The sun shines on semi tool makers


By Hank Hogan

Semiconductor tool makers might switch some U.S. production to equipment that manufactures photovoltaics, which convert sunlight into electricity. However, this production change may not happen soon due to various issues, say analysts.

At first glance, photovoltaics seem like an ideal target for tool makers. At their heart, today’s solar cells are doped silicon and metallic conductors fabricated on wafers. That’s a combination equipment makers are very familiar with. A potential successor technology, thin-film polysilicon, is also well known to tool makers.

What’s more, the growth in photovoltaics is high and predicted to stay that way. “We’ve seen the growth rate for revenue from solar cells running about 40 percent a year for the last few years,” says Gartner research director Jim Hines.

As an added incentive for tool makers, the waiting time for photovoltaic manufacturing equipment can be long. Eddy Blokken, director of standards and technology for the trade group SEMI Europa, has global responsibility for photovoltaics. He notes that tool lead time can be 12 to 18 months. “It’s at this moment more of a vendor’s market,” he says.

Understandably, photovoltaics are attracting attention from a variety of equipment manufacturers. Applied Materials (Santa Clara, CA), a well known semiconductor tool maker, has acquired a number of companies and formed a solar business group. Meyer Burger (Thun and Baar, Switzerland) makes wafer cutting equipment used in chip manufacturing. The company is pushing its technology in the solar market. And Blaubeuren, Germany-based Centrotherm, which makes furnaces for semiconductor manufacturing, is also moving into photovoltaics.

Much of this activity is in Europe, partly as a result of substantial government subsidies for photovoltaics. However, there are reports that Applied is thinking of transferring some of its solar production to the U.S., perhaps making equipment in Texas if the right incentive package can be hammered out.

SunFab thin-film solar cell production line. Photo courtesy of Applied Materials.
Click here to enlarge image

That brings to a point the major hurdle tool makers face. Photovoltaics have no equivalent to Moore’s Law, the observation that the number of transistors on a semiconductor chip doubles roughly every two years. Moore’s Law translates into complex and constantly evolving processes and tools.

In contrast to semiconductors, solar cells have simpler manufacturing, with much less stringent contamination and process control requirements. In part because there’s no solar Moore’s Law, photovoltaics compete on cost alone, making incentives important.

This doesn’t mean that semiconductor expertise can’t come in handy in solar cell manufacturing, notes Gartner’s Hines. For instance, the cost of silicon is currently a major contributor to the overall photovoltaic cost. Thus, semiconductor dicing technologies that keep waste silicon to a minimum are of interest.

As solar cell manufacturing scales up to cut costs, the material handling knowledge from semiconductors could be important. “There’s some learning that could be transferred from the semiconductor industry in that area, particularly when you look at some very large-scale operations,” says Hines.

Today, equipment is about a third of the photovoltaic supplier market, with the rest material. As photovoltaics mature, SEMI Europa’s Blokken sees the ratio changing. This shift could make more complex tooling attractive, as well as making semiconductor-style process and contamination control techniques more applicable.

However, the benefit of greater cleanliness and more expensive tooling will have to be weighed against its cost. “For the photovoltaic industry, it will always be a balancing act,” says Blokken.