The fragility of microprocessors

August 10, 2006

I work in the computer industry as a systems architect/engineer. My father got in on the ground floor, programming computers with wires before there were even punch cards. As far as I could tell, his job was to draw squares, circles, and triangles and connect them with arrows. I used to fill the flow charts in with crayons when I was younger.

I took an introductory course to find out what Dad had been doing, and was hooked. I couldn’t believe you could get paid to solve intricate and interesting puzzles. I abandoned my plans to get a PhD in molecular biology and started working at EDS.

I think computers are the most amazing achievement of mankind. I especially like being in touch with family, friends, and new acquaintances from around the world with common interests.

The first computer, the ENIAC, built in 1940, took up 1500 square feet. The same floor space now could contain 1.4 million microchips, each with orders of magnitude more computing power. A car now has more computing power than the first lunar spacecraft.

Microchip fabrication 44 45

Creating a chip begins by cutting a thin 12 inch slice, called a wafer, from a 99.9999999% pure silicon crystal, one of the purest materials on earth. Wafers require such a high degree of perfection that even a missing atom can cause unwanted current leakage and other problems in manufacturing later on. This is the platform that about 5000 computer chips will be built on. Each chip will contain millions of transistors, capacitors, diodes, and resistors built by punching and filling in holes in more layers than a Queen’s wedding cake.

Cleanliness

Particles 500 times smaller than a human hair can cause defects in microchips. The more particles that get on a wafer, the greater the chance there is of a killer defect. Some particles are worse than others — a single grain of salt could ruin all the chips on a wafer. Sodium can travel through layers even faster than stray bits of metal. Particles that outright kill a chip are caught during the testing phase at the factory. Sometimes only 20% make to the end. The traveling particles are insidious, and can cause a chip to malfunction, perform poorly, or die later on (hopefully before your warranty expires). Consumer reports recommends not even trying to repair a personal computer after four years, and in the two to four year range it’s a tossup whether to repair or buy a new one.

Typical city air has 5 million particles per cubic foot. There are processes that require a maximum of 1 particle per square cubic foot.

People are among the worst offenders, as far as particle generation goes. If you walk at a good clip, you emit 7.5 million particles per minute. Even sitting still, you are still emitting particles. A smoker is a particle-emitting dragon long after the cigarette, and a sneezing worker is even worse, a veritable Krakatoa.

City water is not pure enough to be used — it’s full of bacteria, minerals, particulates, and other junk. To make city water clean enough requires many filters, UV-light, and other water treatments. Some fabrication plants use millions of gallons of water a day, requiring a huge investment in water processing and delivery systems.

Microchip fabrication is primarily a chemical process, requiring ultra-clean 99.9999% chemicals and 99.9999999% gases. About one in five steps use water or chemicals to clean the wafers or prepare their surface for the next layer.

Firemen practically need a chemical engineering degree to inspect and fight fires in a chip fabrication plant. During a fire, they risk being exposed to volatile, flammable, or combustible solvents, and chemicals like arsine, used in chemical warfare.

The chips also require humidity to be just right. If the humidity is too high, the wafers accumulate moisture, and the layers won’t stick. Too dry and static electricity will suck particles out of the air and practically glue them to the surface, they’re so hard to remove.

So it shouldn’t surprise you that it costs over 3 billion dollars to build a clean room. The inside is composed of non-shedding materials, especially stainless steel. Floors have sticky mats to pull dirt off of operators’ shoes. Pens, notebooks, tools, and mops – everything is built of material that sheds as few particles as possible, but even so, equipment particles cause a third of the contamination.

How chips are made

Wafers move from workstation to workstation and have different operations performed on them at each one. Wafer fabrication for a chip might involve 450 processes with operations that overall take several thousand individual steps. The machines that make this all happen include high-temperature diffusion furnaces, wet cleaning stations, dry plasma etchers, ion implanters, rapid thermal processors, vacuum pumps, fast flow controllers, residual gas analyzers, plasma glow dischargers, vertical furnaces, optical pyrometers, etc.

If you were shrunk to chip size and tied to a wafer, you’d go through the car wash from hell. You’ll be moved along by robotic wafer handlers from one machine to the next, where you’d be layered with different materials, centrifuged, electro-polished, dyed, scraped, heated to 1,800 F, ultrasonically agitated, sputtered, doped, hard baked, dipped in toxic chemical baths, irradiated, blasted with ultrasonic energy, spray-cleaned, dry-cleaned, scrubbed, micro-waved, x-rayed, shot with metal, etched, and probed.

At various points, the “Survivor” show comes on. Chips are examined at an atomic level for defects, and their electrical functioning tested. They’re usually thrown out if anything is wrong, since most mistakes can’t be fixed.

