New ‘3-D’ Transistors Promising Future Chips, Lighter Laptops

Researchers from Purdue and Harvard universities have created a new type of transistor made from a material that could replace silicon and have a 3-D structure instead of conventional flat computer chips.

The approach could enable engineers to build faster, more compact and efficient integrated circuits and lighter laptops that generate less heat than current models. The transistors contain tiny nanowires made not of silicon, like conventional transistors, but from a material called indium-gallium-arsenide. Indium-gallium-arsenide is the same compound recently used in a high-performing solar cell.

Computers implementing these new 3-D transistors will be able to run faster— and should also weigh less and generate less heat than their present-day flat-transistor-using counterparts.

Transistors contain critical components called gates, which enable the devices to switch on and off and to direct the flow of electrical current. In today’s chips, the length of these gates is about 45 nanometers, or billionths of a meter. However, in 2012, the industry will introduce silicon-based 3-D transistors having a gate length of 22 nanometers.

Their new and improved shorter gates are made from dielectric-coated silicon nanowires, and it is estimated that such gates could be further shortened to about 14 nanometers within a few years. In order to go any shorter, however, a material is needed that can move electrons faster than silicon is able to.

Studies of the indium-gallium-arsenide gates suggest that they should be able to move electrons five times faster than silicon gates, allowing for gate lengths in the neighborhood of just 10 nanometers.

At any length below 14 nanometers, the silicon dioxide insulating layer currently used on transistor gates no longer works properly, allowing the electrical charge to leak out.

The production process for the 3-D indium-gallium-arsenide transistors could be easily implemented into existing manufacturing processes, the scientists report, so adoption of the technology on a wide scale ought to be feasible.

Next year, if you buy a computer, it will have the 22-nanometer gate length and 3-D silicon transistors.