Jack Kilby and Robert Noyce

By Julien Moreau

In the summer of 1958, Jack Kilby was the new man at Texas Instruments, and he had no vacation coming. While his colleagues were away in July, he sat alone with the problem that was strangling electronics: circuits were assemblies of separate transistors, resistors, and capacitors, soldered together by hand, and every solder joint was a potential failure. The 'tyranny of numbers' meant complex circuits could not be built reliably at all. Kilby's notebook entry of July 24 proposed the escape: make all the components out of one piece of semiconductor, with no separate wires. On September 12, 1958, he demonstrated a sliver of germanium carrying a complete oscillator circuit, components and interconnections carved from the same crystal. It worked. Six months later and two thousand miles away, Robert Noyce at Fairchild Semiconductor in California independently reached the same idea and improved it decisively: build the circuit in silicon, not germanium, and use the planar process to insulate components with silicon dioxide and connect them with evaporated metal lines on the surface. Noyce's version could be manufactured. The two companies fought a decade-long patent war that ended in cross-licensing; history credits both men, Kilby with the concept demonstrated first, Noyce with the manufacturable form that conquered the world. Kilby, born in Jefferson City, Missouri, in 1923, also co-invented the handheld calculator; he received the Nobel Prize in Physics in 2000, Noyce having died in 1990 and Nobels not being awarded posthumously. Noyce, born in Burlington, Iowa, in 1927, went on to co-found Intel, the company that turned the integrated circuit into the microprocessor and the microprocessor into the modern world. Their invention took the transistor, already revolutionary, and removed the last barrier to complexity: from a handful of components per chip in 1959 to tens of billions today, the integrated circuit is the reason electronics could follow the exponential curve that made the digital age. The phrase that defined the problem came from a 1958 symposium: the 'tyranny of numbers,' the observation that as circuits grew more complex, the number of hand-soldered connections grew faster than any factory could reliably make. Kilby's answer, written in his notebook on July 24, 1958, was disarmingly simple: make the whole circuit out of one material. His September demonstration used germanium and tiny flying wires, and Texas Instruments filed the patent in February 1959. Noyce's answer, conceived independently that January, was the manufacturable one: silicon, the planar process, components isolated by grown oxide and wired by metal evaporated onto the surface, all in one flat, photographable structure. Fairchild filed in July 1959. The patent offices declared an interference, the companies sued and countersued for a decade, and in the end the courts split the honors and the companies cross-licensed; the industry got the technology regardless. Kilby went on to co-invent the handheld electronic calculator, patented in 1967, the device that killed the slide rule within five years. Noyce co-founded Intel in 1968 with Gordon Moore, and ran it as the company that turned integration into the microprocessor in 1971. Kilby received the Nobel Prize in 2000 and, in his acceptance, credited the thousands of engineers who had carried the idea further; Noyce, dead since 1990, could not share it, a fact Kilby publicly regretted.

Impact on civilization

The integrated circuit turned the transistor from a component into a civilization. By collapsing entire circuits into a single chip, Kilby and Noyce made complexity cheap: every doubling of transistors made computers twice as capable at the same price, the engine of Moore's law and of the fifty-year free ride in computing power that digitized the planet. Without the chip there are no microprocessors, no personal computers, no smartphones, no internet as we know it, because the machines would be room-sized and priced like real estate. The integrated circuit also redrew the map of economic power, creating the semiconductor industry whose factories and supply chains are now the most contested industrial assets on earth. Two men, working independently, each holding half the answer, together removed the ceiling on what electronics could become. The integrated circuit is the physical form of Moore's law. Because integration made each generation cheaper per function, the industry could reinvest in the next, a self-financing exponential that ran for fifty years and shows no sign of stopping at the frontier, whatever the pace. It also created the fabless economy: design separated from manufacturing, so that a startup with no factory can ship chips made in Taiwan, a division of labor Kilby and Noyce never imagined but their invention made inevitable.