Hafnium diselenide and zirconium diselenide both form stable, high K oxides in layers just a few atoms thick with a similar bandgap to silicon. The new materials can also be shrunk to functional circuits just three atoms thick and they require less energy than silicon circuits. Although still experimental, the materials could be a step toward the kinds of thinner, more energy-efficient chips says Eric Pop, an associate professor of electrical engineering.
“Engineers have been unable to make silicon transistors thinner than about five nanometers, before the material properties begin to change in undesirable ways,” said Pop, who co-authored with post-doctoral scholar Michal Mleczko a paper that appears in the journal Science Advances.
“Silicon won’t go away, but for consumers this could mean much longer battery life and much more complex functionality if these semiconductors can be integrated with silicon,” he said.
The next step is to refine the electrical contacts between transistors on the ultrathin diselenide circuits. “These connections have always proved a challenge for any new semiconductor, and the difficulty becomes greater as we shrink circuits to the atomic scale,” said Mleczko.
The materials will also have to be integrated with other materials and then to scale up to working wafers and complex circuits. “There’s more research to do, but a new path to thinner, smaller circuits – and more energy-efficient electronics – is within reach,” said Pop.