The ‘micro’ enterprise that is chip repair
Rodrigo Alvarez can’t afford to replace the defective microprocessors on which his PhD depends, and so he’s learning to fix them himself.
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The computer screen shows a rectangular pit excavated like a limestone quarry. Stripes run across the pit’s walls, like layers in a slice of birthday cake – alternating layers of metal and insulator buried in the chip, each 1/200th the width of a human hair.Skip to next paragraph
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Only by counting those layers can Alvarez tell how deep he is. If he burrows too deep, he’ll ruin the chip. He squints and pauses.
“I’m really at a loss,” he says. “I have no idea what these layers are.” He glances at a diagram of the chip, combs his fingers through his hair. “I guess let’s just make another hole and see what’s underneath.”
In this work, the manual dexterity that Alvarez developed from years of handling circuit boards counts for nothing. Instead, the laws of physics must serve as surrogate hands. Alvarez focuses the ion beam to a point using a magnetic field. He adjusts it by turning knobs, slow turns between thumb and forefinger. He is infused with Buddha-like calm and the concentration of a bomb-squad officer.
Now and then, problems appear.
Metal vaporized by the ion beam billows up in tiny clouds and condenses on the walls of the pit, like steam on a bathroom mirror. The metal condensation forms ornate curves. These “decorations” obscure the layers that Alvarez is straining to read. “It’s very annoying,” he whispers, slowly, as though not very annoyed at all.
As a child in Mexico City in the 1970s, Alvarez used to dawdle about his father’s plastics factory. Machines whined as they extruded noodles of molten plastic, flattened them on rollers, and stretched them into shopping bags. Little Rodrigo inhaled the burning-candle aroma as he wandered the factory floor. By college, he was helping his father redesign those machines to improve their efficiency. The lessons he learned were as much philosophic as scientific.
When his girlfriend’s father challenged him to solve a Chinese solitaire game that had stumped him for months, Alvarez didn’t bother touching the game board. He went home, wrote a computer program to solve the game, and within 30 minutes had a set of winning moves. He demonstrated them to the older man the next morning. He was pretty annoyed, says Alvarez. “He never gave me credit for knowing how to use a tool to solve the problem.”
After graduating from Ibero-American University in Mexico City, Alvarez worked at a social networking website, Chilangolandia.com, founded by some friends. With his earnings, he set up a laboratory in his parents’ basement and spent two years working to design a chip that would mimic the brain and – he hoped – launch him into robotics. But Mexico City offered little opportunity. In 2003 he arrived as a PhD student in Professor Boahen’s laboratory.
Not every PhD student has to learn the obscure skill of chip repair. But not every one gets to learn it either. Alvarez has been forced to learn a lot in a hurry. He has already worked on 10 of his chips. The procedure takes about seven hours, and only one of those 10 chips has survived the procedure so far. He needs six more to finish his PhD.
By 4:30 p.m., Alvarez has uncovered his eight wires. He slices them with a single pass of his ion beam.
Now he welds the eight wires together – a bizarre process in this little world. Pressing a button, he puffs a cloud of gas containing platinum over the chip. He zaps the gas with his ion beam, triggering a microscopic rainstorm. Platinum atoms shower down on the chip at the spot of his choice. A glob of metal accumulates over the wires, like fresh cement. “You have this incredible piece of machinery,” says Alvarez – high-end, but still “very hacky, very primitive.”
As though to illustrate his point, several round divots have appeared around at the edges of the pit – marks left by sparks of static electricity. A human would barely feel those sparks, but here in this tiny Whoville they leave massive craters, as though from errant smart bombs.
Those lightning bolts probably haven’t harmed the chip – or then again they could have singed hundreds of transistors, ruining the chip that Alvarez has worked for hours to save.
He hopes for the best. But not until he solders the chip to a circuit board and plugs it into a computer to test it will he learn that he’s succeeded, and that moment is weeks away.
For now it’s one chip down, six to go.