Jun 8, 2012
Plasma roadmap flags up nano challenges
Plasma science and technology has applications across a wide range of areas - from electronics and materials processing through to environmental clean-up and even wound healing. To bring together an overview of what's happening in this dynamic and multidisciplinary field, 16 world renowned experts have teamed up to create a plasma roadmap (J. Phys. D: Appl. Phys. 45 253001).
Here are just a few of the highlights -
Plasma-etching processes for future nanoscale
Seiji Samukawa, Tohoku University
Over the past 30 years, plasma etching technology has been a leader in the effort to shrink the pattern of ultra-large-scale integrated (ULSI) devices. However, inherent problems in the plasma processes, such as charge build-up and UV photon radiation, limit the etching performance for nanoscale devices. To overcome these problems and to fabricate sub-10 nm devices in practice, tens-of-microsecond pulse-time modulated plasma etching and neutral-beam etching processes have been proposed. These processes can be used to perform damage-free etching atomically and surface modification of inorganic and organic materials. This technique is a promising candidate for practical and accurate fabrication of future nanodevices (read the review section in full on IOPscience).
Nanoparticle formation in chemically reactive plasmas
Uwe Kortshagen, University of Minnesota
Nanodusty plasmas provide a unique synthesis route
Nanoparticle formation in chemically reactive plasmas was initially viewed as a contamination problem in semiconductor processing. However, with the emergence of nanoscience and technology, the ability of dusty plasmas to produce nanoparticles with controlled physical and chemical properties was recognized. Today, it is well understood that particularly for the synthesis of materials that require high synthesis temperatures, such as covalently bonded semiconductors and ceramic nanoparticles, nanodusty plasmas provide a unique synthesis route.
Nanoparticles immersed in a plasma carry a unipolar negative charge once their size grows to several nm during synthesis. This prevents nanoparticle agglomeration and enables the growth of nanoparticles with highly monodisperse size distributions. It also reduces or eliminates diffusional particle losses to the reactor walls (read the review section in full on IOPscience).
Plasma deposition processes for ultimate functional
Masaru Hori, Nagoya University
The development of bottom up CVD techniques for organic materials such as carbon nanotubes (CNTs) and graphene sheets is another area of intensive research. For such materials, PECVD is also a strong contender since low-temperature growth can be achieved. However, there are difficult problems that remain to be solved with regard to crystallographic control, such as control of the chirality of CNTs (read the review section in full on IOPscience).
Uwe Czarnetzki of the Ruhr-University Bochum in Germany explains how plasmas are a key ingredient in many of the technologies that have helped to shape the modern world, including lighting and the production of computer chips.
Nanoscience with non-equilibrium plasmas at atmospheric pressure
J. Phys. D: Appl. Phys. 44 363001
Microplasmas for nanomaterials synthesis
J. Phys. D: Appl. Phys. 43 323001