New fabrication process for diamond for next-era transistors

May 18, 2017 // By Jean-Pierre Joosting
Most transistors are silicon-based and silicon technology has driven the computer revolution by continuously shrinking the average transistor size and dramatically reducing its production costs. The current generation of smartphones, for example, relies on chips that each feature over 3.3 billion transistors.

However, in some applications silicon has significant limitations. These include use in high power electronic devices and in harsh environments like the engine of a car or under cosmic ray bombardment in space. Silicon devices are prone to faltering and failing in difficult environments.

Addressing these challenges, Jiangwei Liu, from Japan's National Institute for Materials Sciences, and his colleagues describe new work developing diamond-based transistors this week in the journal Applied Physics Letters, from AIP Publishing.

"Silicon-based transistors often suffer from high switching loss during power transmission and fail when exposed to extremely high temperatures or levels of radiation," Liu said. "Given the importance of developing devices that use less power and perform under harsh conditions, there has been a lot of interest within the broader scientific community in determining a way to build transistors that utilizes manufactured diamonds, which are a very durable material."

With this very interest in mind, the team developed a new fabrication process involving diamond, bringing "hardened electronics" closer to realization.

"Manufactured diamonds have a number of physical properties that make them very interesting to researchers working with transistors," said Yasuo Koide, a professor and senior scientist at the National Institute for Materials Science leading the research group. "Not only are they physically hard materials, they also conduct heat well which means that they can cope with high levels of power and operate in hotter temperatures. In addition, they can endure larger voltages than existing semiconductor materials before breaking down."