According to science fiction master Arthur C Clarke, any sufficiently advanced technology is indistinguishable from magic. I once spent an afternoon lounging by the pool with Sir Arthur at the Colombo Swimming Club in Sri Lanka. My future life as the Technocrat many years ahead of me, he failed to recognise the gravity of the meeting. But that’s a story for another month. Possibly.
My point is that the complexity and sophistication of modern computers has become, well, quite magical. That may seem like a redundant observation in a technology-based publication as august as PC Plus. However, it’s all too easy to become blasé about the technological wonders that have become our ubiquitous companions on desktops, laps and even in our pockets.
To put the achievements of today’s technologists into context, I like to play a mental game. I imagine which of today’s digital devices would make the most spectacular impression on an engineer from the early days of the computing industry – around the late ’60s or early ’70s. The reason I choose that time period is to avoid Clarke’s maxim. Show a laptop to a 19th century engineer and it would seem magical, but the onlooker wouldn’t comprehend what was in front of him. A technologist from 40 or 50 years ago? You’d blow his tiny mind.
My brain-bending weapon of choice varies. Five or six years ago, I preferred a thin and light notebook. Then Sony launched the PSP portable gaming console. Imagine the impact the real-time 3D rendering and screen technology would make in such a small package.
More recently, I’ve been thinking one of the latest HD smartphones would be a great choice for blowing off some ’60s socks. The bandwidth of the 3G cellular networking alone would seem absolutely bonkers. But my current favourite is the iPad. An obvious choice, but a technical marvel all the same. What a spectacle it would be to give someone their first taste of the web courtesy of that delightful finger-swishing interface.
Just as astonishing is the technological effort involved in making the chips that power these devices. I wonder not just what a historical engineer would make of a modern processor, but also how many people today appreciate the scale and complexity of chip making.
It all starts with silicon, which just so happens to be the most common element in the Earth’s crust. It’s actually a little tricky to get at, and must be purified to the nth degree before it can be used in integrated circuits. Anyway, the ultra pure silicon is formed into large, solid cylinders and then sliced and polished into 1mm-thick discs, which the industry calls wafers.
Next up, a patterned layer of material known as photo resist is applied to the surface of the wafer. This effectively forms a stencil and in turn enables a layer of charged atoms or ions to be embedded in a precise pattern. The wafer surface now has a complex pattern of conductive and non-conductive traces.
The dielectric or insulation must be added in layers as thin as a single atom. Photo resist, ultra-violet light and an incredibly intricate mask are used to etch the dielectric into a pattern that matches the conductive and non-conductive silicon. Add another layer of insulator and you effectively have your transistors.
Remember, in a modern PC processor there may be a billion or more transistors per CPU die. That translates into as many as 150 billion transistors in a typical 300mm silicon wafer. The final job of major significance is wiring up the transistors. With a billion or so per CPU die, this is no mean job and must be done by building the interconnects in painstaking layers of copper, first deposited, then etched away.
All of the above requires incredible accuracy, consistency and purity from the equipment and materials involved. More than anything, that means cleanliness. Just a few particles of dust can ruin a processor die, so factories scrub the air tirelessly, reducing dust levels from hundreds of thousands of particles per cubic foot to as low as a single particle.
Then, of course, there’s the sheer scale of the facilities required to bang out millions of chips. The biggest current processor-making plants cover an area roughly the size of 20 football pitches. Needless to say, building a clean facility on such a scale costs serious cash. Intel and AMD combined recently invested over $10 billion in their respective 32nm chip production facilities. That investment will have to be repeated as the industry switches to 22nm technology. It’s a lot of money, but the results are undoubtedly magical.