Image courtesy of Science/AAAS
Summary – This is huge. IBM is using nanotip fabrication at 15nm resolution now. The nanotip fabrication is faster than ebeam lithography, higher resolution than ebeam and cheaper. They can go to higher resolution. Sounds like 1 nanometer resolution is possible as that is the scanning accuracy. they etched a 25 nm high Matterhorn to 5 billion times smaller scale in 3 minutes. They can do 3D work. IBM is the developer so this will not languish for lack of resources.
Using a novel nanotip-based patterning technique, IBM scientists have created a 25 nanometer-high replica of the Matterhorn peak, a famous Swiss mountain that soars 4,478 m (14,692 ft) high on a piece of molecular glass, representing a scale of 1:5 billion (1 nanometer corresponds to 57 altitude meters). To create the 3D replica 120 individual layers of materials were removed. IBM Research web page for Nanometer-scale direct-write 3D patterning using probes
Published in Science and Advanced Materials.
A nanoscale tip with a sharp apex – 1 million times smaller than an ant – is used to create 2D and 3D patterns and structures as small as 15 nanometers at greatly reduced cost and complexity. This patterning technique opens new prospects for fabricating nanosized electronics and objects in fields ranging from future chip technology to opto-electronics to medicine and life sciences. EETimes reports that the 3D nanoprobe fabrication at the atomic scale outperforms e-beam lithography in speed and resolution at lower cost.
The Nano Mattahron was created in less than 3 minutes with a silicon tip similar those used in atomic-force microscopes, but measuring just 500 nanometers in length and only a few nanometers wide at its apex. The tip was attached to a flexible cantilever that IBM says can scan the surface of any substrate with 1-nm accuracy.
IBM’s setup operates like a nanoscale milling machine; by applying heat and force to the tip, any nanoscale pattern can be etched into substrate materials. The researchers modulated the force and heat to create the images by removing unwanted layers the way a sculptor removes stone from a statue; the Matterhorn rendering.
Science Express – Nanoscale 3D patterning of molecular resists by scanning probes by D. Pires, J. L. Hedrick, A. De Silva, J. Frommer, B. Gotsmann, H. Wolf, M. Despont, U. Duerig and A. W. Knoll. (April 22,2010)
Abstract – For patterning organic resists, optical and electron beam lithography are the most established methods, but at resolutions below 30 nanometers, inherent problems result from unwanted exposure of the resist in nearby areas. We present a scanning probe lithography method based on the local desorption of a glassy organic resist by a heatable probe. We demonstrate patterning at a half pitch down to 15 nanometers without proximity corrections and with throughputs approaching those of Gaussian electron beam lithography at similar resolution. These patterns can be transferred to other substrates, and material can be removed in successive steps in order to fabricate complex three-dimensional structures
The new patterning technique currently has a resolution of about 15 nm—about twice as small as e-beam lithography—and potentially could go even smaller. The patterning device costs from one-fifth to one-tenth the price of e-beam lithography and is much faster, according to the researchers.
Thus far IBM has demonstrated the technique on two substrate materials: a polymer called polyphthalaldehyde, developed by IBM fellow Hiroshi Ito in the 1980s, and a molecular glass similar to conventional resists.
The system also offers precise control over depth of carving. The team suggests the technique could, for example, be used to create tiny lenses for optical connections on silicon chips so small that the electronic wires used to carry current no longer function efficiently.
They carved their microscopic Matterhorn from a glassy organic material whose molecules are held together by hydrogen bonds, forces of attraction between partially positive hydrogen ions in one molecule and electron-rich oxygen ions in another.
Flashes of heat only a few microseconds long from the needle can break these hydrogen bonds but are too weak to unlock the chemical bonds within molecules, in which electrons are shared between atoms.