Nanotechnology

  2010 MAR 22 - (VerticalNews.com) -- "Boron was delta (delta) introduced in SiGe/Si quantum dots (the delta-QD sample) or Si spacers (the delta-spacer sample) in SiGe/Si quantum dot infrared photodetectors (QDIPs) to provide the quantum dots with a sufficient hole concentration for infrared excitation," scientists writing in the journal Thin Solid Films report.

  "The influence on dark currents due to the different positions of delta-doping layers is studied. The current mechanisms of the delta-QD sample and the delta-spacer sample in metal-oxide-semiconductor structures are discussed," wrote C.H. Lin and colleagues ...read more

  2010 MAR 22 - (VerticalNews.com) -- According to a study from Louvain, Belgium, "Low temperature epitaxial growth of group-IV alloys is a key process step to realize the advanced Si-based devices. In order to keep high growth rate below 600 degrees C, trisilane (Si3H8) was used for their growth as an alternative Si precursor gas."

  "Then, we compared the use Of Si3H8 versus SiH4 for Si1-xGex growth in H-2. and N-2 as carrier gas by low temperature chemical vapor deposition. By using Si3H8 and controlling GeH4 flow rate, Si1-xGex growth with high growth rate and wide range of Ge concentration has been achieved compared to SiH4-based process. The growth rate and Ge concentration in Si1-xGex with Si3H8 grown at 600 degrees C ranged from 11 to 74 nm/min and from 0 to 40%, respectively. The obtained growth rates with Si3H8 are between 1.5 and 6 times higher than for SiH4 at a given growth condition," wrote S. Takeuchi and colleagues ...read more

  2010 MAR 22 - (VerticalNews.com) -- According to recent research from Rehovot, Israel, "We have previously described nanoparticle nanotubes (NPNTs), i.e., tubular metallic nanostructures comprising coalesced nanoparticles (NPs), obtained by passing citrate-stabilized metal (Au, Ag, Pd) NP solutions through aminosilane-modified nanoporous alumina membranes. Here we show that the mechanism of NPNT formation involves two stages: (i) electrostatic binding of a monolayer of metal NPs to the amine groups on the membrane pore walls; and (ii) accumulation of NP multilayers and room-temperature coalescence to form solid nanotubes. ...read more