While lying on the beach during a vacation on the Spanish coast in 1999, physicist Jamal Ramdani had an epiphany. As the sand complied to the contours of his body, Ramdani, a researcher at Motorola Labs in Tempe, AZ, suddenly envisioned a solution to a puzzle that had perplexed the semiconductor industry for 30 years: how to combine cheap silicon with high-speed, light-emitting but far more expensive semiconducting materials like gallium arsenide, all on a single wafer.

Because the materials are physically mismatched, layering one on top of the other to produce a chip with optimal electronic and optical properties has been virtually impossible. It may have been the sand on that Spanish beach, which is made of the same mineral from which silicon wafers are derived, that provided Ramdani with the pivotal hint. In any case, Ramdani recalls, "I came back to Phoenix, borrowed a machine for growing compound semiconductors, and in two or three shots, we had gallium arsenide sitting on silicon."

The benefits of having the functionality of gallium arsenide-particularly its abilities to handle wireless communications and emit light-on an inexpensive silicon chip were not lost on Motorola executives. High-performance chips made out of gallium arsenide and other so-called compound semiconductors are widely used in everything from cell phones to switches in optical communications networks. At the very least, Ramdani's invention could mean replacing these costly chips with far less expensive gallium-arsenide-on-silicon ones. In the two years since Ramdani's breakthrough, Motorola has filed over 300 patents on the technology; last fall, the company used Ramdani's method to build prototype chips for boosting signals in cell phones. To commercialize the new material, Motorola has started up a wholly owned subsidiary-Thoughtbeam, in Austin, TX-promising the new materials will find their way into electronic and optical devices within the next two years.