Small is beautiful
This is a periodic table with a difference – it’s a world record breaker. Gold was deposited onto a monocrystalline piece of silicon using a combination of electron beam lithography (EBL) and thermal evaporation. It’s the smallest periodic table in the world.
The record-breaking table was created to mark a visit to the University by Professor Yuri Organessian – the only living person with an element named after him – and to commemorate the 150th anniversary of the periodic table. Miniaturised portraits of Organessian and the creator of the periodic table, Dmitri Mendeleev, were etched into the silicon alongside the table.
We use silicon extensively in EBL as it can be made into extremely flat and smooth wafers and its semi conductor properties means it’s possible to create nanometre (nm)-sized features. It is also relatively easy to etch using a plasma etcher – allowing us to create the three-dimensional portraits.
"By using EBL we were able to make a periodic table that had a surface area over 40 times smaller than the previous record."
By using EBL we were able to make a periodic table that had a surface area over 40 times smaller than the previous record. While creating the portraits is just a bit of fun, the ability to create three-dimensional structures in silicon with resolution in the 10s of nanometres range gives us the opportunity to make devices such a micron-sized lenses.
The ability to create structures with nm precision is of vital importance to a huge number of different research groups, from those wanting to create the next generation of electrical components to others wanting ways to trap and manipulate nm sized structures such as cancer cells so they can better image and understand them.
Dr Richard Cousins is a Senior Electron Beam Lithography Technician at the University’s Nanoscale and Microscale Research Centre.