While every semiconductor company around seems to be losing its head in the rush to copper, Intel Corp. is quietly planning its strategy.

The next-generation semiconductor technology has been the subject of relentless hype since last fall, when IBM Corp. disclosed its dual-Damascene fabrication process. Now, everybody's rushing to board the bandwagon.

Though IBM has gotten the most publicity, Motorola and AMD have also been pacing the pack. For example, AMD has successfully fabricated two test chips with copper interconnects.

To take the technology to the next step, AMD and Motorola's Semiconductor Products Sector have linked up in a seven-year strategic alliance to develop copper for microprocessors and flash memory.

Amid such announcements, observers have been wondering about Intel. Well, the semiconductor giant is not talking much about its stance. "Intel doesn't believe that the tools to implement copper metallization are widely available yet and will wait until the equipment for volume manufacturing is available," a company spokeswoman told me. "We will likely transition to copper at 0.13-micron generation."

But Intel has quietly taken part in the most interesting piece of research in the industry. Rather than deposit the copper interconnect onto the silicon, which is the way IBM's Damascene process works, Intel has tried to figure out how to etch copper interconnects onto a silicon substrate.

That's tough to do, yet Intel's work (conducted with semiconductor-equipment vendor Applied Materials Inc.) may offer the best chance for a practical way to fold copper into a mainstream fab line. Early results are promising. A paper by 11 engineers from the two companies tells the story.

"Recent joint-process development efforts in copper-etch processing with Intel and Applied Materials have shown promising results in areas that had once been significant challenges for this new technology," they write. "Copper-etch process in comparison to aluminum etch included low etch rate, rough sidewall and poor etch profile." These challenges stem mainly from the unique physical and chemical properties of the copper film.

Initial tests produced spectacular results: copper-etch rates of greater than 5,000 A/minute. In addition, post corrosion-free copper-etch performance has been demonstrated for times in excess of 72 hours. These results weren't just for a single wafer, but for 500 wafers, holding out hope that process stability and repeatability may be in the cards.