SAN JOSE, Calif. — On April 19, 1965, Electronics magazine published a paper in which Gordon Moore made a stunning observation: About every two years, engineers should be able to cram twice as many transistors into the same area of a silicon chip.
Over the next 50 years, engineers more or less managed to maintain that predicted pace of innovation, delivering dramatically better semiconductors. Their efforts were central to the seeming magic of a high tech sector riding an exponential growth curve that became known as Moore’s law.
Of the thousands of engineers who have kept Moore’s law going, EE Times interviewed a trio of top chip technologists who shared their stories and optimism that progress will continue.
To date the progress Moore’s law represents has not been limited to “just ever faster and cheaper computers but an infinite number of new applications from communications and the Internet to smart phones and tablets,” said Robert Maire, a semiconductor analysts writing in a recent newsletter.
“No other industry can claim similar far reaching impact on the lives of so many people…[in] less than a lifespan, more changes in the world can be traced back to the enabling power of the semiconductor industry than any other industry…More lives have been saved and fortunes impacted,” Maire wrote.
Those benefits are measured in trillions of dollars, according to G. Dan Hutcheson, chief executive of VLSI Research. He calculates the deflationary value of packing more features into the same silicon area at $67.8 billion last year alone, with a knock-on value of half a trillion dollars to the overall electronics industry that used the chips.
“The market value of the companies across the spectrum of technology driven by Moore’s Law amounted to $13 trillion in 2014,” Hutchison estimated. “Another way to put it is that one-fifth of the asset value in the world’s economy would be wiped out if the integrated circuit had not been invented and Moore’s law never happened,” he said.
For engineers like Mark Bohr, Moore’s law was the heartbeat of daily life at Intel, driving it to its longstanding position as the world’s biggest chip maker.
“By the time I joined the company in 1978, the concept was well engrained in Intel culture,” said Bohr, now a senior fellow in Intel’s manufacturing group. “What started out as an observation became a guide for us all that we felt we needed to follow and, if possible, faster than anyone else in the industry,” he said.
Bohr still recalls one of his rare interactions with Moore who in 1978 was Intel’s chief executive. As a recent college grad six months into his job at Intel, Bohr developed a new contact etching process and sent a report on it to his boss and senior engineers in his group, copying Moore.
“I knew Gordon was an engineer at heart and thought he might be interested,” Bohr recalled. “A week later he sent back the front page where he wrote, ‘Hey Mark, looks great. Make sure other engineers know about it,’” he said, noting he still keeps the page in his office.
“I spent rest of my career in Oregon so we rarely met and interacted, but I was in a few meetings where some of my superiors gave presentations to him,” Bohr recalled. “He was more the quiet type and listened and then spoke up occasionally with words of wisdom — he was not a table pounder like some CEOs,” he said.
Chenming Hu is often cited as the father of the FinFET, the 3-D transistor that is one of the latest advances driving Moore’s Law. He still recalls meeting Moore at a lunch in 1969 when he turned down a job offer to work under him:
I was a grad student from Taiwan at Berkeley and [Intel executive] Andy Grove taught one of my courses. At the end of the course I got a call in the dorm and at the other end was Andy. He said why not come for an interview at Intel. I had lunch with Gordon and Robert Noyce as well. I was offered a job at Intel, but I turned it down to stay for a PhD because that’s what my parents wanted me to do.
Things worked out. Today Hu is professor at Berkeley and a former chief technologist at Taiwan foundry giant TSMC.
Hu considers Moore’s Law “a challenge, a self-fulfilling prophecy…and a testament to the ingenuity of engineers, in particular the manufacturing engineers who make things so small…They are the heroes and should be given more credit than they usually get. It’s not clever ideas so much as tens of thousands of engineers who make things small and at such high yields,” he said.
In the mid-1990s simulations started showing that transistors would become so small they would be hard to turn completely off. Like leaky faucets they would begin to drain away more power than they actually consumed.
“People were thinking CMOS would not go beyond 0.1 micron — we didn’t even use nanometer measurements then,” Hu said.
To address the looming crisis, the U.S. Defense Advanced Research Projects Agency launched a program to create a new kind of 25nm switch. In 1997, Hu proposed two ideas and won a contract to work on them. Two years later he reported his ideas — the ultra-thin body silicon-on-insulator (UTB SOI) and a new kind of 3D transistor he called the FinFET.
At that time, engineers debated whether the industry could ramp up sufficient supply of SOI wafers with the 5nm thin films required for UTB.
“That was 20x thinner than could be done in the year 2000,” Hu said. “Most companies decided it was easier to develop the skills to etch a thin fin than to work on the SOI industry,” he added.
Fast forward to 2015 and the availability of thin-film SOI wafers is no longer an obstacle. STMicroelectronics, Samsung and others are backing the technology, but an even broader set of companies is adopting FinFETs.
“I think both will coexist,” said Hu. “The thing that stuck in my mind was how quickly the industry picked up on FinFETs.
“I had been in long term research for a long time and had never seen a case where industry immediately picked something up,” he said. “I was invited to several companies — multiple times to Intel — and within two years FinFETs were on the industry road map as a successor to the planar transistor and UTB SOI was added a year later — that was quite a surprise to me,” he added.
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