GAINESVILLE --- The era of smaller, faster and cheaper computers may soon end because microscopic silicon chips are getting so small that eventually they will contain too few atoms to work, warn two University of Florida researchers.
"The 'road map' says that in about the year 2010 the limit will be reached. Microprocessors will be as small and as fast as they can get. This unhappy news will have an enormous impact on the national economy," said Kevin Jones, professor of materials science and engineering and co-director of UF's SoftWare and Analysis of Advanced Material Processing, the SWAMP Center.
Jones and SWAMP co-director Mark Law are concerned that the heart of the Pentium processor transistor, a layer that once was thousands of atoms thick, is getting so small that it soon will be only 50 atoms thick. They say the Pentium processor may eventually shrink itself out of function when it gets to be fewer than 10 atoms thick, in just over a decade. That means unless there is a revolutionary change in computer technology, the trend toward smaller, faster computers will have reached its limit.
"The computer industry has its back against the wall," said Law, professor of electrical and computer engineering. "The enormous increase in speed and memory of today's computers came from the ability to make the heart of the microprocessor smaller. But the smaller devices get, the fewer atoms they contain. If the computer industry is going to keep growing and continue to deliver faster products to keep up with consumer expectations, this is a serious challenge that has to be overcome today."
The crisis, they say, was predictable, but the industry has always been able to dodge the bullet.
"For 30 years, people in the computer industry have predicted the 'just-a-decade-away' demise of the continually shrinking, ever-faster but still inexpensive computer chip," said Law. "But clever people have been able to push that 10-year window ever farther out."
The effectiveness of the incredible shrinking Pentium processor is threatened not only by the declining number of atoms, but also by the impurities in microscopic silicon chips. To shrink the transistors requires an understanding of the impurities. Law and Jones are using 3-D computer simulation to investigate the nature of the impurities in silicon, which Law said can cause current to flow where it is not supposed to.
"The bottom line is that impurities in silicon affect the transistors," said Jones. "The question facing us now is, how do you keep three atoms where you put them and keep the impurities from washing out the crystal? Impurities can cause catastrophic failure."
The failure can occur when the impurities run into the crystal and cause the electronic switches to short circuit, said Law.
"We are making predictive models for the industry, trying to do as much testing as possible using computer simulation because testing with real materials is so expensive. We need to know how impurities diffuse, at what rate and at what temperature," said Law. "We can then code that data and build predictive models that allow the industry to design and build better chips."