down to rt leads to a higher content of carbon and CH-species. We also find a decrease of the refractive index and of the oxygen to aluminum elemental ratio as well as an increase of the growth rate whereas the homogeneity of the film growth is

Evolution of microstructure and related optical properties of ZnO grown by atomic layer deposition

• Adib Abou Chaaya,
• Roman Viter,
• Mikhael Bechelany,
• Zanda Alute,
• Donats Erts,
• Anastasiya Zalesskaya,
• Kristaps Kovalevskis,
• Vincent Rouessac,
• Valentyn Smyntyna and
• Philippe Miele

Beilstein J. Nanotechnol. 2013, 4, 690–698, doi:10.3762/bjnano.4.78

• growth rate calculated from all results is 2.5 Å per cycle. Results of ellipsometric measurements are presented in Table 1. SEM images of ZnO thin films grown by ALD on Si substrates at 200, 500, and 1000 cycles are shown in Figure 1a. The images indicate conformal coating of the Si substrate. A rough

The role of electron-stimulated desorption in focused electron beam induced deposition

• Willem F. van Dorp,
• Thomas W. Hansen,
• Jakob B. Wagner and
• Jeff T. M. De Hosson

Beilstein J. Nanotechnol. 2013, 4, 474–480, doi:10.3762/bjnano.4.56

• it is observed that the growth rate is lower at higher substrate temperatures. From Arrhenius plots we calculated the activation energy for desorption, Edes, of W(CO)6. We found an average value for Edes of 20.3 kJ or 0.21 eV, which is 2.5–3.0 times lower than literature values. This difference

• , since (amongst others) it determines the residence time of the precursor molecules on the surface, which in turn affects the growth rate. The activation energy for desorption can be determined from FEBIP experiments by measuring the deposition rate as a function of substrate temperature and constructing

• forces for FEBIP, the amount of desorption from the surface may be significant during electron irradiation. We determined the growth rate for W(CO)6 as a function of substrate temperature and compare the extracted energies Edes with values found in the literature. Results and Discussion Arrays of dots

Grating-assisted coupling to nanophotonic circuits in microcrystalline diamond thin films

• Patrik Rath,
• Svetlana Khasminskaya,
• Christoph Nebel,
• Christoph Wild and
• Wolfram H.P. Pernice

Beilstein J. Nanotechnol. 2013, 4, 300–305, doi:10.3762/bjnano.4.33

• interferometric measurement to allow for precise thickness monitoring. Because the growth rate is moderate and reproducible, the final film thickness can be controlled with high precision. After growth, the samples are cleaned in concentrated HNO3/H2SO4 to remove remaining surface contamination. Following the

Low-dose patterning of platinum nanoclusters on carbon nanotubes by focused-electron-beam-induced deposition as studied by TEM

• Xiaoxing Ke,
• Carla Bittencourt,
• Sara Bals and
• Gustaaf Van Tendeloo

Beilstein J. Nanotechnol. 2013, 4, 77–86, doi:10.3762/bjnano.4.9

• context where only low-dose deposition is studied, the growth rate may not be as important, whereas the formation of the stripe pattern can be attributed to regime shift during pattering along the X and Y axes. In the deposition using a 30 kV electron beam, the working regime is mainly electron-limited

Characterization and properties of micro- and nanowires of controlled size, composition, and geometry fabricated by electrodeposition and ion-track technology

• Maria Eugenia Toimil-Molares

Beilstein J. Nanotechnol. 2012, 3, 860–883, doi:10.3762/bjnano.3.97

• , probably due to the higher growth rate. Increase of surface roughness with increasing deposition potential has also been observed in the case of Bi compound wires [58]. X-ray diffraction (XRD) performed on the single-crystalline nanowire arrays by using a four-circle diffractometer, revealed a preferred

• electrodeposition conditions were studied in order to obtain mechanically stable nanocones with good electrical contact to the substrate. Electrodeposition by using a CuSO4-based electrolyte in a two electrode configuration, with U = −40 mV leads to a slow growth rate, resulting in a large uniform array of

Paper modified with ZnO nanorods – antimicrobial studies

• Mayuree Jaisai,
• Sunandan Baruah and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2012, 3, 684–691, doi:10.3762/bjnano.3.78

