Engineers enter fourth dimension with Christmas tree transistors

Scientists at the University of Purdue reckon they can give conventional silicon-based electronics a run for its money with the development of festive ‘4D’ transistors.

The researchers had previously completed plain old three dimensional structures using indium gallium arsenide, a material that is being developed as a potential successor to silicon in computer chips. However, the team’s endeavours into abstract space have revealed the contents of the fourth dimension – Christmas tree shaped transistors.

The Purdue researchers say they have created a system using three nanowires, progressively smaller, creating a tapered cross section that apparently resembles a Christmas tree shape.

Apparently the fourth dimension comes into play with the stacked nanowires also speeding up the operation of the transistors, in addition to the added height.

“A one-story house can hold so many people, but more floors, more people, and it’s the same thing with transistors,” Peide “Peter” Ye, one of the researchers, explained. “Stacking them results in more current and much faster operation for high-speed computing.

“This adds a whole new dimension, so I call them 4-D.”

By creating stacked transistors in this way, the continuation of creating smaller microchips can be continued Ye says.

Engineers are facing increasing difficulties in shrinking silicon based electronics to ever smaller nano-scale processes. Once chip designs pass the 7 nanometre process, creating workable designs becomes much tougher, and engineers are on the lookout for new technologies that can continue Moore’s Law.

Ye believes that the ‘4D’ transistors give a glimpse of the post-silicon world of chips. “It’s a preview of things to come in the semiconductor industry,” he said.