Thin films integrate novel oxides onto silicon substrates

  

The functional materials are oxides, including multiferroic materials, topological insulators and novel ferroelectric materials – all thought to hold promise for applications including sensors, non volatile memory and MEMS.

“These novel oxides are normally grown on materials that are not compatible with computing devices,” said Professor Jay Narayan, pictured. “We are now able to integrate these materials onto a silicon chip, allowing us to incorporate their functions into electronic devices.”

The approach is enabled by two platforms, both of which are compatible with silicon: a titanium nitride platform, for use with nitride based electronics; and yttria stabilised zirconia, for use with oxide based electronics.

Specifically, the team, which included scientists from the US Army Research Office, developed a suite of thin films that connect the silicon chip to the relevant materials by aligning the planes of the crystalline structure in the oxide materials with the planes of the underlying substrate.

With multiferroic materials, researchers use a combination of titanium nitride, magnesium oxide, strontium oxide and lanthanum strontium manganese oxide films. For topological insulators, a combination of magnesium oxide and titanium nitride films is used.

“Integrating novel materials onto silicon chips makes many things possible,” Prof Narayan said. “For example, this allows us to sense or collect data, manipulate that data and to calculate a response – all on one chip. This makes for faster, more efficient, lighter devices.”

It may also be possible to integrate LEDs on silicon chips to make ‘smart lights’.