A fab is a factory for producing integrated circuits. It is a short form of "fabrication". Another term commonly used is semiconductor foundry.

Semiconductor manufacturers gain advantage by having access to specific manufacturing technologies, known in the industry as process technology. These technologies may lie in the most up-to-date areas for mass market devices or in niche areas, such as mixed-signal circuits, which offer advantages in certain markets.

Typically an advance in chip-making technology requires a completely new fab to be built. In the past, the equipment to outfit a fab was not terribly expensive and there were a huge number of smaller fabs producing low-volume chips. However, the cost of the most up-to-date equipment has since grown to the point where a new fab typically costs in the order of several billion dollars.

This has led to the rise of "fabless" design firms or fabless semiconductor company who do not produce their own chips. Instead they create the design itself, and have another company produce the actual chips for them. They are also known as IP firms. ARM is perhaps the best example.

Another side effect of the cost has been the challenge to make use of older fabs. For many companies these older fabs are useful for producing designs for unique markets, such as embedded processors , flash memory, and microcontrollers. However for companies with more limited product lines, it's often best to either rent out the fab, or close it entirely.

See also

• Cleanroom
• Foundry
• Semiconductor device fabrication

Fab is also a slang word common in the gay community that is short for fabulous.