How microchips are made

Photographs and Video by Philip Cheung, text by Don Clark, The Huge Endeavor to Produce a Tiny Microchip, NYTimes, April 8, 2022.

High tech runs on microchips. They are difficult to design and fabricate; the "fabs" are major projects in themselves.

Why chip-making is so difficult:

Chip makers are packing more and more transistors onto each piece of silicon, which is why technology does more each year. It’s also the reason that new chip factories cost billions and fewer companies can afford to build them.

In addition to paying for buildings and machinery, companies must spend heavily to develop the complex processing steps used to fabricate chips from plate-size silicon wafers — which is why the factories are called “fabs.”

Enormous machines project designs for chips across each wafer, and then deposit and etch away layers of materials to create their transistors and connect them. Up to 25 wafers at a time move among those systems in special pods on automated overhead tracks.

Processing a wafer takes thousands of steps and up to two months. TSMC has set the pace for output in recent years, operating “gigafabs,” sites with four or more production lines. Dan Hutcheson, vice chair of the market research firm TechInsights, estimates that each site can process more than 100,000 wafers a month. He puts the capacity of Intel’s two planned $10 billion facilities in Arizona at roughly 40,000 wafers a month each.

Factories must be super-clean:

Intel chips typically sell for hundreds to thousands of dollars each. Intel in March released its fastest microprocessor for desktop computers, for example, at a starting price of $739. A piece of dust invisible to the human eye can ruin one. So fabs have to be cleaner than a hospital operating room and need complex systems to filter air and regulate temperature and humidity.

Fabs must also be impervious to just about any vibration, which can cause costly equipment to malfunction. So fab clean rooms are built on enormous concrete slabs on special shock absorbers.

Also critical is the ability to move vast amounts of liquids and gases. The top level of Intel’s factories, which are about 70 feet tall, have giant fans to help circulate air to the clean room directly below. Below the clean room are thousands of pumps, transformers, power cabinets, utility pipes and chillers that connect to production machines.

Fabs require lakes of water "to clean wafers at many stages of the production process." Constructing fabs is difficult:

Excavating the foundations is expected to remove 890,000 cubic yards of dirt, carted away at a rate of one dump truck per minute, said Dan Doron, Intel’s construction chief.

The company expects to pour more than 445,000 cubic yards of concrete and use 100,000 tons of reinforcement steel for the foundations — more than in constructing the world’s tallest building, the Burj Khalifa in Dubai.

Some cranes for the construction are so large that more than 100 trucks are needed to bring the pieces to assemble them, Mr. Doron said. The cranes will lift, among other things, 55-ton chillers for the new fabs.

There's more at the link.

I have some remarks on chip fabrication in Stagnation 1: The phenomenon and a simple-minded model with some remarks on search (pharmaceuticals) and process re-engineering (semiconductors). In particular, I remark on the fact the the laws of the quantum world are different from those of the macroworld.