A semiconductor plant, commonly called a “fab” (short for fabrication facility), is a factory purpose-built to manufacture microchips. These are the facilities where thin discs of silicon are transformed into the processors, memory chips, and sensors inside phones, cars, medical devices, and data centers. Building a single cutting-edge fab costs between $15 billion and $20 billion, making these plants among the most expensive industrial projects on Earth.
What Happens Inside a Fab
The core job of a semiconductor plant is to take a blank silicon wafer and build billions of tiny electronic components onto its surface: transistors, capacitors, resistors, and the wiring that connects them all. A finished chip may be no larger than a fingernail, but modern designs pack those billions of components into more than eleven layers of metal, produced across 300 or more sequential processing steps.
The overall manufacturing flow breaks down into several major stages. First, a pure silicon wafer is prepared and coated with a light-sensitive material. Next, a circuit pattern is projected onto the wafer using a process called lithography, essentially printing the chip’s blueprint with light. The exposed areas are then etched away with chemicals or plasma to carve out microscopic channels. Thin films of insulating or conducting material are deposited on top, and metal interconnects are added to wire the components together. After all layers are complete, each chip on the wafer is electrically tested, cut apart, sealed into a protective package, and tested again before shipping.
This cycle of coating, exposing, etching, and depositing repeats dozens of times. Each pass adds another layer of circuitry, and the tolerances are extraordinarily tight. A single speck of dust landing on the wafer at the wrong moment can ruin a chip.
Why Cleanrooms Are Essential
The features on a modern chip are measured in nanometers, thousands of times smaller than the width of a human hair. At that scale, ordinary airborne particles are enormous by comparison, so the entire production floor sits inside a cleanroom with strict air filtration. The most advanced fabs operate at ISO Class 1 or Class 2 standards. An ISO Class 1 cleanroom allows no more than 10 particles (0.1 micrometers or larger) per cubic meter of air. For perspective, a typical office might contain millions of particles in the same volume.
Workers inside the cleanroom wear full-body “bunny suits,” including hoods, gloves, and face masks, to keep skin cells, hair, and lint away from wafers. Air flows continuously through ceiling-mounted filters and exits through floor grates, flushing particles downward and out. Temperature and humidity are held within narrow bands, because even small fluctuations can warp the precision of chemical reactions on the wafer surface.
The Machines That Make Chips
A semiconductor plant is packed with highly specialized equipment, often running around the clock. The single most critical tool is the lithography machine, which uses light to project circuit patterns onto the wafer. For decades, fabs relied on deep-ultraviolet light for this step. The latest generation uses extreme ultraviolet (EUV) lithography, which produces light capable of printing features smaller than 12 nanometers, at least three times finer than previous technologies. Only one company in the world, ASML in the Netherlands, manufactures EUV lithography machines, and each one costs well over $100 million.
Beyond lithography, a fab contains etching tools that carve patterns into silicon and thin-film materials, deposition chambers that lay down atom-thin layers of metal or insulator, chemical-mechanical polishing machines that flatten each layer to nanometer-level smoothness, and ion implanters that inject precise amounts of other elements into the silicon to change its electrical properties. Automated transport systems shuttle wafers between stations in sealed carriers, minimizing human contact.
Chemicals and Gases Involved
Chip manufacturing relies on a wide array of specialty gases and chemicals. The National Institute of Standards and Technology maintains a database listing more than 40 process gases used in semiconductor fabs. These include chlorine and hydrogen fluoride for etching, silane for depositing silicon-based films, ammonia and nitrogen for various chemical reactions, and tungsten hexafluoride for filling metal interconnects. Many of these substances are toxic, corrosive, or flammable, which is why fabs have elaborate gas-handling and exhaust-treatment systems. Sensors continuously monitor air quality throughout the facility, and hazardous materials are stored in double-walled containment areas.
Cost and Construction Timeline
A leading-edge fab capable of producing 3-nanometer chips runs between $15 billion and $20 billion to build and equip. The vast majority of that cost goes to the machinery itself. Construction from groundbreaking to the start of high-volume production typically takes about two years, though more complex projects can stretch longer. Intel’s time-lapse documentation of a fab build in Hillsboro, Oregon captured more than two years of continuous work before the facility was ready.
Even older-generation fabs producing chips at larger feature sizes cost several billion dollars. The price tag limits the field to a handful of companies: TSMC, Samsung, and Intel account for the bulk of leading-edge production worldwide. Smaller firms that design chips but cannot afford their own fabs (called “fabless” companies) send their designs to these manufacturers for production.
The Push to Build More Fabs
Supply-chain disruptions during the pandemic exposed how concentrated chip manufacturing had become, with the majority of advanced production located in East Asia. That prompted governments to invest heavily in domestic capacity. In the United States, the CHIPS and Science Act committed nearly $53 billion in federal funding to bring semiconductor manufacturing back onto American soil. As of mid-2024, the Commerce Department had announced over $30 billion in proposed investments across 23 projects in 15 states, including 16 new manufacturing facilities expected to create more than 115,000 construction and manufacturing jobs.
Europe, Japan, and India have launched similar incentive programs. The goal across all of these efforts is the same: reduce reliance on a small number of overseas fabs for the chips that power everything from military hardware to household appliances. For any single plant, though, the challenge remains the same. Semiconductor manufacturing is one of the most technically demanding and capital-intensive industries that exists, and every new fab represents a years-long bet that the technology inside it will still be competitive when the first wafers roll off the line.