September 16, 2002 9:00 PM PDT
Intel unfurls experimental 3D transistors
At a presentation in Japan this week, the Santa Clara, Calif.-based chipmaker plans to unveil more technical details behind its Tri-Gate transistor, an experimental circuit that could become a crucial element in the company's efforts to continue to heed Moore's Law by making smaller and faster chips.
Tri-Gate transistors differ from current technology in that, as the name suggests, they have three gates rather than one, said Gerald Marcyk, director of components research at Intel. As a result, they behave more like three-dimensional objects. Transistor gates essentially control the flow of electrons between two structures inside a transistor called the source and the drain. Letting electrons pass, or impeding their movement, creates the ones and zeros that are essential to computing.
Increasing the number of transistor gates increases the amount of current that can be handled, and that boosts performance, said Marcyk, who is presenting a paper on the technology at the International Solid State Device and Materials Conference in Nagoya, Japan.
More importantly, Tri-Gates will cut down on leakage, or inadvertently dissipated electricity, because the required current can be diverted into three channels. Transistor gates right now are only a few atoms thick, and a substantial amount of electricity slips away in transmission, a problem that will get worse as the building blocks of chips shrink.
"We're going to have to have some breakthroughs," he said. "We've been working with planar silicon for 35 years. The ability to get (further) performance, especially power performance, is limited."
The extra gates come from a redesign of the basic transistor structure. Current transistors are essentially flat, with the channel of electrons flowing in a plane on top of the source and drain. "The flow of electrons is planar--it is parallel to the silicon," Marcyk said.
In Tri-Gates, the transistor components rise out of the silicon substrates, like tiny mesas. The three gates sit on top and ride on the two vertical sides of the bulges.
Rival IBM is currently working on a double-gate transistor and has managed to make an entire chip with these types of transistors. Intel so far has only made experimental transistors. Advanced Micro Devices is also performing research on double gates.
None of these companies has fully committed to adopting these sort of transistors for future chips, partly because engineers can still squeeze additional performance out of existing transistors. Other alternatives also exist, Marcyk said. Nonetheless, the early research is promising, he added. Tri-gate transistors can also be made on the existing lithographic processes, which means no breakthrough in manufacturing technology is necessary.
"It's still in the early phase. The device performance is very good," he said. "This is a second-half-of-the-decade kind of thing. It will depend on how much progress we made with it."