The novelties of nanotech
Carbon nanotubes could perform a number of functions inside of future chips. Certain types of nanotubes could be used inside a transistor to control the flow of electrons, replacing silicon. Additionally, slightly different nanotubes could replace the copper wire connecting transistors. Generally, a given material (carbon) won't behave as would a semiconductor, like silicon, or a metal, like copper. The properties of nanotubes change with how the atoms are arranged, even though they're all made of carbon. It's one of the novelties of nanotechnology.
The tubes could also be used to conduct heat out of a computer. Using nanotubes inside transistors or to connect them may not start happening in chips until 2012 or 2015, David speculated, but they could start to serve as a way to cool PCs earlier.
Experimental results with nanotube and nanowire transistors show that these elements could provide three times the performance of conventional transistors at the same power level. Like other companies, such as NEC, Intel is experimenting with ways of growing the nanotubes directly onto a silicon wafer.
This process requires a 900 degree Celsius environment, microscopic balls of iron, and a gaseous bath of hydrogen and carbon monoxide. Now, many of the experimental nanotube transistors are made by creating a nanotube in a separate chamber and surgically inserting it into a silicon wafer.
Intel is also tinkering with ways of making chips out of wafers with layers of gallium arsenide and other so-called "III-V" compounds. Some communications chipmakers use these materials now, but "it is really hard to build these things on a large scale," David said. Ideally, Intel would like to figure out a way of retaining silicon as the basic wafer material and graft in layers of III-V materials.
Then, sometime around 2020, developing tricks to shrink CMOS or CMOS-flavored transistors will come to an end. Transistors will consist of only a few atoms, making it impossible to shrink them further.
Among some of the more promising ideas are spintronics, the science of creating ones and zeros by controlling the spin of electrons. Another possibility is the use of "phase change" devices, in which data is recorded by changing the physical state of a medium. Compact-disc-like material that can be melted, or crystallised, in microseconds is an example of a phase change substance. Optical technology may also get integrated into chips.
Intel is seeding university labs to conduct experiments on these projects. Projects are ongoing at the University of California at Santa Barbara, the Georgia Institute of Technology and Yale University.
Although developing these new chips and materials won't be easy, with the advent of nanotechnology, governments around the world have dramatically increased their investment in chip technology. In 1997, government-funded research worldwide for nanotechnology in came to around $500 million. In 2003, it rose to $3.5 billion.
"For 20 years, there had been no investment in the basic sciences," Gargini said. "It was like Santa Claus was coming to town."
