The road to miniaturization

Silicon microelectronics has revolutionized the way we live, but how long can the relentless downsizing of devices continue? Hei Wong and Hiroshi Iwai describe the challenges facing the semiconductor industry today. For the last four decades the miniaturization of the microchip has been the driving force behind developments in all kinds of technology, from home entertainment to space exploration. At the heart of this revolution lies the metal-oxide-semiconductor (MOS) transistor, which has evolved in two ways. First, it has become smaller, with the latest devices measuring a thousandth of their original size. Second, the number of transistors that can be interconnected on a single chip has risen from a few tens to hundreds of millions. The density of microchips has followed an exponential trend that was famously identified by Gordon Moore of Intel in 1965. Moore predicted that the number of components that could be crammed into an integrated circuit would double every two years for the foreseeable future. In fact, he slightly underestimated the trend, because the average number has actually doubled every 18 months. The question keeping chip manufacturers awake in 2005 is how long this exponential growth can continue. (U.K.)