A spacing of 14 nanometres, would increase in the capacity of the memory chips of, for example, new generation mobile phones tenfold.
Sidorkin used a Helium Ion Microscope (HIM) to create helium beams, and was able to draw dots having a diameter of only six nanometre.
Sidorkin compared the performance of the helium ion beam with an electron beam, and found that using helium ions made it possible to etch structures much closer together. Since helium ions are larger and heavier than electrons, they can be fired at the substrate surface with less speed and still deliver the same collision energy. As the result helium ions also do much less damage to the surrounding material, because they rebound less far off the surface and penetrate sideways less far into the structure itself.
To allow the distance between separate patterns to be reduced to a minimum an ultra-thin hydrogen silsequioxane (HSQ) lacquer was developed specially for this purpose by TU Delft.
To make a computer chip, silicon wafers are first coated with a thin layer of lacquer called photoresist. This layer is then exposed to light in the pattern desired, using a laser, an electron beam or an ion beam. Electron beams and ion beams are much slower in operation than are laser beams, but they can ‘write’ much smaller patterns onto the lacquer layer. The wafer is then treated so that only the lacquer that was exposed to the ion beam remains.