From Technology Review: IBM researchers have invented a low-cost and relatively simple fabrication tool capable of reliably creating features as small as 15 nanometers. To show off the tool, the researchers at IBM’s Zurich lab made a three-dimensional map of the Earth so small that 1,000 of them would fit onto a single grain of salt.
Existing nano-fabrication techniques like electron beam lithography have difficulty making features much smaller than 30 nanometers and are expensive and complex instruments. In contrast, the IBM researchers say their new fabrication tool sits on a tabletop at one-fifth to one-tenth the cost.
The new instrument is a descendant of the scanning tunneling microscope (STM) invented by IBM Zurich scientists in the early 1980s. That microscope made it possible, for the first time, to image and manipulate atoms. The new instrument uses an extremely small silicon tip that is rapidly scanned across the surface of the substrate. The tip is cantilevered like those used in atomic force microscopy (or AFM: an offshoot of STM that was invented in 1986), enabling it to apply nanonewtons of force to the surface. But unlike AFM, the tip is heated.
Where it touches the substrate, the thermal energy at the tip is sufficient to break weak bonds within the material.