Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Infrared light visualizes nanoscale strain fields

12.01.2009
A joint team of researchers at CIC nanoGUNE (San Sebastian, Spain) and the Max Planck Institutes of Biochemistry and Plasma Physics (Munich, Germany) report the non-invasive and nanoscale resolved infrared mapping of strain fields in semiconductors.

The method, which is based on near-field microscopy, opens new avenues for analyzing mechanical properties of high-performance materials or for contact-free mapping of local conductivity in strain-engineered electronic devices (Nature Nanotechnology, advanced online publication, 11 Jan. 2009).


Infrared visualization of nanocrack evolution. a) Topography of triangular indents (depressions) at the surface of a SiC crystal. Indentation was performed by pressing a sharp diamond tip into the crystal surface. With increasing force F, the depression becomes larger and deeper. b) The infrared near-field images recorded at about 10 µm wavelength clearly show the regions around the indent where the crystal lattice is compressed (bright) or stretched (dark). Because of the exceptional high spatial resolution, the images reveal the onset and formation of nanoscale cracks (marked by dashed blue circlse) when the indentation force is increased. Copyright: Andreas Huber, Max Planck Institute of Biochemistry, Martinsried

Visualizing strain at length scales below 100 nm is a key requirement in modern metrology because strain determines the mechanical and electrical properties of high-performance ceramics or modern electronic devices, respectively. The non-invasive mapping of strain with nanoscale spatial resolution, however, is still a challenge.

A promising route for highly sensitive and non-invasive mapping of nanoscale material properties is scattering-type Scanning Near-field Optical Microscopy (s-SNOM). Part of the team had pioneered this technique over the last decade, enabling chemical recognition of nanostructures and mapping of local conductivity in industrial semiconductor nanodevices. The technique makes use of extreme light concentration at the sharp tip of an Atomic Force Microscope (AFM), yielding nanoscale resolved images at visible, infrared and terahertz frequencies. The s-SNOM thus breaks the diffraction barrier throughout the electromagnetic spectrum and with its 20 nm resolving power matches the needs of modern nanoscience and technology.

Now, the research team has provided first experimental evidence that the microscopy technique is capable of mapping local strain and cracks of nanoscale dimensions. This was demonstrated by pressing a sharp diamond tip into the surface of a Silicon Carbide crystal. With the near-field microscope the researchers were able to visualize the nanoscopic strain field around the depression and the generation of nanocracks (see Figure). "Compared to other methods such as electron microscopy, our technique offers the advantage of non-invasive imaging without the need of special sample preparation" says Andreas Huber who performed the experiments within his Ph.D. project. "Specific applications of technological interest could be the detection of nanocracks before they reach critical dimensions, e.g. in ceramics or Micro-Electro-Mechanical Systems (MEMS), and the study of crack propagation", says Alexander Ziegler.

The researchers also demonstrated that s-SNOM offers the intriguing possibility of mapping free-carrier properties such as density and mobility in strained silicon. By controlled straining of silicon, the properties of the free carriers can be designed, which is essential to further shrink and speed-up future computer chips. For both development and quality control, the quantitative and reliable mapping of the carrier mobility is strongly demanded but hitherto no tool has been available. "Our results thus promise interesting applications of s-SNOM in semiconductor science and technology such as the quantitative analysis of the local carrier properties in strain-engineered electronic nanodevices" says Rainer Hillenbrand, leader of the Nano-Photonics Group at MPI and the Nanooptics Laboratory at nanoGUNE.

Original publication:
A. J. Huber, A. Ziegler, T. Köck, and R. Hillenbrand, Infrared nanoscopy of strained semiconductors, Nat. Nanotech., advanced online publication, 11. Jan. 2009, DOI 10.1038/NNANO.2008.399.
Contact:
Dr. Rainer Hillenbrand
Nanooptics Laboratory
CIC nanoGUNE Consolider
20009 Donostia - San Sebastian, Spain
phone: +34 943 574 007
r.hillenbrand@nanogune.eu
and
Nano-Photonics Group
Max-Planck-Institut für Biochemie
82152 Martinsried, Germany

Eva-Maria Diehl | Max-Planck-Gesellschaft
Further information:
http://www.biochem.mpg.de/hillenbrand
http://www.nanogune.eu
http://www.biochem.mpg.de/en/news/pressroom/TeraHerzNanoletters_081008.pdf

More articles from Materials Sciences:

nachricht Researchers devise microreactor to study formation of methane hydrate
23.08.2017 | NYU Tandon School of Engineering

nachricht Meter-sized single-crystal graphene growth becomes possible
22.08.2017 | Science China Press

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>