• concentrations of zinc nitrate and hexamine were used for the nanorod growth in this work, i.e., 10 mM and 20 mM, with growth durations varied between 5, 10 and 20 h in both the cases. The reaction bath was replenished every five hours to maintain the growth rate, as discussed elsewhere [26]. The substrate was

Focused electron beam induced deposition: A perspective

• Michael Huth,
• Fabrizio Porrati,
• Christian Schwalb,
• Marcel Winhold,
• Roland Sachser,
• Maja Dukic,
• Jonathan Adams and
• Georg Fantner

Beilstein J. Nanotechnol. 2012, 3, 597–619, doi:10.3762/bjnano.3.70

• [22] where J is the precursor flux modified by the sticking coefficient s. The local growth rate R(r) of the deposit, assuming the volume V for the nonvolatile dissociation product of an individual precursor molecule, is then obtained from with tD denoting the beam dwell time. Valuable insight can be

• result obtained from this analysis is the generic shape of the deposit growth rate R as a function of the dwell time tD, as is shown in Figure 2. For the calculation, the a priori unknown model parameters σ and τ are needed. These can in fact be obtained from fitting of the dwell-time-dependent growth

• rates for different precursor flux settings J by using Equation 6, as e.g., detailed in Utke et al. [6]. Here parameters for the precursor Me3Pt(IV)CpMe have been used, as given in the figure caption. Apparently the growth rate is proportional to the electron flux for very short dwell times, which is

Synthesis and electrical characterization of intrinsic and in situ doped Si nanowires using a novel precursor

• Wolfgang Molnar,
• Alois Lugstein,
• Tomasz Wojcik,
• Peter Pongratz,
• Norbert Auner,
• Christian Bauch and
• Emmerich Bertagnolli

Beilstein J. Nanotechnol. 2012, 3, 564–569, doi:10.3762/bjnano.3.65

• [20]. Unfortunately, such in situ doping can negatively affect the actual growth process. B2H6 for example triggers the formation of an amorphous Si shell [23], whereas PH3 reduces the growth rate and completely inhibits NW growth at higher PH3 partial pressures [24]. Furthermore, the doping often

• decomposition of the precursor and therefore increases the growth rate. With PCl3 as the dopant, at least 800 °C, 20 sccm H2, and a 2 nm layer of Au were needed to produce epitaxial NWs in considerable quantity. For a more detailed view of the morphology of the intrinsic and doped Si-NWs we performed HRTEM

Directed deposition of silicon nanowires using neopentasilane as precursor and gold as catalyst

• Britta Kämpken,
• Verena Wulf,
• Norbert Auner,
• Marcel Winhold,
• Michael Huth,
• Daniel Rhinow and
• Andreas Terfort

Beilstein J. Nanotechnol. 2012, 3, 535–545, doi:10.3762/bjnano.3.62

• such as octachlorotrisilane [36] and disilane [37] have similar properties to their monomeric analogues, although both of these precursors are reported to have an exceptionally high growth rate compared to their analogous monosilanes. This is due to the fact that the dissociation energy of the Si–Si

Self-assembly of octadecyltrichlorosilane: Surface structures formed using different protocols of particle lithography

• ChaMarra K. Saner,
• Kathie L. Lusker,
• Zorabel M. LeJeune,
• Wilson K. Serem and
• Jayne C. Garno

Beilstein J. Nanotechnol. 2012, 3, 114–122, doi:10.3762/bjnano.3.12

• with organosilanes such as OTS [10][11][45][46][47][48][49][50]. Preparation methods affect the growth rate, surface coverage and orientation of OTS [51]. Molecular-level differences in the thickness and morphology of OTS nanostructures prepared by different lithography procedures can be investigated

Electron-beam patterned self-assembled monolayers as templates for Cu electrodeposition and lift-off

• Zhe She,
• Andrea DiFalco,
• Georg Hähner and
• Manfred Buck

Beilstein J. Nanotechnol. 2012, 3, 101–113, doi:10.3762/bjnano.3.11

• interplay between growth rate and morphology. So far the scheme has been demonstrated for Cu, and it will be of interest to extend this to other metals, such as Ag or Au, and to see how the different interactions between these metals and the SAM will affect the deposition process. Another aspect is to

Self-assembled monolayers and titanium dioxide: From surface patterning to potential applications

