The chip shortage keeps getting worse. Why can’t we just make more?

Shortages of semiconductors are battering automakers and tech giants, raising alarm bells from Washington to Brussels to Beijing. The crunch has raised a fundamental question for policymakers, customers and investors: Why can't we just make more chips?

There is both a simple answer and a complicated one. The simple version is that making chips is incredibly difficult—and getting tougher.

"It's not rocket science—it's much more difficult," goes one of the industry's inside jokes.

The more complicated answer is that it takes years to build semiconductor fabrication facilities and billions of dollars—and even then the economics are so brutal that you can lose out if your manufacturing expertise is a fraction behind the competition. Former Intel Corp. boss Craig Barrett called his company's microprocessors the most complicated devices ever made by man.

This is why countries face such difficulty in achieving semiconductor self sufficiency. China has called chip independence a top national priority in its latest five-year plan, while US President Joe Biden has vowed to build a secure American supply chain by reviving domestic manufacturing. Even the European Union is mulling measures to make its own chips. But success is anything but assured.

Manufacturing a chip typically takes more than three months and involves giant factories, dust-free rooms, multi-million-dollar machines, molten tin and lasers. The end goal is to transform wafers of silicon—an element extracted from plain sand—into a network of billions of tiny switches called transistors that form the basis of the circuitry that will eventually give a phone, computer, car, washing machine or satellite crucial capabilities.

So Small Yet So Complex

Most chips are groups of circuits that run software, manipulate data and control the functions of electronic devices. The arrangement of those circuits gives them their specific purpose. Below is Nvidia's GeForce RTX 3090, currently the best at turning computer code into realistic video game graphics.

Chip companies try to pack more transistors into chips, enhancing performance and making devices more power efficient. Intel's first microprocessor—the 4004—was released in 1971 and contained only 2,300 transistors with a node size of 10 microns, or 10 millionths of a meter. But Intel's undisputed leadership of the following decades ended between 2015 and 2020 when rivals Taiwan Semiconductor Manufacturing Co. and Samsung Electronics Co. started building chips with better transistors: ones with dimensions down to 5 nanometers, or 5 billionths of a meter (for comparison, an average human hair is 100,000 nanometers wide.)

Cleaner Than a Surgery

Before you put silicon into chipmaking machines, you need a clean room. A very clean room. Individual transistors are many times smaller than a virus. Just one speck of dust can cause havoc and millions of dollars of wasted effort. To mitigate this risk, chipmakers house their machines in rooms that essentially have no dust.

To maintain that environment, the air is constantly filtered and very few people are allowed in. If more than one or two workers appear on a chip production line—wrapped head-to-toe in protective equipment—that could be a sign something's wrong. The real geniuses behind semiconductor design and development work miles away.

Even with all those precautions, the wafers of silicon can't be touched by humans or exposed to the air. They travel between machines in cartridges carried by robots that run on tracks in the ceiling. They only emerge from the safety of those cartridges when they're inside the machines and it's time for a key step in the process.

Atomic-Level Manufacturing

Chips consist of as many as 100 layers of materials. These are deposited, then partially removed, to form complex three-dimensional structures that connect all the tiny transistors. Some of these layers are just one atom thin. Machines made by Applied Materials Inc., Lam Research Corp. and Tokyo Electron Ltd. juggle a host of variables, such as temperature, pressure, and electrical and magnetic fields, to make this happen.

One of the most difficult parts of the process is lithography, which is handled by machines made by ASML Holding NV. The company's gear uses light to burn patterns into materials deposited on the silicon. These patterns eventually become transistors. This is all happening at such a small scale, the current way to make it work is to use extreme ultraviolet light, which usually only occurs naturally in space. To recreate this in a controlled environment, ASML machines zap molten droplets of tin with a laser pulse. As the metal vaporizes, it emits the required EUV light. But even that is not enough. Mirrors are needed to focus the light into a thinner wavelength.

Burdensome Economics

Chip plants run 24 hours a day, seven days a week. They do that for one reason: cost. Building an entry-level factory that produces 50,000 wafers per month costs about $15 billion. Most of this is spent on specialized equipment—a market that exceeded $60 billion in sales for the first time in 2020.

Three companies—Intel, Samsung and TSMC—account for most of this investment. Their factories are more advanced and cost over $20 billion each. This year, TSMC will spend as much as $28 billion on new plants and equipment. Compare that to the US government's attempt to pass a bill supporting domestic chip production. This legislation would offer just $50 billion over five years.

Once you spend all that money building giant facilities, they become obsolete in five years or less. To avoid losing money, chipmakers must generate $3 billion in profit from each plant. But now only the biggest companies, in particular the top three that combined generated $188 billion in revenue last year, can afford to build multiple plants.

Big-Fish Industry

Intel, Samsung and TSMC generated almost as much revenue in 2020 as the next 12 largest chipmakers combined.

The more you do this, the better you get at it. Yield—the percentage of chips that aren't discarded—is the key measure. Anything less than 90% is a problem. But chipmakers only exceed that level by learning expensive lessons over and over again, and building on that knowledge.

The brutal economics of the industry mean fewer companies can afford to keep up. Most of the roughly 1.4 billion smartphone processors shipped each year are made by TSMC. Intel has 80% of the market for computer processors. Samsung dominates in memory chips. For everyone else, including China, it's not easy to break in.

Disclaimer: This article first appeared on bloomberg.com, and is published by special syndication arrangement.