AKA single-crystal silicon, Si, or mono c-Si, is the base material for silicon-based discrete and IC components in modern electronics. High-purity semiconductor grade silicon is used and incorporates a donor seed to maintain the formation of a continuous single crystal.

There are two methods to achieve this, CZ (Czochralski) and FZ (Floatzone) both requiring a single crystal grown by contacting polycrystalline silicon with a monocrystalline seed. “Doping” by the addition of other elements such as boron or phosphorus determines its resistivity of p-type or n-type respectively.