Lasers make the cut as small tech shrinks

HANNOVER, Germany, April 18, 2002 — Udo Klotzbach, of the Fraunhofer Institute for Material and Beam Technology, summed it up when asked why lasers will play a larger role in small tech.

“Because we don’t have anything much smaller than a 10 micrometer drill,” he said.

As microsystems get smaller and smaller, it will become essential to use laser light to drill under the 10 micrometer range.

Lasers are nothing new, of course, but they are finding more applications in everything from thin-film technology to sensors to micromachining, and the market is growing. According to the German Engineering Federation (VDMA), the market for lasers in Germany was worth $659 million last year. Worldwide sales of laser systems rose from $1 billion in 1990 to $3.6 billion in 2000 — an average annual growth rate of 12 percent. The VDMA expects that growth to increase to 20 percent over the next few years.

Twenty-four laser technology exhibitors are on hand at the Hannover Trade Fair this week to show off their latest developments. Not all are involved in small tech; some specialize in engraving applications, macroprocessing technologies, or modeling and simulation. But others have aimed their beams at micro targets; here, the benefits of laser light become crystal clear.

Laser beams can be focused finely enough to ensure precision even down into the micrometer range. Holes in the range of several hundred nanometers are possible with lasers, as is generating microstructures that require the tiniest cuts and bores in metals, ceramic disks or silicon wafers. Other methods, such as diamond sawing, punching, or eroding are not as precise, can be too slow and can wear down tools.

“You never have to resharpen a laser,” said Gerd Spiecker of Lambda Physik, one of the leaders in the German laser field.

Process efficiency is also higher compared to other techniques. The laser converts most of the energy it absorbs into the actual process, with little heating of the environment. Therefore, lasers treat sensitive components gently, keeping material properties intact and allowing mechanical components to keep their dimensional accuracy.

There are two developments in laser technology that have a lot of people talking this year. The first is lasers using Extended UV (EUV) beam source technology. These lasers are going to figure large in the semiconductor industry as the need for smaller, more precise processing is called for.

Current state-of-the-art lasers have a wavelength of 248 nanometers, which is sufficient for them work with the latest Intel processor chips, for example. But the next step is to get the wavelength down — first to 157 nanometers and then, with the EUV lasers, down to 13.5 nanometers, which allows for better focusing, smaller cutting groove widths and much higher precision for the smaller feature sizes of future chips.

“The market potential for this laser is huge,” said Alexander Bayer of the Fraunhofer Laser Technology Institute. Unfortunately, it’s still a way off. While predictions are that lasers with 157 nanometer wavelengths will appear in three or four years, the EUV 13.5 nanometer wunderkind is not expected to go into production until 2008 or so.

Another development that is somewhat further along and has the industry buzzing is the femtosecond laser, a machine that emits ultrashort pulses of light in the range of several hundred femtoseconds. A femtosecond is one quadrillionth of a second — not a very long period of time. In fact, a femtosecond is to a second what a second is to 32,700,000 years.

The pulses of light from the laser are so short that they do not have the thermal effects on materials that other lasers have, nor do they leave even the minutest amount of residue around the hole or canal that has been made. The damage-free work of this laser, plus its ability to create structures in the submicron range, are what make it such an exciting development, according to Michael Botts of the Hannover Laser Center, a research and development consulting institute.

“Now, we wouldn‘t use a femtosecond laser to cut a car door,” he said. “But in the micromachining range, we’re talking about working on materials that are very sensitive to heat or just making very, very fine structures in materials.”

Potential applications include microdrilling holes of 100 to 200 microns in diameter in fuel injection nozzles, cutting stents for the treatment of arteriosclerosis or restructuring the bones of the inner ear.

Klotzbach of the Fraunhofer Institute said femtosecond lasers now are somewhere between the lab and the market. “You can get one, but you‘ll have to pay about $250,000, plus hire a physicist to help you run it,” he said. “But just give it a little more time, then you’ll see them everywhere.”

At Hannover, one booth in the Laser Technology section was devoid of high-tech equipment, yet caught the eye of more than a few passers-by. It was run by Deutsche Bank. Kai Rugowsky is the head of the bank‘s “Innovation Team,” which tries to hook up investors with small- and medium-sized laser and microtechnology companies.

“It‘s not easy, but it’s not impossible,” he said when asked how difficult it is for new laser technology companies to find capital these days. He said investors want to know if companies have real markets now, or if the markets haven’t developed yet, when they will.

“Substance is what investors want in a company,” he said. “Even if it just works with rays of laser light, substance is still important.”

More news from Hannover Fair 2002
Solutions come in small packages for German firm with new process
Microtechnology road maps point in different directions
Microtech section is small, but it’s ‘where the action is’


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