3D Chip Breakthrough Could Extend Moore's Law, Researchers Say

Researchers at the University of Illinois Urbana-Champaign have developed a method to stack silicon transistors vertically, creating true 3D computer chips that could extend Moore's Law into the next decade.

Moore's Law, the 1960s prediction by Intel co-founder Gordon Moore, states that the number of transistors on a chip should double every two years at the same cost. But manufacturers have hit physical limits on how small they can make components on a flat surface.

Instead of shrinking further, the team built upward. They used 'junctionless' transistors and ultra-thin silicon nanomembranes, which can be applied at temperatures below 200°C, avoiding damage to lower layers that occurs with traditional high-temperature fabrication at 1,000°C.

This 'monolithic' integration method allowed the researchers to stack three functional layers, including working logic circuits and memory. They say it can be scaled commercially, though higher voltages are still required for operation.

"It's like replacing a sprawling suburb with high-rises," said materials scientist Qing Cao. "You get the same functionality, but the spatial footprint is reduced while communication between layers is faster and more efficient."

The research was published in the journal Nature.