American Scientist

March-April 2009

Volume: 97 Number: 2

The first transistor was a relatively monstrous device, about half an inch tall. Nowadays there can be up to a billion transistors on a tiny silicon chip, and hundreds of chips are fabricated simultaneously on a silicon wafer. Integrated circuits are etched onto silicon chips in patterned layers that are precisely doped with specific impurities to make up the myriad of components, as shown the scanning elctron micrograph on the cover. Although transistors have changed dramatically in size, material and fabrication method since they were first conceived about 60 years ago, there has yet to be another device to come along that could replace them in computers. Robert W. Keyes explains why in "The Long-lived Transistor" and argues that the transistor will still be around for years to come.