"Unless we do something radical pretty soon, the microelectronics revolution that has enriched our lives in so many different ways might come to a screeching halt," predicts Jesus del Alamo, a professor of electrical engineering and computer science at Massachusetts Institute of Technology.
The problem? Silicon transistors within the next 10 to 15 years will reach size and performance limits, engineers estimate. That is why del Alamo and others researchers are looking at alternative semiconductor materials.
A particularly hot prospect is indium gallium arsenide, or InGaAs. Electrons in the material travel many times faster than in silicon, so it should be possible to make smaller, faster-switching transistors. Del Alamo's group recently demonstrated an InGaAs transistor that carries 2.5 × more current than state-of-the-art silicon equivalents. The ability to carry higher current is key to faster operation. Further, InGaAs transistors are only 60 nm in length, similar in size to cutting-edge 65-nm silicon technology, and run on supply voltages of about 0.5 Vdc.
Many challenges remain, however, not the least of which is how to mass produce the transistors. For example, InGaAs tends to break easier than silicon. Still, del Alamo expects to build prototype InGaAs microdevices at the needed dimensions within two years, with full production ramping up in a decade or so.
