PHIAR'D UP: Phiar's metal-insulator technology stacks metals and insulators at nanoscale thicknesses to enhance the performance and cut the costs of wireless networks, introducing a simpler, less expensive manufacturing process compared to silicon-based semiconductors. Image: Courtesy of Phiar Corp.
Wireless networking technology will one day deliver high-definition video content and other large data files via the airwaves far faster than that information can be now be delivered over wired systems. But it will take major advances in the electronics that drive computer and radio-frequency systems to create such a high-powered wireless highway.
One of the most basic examples of such a system is a laptop computer equipped with a radio for wireless connectivity. The computer's performance has generally been improved through upgrades in digital semiconductor performance: shrinking the size of the semiconductor's transistors to ramp up transaction speed, packing more of them onto the chip to increase processing power, and even substituting silicon with compounds such as gallium arsenide or indium phosphide, which allow electrons to move at a higher velocity.
The key to squeezing higher performance out of the radio side of the equation, according to one company, is using metal-insulator components. "We are potentially at another stepping point, where instead of solid-state semiconductor electronics, we will have metal-insulator electronics," says Garret Moddel, chief technology officer and chairman of Phiar Corporation in Boulder, Colo.
Moddel has good reason to believe this, given that his company builds diodes, radio-frequency (RF) detectors and RF receivers using metal-insulator technology.
Although Phiar's technology will not be commercially available until next year, the company's approach is expected to enhance the performance and cut the costs of wireless networks by introducing a simpler, less expensive manufacturing process. The company does this by using stacks of metals and insulators at nanoscale thicknesses—tens of angstroms, a unit of length equal to one ten-billionth of a meter; the space between atoms is generally two or three angstroms—to create high-frequency, up to three terahertz. (A terahertz is a trillion hertz, a thousand times speedier than a gigahertz-level processor, but slower than an optical network.)
"We're bridging the performance between photonics and electronics," says Adam Rentschler, Phiar's director of business development.
Conventional semiconductors are built using silicon-based substrates (the material upon which semiconductor devices are fabricated), but metal-insulator electronics can be made atop less pricey glass, metal or plastic substrates. Phiar's approach is to place two metal layers on either side of a double layer of insulation. When voltage is applied, electrons tunnel through the insulator layers with the help of a "quantum well" that forms between the two insulators.
Phiar will not specify which metals it uses, it is a trade secret, but says they are amorphous rather than crystalline, like silicon. This means these metals can be layered on top of a variety of other substances, including standard complementary metal–oxide semiconductor (CMOS) circuitry. As such, Phiar's metal-insulator diodes or other electrical components could be combined with semiconductors on the same microchip. Among other potential options: using metal-insulator radios to replace the copper chip-to-chip interconnect wires on today's printer circuit boards, eliminating one of computing's worst performance bottlenecks. In the more distant future, metal-insulator devices could even replace the digital transistors within a semiconductor.
Phiar's technology is expected to hit the market through a series of partnerships. Phiar and Motorola, Inc., last year signed a joint development agreement that could make Phiar's metal-insulator electronics an integral part of the 60-gigahertz mobile wireless high-definition multimedia interfaces and imaging technologies that Motorola is developing. Motorola has successfully incorporated Phiar's metal-insulator diodes into a 60-gigahertz prototype system and demonstrated multigigabit-per-second data rates.