Wafers

Wafer is a term used for two main forms of a thin, flat sheet: edible wafers and semiconductor wafers. In food, wafers are thin, crisp sheets made from flour-based batter or dough, sometimes with sugar and fat. They are baked or dried to a light, delicate texture and may be used plain or to enclose fillings as wafer cookies or in confectionery products. Historically associated with communion wafers in Christian ritual, edible wafers later evolved into mass-produced wafer biscuits found in many cultures, often flavored or layered with cream between two sheets.

In electronics and solar energy, a wafer is a thin slice of crystalline material, typically silicon, that serves as a substrate for devices and circuits. Semiconductor wafers are produced by growing a single crystal ingot and slicing it into discs, then polishing the surfaces to create a smooth, defect-free plane. Diameters commonly range from about 25 to 300 millimeters, with thicknesses around 0.3 to 0.8 millimeters. The wafer undergoes further processing, including cleaning, doping, deposition, lithography, and etching, to form electronic components such as transistors, diodes, and integrated circuits. In solar technology, silicon wafers serve as the base for photovoltaic cells.

Other specialized wafers exist for microelectromechanical systems and sensors. Across both domains, wafers are valued for their flatness, uniform thickness, and clean surfaces, which enable precise manufacturing and reliable performance.