Silicon pillars yield like metal

Researchers in Switzerland have demonstrated how minute silicon pillars yield to pressure under load and undergo plastic deformation in the same way as metal.

The findings from Empa (Swiss Federal Laboratories for Materials Testing and Research) are contrary to long-held beliefs about the properties of silicon.

Silicon is usually considered to be as brittle and breakable as window glass. The Empa research team demonstrated that this is not the case if silicon is fashioned into pillars of diameters less than 400nm.

Silicon is the most commonly used raw material in the semiconductor and photovoltaic industries, yet the material’s brittleness presents limits.

Johann Michler, head of Empa’s Mechanics of Materials and Nanostructures laboratory in Thun, and his colleagues showed how this brittleness disappears on the nanometre scale.

The team demonstrated this by treating a silicon plate using a Focused Ion Beam (FIB) instrument, which is used for the analysis and preparation of surfaces.