By Jo McIntyre
Small Times Correspondent

PORTLAND, Ore., Oct. 12, 2001 — As high-tech products grow smaller, engineers require smaller instruments to work on them.

At the heart of some of those instruments might be cone-shaped carbide crystalline tips with a radius of 100 angstroms, or 10 nanometers at the top and 0.5 micron at the base. Electrons stream off of these tips to do their jobs.

That’s where Applied Physics Technologies Inc. of McMinnville, Ore., shines. The company makes the metal carbide tips that emit electrons in a tiny beam that can be

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This carbide crystalline tip, with a radius of 100 angstroms, or 10 nanometers at the top and 0.5 micron at the base, emits electrons in a tiny beam.

directed to many uses, such as inspection or manufacture of integrated circuits. They might even find their way into a spacecraft propulsion system.

“We’re getting calls daily looking for electron sources for those uses,” says William A. Mackie, president and co-founder of the company, known as Aptech in Oregon. The company is not to be confused with Aptech Systems, Inc., of Maple Valley, Wash., which makes software that analyzes statistical data.

Applied Physics’ devices “are robust and can work in hostile environments,” Mackie said. He recently fielded a call from a “well-known aeronautics company” about whether the company could make sources for a type of ion thruster that could be used at very high altitudes. The answer is “Yes.”

Founded in 1995, the company is privately held and self-funded by Mackie and co-founder Gary Cabe. It was formed as an outgrowth of research conducted for more than a decade on transition metal carbides and field emission sources.

There are nine transition metals in Groups IV to VI on the periodic table of elements. Tungsten is the most popular, but other metals are zirconium, hafnium and molybdenum. Each metal element can combine with carbon to form a new substance, a transition metal carbide or a refractory carbide.

In addition to their stability at high temperatures, these compounds are extremely hard, and therefore are finding industrial uses in cutting tools and wear-resistant parts, as well as tips for Aptech’s beam emitters.

Aptech specializes in these substances and related support systems to provide electron sources for use in various potential applications, including flat panel displays and other high brightness sources, charge neutralization systems and space propulsion systems.

The company has facilities for growing single crystals of various transition metals and carbides as well as mounting and etching methods for field emitter manufacture. They can also vapor deposit carbide films for various applications.

Other services include electron emission measurements on custom products. “We are also looking at several new materials for use in hostile environments. These products can operate at higher pressures approaching one atmosphere, or standard air pressures,” he explained. Most electron sources run in an ultra high vacuum.

Mackie and Cabe’s early research was done at Linfield Research Institute, based at Linfield College in McMinnville, where Mackie received his undergraduate degree. Aptech already has 20 employees as demand for their products by industrial, government and academic research labs increases.

The company has no plans for a public stock offering at this time, but Mackie does not preclude the possibility if the company develops a sudden need for a large infusion of capital.

The tall physicist obtained his advanced degrees from Beaverton-based Oregon Graduate Institute, OGI, a formerly private school dedicated to providing advanced engineering and physics education. OGI recently merged with Oregon Health Sciences University to add a medical and biological component to its offerings. The combined institution is now known as Oregon Health and Science University.

“We just got a call from a U.S. company in Germany needing inspection tools for integrated circuit wafers,” Mackie said. IC wafers contain memory chips used in computers and other electronic products. The inspection tools use an electron beam to inspect the wafer. These beams can also be used in electron beam lithography – an imaging process for IC manufacturing.

Semiconductor manufacturers like Intel use electron beams to write on mask layers to make electronic circuits on the chip. The electron beam lithography devices are installed in micro-electronic manufacturing systems, MEMS, and used to make both etching tools and inspection devices. Electron beam lithography make it possible for the ICs to be even smaller, getting more information into less space.

In flat panel video displays, electron emitters energize the phosphers in the panels to make the pictures, used on laptop and hand-sized computers, cell phones and products displaying information on flat surfaces.

Aptech also is working on a particle thruster, which emits both ions and electrons to propel spacecraft in space. Originally it was to be an ion thruster, but losing all the ions charged the spacecraft and drew it back to its original position. Researchers had to devise a way to emit electrons to neutralize the spacecraft, so it could be propelled in a desired direction.

Capp Spindt is a leading researcher at SRI International, a 55-year-old nonprofit organization based in Menlo Park, Calif., which conducts scientific research in chemistry, physics and engineering for government, industry and universities.

In research on using microfabrication techniques to make field emission sources operate at low voltage, the most exciting application today is for use on spacecraft, such as communication satellites, he said.

Spindt is involved in vacuum microelectronics technology, field electron and ion emission devices, and high performance field-emitter array cathodes. He has worked with Mackie for years on microfabrication of structures for use in vacuum environments.

While Aptech’s “core business is the field emission and general electron sources, the company’s major research thrust is now in space applications,” he said. “As spacecraft move through space, they accumulate charge from a variety of sources. That can disrupt communications and can damage the electronics aboard the craft as well and is a main cause of failure of solar panels.”

That’s where Aptech fits in. “Our niche is that our carbides work in more hostile environments and at higher currents,” Mackie said.

The company is also working on tethers for low or high orbit altitude adjustments. Right now, there is no easy way to get rid of “space junk,” satellites floating in space. In the future, tethers will be tied to satellites and, powered by electron currents in the tether, would pull a spacecraft down to burn up in the atmosphere.

Their bread and butter is large transition metal and refractory metal crystals. “This is the fun stuff,” Mackie says, with a grin.