There are many problems that can cause a chip to fail besides contamination. The wafer must be perfectly flat in structure and while it goes through the workstations. If the wafer were 10,000 feet high, you’d see bumps or holes no higher than 2 inches – more than that and the layering is thrown off. If the wrong step was performed after 3,841 correctly performed steps, the chip was under or overheated, the layer didn’t fully stick, was improperly aligned before the next layer was added, or a chemical misapplied, the chip is thrown out. It’s amazing any chips make it out the door.

After your makeover, you’d emerge in a designer outfit composed of up to 25 layers embedded with millions of transistors, diodes, and resistors. You’ll find yourself “best in show” at tattoo competitions and irresistible to Terminator fans.

The Case for collapse starting sooner than later

Jared Diamond lists five main factors for the collapse of civilization.46 All five are evident. The first two reasons, collapse from environmental reasons and climate change are so evident they require no further comment.

The third factor is not being able to adapt to new conditions. Dmitry Orlov makes a good case for the eventual collapse in the United States being much harder than the recent collapse in the former Soviet Union due to our cultural weaknesses.47 Ecologists believe that we needed to have started adapting to the decline of energy in the 1970’s by reducing our population and encouraging small family farms to get people back to the land.

The fourth reason for collapse is “relations with hostile neighbors”. There is reason to believe sleeper Jihad cells lie in wait of an opportunity to blow up key pieces of infrastructure in America. Russia, China, and Europe may unite against the U.S. to prevent America from taking the lions’ share of the remaining oil.

On the fifth factor, relations with friendly nation, Diamond said: “Almost all societies depend in part upon trade with neighboring friendly societies, and if one of those friendly societies itself runs into environmental problems and collapses, that collapse may then drag down their trade partners. It’s something that interests us today, given that we are dependent for oil upon imports from countries that have little political stability in fragile environments”.

Diamond’s “loss of trading partners” factor is another reason computers won’t survive PetroCollapse. As global shipping, factories, and countries have a hard time keeping the lights on; computers will stop being made as supply chains break down. If even one of the dozens of types of single-sourced equipment or pure chemical suppliers goes out of business, the assembly line stops.

Andrew Gould, CEO of Schlumberger, said of the oil decline that “An accurate average decline rate is hard to estimate, but an overall figure of 8% is not an unreasonable assumption”.48

Matt Simmons also believes that an 8% rate of decline is possible, given how Saudi Arabia’s fields were mismanaged, the use of technology to extract the oil sooner than it would have otherwise been pumped, other super giant oil fields having depleted rapidly after their peak, and the likelihood that Saudi oil reserves are probably half of what is reported.

The decline after peak might initially be low, buying a few years of time, but if it does reach 8% per year, world oil extraction would decline by almost half in eight years. That is likely to lead to the collapse of civilization, because there is too little time to adapt.

Preservation of Knowledge

A project to preserve knowledge may be unable to continue in an unstable society beset with power outages, hunger, and crime. Once rationing and shortages begin, agriculture and other essential services will receive the most energy. Scientists will be unemployed. It is very likely that resource wars will erupt all over the globe, so the military will be taking a large portion of the dwindling energy resources as well. 49 50 51 52 53 54 55

The time to begin is now, before we begin the inexorable retreat to wood as civilizations’ main energy source.

We’ve reached the point where we need to be concerned about the preservation of knowledge. This cannot be done with computers, which are the least likely component of all to survive long-term, but this is the main plan for storing knowledge at institutions dedicated to this issue.

Computers are the top cards in the civilization house of cards. Knock out any below and it all crumbles. Computers have too many complex, energy intensive inputs and dependencies. 56 57 58 59

How can it be done?

We may be able to cannibalize computers for parts to keep some machines running, but eventually all the knowledge stored in computers will be unavailable. By that time, most of the paper in library books will have decayed, become nesting material for rodents, or burned to heat homes.

Although archival paper and microfiche can last for five hundred years when kept at ideal temperatures and humidity, power outages will make it impossible to maintain them for that long.

It’s likely the unprecedented stable weather we’ve had the past ten thousand years will change, not only given the earth’s past history, but from our chemical alteration of the atmosphere. While there may be initial global warming, that could change quickly to an ice age, or to extreme weather, with the climate warming and cooling so quickly that agriculture becomes tenuous.60

If it is possible to etch words into metallic or other extremely durable substances, we ought to do it, not only for the coming dark ages, but to enable some knowledge to survive through future climate changes.

After all, we once put a disk on a space probe to explain humanity to potential aliens, why can’t we do that for our descendants?

Clearly not everything in print can or should be saved. Priority should be given to information that would be useful to a society far simpler than ours.

We should leave our descendents with information they can use and be amazed by. We owe it to them. It’s the least we could do considering we’ve driven so many species to extinction and left much of the land a toxic, deforested, desert. If we can spend billions on microchip factories that are out-of-date within two years, surely we have the resources to save some useful knowledge and music for our descendants.

We need to find better materials than paper and clay tablets to preserve knowledge. Someday there will be a new renaissance.

Maybe it’s as simple as converting Coca-cola factories from making soda cans to printing aluminum texts.


Tags: Education, Technology