In late 1971, Intel brought out the first microprocessor. A few months later, EE Times – long a go-to for news and insights on the semi-conductor world, embedded systems, AI, and other trends – brought out its first issue. While semi-conductor history goes back a lot further than fifty years, it was the microprocessor that ignited the process that took computing from the realm of the mainframes; to personal computing using workstations, desktops, and laptops; to today’s era of ubiquitous computing on all sorts of devices.
EE Times is kicking off its Golden Anniversary celebration with a series by Malcolm Penn on the roots of the industry, focusing on Silicon Valley where so many things began. Penn takes us back to the 1930’s when, among other key events, Bill Hewlett and David Packard, young engineers with EE degrees from Stanford, famously formed Hewlett-Packard in a Palo Alto garage. Some consider that garage the birthplace of Silicon Valley. But Penn – and IEEE – credit the Mountain View address of Shockley Semiconductors, which was established in 1956.
That same year, founder William Shockley, with his colleagues John Bardeen and Walter Houser Brattain, was awarded the Nobel Prize in Physics for their invention of the transistor. That invention occurred in 1947, so the transistor is, like the microprocessor, observing a major anniversary this year, too.
Gordon Moore, of Moore’s Law and Intel fame, was one of the first employees of Shockley Semiconductors.
Unfortunately, Shockley was very difficult as a manager and by 1957, employees were bailing out on him. The core engineering staff, including Moore, that Shockley had recruited – later dubbed “the traitorous eight” – got backing from Fairchild and went off to found Fairchild Semiconductors.
It quickly grew to be among the top semiconductor industry leaders, spurred on by the successful development of the silicon planar transistor.
Transistors, however, were already presenting a new challenge, dubbed the “tyranny of numbers”. If you wanted to make a simple flip-flop, it needed four transistors. About 10 wires were needed to connect them. Interconnecting two flip-flops required not only twice the number of transistors and wires but also four or five additional wires to connect the two devices. So, four transistors needed 10 wires, eight needed 25, 16 needed 60 to 70 wires. In other words, as the transistor count increased linearly, the number of connections grew exponentially, where the exponential was greater than one but less than two.
While transistors were relatively easy to mass produce, connections were much more difficult since wires had to be soldered together by hand and took up a lot of space. The industry’s desire to build bigger and more complex systems was stymied by the difficulty in wiring everything together. To this point, few had paid much attention to wiring, but connections would soon become a potential show-stopper, driving the need for the integrated circuit. (Source: EE Times – Roots of Silicon Valley, Part 2)
The solution was planar technology, which “protect[ed] the transistor surface with a passivation, or protection, layer of silicon dioxide (SiO2), grown or deposited on top of the structure.” This created a flat surface that enabled enhanced automation of the production process.
Penn deems planar technology “the second most important invention in the history of microelectronics — after the invention of the transistor — laying the foundation for future integrated circuits.”
There’s more to the story. There always is. This time, the story takes us out of Silicon Valley and deep into the heart of Texas, where Texas Instruments, which had been working in the same arena, disputed the patent claims of Fairchild engineers. (Both organizations ended up with valid patents.)
Even with the breakthrough that planar technology provided, there was still an issue that was keeping IC’s from becoming commercially viable: preventing adjacent transistors from interfering with each other. Fairchild solved his problem, and in 1960 “the first working device was produced.”
Then, in March 1961, “Fairchild announced the world’s first standard logic family of ICs, direct-coupled transistor logic.” The industry started to take off, with Signetics and TI competing with Fairchild, leapfrogging each other with new and improved editions.
Just as core engineers abandoned Shockley, core engineers began defecting from Fairchild. These engineers:
…eventually known as “Fairchildren,” directly or indirectly creating dozens of corporations, including Intel and AMD. In doing so, Fairchild sowed the seeds of innovation across multiple companies in the region that would eventually become known as Silicon Valley. (Source: EE Times – Roots of Silicon Valley, Part 3)
Despite the defections, Fairchild didn’t go anywhere, and Penn goes on to talk about Fairchild, TI, and emerging companies – AMD, Intel, National Semiconductor, et al. – and the roles they all played. Lots of interesting detail in there, but Penn doesn’t get into Intel and the microprocessor breakthrough. Hopefully, there’ll be more to come in this series on where and how it all began.
This is a link to the first article in the series, which was not directly cited in this post.