A new material helps transistors become vanishingly small

THERE IS ANBN old joke in the semiconductor business that the number of people predicting the death of Moore’s law doubles every two years. This refers to another prediction, made in the 1970s by Gordon Moore, one of the founders of Intel, a giant chipmaker, that the number of transistors which can be crammed onto a silicon chip doubles every two years. When that number exceeded 1m in the mid-1980s, some said the rate of progress had to slow down. By 2005 the number of transistors on a chip rose above 1bn, which many thought was unsustainable. But there are now around 50bn transistors jostling for space on some chips and producers are gunning for more.In the current state of the art, the smallest components (transistors and diodes) made on a silicon chip are about seven nanometres (billionths of a metre) across. That is a thousandth of the diameter of a red blood cell. But problems are mounting. As components shrink, electrons start to leak from the connections between them, causing interference and unreliability. The prophets of doom have therefore returned. Once again, however, they look like being wrong. The answer to the electron-leakage problem is better insulation between chip components. And a group of researchers in South Korea and Britain think they have the insulator required. It is called thin-film amorphous boron nitride (a-).