Intel announces TeraHertz transistor

Intel announced the development of a new transistor that can be turned on and off 1 trillion times per second, roughly 500 times faster than the transistors used in today's leading-edge 2 gigahertz Pentium 4 processors.

Unlike other recent dramatic transistors advances, the Intel component is highly manufacturable in the next few years. The so-called TeraHertz transistor solves two of the most difficult challenges in making transistors smaller and faster. The first problem is the increased heat transistors produce as they are packed closer together.

"What's going to limit transistor performance is the power consumption, not the speed or the size," said Gerald Marcyk, director of components research in Intel's technology and manufacturing group. "Our goals is to have 25 times more transistors in processors than in current ones, running at 10 times the speed, yet with no increase in power."

The other problem is that as transistors get smaller the distances between the "source" and "drain" in a transistor gets smaller. This frequently causes what is knows a "off-state leakage," in which electrons pass from the source to the drain when no power is supplied to the transistor's "gate." Intel engineers were able to reduce the level of off-state leakage by a factor 100 compared to other transistors using the new silicon-on-insulator substrate technique.

The reduction in off-state leakage was achieved by what Intel calls a "depleted substrate transistor." Using a "silicon-on-insulator" substrate, the transistor is built in an ultra-thin layer of silicon on top of an embedded layer of insulator.

Because this insulator is thinner than other types now used, all of the electrons get used up. That results in what is called "maximum drive current," which in turn switches the transistor on and off faster.

The new transistors will be available in portions of Intel's microprocessors as early as 2005 models. "The real significance is that they've invented a new transistor technology that is both fundamentally different and manufacturable. They've completely re-engineered the transistor as we know it," said Dan Hutchinson of the San Jose market research firm VLSI Research.

The TeraHertz transistor will almost certainly allow Intel and the rest of the semiconductor industry to extend the famous 1965 "Moore's Law" that states that the number of transistors on a chip doubles every 18 months to 24 months with a 50 percent reduction in cost.

Intel's Pentium 4 has 42 million transistors. With the new transistors, Marcyk foresees processors that will contain more than 1 billion transistors by the end of this decade as Moore's law would dictate. Intel also said it has developed a new proprietary insulator material replacing the traditional silicon-dioxide (glass) on the wafer. The insulator layer sits at the bottom of the gate and between the source and the drain.

Intel said that this new material reduces gate leakage by more than 10,000 times compared to silicon dioxide. The huge increase in transistor speed results from the compounded effect of the reduced power consumption and leakage.