The future of chip technology

New manufacturing techniques will drive the next big breakthrough in chip miniaturization.

The current method, optical lithography, uses ultraviolet light to record the image of a circuit on silicon. Intel intends to replace that with extreme ultraviolet lithography, a laser technology out of the Star Wars program, which was a U.S. government project to launch a network of laser-armed satellites that would destroy nuclear missiles fired at the U.S. and its allies.

As the Cold War ended and government funding dried up, an Intel-led consortium of semiconductor companies came together to fund extreme ultraviolet research. The first working extreme ultraviolet tool is now available. By 2005, commercial machines using the technology have started building the chips that allow 0.07-micron (and lower) chip technology.

IBM has a competing technology, Prevail, that it is developing with Nikon. Lucent Technologies also competes, with Scalpel. Yet another technology considered is ion beam projection.

After these problems are solved, there will still be some fundamental problems with chip design.

Since their birth, microprocessors have been built around a clock. With each tick, the entire state of the chip changes. The clock-speed of a microprocessor determines how many instructions per second it can execute a one-GHz clock-speed represents a billion cycles per second.

"That is very cumbersome," said Steven Hillenius, director of the silicon device research department at Lucent Technologies' Bell Labs. "The clock signal has to be communicating to the whole chip at the same time." A new design could change that. "Instead of having individual binary logic, we will start looking at logic that's not binary, like neural networks," said Hillenius. A neural network is a type of artificial intelligence that imitates the brain. "If you could make a device that looks more like an animal's brain, it would work better in silicon than in carbon," Hillenius added. Instead of counting ones and zeroes, a neural network is a series of interconnected processing elements, the computer equivalent of a brain's neurons and synapses.

"When you compare a super-computer recognizing a fly and producing a response, with a frog doing the same thing, it becomes very clear that the frog can do it better," suggested Hillenius. Bill Ditto, a professor of biomedical engineering at the Georgia Institute of Technology, calls biology-based computers "the next, next generation of computers". Using neurons to perform computing is exciting, he said, because unlike silicon-based chips, an upgrade to the next level of processor isn't necessary to get more speed. "It does computations through making more connections and adding more neurons," Ditto said.

While scientists see evidence that biological computers will work, they still haven't found a way to program them. That's what Ditto is working on. His research team has succeeded in using leech neurons to do arithmetic. They hooked up the neurons to a personal computer. They stimulated the cells, using the principles of chaos theory. The PC then used the biochemical response to do simple addition.

"It's a first step. Think back to the early days (of silicon computing) when you had giant transistors. You know the writing is on wall but you don't know if a use for the technology is five years out or 30," Ditto said.

Two other promising developments include work at the California Institute of Technology where neurons were successfully connected to a computer to control a simulated animal. At Northwestern University, researchers have been using a lamprey brain stem to detect light from an artificial eye to help steer a mobile robot. "My interest is not to create a cyborg," said Sandro Mussa-Ivaldi, associate professor at Northwestern's department of physiology, "but to use this behavior to understand connections in the brain." Such research will help build a functioning bio-computing device one day. Ditto's hopes to have proof of concept for such a device within five years. He believes something useful will come within ten years. "We are shooting to have a box with something living inside it that can solve a problem a hell of a lot faster than a conventional computer by then," Ditto said.

While fascinating strides are being made with living cells, some researchers are going even smaller in the field of molecular computing.

Current computers use switches etched in silicon but future computers might use molecules, clusters of atoms. That would mean that molecular electronics - or moletronics - could replace transistors, diodes, and conductors in conventional microelectronic circuitry.

Mark Reed, chairman of electrical engineering at Yale University, and James Tour, an organic chemist at Rice University, are heading a team in this research. They have developed a one-molecule on-off switch that works at room temperature. Strings of molecules would be assembled together to form simple logic gates that function like today's silicon transistors.

In the June 2000 issue of Scientific American magazine, Reed and Tour wrote: "If the conventional transistor were scaled up so that it occupied the printed page you are reading, a molecular device would be the period at the end of this sentence.

Even in a dozen years, when industry projections suggest that silicon transistors will have shrunk to about 120 nanometers in length, they will still be more than 60,000 times larger in area than molecular electronic devices."

The size advantage means a molecular computer would consume very little power. It also "has the potential of vaster computing power," said Reed, though he cautioned, "it's a field in initial stages of development," adding estimates of when the technology could be commercialized are pure speculation.

Similar research is going on at Xerox in Mississauga, a Toronto suburb.

Chemists are engineering transistors made of molecules that will be strung together into nano-circuits by scientists at Xerox PARC, in Palo Alto, California. Dow Chemical and Motorola are also involved.

The resulting "plastic" circuits aren't designed to replace silicon microprocessors, said Sophie Vandebroek, vice-president, Xerox Research and Technology, but they could provide new display technologies, control electronic paper, and work with silicon microprocessors.

One of the offshoots of molecular computing is DNA computing. DNA (deoxyribonucleic acid) refers to the double helix molecules that are the blueprints of an organism.

Researchers believe it is possible to build microscopic ultra-fast devices with awesome computing power out of DNA.

"DNA computing is the most manageable form of molecular computing that we know of," said Nadrian Seeman, a chemist at New York University who has made cubes, rings, octahedrons, and other unusual shapes from DNA molecules.

What's exciting about these building blocks is they can be programmed to do nano-assembly, meaning they can be used in the construction of ultra-small devices. That includes computer circuits only nanometers in size storing information in a single molecule. Miniature medical robots reproducing themselves by the billions that scour a patient's body to assassinate viruses could also be built.

Then there's quantum computing, where the sub-atomic world is used to do basic math using the bizarre and often counterintuitive principles in quantum physics.

« Previous Page  1 | 2 | 3  Next Page »

Enter your search terms Submit search form Cyberwalker.com Web