Wafer (electronics) - Definition and Overview

See Wafer (cooking) for the original meaning of the word.

In microelectronics, a wafer is a thin slice of semiconducting material, such as a silicon crystal, upon which microcircuits are constructed by diffusion and deposition of various materials. Wafers are thus of key importance in the fabrication of semiconductor devices. They are made in various sizes ranging from 1 inch (25.4 mm) to 300 mm (11.8 inches).

Note: Millions of individual circuit elements, constituting hundreds of microcircuits, may be constructed on a single wafer. The individual microcircuits are separated by scoring and breaking the wafer into individual chips ("dies").

Source: from Federal Standard 1037C