How a Semiconductor Factory Works

An inside look at the four levels of an Intel fab

First level: Interstitial and fan deck

The fan deck houses systems that keep the air in the clean room particle-free and precisely maintained at the right temperature and humidity for production.

Second level: Clean room level

A clean room is made up of more than 1,200 factory tools that take pizza-size silicon wafers and eventually turn them into hundreds of computer chips. Clean room workers wear bunny suits to keep lint, hair and skin flakes off the wafers.
Fun fact: Clean rooms are usually lit with yellow lights. They are necessary in photolithography to prevent unwanted exposure of photoresist to light of shorter wavelengths.

Third level: Clean sub fab level

The clean sub fab contains thousands of pumps, transformers, power cabinets and other systems that support the clean room.
Large pipes called “laterals” carry gases, liquids, waste and exhaust to and from production tools. Workers don’t wear bunny suits here, but they do wear hard hats, safety glasses, gloves and shoe covers.

Fourth level: Utility level

Electrical panels that support the fab are located here, along with the “mains” — large utility pipes and ductwork that feed up to the lateral pipes in the clean sub fab. Chiller and compressor systems also are placed here. Workers who monitor the equipment on this level wear street clothes, hard hats and safety glasses.