• Yaron Paz

Beilstein J. Nanotechnol. 2011, 2, 845–861, doi:10.3762/bjnano.2.94

• ) route [33]. Here, the sulfonate group provides high local acidity and negative charge even at low pH, thus promoting the hydrolysis and surface attachment of solvated titanium-containing species. It is noteworthy that the fast growth rate on sulfonic-terminated SAMs was also found when the titanium

• precursor [82]. It is noteworthy that the growth rate of anatase on top of SAMs (methyl-terminated or even amino-terminated) is significantly lower than that measured on top of amorphous TiO2 underlayer. This was exploited for the growth of a patterned anatase layer on top of amorphous TiO2 grown on

Formation of SiC nanoparticles in an atmospheric microwave plasma

• Martin Vennekamp,
• Ingolf Bauer,
• Matthias Groh,
• Evgeni Sperling,
• Susanne Ueberlein,
• Maksym Myndyk,
• Gerrit Mäder and
• Stefan Kaskel

Beilstein J. Nanotechnol. 2011, 2, 665–673, doi:10.3762/bjnano.2.71

• sizes ranging from 7 nm to about 20 nm according to BET and XRD measurements are produced. The dependency of the particle size on the process parameters is evaluated statistically and explained with growth-rate equations derived from the theory of Ostwald ripening. The results show that the particle

• the Lifshitz–Slyozov–Wagner (LSW) theory [26][27], which has also been adopted for description of the growth of nanoparticles from the gas phase [28]. The surface kinetics in a plasma is increased [29], driving the growth process into a diffusion limit. The particle growth rate is therefore given by

• equation describes the growth rate of larger particles, which is known as Ostwald ripening, resulting in the well-known log-normal distribution of the particle sizes. Taking into account, that D = ƒ(1 = ptotal, Tx), with 1 ≤ x ≤ 2, one can give the following proportionalities for the growth rate of a

Dense lying self-organized GaAsSb quantum dots on GaAs for efficient lasers

• Thomas H. Loeber,
• Dirk Hoffmann and
• Henning Fouckhardt

Beilstein J. Nanotechnol. 2011, 2, 333–338, doi:10.3762/bjnano.2.39

• GaSb QDs were grown on an As-rich surface. The nominal coverage for all samples was 3 monolayers (ML) with a growth rate of ≈0.3 ML/s. The samples were cooled down to room temperature under the adjusted Sb flux immediately after the QD growth for topographic tapping-mode measurements with a Park XE-70

Formation of precise 2D Au particle arrays via thermally induced dewetting on pre-patterned substrates

• Dong Wang,
• Ran Ji and
• Peter Schaaf

Beilstein J. Nanotechnol. 2011, 2, 318–326, doi:10.3762/bjnano.2.37

• and Thompson has shown that the void growth rate Rv decreases with increasing film thickness t dramatically (Rv t−3) [32]. Therefore, it is reasonable that the particle size and particle spacing increases with film thickness (Figure 8). Dewetting of the Au films on the substrate A (pyramidal pits

Studies towards synthesis, evolution and alignment characteristics of dense, millimeter long multiwalled carbon nanotube arrays

• Pitamber Mahanandia,
• Jörg J. Schneider,
• Martin Engel,
• Bernd Stühn,
• Somanahalli V. Subramanyam and
• Karuna Kar Nanda

Beilstein J. Nanotechnol. 2011, 2, 293–301, doi:10.3762/bjnano.2.34

• molecular source used and additional growth promoters such as H2, as well as H2O or oxygen containing organic molecules such as ethers, or ketones as oxidizing agents, have a subtle influence on the purity, growth rate and final growth height of vertically oriented CNTs. Oxygen containing organic molecules

Recrystallization of tubules from natural lotus (Nelumbo nucifera) wax on a Au(111) surface

• Sujit Kumar Dora and
• Klaus Wandelt

Beilstein J. Nanotechnol. 2011, 2, 261–267, doi:10.3762/bjnano.2.30

• . Comparing the growth of both tubules – 1 and 2 in Figure 1 (plotted in Figure 3a) – it is obvious that the growth rate of tubule 2 was lower and its final length was shorter, but both tubules reached their final length after the same time (about 3.5 hours). On the other hand, although radial growth follows

• concentration of molecules in solution. These two observations combined suggest that both the growth rate as well as the saturation length depends on the availability of molecules on the surface, or more precisely, within the “capture zone” surrounding each tubule. Discussion As on many other substrates such as