In a breakthrough for nanotechnology, which could mean fast prototyping of nano-sized devices for future computer chips, IBM scientists have developed new, 'low cost' a nono-technique that they've demonstrated by creating a 3D map of the earth so small that 1,000 of them could fit on one grain of salt.
The scientists accomplished this impressive nano-feat through a new, breakthrough technique that uses a tiny, silicon tip with a sharp apex — 100,000 times smaller than a sharpened pencil — to create patterns and structures as small as 15 nanometers at greatly reduced cost and complexity. This patterning technique opens new prospects for developing nanosized objects in fields such as electronics, future chip technology, medicine, life sciences, and optoelectronics.
To demonstrate the technique's unique capability, the team created several 3D and 2D patterns, using different materials for each one as reported in the scientific journals Science and Advanced Materials, including a 25-nanometer-high 3D replica of the Matterhorn, the famous Alpine mountain that soars 4,478 m (14,692 ft) high. The nano-replica was created in molecular glass, representing a scale of 1:5 billion.
The complete 3D map of the world measures only 22 by 11 micrometers was "written" on a polymer. At this size, 1,000 world maps could fit on a grain of salt. In the relief, one thousand meters of altitude correspond to roughly eight nanometers (nm). It is composed of 500,000 pixels, each measuring 20 nm2, and was created in only 2 minutes and 23 seconds.
The core component of the new technique, which was developed by a team of IBM scientists, is a tiny, very sharp silicon tip measuring 500 nanometers in length and only a few nanometers at its apex.
"Advances in nanotechnology are intimately linked to the existence of high-quality methods and tools for producing nanoscale patterns and objects on surfaces," explains physicist Dr. Armin Knoll of IBM Research – Zurich. "With its broad functionality and unique 3D patterning capability, this nanotip-based patterning methodology is a powerful tool for generating very small structures."
The tip, similar to the kind used in atomic force microscopes, is attached to a bendable cantilever that controllably scans the surface of the substrate material with the accuracy of one nanometer—a millionth of a millimeter. By applying heat and force, the nano-sized tip can remove substrate material based on predefined patterns, thus operating like a "nanomilling" machine with ultra-high precision.
Similar to using a milling machine, more material can be removed to create complex 3D structures with nanometer precision by modulating the force or by readdressing individual spots. To create the 3D replica of the Matterhorn, for example, 120 individual layers of material were successively removed from the molecular glass substrate.
The new IBM technique achieves resolutions as high as 15 nanometers—with a potential of going even smaller. Using existing methods such as e-beam lithography, it is becoming increasingly challenging to fabricate patterns at resolutions below 30 nanometers, where the technical limitations of that method are reached.
You can find out more about how it works it in this video, below.
Compared to expensive e-beam-lithography tools that require several processing steps and equipment that can easily fill a laboratory, the new tool created by IBM scientists—which can sit on a tabletop—promises improved and extended capabilities at very high resolutions, but at one-fifth to one tenth of the cost and with far less complexity.
Yet another advantage of the nanotip-based technique is the ability to assess the pattern directly by using the same tip to create an image of the written structures, as the IBM scientists demonstrated in their experiments.
Potential applications range from the fast prototyping of nano-sized devices for future computer chips to the production of well defined micron-sized optical elements like aspheric lenses and lens-arrays for optoelectronics and on-chip optical communication.
IBM has been a pioneer in nanoscience and nanotechnology ever since the development of the scanning tunneling microscope (STM) in 1981 by IBM Fellows Gerd Binnig and Heinrich Rohrer. For this invention, which made it possible to image individual atoms and later on to manipulate them, Binnig and Rohrer were awarded the Nobel Prize in Physics in 1986. The atomic force microscope, an offspring of the STM, was invented by Binnig in 1986. The STM is widely regarded as the instrument that opened the door to the nanoworld.
In fact, it was 20 years ago this month that IBM Fellow Don Eigler reported the first controlled movement of individual atoms, famously using a scanning tunneling microscope to spell out the letters "I B M" with 35 xenon atoms.
These historic breakthroughs laid a solid foundation for IBM's continued research in nanoscience.
Contributing to this rich history for years to come, a new world-class collaborative nanoscale research lab is currently under construction on the campus of IBM Research – Zurich. This state-of-the-art nanotech center, which will open next year, is part of a strategic partnership in nanotechnology between IBM Research and ETH Zurich, one of Europe's leading technical universities.
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