Moore's Law

Moore's Law was expounded in a 1965 Electronics Magazine article by Gordon Moore, who was then the research director at Fairchild Semiconductor. Moore noted that since the invention of the integrated circuit, the number of transistors per square inch on those circuits had doubled each year. Moore, who co-founded Intel Corp. in 1968, projected that this doubling would continue into the foreseeable future. This proved essentially correct, with subsequent data density doubling about every 18 months.

In 1975, Moore modified his law, stating that the increasing technical difficulties associated with the production of enhanced microchips would cause the number of devices located on a chip to double every two years, another prediction born out by industry trends. He noted that as microprocessor circuits get smaller, future silicon chips could contain the modem, graphic, and memory-control functions previously housed on discrete hardware in computers. Among other things, Moore's Law explains why computer technology drops in price so rapidly and so quickly becomes obsolete, giving the average computer a competitive life span of only three years.

Among the technical difficulties linked to producing shrinking chips containing ever more options is the inclusion of dopant impurities mixed into silicon to increase its capacity to hold electric-charges. As transistors get smaller, they still must hold the same charge. Thus, the silicon must include a higher percentage of dopants. But at a certain limit, dopant atoms conglomerate into electrically inert clumps. Chips manufactured by 2000 were reaching that limit of operability. The "gates" that regulate electron flow in chips posed another problem. They had grown so minute that they were susceptible to a quantum effect in which electrons burrow through the gates even when closed. If the gates fail to block the electron stream completely, chips won't function.

In 1995, Moore presciently observed that although such technical difficulties could hamper the sustained pace of microprocessor growth, increasing manufacturing costs could prove an even bigger obstacle. Though processing equipment cost about $12,000 when Moore founded Intel, by 1995 it had risen to about $12 million, while productive output remained constant. As chip technology becomes more sophisticated, the cost of manufacturing chip grows exponentially. As capital costs outstrip income, eventually it will no longer be financially feasible to produce ever-more complex chips. This observation became known as Moore's Second Law.

Moore prophesied the end of his law in 2000 at an Intel Developer Forum, pronouncing that the technical ability to downsize microprocessors would soon collide with the finite size of atomic particles. Unless microprocessing technology changed dramatically, this would eventually halt the growth of microprocessor capacity. Moore predicted that the industry could reach such physical limitations by 2017.