PEALD Publication Histograms for 2014 by The Plasma-ALD-Guy

The Plasma-ALD-Guy has created a histogram of the regions which have produced plasma ALD publications that were accepted during 2014. The region for a paper is determined from the first author affiliation (here). In addition, he has compiled a similar histogram for Plasma ALD Film Type also for 2014 Publications (here). Both are reproduced below with permission.

Knowing that both BENEQ and Picosun are manufacturing and shipping PEALD reactors the low number of Finnish PEALD publications is surprising. No surprise though that USA and South Korea is pumping out PEALD publications and that many of them are for classic materials like Al2O3 and SiO2 and also for AlN that is just about impossible to realize in thermal mode.

The Plasma-ALD-Guys tells me that there are more publication histograms to come and I am very eager to see those - stay tuned for more!

Brown University uses silicon telluride to produce multilayered two-dimensional semiconductor materials

A new process developed by researchers at Brown University uses silicon telluride to produce multilayered two-dimensional semiconductor materials in a variety of shapes and orientations.

 

 By adjusting the fabrication technique, researchers can make different semiconductor structures, including nanoplates that lie flat or stand upright. Koski lab/Brown University

 

A Silicon-Based Two-Dimensional Chalcogenide: Growth of Si2Te3 Nanoribbons and Nanoplates
Sean Keuleyan , Mengjing Wang , Frank R. Chung , Jeffrey Commons , and Kristie J. Koski
Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
Nano Lett., Article ASAP
DOI: 10.1021/nl504330g

We report the synthesis of high-quality single-crystal two-dimensional, layered nanostructures of silicon telluride, Si₂Te₃, in multiple morphologies controlled by substrate temperature and Te seeding. Morphologies include nanoribbons formed by VLS growth from Te droplets, vertical hexagonal nanoplates through vapor–solid crystallographically oriented growth on amorphous oxide substrates, and flat hexagonal nanoplates formed through large-area VLS growth in liquid Te pools. We show the potential for doping through the choice of substrate and growth conditions. Vertical nanoplates grown on sapphire substrates, for example, can incorporate a uniform density of Al atoms from the substrate. We also show that the material may be modified after synthesis, including both mechanical exfoliation (reducing the thickness to as few as five layers) and intercalation of metal ions including Li⁺ and Mg²⁺, which suggests applications in energy storage materials. The material exhibits an intense red color corresponding to its strong and broad interband absorption extending from the red into the infrared. Si₂Te₃ enjoys chemical and processing compatibility with other silicon-based material including amorphous SiO₂ but is very chemically sensitive to its environment, which suggests applications in silicon-based devices ranging from fully integrated thermoelectrics to optoelectronics to chemical sensors.

Tuning the nanopore diameter using ALD

Working on deep deep nano holes and tubes for a long time (DRAM) and for a lab growing nanowires I found this an interesting paper on how ALD can be used to tune the nanopore diameter. Nanopore (NP) technologies have been researched the last 10 years or so. According to the paper "The next major breakthrough" of this technology will depend on :

• the fundamental understanding of the dynamical processes that govern macromolecules translocation through NP
• the availability of methods that allow routine fabrication of nanoscale materials. 

Particles, holes, tubes, wires, pores, ..., transistors etc. - what else could you do nano?

Influence of nanopore surface charge and magnesium ion on polyadenosine translocation

Mathilde Lepoitevin, Pierre Eugène Coulon, Mikhael Bechelany, Julien Cambedouzou, Jean-Marc Janot and Sebastien Balme
Mathilde Lepoitevin et al 2015 Nanotechnology 26 144001
doi:10.1088/0957-4484/26/14/144001

We investigate the influence of a nanopore surface state and the addition of Mg2+ on poly-adenosine translocation. To do so, two kinds of nanopores with a low aspect ratio (diameter ~3–5 nm, length 30 nm) were tailored: the first one with a negative charge surface and the second one uncharged. It was shown that the velocity and the energy barrier strongly depend on the nanopore surface. Typically if the nanopore and polyA exhibit a similar charge, the macromolecule velocity increases and its global energy barrier of entrance in the nanopore decreases, as opposed to the non-charged nanopore. Moreover, the addition of a divalent chelating cation induces an increase of energy barrier of entrance, as expected. However, for a negative nanopore, this effect is counterbalanced by the inversion of the surface charge induced by the adsorption of divalent cations.

Cartoon to illustrate polyA translocation through NP and the electrolyte distribution. (a) Native -NP at NaCl 150 mM (b) native-NP at NaCl 500 mM and (c) TMS-NP at NaCl 150 mM.

Check out The Nanopore Site!