'Ion pen' used to draw graphene circuits

Graphene is already being talked about as a potential replacement to silicon, but certain problems have to be negotiated around if the wonder material is to power a future generation of chips.

There are various barriers to the commercialisation of graphene – for example, band gap problems – meaning that circuit production from one atom thick sheets is still a while away. 

Another problem is how to reliably manufacture the material on a large scale without damaging graphene’s ‘wonder’ properties.

A team of researchers at the University of Florida has developed a new technique that stops the thermal ‘etching’ process in circuit production from affecting the graphene.

Creating graphene patterns on top of sheets of silicon carbide at high temperatures of 1,300 Celcius, the team was able to vaporise the silicon. This left just carbon, which is then able to grow into pure graphene.

Usually an etching process would be used, but this can introduce defects or chemical contaminants which can reduce graphene’s electron mobility – one of its prime qualities.

The team’s technique meant that it could grow tiny areas of graphene with great accuracy.  Furthermore, by implanting gold or silicon ions, the team was able to drop the temperature at which grapheen formed by 100 degrees. 

This meant then were able to ‘draw’ on the implanted ions wherever they wanted, before increasing the heat to 1,200 Celcius.  In turn, the rest of the silicon carbide remained the same, while the ‘ion pen’ markings formed the graphene circuitry.